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1993

Krakow 1994 Report No 1669

PRINTED AT THE HENRYK NIEWODNICZANSKI INSTITUTE OF NUCLEAR PHYSICS

Cover designed by J. Grebosz

Editorial Board: J. Bartke, D. Erbel (Secretary), B. Fornal, L. Friendl, J. Grebosz, M. Krygowska-Doniec, P. Malecki, M. Waligorski and H. Wojciechowski.

e-mail: [email protected] , [email protected]

Kopia offsetowa, druk i oprawa: DRUKARNIA IFJ Wspotpraca wydawnicza: SEKCJA WYDAWNICTW DZIAtU INFORMACJI NAUKOWEJ IFJ Wydanie I zam. 29/94 NaWad 450 egz. Henryk Niewodniczanski 1900 - 1968

25 years ago, on 20 December 1968, Professor Henryk Niewodniczanski, the founder of our Institute, died. To commemorate this event, we held a small session to recall his achievements as a scientist, teacher and administrator. Professor Niewodniczanski, a brilliant experimental physicist, began his research in the early twenties in the field of atomic optics. He discovered the forbidden dipole magnetic transition in Pb atoms. His interest in nuclear physics was aroused by Lord Rutherford of Nelson in whose laboratory he worked in the middle 'thirties. After World War II Professor Niewodniczariski initiated research in nuclear physics at the Jagellonian University. His enthusiasm and great organizational talent resulted in the establishment of the Institute of Nuclear Physics in Krakow under his directorship. Thanks to his prolific vision, international reputation and managing abilities, the Institute in Krakow soon reached the position of an advanced research centre highly respected in Poland and abroad. Professor Niewodniczanski was also an accomplished teacher. Many of his pupils are now spread all over the world continuing the spirit of good scientific research instilled by their great Master. This volume describes our research activities through 1993. We have pursued our traditional directions of research, i.e. elementary particle physics, nuclear reaction and nuclear spectroscopy, physics of condensed matter applying nuclear methods, theoretical physics, nuclear geophysics and hydrology, radiobiology, radiochemistry, nuclear medicine including NMR imaging, environmental studies with nuclear and non-nuclear methods, TLD dosimetry and several technical enterprises, such as the construction of particle accelerators, semiconductor detectors for low, intermediate and high energy physics, ion implantation and development of computer networks for scientific purposes. The 3.5 MeV pressurized Van de Graaff accelerator installed in 1992 has successfully completed its first full year of operation. Several experiments in various fields such as sample analysis for medicine and for evironmental studies as well as studies of the surface structure of solids were performed using its beam. The 144 cm isochronous cyclotron was tested with a high-intensity accelerated beam. An internal deuteron beam of 300 /*A was obtained. The cyclotron has now been taken over by the operation team and is waiting (due to lack of funding) to be moved to a permanent site where it will be exploited. The ion implantation plant has been upgraded and is now able to use two ion beams for producing multilayer surfaces. In spite of severe financial difficulties we were able to maintain our staff of about 580 persons. We consider it as a good prospect for the future that 15 fresh postgraduates and postdoctoral workers have joined our staff this year. Our main collaboration partners were: the CERN Organization in Geneva, the Hahn-Meitner Institute in Berlin, the Julich. Kernforschungszentrum, the University of Munster, GSI Darm- stadt, CRN Strasbourg, Laboratoire du GANLL Caen, DESY Hamburg, KfK Karlsruhe, LNL Legnaro, Argonne National Laboratory, Purdue University, Brookhaven National Laboratory, Fermilab, Louisiana University at Baton Rouge, the JENR in Dubna and the Institute of Nuclear Physics of the Ukrainian Academy of Sciences in Kiev. The Institute has actively participated in the preparation of experiments for the new colliders: the LHC at CERN (ATLAS and ALICE) and the RHIC at Brookhaven (PHOBOS). Considerable effort has been undertaken in preparing experiments for the cooler synchrotron COSY at Julich (COSY 10 and COSY 11), the Vivitron accelerator at Strasbourg and the Alpi facility at Legnaro (Eurogam and Gasp). We have published over 400 papers, of which about 200 were accepted by highly regarded international journals. We are particularly proud of two distinguished prizes received by our scientists: The Maria Sklodowska-Curie prize of the Polish Academy of Sciences was awarded to Professor Jan Kwie- cinski for his brilliant results on the physics at small x. Dr Wojciech Florkowski was awarded the Henryk Niewodniczanski prize of the Jagellonian University for his excellent work on multihadron production. The Institute organized together with CERN, the European School of High Energy Physics in Zakopane-Zgorzelisko, Poland, which was highly praised by its participants and by the CERN administration. The international conference on "Meson-Nucleus Interactions" held at the In- stitute was also a considerable success, as were many other scientific meetings and conferences held on the Institute's premises.

A. Budzanowski DIRECTORATE: General Director: Professor Andrzej Budzanowski Deputy Directors: Assoc.Prof. Piotr Malecki, Dr Maria Pollak-Stachurowa, Prof. Michai Turaia

SCIENTIFIC COUNCIL: Chairman: Prof. Krzysztof Rybicki A. REPRESENTATIVES OF SCIENTIFIC STAFF: Jerzy Bartke, Prof., Jan Lasa Prof., Rafal Broda, Prof., Leonard Lesniak, Assoc.Prof., Andrzej Budzanowski, Prof., Piotr Malecki, Assoc.Prof., Tomir Coghen, Prof., Jacek Okolowicz, Dr, Zygmunt Chyliriski, Assoc.Prof., Krzysztof Parliriski, Prof., Jan Czubek, Prof., Grzegorz Polok, Dr, Andrzej Eskreys, Prof., Jan Styczen, Prof., Jacek Hennel, Prof., Michai Tuxala, Prof., Andrzej Hrynkiewicz, Prof., Michai Waligorski, Assoc.Prof., Jerzy Janik, Prof., Tadeusz Wasiutyriski, Assoc.Prof., Edward Kapuscik, Prof., Kacper Zalewski, Prof., Jan Kwiecinski, Prof., Andrzej Zuber, Prof.

B. REPRESENTATIVES OF TECHNICAL PERSONNEL: Bronislaw Czech, E.Eng., Ewa Krynicka, M.Sc, Jan Godlewski, M.Sc, Mieczyslaw Kubica, Wieslaw Iwanski, M.Sc., Piotr Skora, M.Sc., Ewa Kozynacka, Zbigniew Szklarz, Zbigniew Krol, M.Eng., Wladyslaw Wiertek C. REPRESENTATIVES FROM OTHER INSTITUTES: Andrzej Bialas, Prof. - Jagellonian University, Wieslaw Czyz, Prof. - Jagellonian University, Jerzy Niewodniczanski, Prof. - Academy of Mining and Metallurgy, Head of The Polish Atomic Agency. CONTENTS: page

Department of Nuclear Reactions 1 i ',1

Department of Nuclear Spectroscopy 33 '

Department of Structural Research 101 ' , :

Department of Theoretical Physics Ill • - '

Department of High Energy Physics 135 ' *

Department of Environmental and Radiation Transport Physics 213 ' -•

Department of Radiation and Environmental Biology 223 ' 14

Department of Nuclear Radiospectroscopy 237 ''"'

Department of Nuclear Physical Chemistry 249 '

Health Physics Laboratory 267 ' ! •-->

Cyclotron Laboratory 279 ' . <

Cyclic Accelerator R & D Laboratory 283 : '

Electronics Laboratory 288

Computing and Networks 295 •'• i

Division of Mechanical Constructions 297

Energy Efficiency Center 302 < '• U

INP Author Index 305 ' -i Department of Nuclear Reactions DEPARTMENT OF NUCLEAR REACTIONS

Head of Department: Prof. Andrzej Budzanowski Deputy Head of Department: Assoc. Prof. Stanisław Drożdż Secretary: Jadwiga Gurbiel telephone: (48) (12) 37-02-22 ext.: 210 e-mail: [email protected]

PERSONNEL:

Research staff (physicists): Andrzej Adamczak, Henryk Dąbrowski, Ludwik Freindl, Kazimierz Grotowski, Professor, Elżbieta Gula, Jacek Jakiel, Piotr Kamiński, Waldemar Karcz, Stanisław Kliczewski, Ewa Kozik, Jerzy Łukasik, Marian Madeja, Jacek Okołowicz, Michał Palarczyk, Regina Siudak, Artur Siwek, Irena Skwirczyńska, Tomasz Srokowski, Paweł Staszel, Antoni Szczurek, Jarosław Szmider, Henryk Wojciechowski, Roman Wolski, Michał Ziółkowski,

Technical staff: Edward Białkowski, Janina Chachura, Bronisław Czech, Marek Gruszecki, Wiesław Kantor, Kazimiera Pogorzelska,

Administration: Jadwiga Gurbiel

GRANTS:

1. Prof. A. Budzanowski, grant No 203349101, (The State Committee for Scientific Research), "Investigation of resonances in ^O^C) system". 2. Assoc. Prof. S. Drożdż, grant No 224099102, (The State Committee for Scientific Research), "Investigation of strong interactions in nuclear many-body systems". 3. Assoc. Prof. S. Drożdż, grant No 2P30215704, (The State Committee for Scientific Research), "Nonlinear and topological effects in nuclear dynamics". PL9600976 4. Dr. S. Kliczewski, grant No 2P30202505, (The State Committee for Scientific Research), "Experimental investigation of low-lying states of pionic atoms at COSY (Julich)". 5. Dr A. Adamczak, grant US National Science Foundation No INT 91-19223, "Theory of scattering of muonic hydrogen atoms on molecular targets".

OVERVIEW: In 1993 we have maintained the main directions of research in the field of nuclear reactions. We have studied experimentally the 28Si(4He,16O)16O reaction and have found the proper angular momenta in the entrance and outgoing channels which provide a good Hauser Feshbach description of the data. Search for multifragmentation in the 32S + 58Ni reactionat 840 and 960 MeV resulted in finding the contribution from three expected processes namely evaporation, fission and multifragmentation. The emission of three intermediate mass fragments was found to be preponderantly of sequential fission character. New results have been obtained in studying chaotic properties of nuclear systems. 57 years after Bohr's hypothesis of the formation of compound nucleus we have succeded in describing the time dependence of its formation and decay in terms of classical molecular dynamics. New results have been obtained in chaos driven decay of nuclear giant resonances and chaotic properties of nuclear spectra. The onset of colour transparency has been studied in (ee'p) reactions. Multifragmentation of heavy nucleus excited without compression was found for the a + 197A system at the energies 1 GeVA and 3 GeVA. Tunneling of generalized wave packed in the presence of external driving in N-body system with SU2 control was also studied. The elastic, inelastic and single-nucleon transfer cross sections in the collision of 116 MeV 14N ions with 12C, 13C and radioactive 14C targets were analyzed using the coupled reaction channel method. Good agreement between measured and calculated cross sections was obtained. For the first time the external beam of protons at the energy 600 MeV from the COSY synchrotron was registered in the GEM detector (based on the Big Carl Spectrometer within the COSY 11 collaboration). Our traditional partners were: FZ Julich, JINR Dubna, Hahn-Meitner Institute, LAMPF and Institute of Nuclear Physics of the Ukrainian Academy of Sciences. We organized a Conference on the Meson-Nucleus Interactions which turned out to be a success.

REPORTS ON RESEARCH: PL9600977 Modeling Complex Nuclear Spectra "> -, - Regularity versus Chaos S. Drozdz, S. Nishizaki", J. Spethh and J. Wambach6

a) College of Humanities and Social Science, Iwate Univ., Maiioka. 020, Japan, b) IKP (Theorie), Forschungszentrum Julich GmbH, Julich, Germany. In the quantum many-body description of a collective state the full Hilbert space is usually divided into two sectors consisting of 'simple' states, |1), and 'complicated' states, |2). At the same time, the Hamiltonian is represented as H = Ho + V, such that (l|_ffo|l') = €°8u<, 1 2') = €|622» and (l\Ho\2) = 0. The collective state defined as \f) = £1 Al ) is not an eigenstate of H but rather a wave packet which 'leaks' into the space of complicated states. This constitutes a mechanism for dissipation. For the time-dependent state one has: 1/(0) = £ A(*)ii>+£ />(*)|2), ih{t = o) = o) (i) 1 and the Schrodinger equation reads:

l dt[h\ ~ [HiV H \ [fv Applying the Nakajima-Zwanzig projection technique [1] by redefining the basis |2) such that it becomes diagonal in H, i.e (2| j|2') = ^ii'i yields:

TM E £ f drfv{t - T)VU,(T), (3) i' i' ^° where: «H'(T) = -i E Hi2H21> exp(-ze2T). (4) 2 The matrix elements H\t — {\\H\2) describe the degree of mixing between the simple and the complicated states. Ideally, the space of complicated states should contain all possible npnh excitations and thus reflects the complexity of the nuclear compound spectrum. This, however, does not seem necessary. The nuclear Hamiltonian involves predominantly two-body interactions and thus couples the collective state chiefly to 2p2h excitations. Restricting to this subspace the question arises as to whether there are signatures of chaotic motion already at this level. More specifically, is the energy distribution of 2p2h levels, especially the fluctuations, consistent with the Gaussian Orthogonal Ensemble (GOE) of random matrices [2] thus rendering the underlying dynamics chaotic? To make the analysis as conclusive as possible we have chosen a realistic Hamiltonian H ensuring a proper description of the transition strength distribution. To obtain a manageable number of 2p2h states, monopole excitations (J* = 0+) in 40Ca have been selected. We then obtain about 2800 2p2h states which is a meaningful statistical sample. The most obvious measure of spectral fluctuations is the nearest-neighbor spacing (NNS) distribution of energy eigenvalues, e2. A standard procedure is to normalize the spectrum so that the fluctuations on different energy scales become directly comparable. We perform the corresponding unfolding [3] by fitting the integrated density of states to a 12th-order polynomial. Depending on how the 2p2h subspace is treated we find three qualitatively different situations as illustrated in Fig. 1. Part (a) shows the NNS distribution for the spectrum of unperturbed 2p2h states in which the residual interaction V has been neglected. Such a spectrum is not generic and is characteristic for a narrow class of integrable systems involving extra correlations in the Hamiltonian [4]. The pronounced peak for small nearest-neighbor separations illustrates a strong tendency of states for clustering because of degeneracies. Including residual interaction effects but retaining only pp and hh matrixelements immediately brings the spectrum (Fig. l(b)) to the known universality class of generic integrable systems [4] characterized by a completely uncorrelated sequence of eigenenergies. The other important element which makes the spectrum uncorrelated is that, at this level, the 2p2h space remains a product of two subspaces in which only particle pairs and hole pairs are interacting. The crucial step is the inclusion of the ph-type matrix elements. Now the two subspaces can mix and the resulting NNS distribution (Fig. l(c)), almost perfectly, follows a Wigner distribution, i.e. is consistent with the GOE. In fact, considering only these types of matrixelements and ignoring the others gives the same result. The GOE-like behavior is also robust to variations in the strength of the residual interaction, V, as well as the size of the 2p2h space, within reasonable limits (upper part of Fig. 2).

O.B b *•" a. fV\ 0.4

0.8 c I? a. 0.4

0.0

Fig. 1. Nearest-neighbor spacing distributions (histograms) for the sequence of 2p2h states cou- T Fig. 2. Nearest-neighbor spacing distribution pled to J — 0+ as a function of the normalized (histogram in the upper part) and the A3 statis- relative distance s. Part (a) displays the unper- tics (diamonds in the lower part) for a sequence turbed case, (b) corresponds to the results from a of 400 low-energy states. The dotted lines refer diagonalization including pp-and hh interactions to the Poissonian spectrum and the solid lines to only and (c) includes all effects of the residual in- GOE predictions. teraction. The dotted lines represent the Poisson and the solid lines the Wigner distributions. As another indicator of chaotic dynamics we have considered the A3 statistics [5] which are a measure of the rigidity of the spectrum. The A3(L) statistics are calculated as an average of the mean-square deviation of the integrated density of (unfolded) states from a straight line at an interval of length L. A comparison with the corresponding Poisson and GOE predictions [2] (lower part of Fig. 2) reiterates that, when the full residual interaction in the 2p2h space is included, the level statistics signal chaoticity.

References

[1] S. Nakajima, Prog. Theor. Phys. 20, 948 (1958); R. Zwanzig, J. Chem. Phys. 33, 1338 (1960) [2] T.A. Brody, J. Flores, J.B. French, P.A. Mello, A. Pandey and S.S.M. Wong, Rev. Mod. Phys. 53, 385 (1981) [3] 0. Bohigas, M.J. Giannoni and C. Schmit, in "Quantum Chaos and Statistical Nuclear Physics", edited by T.H. Seligman and H. Nishioka, Lecture Notes in Physics Vol. 263 (Springer-Verlag, Heidelberg, 1986) [4] M.V. Berry and M. Tabor, Proc. R. Soc. Lond, A356, 375 (1977) [5] F.J. Dyson and M.L. Mehta, J. Math. Phys. 4, 701 (1963) PL9600978 Chaos Driven Decay of Nuclear Giant Resonances: Route to Quantum Self-Organization S. Drozdz"-6'0, S. Nishizakic'd, and J. Wambachoc X

a) Department of Physics, University of Illinois at Vrbana, IL 61801, USA b) Institute of Nuclear Physics, PL - 31-342 Krakow, Poland c) Institut fur Kernphysik, Forschungszentrum Jiilich, D-5170 Jiilich, Germany d) College of Humanities and Social Sciences, Iwate University, Ueda 3-18-34, Morioka 020, Japan Nuclear giant resonances carry a large fraction of the total transition strength and are located many MeV above the ground state, in the energy region which is expected to be dominated by chaotic dynamics. They, therefore, constitute an interesting phenomenon for studying the coexistence of collectivity and chaos. The giant resonance, as a short time phenomenon, involves simple configurations of a one- particle one-hole (lp-lh) type. Chaos may influence the subsequent decay of these components which occurs on longer time scales and gradually evolves into more and more complex configurations. Eventually, the initial energy deposited in the nucleus is redistributed over all available degrees of freedom and the limit of the compound nucleus is reached. This is the limit of fully developed chaos. The process of giant resonance formation and its subsequent decay towards the compound nucleus occurs in a closed system, and the most basic approach is in terms of a single Hamiltonian acting in a rich enough Hilbert space so that the relevant degrees of freedom are included. This also provides the most natural scheme for the coupling between a collective state and the complex background. In quantum mechanical terms one can then speak about the large and the small components of the nuclear wave function. It is the purpose of the present study to work out such a scheme, to identify which ingredients are relevant, to study the role of chaos on the giant resonance physical observables and finally, from a more general perspective, to contribute to the understanding of the universal aspects of the coexistence between collectivity and chaos in small many-body quantum systems. For the specific case of the isovector quadrupole response in 40Ca, considered here, we have chosen the mean field and residual interaction as in ref. [2] including two major shells above and below the Fermi level. Our study is based on an explicit diagonalization which involves more than 11000 states out of which only 26 are lp-lh states. Computational restrictions require the limiting of the number of 2p-2h states. It turns out that, including those up to 50 MeV excitation energy, there are sufficient for a realistic description of the measured response function. This yields altogether 3014 of 2+ states which is numerically manageable. The result displayed in Fig. 1 yields a mean excitation energy (E) of 30.84 MeV for the isovector transitions, independent of the mixing with 2p-2h states. Motivated by our previous results [1] on the level fluctuations in the prediagonalized 2p-2h space we distinguish three cases: (1) no residual interaction in this space (the corresponding strength distribution is shown in Fig. lb) for which the nearest-neighbor spacing distribution is sharply peaked near zero, because of degeneracies, (2) the inclusion of particle-particle and hole-hole two-body matrixelements (Fig. lc) which results in a Poissonian distribution, (3) the use of the full residual interaction (Fig. Id) which yields the fluctuations of the Gaussian orthogonal ensemble (GOE) characteristic of classically chaotic systems. All three cases introduce significant modifications of the lp-lh 'doorway' strength distribution (notice the change in magnitude of the transition matrixelements) resulting in a gradual reduction of the large components accompanied by a simultaneous amplification of the smaller ones when going from case (1) to case (3). The most interesting effect is that the isovector strength is distributed much more uniformly, not only in excitation energy but also in magnitude. A bit of imagination may even suggest a certain kind of self-similarity regarding the clustering and the relative size of the transitions. The picture in Fig. Id becomes reminiscent of a self-organized system at its critical state [3, 4] where the equilibrium balance reduces the dimensionality. This observation finds confirmation in more quantitative terms. Fig. 2 shows the total number N of transitions of magnitude smaller than a given threshold value Sth, as a function of Sth- For the isovector resonance in the chaotic case

(Fig. Id) we find, except for the largest transitions, a scaling law of the form N ~ Sfh (a ss 0.50) (indicated by the straight line fit in Fig. 2) which indeed signals a reduction of dimensionality. The two nonchaotic cases (Figs, lb and c) display a more complicated behavior. CaJ*=2* isovector 200 150 (a) 100 50

40 (b) 30 20 10

40 (c) 30 20 Fig. 1. The isovector quadrupole strength dis- 40 10 tribution in Ca: (a) no coupling to the 2p- 2h subspace (b) no residual interaction in 2p-2h 12 subspace (c) including only particle-particle and 9 (d) hole-hole tnatrixelements in the diagonalization 6 of the 2p-2h subspace (d) diagonalization of the full residual interaction in the 2p-2h subspace. 3 0 10 20 30 40 50 Energy (MeV)

Fig. 2. The total number N of transitions of

given strength below a threshold value Sth as a function of Sth.. The open triangles refer to the case (b), the open squares to the case (c) and thick dots to the case (d) of Fig. 1. The solid line indicates the best lit to the later case. The thin solid lines represents the same quantity de- -16 -10 termined from a Porter-Thomas distribution [7]. log S th The strength distribution can be considered as an attractor for the decay process starting out of equilibrium. It is nothing but the Fourier transform of the time correlation function (F(0)\F(t)) which, in the form of an envelope [5], describes the process of gradual convergence to such an attractor and, thus, resolves it. This sets the parallel to a procedure [6] which resolves the self-similarity and the scale invariance in classical chaos. This analogy provides further arguments for interpreting the above scaling law as another manifestation of 'l/f'-type behavior. So far, such behavior has been identified mostly on the classical level for a variety of observables and models. In the present case of an 'avalanche' of the decaying giant resonance it is reflecting the chaotic properties of a strictly quantum mechanical phenomenon.

References

[1] S. Drozdz, S. Nishizaki, J. Speth and J. Wambach, Phys. Rev. C49, No. 2 (1994), to appear [2] B. Schwesinger and J. Wambach, Nucl. Phys. A426, 253 (1984) [3] P. Bak, C. Tang and K. Wiesenfeld, Phys. Rev. Lett. 59, 381 (1987); Phys. Rev. A38, 364 (1988) [4] L.P. Kadanoff, S.R. Nagel, L. Wu and S. Zhou, Phys. Rev. A39, 6524 (1989) [5] E.J. Heller, J. Chem. Phys. 72, 1337 (1980); Phys. Rev. A35, 1360 (1987) [6] S. Drozdz, J. Okotowicz and T. Srokowski, Phys. Rev. E48, no. 6 (1993) [7] C.E. Porter and R.G. Thomas, Phys. Rev. 104, 483 (1956) PL9600979 Molecular dynamics approach: from chaotic to statistical aspects of nuclei A. Budzanowski, S. Drozdz, J. Okolowicz and T. Srokowski

In the description of compound nuclei molecular dynamical approaches [1] (MDA) generating chaotic behaviour appear to provide an interesting alternative to quantum stochastic methods [2] based on the random matrix theory. Indeed, the resulting exponential decay of the classical survival probability reflects the presence of Ericson fluctuations as can be seen [3] from the semi- classical energy autocorrelation function of an S-matrix element. The corresponding unitarity deficit allows one to determine [1] the probability for the compound nucleus formation. An important related issue which, however, finds no quantitative documentation in the literature so far is the problem of statistical properties of compound nuclei formed within the molecular dynamics frame. These properties are responsible for the decay characteristics such as energetic and angular distributions of the outgoing particles. The Maxwell form of the energy distribution and the symmetry with respect to TT/2 of the angular distribution are considered to constitute the most convincing signatures that memory is lost and that a certain kind of equilibrium is reached. Because of an explicitly dynamical character MDA offers a very attractive framework for addressing the related questions. In particular, under what conditions the system reaches equilibrium and what are the time scales involved. The results of our investigations using the model of ref. [1] are summarized in Figs. 1 and 2. Even though effectively only six constituents (a-clusters) are involved in these numerical experiments one observes a clear evidence of stochasticity for those events which survive times of the order of 2 • 10~21s before the compound system decays. Already, within such time intervals the energies of the particles approach the stable distribution which has the Maxwell form (Fig.l) and the angular distribution of the emitted a-particles becomes symmetric with respect to x/2 (Fig.2). By comparing the time intervals listed with the form of the corresponding survival probabilities one concludes that the onset of the attributes of stochasticity is correlated with time the decay becomes exponential, i.e. the dynamics is governed by hyperbolic instabilities generating chaotic behaviour. These are, thus, responsible for the underlying memory lost effects. £

-12 -5 0 5 10 n/2 3n/4 E [MeV] T> [rad]

Fig. 1: Energy distribution of particles for12 C + Fig. 2: Yield of outgoing a-paiticles horn the a + 12 C head on reaction at 20 MeV incident energy: 20Ne head on reaction (I = 0) at 15 MeV incident before collision (full circles - solid line is to guide energy as a function of scattering angle. Triangles the eye), at the initial stage (t = 0 in our time represent those cc-particles escaped before t = 11 • scale) - when the relative momentum of the two 10~22s and circles represent those escaped after 12 C becomes zero (squares - solid line represents t = 50 • 10"22s. Full line is a linear fit to the Gaussian fit), at t = 6 • 10~22s (triangles - long latter. dashed line represents exponential fit), at t = 16 • 10~22s (diamonds - short dashed exponential fit), and at t = 24 • 10~22s (open circles - dot-dashed exponential fit). References:

[1] T. Srokowski, J. Okolowicz, S. Drozdz and A. Budzanowski, Phys. Rev. Lett. 71 (1993) 2867 [2] J.J. Verbaarschot, H.A. Weidenmuller and M.R. Zirnbauer, Phys. Rep. 129 (1985) 367 [3] R. Bliimel and U. Smilansky, Phys. Rev. Lett. 60 (1988) 477

Tunneling control in the driven SU(2) n-body system PL9600980 P. Kaminski1'2, M. Ploszajczak1'2 and R. Arvieu3

1 Institute of Nuclear Physics, Radzikowskiego 152 , PL-31-342 Krakow, Poland 2 GANIL, BP 5027, F-14021 Caen Cedex, France 3 Institut des Sciences Nucleaires, 53 Avenue des Martyrs, F-38026 Grenoble Cedex, France We present results for the tunneling of a generalized wave packet in the presence of external driving in the iV-body system with the SU(2) symmetry [1] . The Hamiltonian written in terms of the quasispin operators Ko, K+, K-, has the form:

= eK0- (1)

The classical limit of the model can be constructed using the SU(2) coherent state representation of Slater determinants (SD). Performing a suitable change of variables [1] , one obtains the Hamilton equations for canonical variables q and p with the classical Hamiltonian 7ici =

8 {i>SD I Ho I ipSD)/Ne . These equations are equivalent to the time-dependent Hartree-Fock (TDHF) equations for the evolution of coherent states. The static (p = 0) part of Hci can be interpreted as an analog of the potential energy. For V > s/(N — 1) it displays two symmetric minima at ±qeq separated by a barrier whose height increases with V. The time-dependent driving in the Lipkin SU(2) model is introduced by adding the time- 9 periodic term a sin (f3t) (K+ + K-) to the unperturbed Hamiltonian Ho. We consider quantum tunneling of the wave-packet starting with q0 = +qeq and p0 = 0, i.e. the coherent state centered in the static HF minimum, to the region q < 0 on the other side of the classical potential barrier. For the purpose of our analysis, we use the Husimi function: W^{q,p;t) ~ \(ipsD(q,p) | *(*))|2 = l(0»P I *(0)|2 > which for any quantum state | ¥) is the positive definite, normalized distribution function in the classical phase-space spanned by the parameters (q, p) of coherent states. We calculate the integral of the Husimi distribution over the half of the phase-space (q < 0, p): P(t) = J *$j + e~"k*$fc) . The tunneling frequency can be well given by the "tunnel splitting" A =| €j — ejt |. A particularly interesting case takes place when this "tunnel splitting" tends to zero, i.e. the oscillation period goes to infinity. We have found in the TDSU(2) model many such quasienergy crossings. In Fig. 1 we present the quasienergy spectrum as a function of the driving amplitude a for the driving frequency /? — 4.5 . The calculation is performed for six fermions and V = 1. At a = 1.154 the two dominant quasienergies form an exact crossing. In Fig. 2 we show the quantity P(t) for two values of the driving amplitude: a = 1.154, 1.16. The coherent tunneling is restored for a = 1.16, i.e. away from the crossing point, whereas for a — 1.154 one finds the strong suppression of tunneling. In principle, one could take as an initial condition, the wave-packet which is the combination of two degenerate quasienergy eigenstates. In this case one would be able to see a complete localization in one of the metastable states of the otherwise unstable quantum system.

2.5 i

Fig. 1. The quasienergy spectrum of the TDSU(2) model with six fermions (N = 6) for V = 1, as a function of the driving amplitude a for the driving frequency fi = 4.5. The arrows indicate the states having the largest overlap with the initial coherent state located in the HF minimum (q > 0) of the unperturbed problem.

-2. 0 0.5 1.0 1.5 2.0 a =1.16

Fig. 2. The probability to find the quantum system on the other side of the classical barrier for the driving amplitudes: a = 1.154 at the crossing point of the dominant quasienergies, and away from it at a = 1.16. 0(=1.154

2000 4000 6000 t For a two-level system it is possible to calculate the quasienergy splitting using perturbation theory [2]. Diagonalizing the one-period propagator one derives the splitting of the quasienergy levels: A (2) ') •

The crossing of quasienergies occurs for zeros of the Bessel function Jo. In the range of /3 from 0.5 to 4, one can observe the linear amplitude - frequency dependence for the points of the exact crossings. For larger frequencies, the crossings take place at smaller amplitudes of driving, and from some critital /3 value, they do not occur at all. Our results agree qualitatively with the finding reported in ref. [3].

References [1] H. J. Lipkin, M. Meshkov and A. J. Glick, Nucl. Phys. 62 (1965) 188. [2] J. M. G. Llorente and J. Plata, Phys. Rev. A45 (1992) R6958. [3] F. Grossmann, P. Hanggi, Europhys. Lett. 18 (1992) 571.

1- Flavour, spin and electromagnetic aspects of the meson cloud in the nucleon Illlllllllllll A. DzczureK PL9600981 Different aspects of the meson cloud of the nucleon have been analysed [1-6]. The cut-off parameters of the underlying vertex form factors have been found by fitting to high-energy baryon (n, A, A) production data [4]. The universal cut-off parameter for processes involving baryons octet was found, if the correct functional form factors had been chosen. The phenomenological determination of the form factors allows one to obtain the flavour and spin content of the nucleon. Both pseudoscalar and vector mesons have been included in the present analysis. The Gottfried Sum Rule obtained from the present analysis [3,4], without any free parameters, agrees with that obtained by the New Muon Collaboration. The ^-dependence of the d — u asymmetry resembles the one found by Martin-Stirling-Roberts by fitting to the world data on deep-inelastic scattering and Drell-Yan processes. The predictions of the Meson Cloud Model for the asymmetry can be tested in the planned Fermilab experiment [2], measuring relative dilepton yield in proton-proton and proton-deuteron collisions. The Meson Cloud Model predicts a very small z-dependent asymmetry between s(x) and s(x) distributions.

10 The calculated axial coupling constants for semileptonic decays of the octet baryons agree with experimental data [4]. The Bjorken Sum Rule obtained from the calculation agrees with the classical value. Although, in comparison with the naive quark model, some reduction of the Ellis-Jaffe Sum Rule for the proton is obtained, the model is unable to reproduce the spin EMC experimental result. From the analysis of electromagnetic form factors [5] of the nucleon the quark core radius is obtained. The analysis strongly suggests that the quark core radius is only about 10% smaller than the nucleon radius. Analysis of the renormalization of the total nucleon-nucleon cross section for the presence of the pionic cloud suggests a similar core radius. The presence of the meson cloud in the nucleon leads to a new mechanism of slow (fixed target experiment) proton production in deep inelastic scattering of leptons on nucleons. The rate of the slow proton production by the new mechanism has been calculated for the (anti) neutrino charged-current deep inelastic scattering [6]. The predictions of the model have been compared with the BEBC results at CERN. The momentum distribution of protons has been calculated.

References

[1] A. Szczurek and J. Speth, Nucl. Phys. A555 (1993) 249. [2] A. Szczurek, J. Speth and G.T. Garvey, Julich preprint, KFA-IKP(TH)-1993-13, in print in Nucl. Phys. A. [3] A. Szczurek and H. Holtmann, Acta Phys. Pol B24 (1993) 1833. [4] H. Holtmann, A. Szczurek and J. Speth, paper in preparation. [5] N.N. Nikolaev, A. Szczurek, J. Speth and V. ZoUer, Julich preprint, KFA-IKP(TH)-1993-35, submitted to Z. Phys. A. [6] A. Szczurek, paper in preparation. PL9600982 Nuclear transparency in (e,e'p) reactions and the onset of ? colour transparency N.N. Nikolaev l>\ A. Szczurek 1-s, J. Speth 3, J. Wambach 3'\ B.G. Zakharov 2 and V.R. Zoller 5

1 IKP (Theorie), Forschungszentrum Julich GmbH, D-52425 Julich, Germany 2 L.D. Landau Institute for Theoretical Physics, GSP-1, 117940, V-334 Moscow, Russia 3 Institute of Nuclear Physics, PL-31-342 Krakow, Poland 4 Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA 5 Institute for Theoretical and Experimental Physics, 117259 Moscow, Russia

The nuclear transparency in the (e, e'p) reaction on nuclei has been carefully studied [1-5]. It has been shown that multiple rescattering effects are extremely important in order to understand the onset of the colour transparency effect predicted by quantum chromodynamics. A realistic model for colour transparency effects in (e,e'p) reactions on nuclei has been constructed [1]. In comparison to early works on colour transparency effects in (e, e'p) scattering we differ significantly in the treatment of the coherency constraint which is treated within coupled-channel theory. The model correctly describes the quantum interference effects in the ejectile propagation through the nuclear medium. It has been found that quantum filtering of the ejectile wave packet from the hard ep scattering on bound nucleons puts stringent constraints on the onset of colour transparency. Even after optimizing the ejectile-state scattering for weak attenuation, a rather slow onset of colour transparency has been found. This can be understood

11 in terms of the large number of excited states needed to produce wave packets of small transverse size. As a side effect we have investigated the role of two-body correlations in nuclear transparency for the quasielastic (e,e'p) reaction [2]. Two different effects (spectator and hole) have been discussed. We find large cancellation of the spectator and hole effects. It has been concluded in Ref. [2] that at low Q2 the uncorrelated Glauber model estimates of nuclear attenuation should be accurate. Another side effect has been discussed in [3]. It has been shown that the electron scattering kinematics, in conjuction with the Fermi motion of the bound nucleons, allows one to control the composition of the ejectile wave packet. Using the diffraction operator technique developed in [1] we derive the dependence of the colour transparency signal on the Bjorken variable x of the scattered electron. The Fermi-motion bias obtained in [3] is much weaker than has been claimed recently. Nonetheless, the observation of the effect and of its specific asymmetry around x = 1 would be a very important test of the colour transparency ideas. The transverse-momentum distribution of struck protons in (e, e'p) reactions at CEBAF energies has been calculated in [4]. At large p± we find significant contributions from multiple elastic rescatterings in the nucleus. These occur in a region where the effect of short-range nucleon-nucleon correlation is thought to play an important role, making the extraction of the latter more difficult. In [4] the multi-nucleon emmision has been estimated. A significant effect on the nuclear transparency from finite transverse momentum acceptance in the experiments has been found. This effect is particularly important for the correct interpretation of results of the recent SLAC NE18 experiment [5]. We find that the effect of the p±-broadening is large even for the deuteron. In conclusion, we have found a rather slow onset of colour transparency in the (e, e'p) reactions on nuclei. Nevertheless, for light nuclei the predicted colour transparency signal is found sufficiently strong for a decisive test of colour transparency ideas at a new European Electron Facility currently under discussion (the ELFE project). Our analysis strongly suggests, however, that electron beams of around 30 GeV are desirable, especially to observe a colour transparency signal for heavy nuclear targets.

References [1] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, in print in Nucl. Phys. A. [2] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, Phys. Lett. B317 (1993) 281. [3] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, Phys. Lett. B317 (1993) 287. [4] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, Julich preprint, KFA-IKP(TH)-1993-33, submitted to Phys. Lett. B. [5] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, paper in preparation.

12 PL9600983 PL9600984 PL9600985 O, Diffusion of muonic deuterium and hydrogen atoms D.J. Abbott, P. Gus, J.B. Kraiman, R.T. Siegel, W.F. Vulcan, D.W. Viel (College of William and Mary, Williamsburg, Virginia, U-S-A.^C Petitjean, A. Zehnder (Paul Scherrer Institute, Villigen, Switzerland),VJ.H. Breunlich, P. Kammel, A. Scrinzi, J. Marton, J. Zmeskal (Institute for Medium Energy Physics, Austrian Academy of Sciences, Vienna, Austria} J.J. Reidy, H. Woolverton (University of Mississippi, Oxford, U.S.A.),F.h Hartmann (Technical University München, Garching, Germany)^ A. Adamczak (Institute of Nuclear Physics, Krakow, Poland), V. Markushin (Russian Scientific Centre, Moscow, Russia)t V. Melezhik (Joint Institute for Nuclear Research, Dubna, Russia)

submitted to Physical Review A

Diffusion of muonic deuterium d/i and muonic hydrogen pfi atoms in D2 and H2 at 300 K was studied at pressures of 47—1520 mbar by measuring the distributions of time intervals between entry of negative muons into the gas and the arrival of the resulting d/x or p\i atoms at foils spaced regularly along the muon beam axis. Results indicate atom energy distributions which are différent for dfi and p/x, and vary with pressure, having mean energies ranging from 1.4 eV for d/j, at 94 mbar to 9.5 eV for pfi at 750 nabar. The interpretation of the data is also sensitive to scattering cross- sections for d\i and pfi, and satisfactory fits required the use of cross-sections obtained from current theoretical calculations.

Spin — flip cross sections in muonic hydrogen scattering on / O hydrogen molecules A. Adamczak (Institute of Nuclear Physics, Krakow, Poland^ V. Korobov, V. Melezhik (Joint Institute for Nuclear Research, Dubna, Russia)

submitted to Hyperfine Interactions The results of calculations of the total cross sections of spin-flip processes in low energy muonic hydrogen scattering on hydrogen molecules are presented. These calculations are based on the respective set of cross sections for muonic hydrogen scattering on hydrogen nuclei, obtained within the framework of the multichannel adiabatic method. All combinations of the three hydrogen isotopes are considered. Molecular binding effects are described in terms of the Fermi pseudopotential method. Electron screening effects are calculated in the distorted wave Born approximation. Rotational and vibrational transitions of the molecules, due to collisions with muonic hydrogen atoms, are taken into account. The molecular and electron screening corrections do not exceed a few tens of a per cent for the lowest collision energies.

Neutron multiplicity in deep inelastic collisions: 380 MeV Ar -f Tb system E. Kozik, A. Budzanowski, M. Bürgel1, H. Homeyer1 and J. Uckert1

1) Hahn-Meitnei Institut für Kernforschung, Berlin, Germany

Energy spectra of projectile-like fragments ( Z=6-20 ) in coincidence with neutrons ( Mn=l- 40 159 16 ) were measured for the Ar + Tb system at E;a(,=9.5 MeV/u. Neutron multiplicity distributions for 20 MeV total kinetic energy loss bins were obtained in the TKEL range 0-240 MeV. In the region between 120 and 220 MeV of TKEL multiplicity distributions exhibit

13 PL9600986

two bell-shaped components, the first one at low multiplicity ( Mn ~ 1.5), and the second one at higher multiplicity, shifted increasingly toward increasing the TKEL (see fig.). The low multiplicity neutrons detected in coincidence with the PLF's may originate from 2 different sources:

i) at high total kinetic energy loss the TLF excitation energy permits the evaporation of light charged particles accompanied by the emission of a few neutrons,

ii) excitation energies shared between the PLF and TLF in proportion to their masses are sufficient for emission of one or two neutrons from PLF.

Now we concentrate our attention on the determination of the source of the low multiplicity neutrons.

=16

TKEL=140 MeV TKEL=160 MeV 200-

100 :

0 i—r~i—i—|—i— 0 5 10 15 20 10 15 20 MULTIPLICITY

Heavy ion emission in the 28Si(a,16O)16O reaction1 I. Skwirczyriska, L. Freindl, S. Kliczewski, M. Madeja, A. Budzanowski, W. Karcz, J. Szmider and R. Wolski

Two possible competing reaction mechanisms : compound nucleus formation followed by fission and cluster transfer, have been suggested for nuclear reaction induced by low-energy light particles. The strong absorption of the incident projectiles favors an evaporation process as described by the statistical model. The cluster structure of 325'[1] suggests the direct cluster transfer contribution to the 28Si(a,16 O)16O reaction cross section. 2S 16 16 The angular distributions at Ea = 24.9 and 25.9 MeV for the reaction Si{a, O) O were measured in 4° steps from 28° to 64° in the lab. system. Experimental data were analysed assuming the presence of the compound nucleus mechanism and the one-step transfer reaction. The Hauser- Feshbach model calculations were done with the computer code HAUFES [2], using the Lang's level density formula [3]. The used optical model parameters and necessary angular momenta limitation in the entrance and exit channels have been described in [4]. The comparison of Hauser- Feshbach model prediction with the excitation function at 90°[4] and the angular distribution (Fig.l) for the 28Si(a,16 O)16O reaction indicates that the average trend is quite well described by this model. The direct part of the cross section was calculated in terms of the exact finite range DWBA theory using the revised version of the code LOLA [5]. A minor modification was made to the code since we assumed the reaction amplitudes as the coherent sum of two terms corresponding 12 12 + to the CGS and Cex(the 2 state at 4.44 MeV). Assuming that the transferred cluster x is

1Research supported by The State Committee for Scientific Research under Grant No 2.0334.91.01

14 bound to cores A or b with angular momenta l2 and l\, respectively, the differential cross section for reaction A(a,b)B where a=b+x, B=A+x, and can be expressed as :

da_ 1 h

In EbEa ka

where A(EX) =

sx, 1, and Ex are spin, angular momentum and energy of the transferred particle, respectively. The number of nodes, N, for the radial wave functions is determined by the harmonic oscillator relation 12 2N t=i where L is the angular momentum of the 12C cluster in the target and the final nucleus and n;, lj is the number of nodes and orbital angular momentum of nucleon with respect to the core, respectively. The values 2N+L were caluculated to be 8 and 7 for the 2sSi nucleus and 2,1 for the 160 nucleus. The finite range DWBA calculations were normalized to the experimental data and the 12C cluster spectroscopic factors were extracted. The direct and compound contributions were added incoherently. The calculations reproduced quite well the general features observed in the experimental angular distribution (Fig.l).

10 -D

(lib/sr)

28Si(a,16O)16O

0.1 30.00 50.00 70.00 90.00

'cm

Fig.l The energy averaged angular distribution for the 28Si(a,18 O)16O reaction. The solid line represents sum of DWBA and Hauser-Feshbach contributions and the dashed line represents the Hauser- Feshbach contribution alone. The experimental spectroscopic factors of 12C- cluster in the 16O nucleus [6] were equal to 0.57 and 1.5 for the ground and excited states, respectively. These values were used to extract the experimental spectroscopic factors of 12C-cluster in 2SSi nucleus. The absolute values of the spectroscopic factors for the ground and excited states of 12C cluster in 2sSi nucleus extracted from the present data are 5.4 x 10~3 and 2.05 X 10~~3, respectively. The theoretically predicted l2 [7] spectroscopic factor for Cex is about five times greater then the one we have obtained.

15 PL9600987

The observed disagreement can be explained as the influence of the sequential clusters transfer (8i?e-nucleus and a particle or three a particles).

References

[1] A.C. Merchant and W.D.M. Rae, Nuci. Phys. A549 (1992) 431 [2] R. DaSilveira, Program Haufes (Saclay 1976) [3] D.W. Lang, Nucl. Phys. 77 (1966) 545 [4] I. Skwirczyńska, L. Preindl, S. Kliczewski, M. Madeja, A. Budzanowski, W. Karcz, J. Szmider, R. Wolski and J. Czakański, Report IFJ No. 1649/P1 [5] R.M. De Vries, Phys. Rev. C8 (1973) 951 [6] T. Yanaya, K. Umeda, T. Suehiro, K. Takimoto, R. Wada, E. Takada, M. Fukada, J. Schimizu and Y. Okuma, Phys. Lett. 90B (1980) 219 [7] D. Kurath, Phys. Rev. C7 (1973) 1390

Investigation of the multifragmentation of target nuclei in 4He+mAu collisions at relativistic energies S.P. Avdeyev, V.A. Karnaukhov, V.D. Kuznetsov, L.A. Petrov (Joint Institute for Nuclear Research, Dubna, Russia), R. Barth, V. Lips, H. Oeschler (T.H. Darmstadt, FRG), O.V. Bochkarev, E.A. Kuzmin, L.V. Chulkov (Kurchatov Institute, Moscow, Russia), W. Karcz (Henryk Niewodniczanski Institute of Nuclear Physics, Kraków), W. Neubert (IKEP-Rossendorf, Dresden, FRG), E. Norbeck (University of Iowa, Iowa, USA), A.S. Botvina (Institute of Nuclear Research, Moscow, Russia)

The experimental studies of multifragment emission have been conducted in the last years by means of 4x-setups on heavy ion beams at both intermediate [1] and high energies [2]. In this paper we present the first results of our investigations using the extreme case of the very asymmetric system 4He + 197Au at incident particle energies up to 3.6 GeV/N. This selection is favoured for various reasons: (i) all detected IMF (intermediate mass fragments) are emitted from the target spectator, (ii) the low center-of-mass velocity allows one to determine with high precision the relative velocities and the relative angular correlations, (iii) with He projectiles dynamical effects are small and the compression of the target nucleus is negligible. The experiments were performed at the synchrophasotron of the JINR (Dubna) using the new 47T-device FASA [3]. The mass yield in IMF region is well described by A~T dependence. The exponent r is shown in Fig.l as a function of the LCP (light charged particles) multiplicity, and a minimum is observed at measured multiplicities of 2-4 LCP. The minimum in dependence of the r-parameter on the excitation energy is expected at the critical point for a liquid-gas phase transition [4]. The total cross-section for the fragmentation process for higher incident energy was estimated to be equal to

16 Table 1 Event class 1 GeV/N 3.65 GeV/N Fission l.l±0.2 l.l±0.2 IMF 3.6±0.6 5.3±0.8

alfa+Au alfa+Au (3.65 GeV/N) 3.65 GoV/N

Fission trigger

2343S789 FMD multiplicity (LCP) n9-1 FMD multiplicity (IMF) Fig.2.

Fig. 1 Fig. 2 The excitation energies were deduced from the measured fission fragment mass spectra according to the procedure described in [5]. The values of Eea. equal from 500 MeV to 700 MeV. The relative velocities of IMF-IMF coincidences for the large correlation angles are shown on Fig.3. For incident energy 3.65 GeV/N the mean value of the relative velocity decreases by 0.2 cm/ns. This reduction of the Coulomb repulsion is either due to a larger breakup volume or to a lighter breakup system or to both effects. Information on the time scale of the multifragmentation process can be obtained from the study of the angular correlation between alfo+Au,IMF-IMFcoinc. large correlation angles coincident fragments at the small correlation 500 angles. The quantitative analysis of the data 450 1 \ a 1C if/H is in progress now. It is expected from the i 400 350 1 \\ magnitude of the effect observed that the 300 1 mean life-time of the system is not larger 250 1 \ 21 J 200 than 10~ sec. / • ISO I ( V \ 100 I/ SO 1f V *>> 1.50 1.93 2.40 2.85 3JO 3.73 4.20 4.S5 5.10 3.53 6.00 Vrelcm/nsec) Fig.3.

Fig. 3 References:

1. D. Fox et al, Phys. Rev. C47 (1993) R421. T. Li et al., Phys. Rev. Lett. 70 (1993) 1924. 2. B.V. Jacak, Nucl. Phys. A488 (1988) 352c. J. Hubela et al., Phys. Rev. C46 (1992) R1577. 3. S.P. Avdeyev,... W. Karcz,...et al., Nucl. Instr. Meth. A332 (1993) 149. 4. P.J. Siemens, Nature 305 (1983) 410. 5. G. Klotz-Engman et al., Nucl. Phys. A499 (1989) 392.

17 PL9600988 Study of properties of Ne - Al neutron rich isotopes at near n=20 magic shell using elastic scattering in inverse kinematic A.G. Artukh1, S.N. Ershov1, F.A .Gareev, G.F. Gridnev1, M. Gruszecki, S. Kliczewski, M. Madeja, S. Yu. Shmakov1, J. Szmider, Yu. G. Teterev1, V.V. Uzhinski1, K. Holy2, P. Povinec2, B. Sitar2, Yu. M. Sereda3 and I.N. Vishnevskî3 1 Joint Institute for Nuclear Research, Dubna, Russia 2 Comenius University, Faculty of Mathematics and Physics, Bratislava, Slovakia 3 Institute for Nuclear Research, Kiev, Ukraine The experimental studies of the neutron drip-line position in C, N and 0 isotopes have shown that neutron number N = 16 is a new shell closure, while the shell closure at N = 20 tends to disappear. The anomalies in behavior of the neutron binding energy of the Na isotopes, the abnormal ground state spin of 31 Na and the very low excitation energy of the 2+ state of 32Mg suggest a large ground state deformation what contradicts expectations of the standard shell model [1,2]. The observed overbinding energies of the neutron rich nuclei can considerably shift the boundary of nuclear stability to super neutron rich isotopes. The existence of shape isomers can lead to the appearance of quasi stable islands of quasi neutron nuclei. Information about the shapes of exotic nuclei can be obtained from the scattering experiments. In this work, the conditions and expected results of elastic scatterings of the heavy (Ne - Al) isotopes on protons have been analysed and are presented. Existing at JINR, Dubna, facilities, e.g. the high intensive accelerators, the magnetic separator and the 4TT detectors fulfill all the conditions necessary to perform an investigation with low intensity secondary beams. The time projection chamber, TPC, is planned to be used as a detector. The TPC allows the reconstruction of multitrac events with high spatial resolution, the identification of charged particles and the rough determination of their energies. Additionally, if necessary, gas filling the chamber can be used as a thick target. Thus, using the TPC one can: measure all tracks of reaction products, their energies and angles of emission, determine trajectories of projectiles, separate with high accuracy elastic, inelastic and rearrangement processes and obtain excitation function, simultaneously. The optimal reaction for production of the (Ne-Al) isotopes seems to be fragmentation of 40 Ar nuclei. The angular distributions of heavy isotopes, elastically scattered on protons are focused inside a narrow forward cone ( QLAB < 3° ). So the registration of scattered projectiles demands a very high precision of angle measurements, while associated recoiled protons have a wide angular distribution and are convenient for registration. Considering a very low intensity of the expected for example, 32Na beam, and calculated cross-sections, angular distributions 32 only in the angle region QLAB ~ 0° - 2° for Na or QLAB = 55° - 90° for protons can be measured. The dependence of the {Q LABIAL AB) angle-angle correlations in the inelastic of the scattering process shows an extremely high sensitivity of recoiled proton angles on even such small variations of excitation energy as 1 MeV in comparison with the 1.6 GeV of the initial energy of the 32Na beam. From dependence of energy on angle it follows that separation of the elastic scattering from the inelastic one needs an energy resolution better then 2% for recoiled protons. Assuming that the intensity of the 32Na beam will be 102 particles/s and using the reasonable surface density of protons and cross-section calculated for the second diffraction maximum, it was estimated that two hours are necessary to measure angular distribution with a 1% statistical error. References: [1] X. Campi, Nucl. Phys. A251 (1975) 193 [2] Yu.S. Lyutostansky et al., Proc. 5-th Int. Conf. on Nuclei Far from Stability, Ontario, Canada, (1987) 727

18 PL9600989 Diagnostic software for read-out electronics of L t ime- pro cect ion- chamb er A.A. Artukh1, M. Gruszecki, S. Kliczewski, M. Madeja, A.A. Semionov1, Yu. M. Sereda2, J. Szmider, Yu. G. Teterev1, F. Than Chang1 and D. Ushakov1

1 Joint Institute of Nuclear Research, Dubna, Russia 2Institute for Nuclear Research, Kiev, Ukraine

Nuclear reactions at high energies, as well as reactions induced by heavy ions produce multiplicity of particles and elements. Detection of as many as possible outgoing fragments, their identification and the determination of their energies and angles of emission provide basic information about correlations among these reaction products. Analyses of these correlations allow one to establish a reaction mechanism and in many cases to deduce the complete dynamic of process. In spite of the development of the acceleration and separation techniques, which resulted in production of secondary radioactive beams, their intensities are still low, 102 - 108 p/sec. Investigation of the interaction between these exotic ions and nuclei promise a new insight into the problem of quasi neutron matter [1] and on the properties of nuclei with large ratio of N/Z. Experimental studies of these problems require a system of detection which would provide the measurements of a full multiparticle kinematics and simultaneously carry out unambiguous identification of all types of particles. The time projection chamber, TPC, as an electronic tracking detector allows a three-dimensional reconstruction of multitrack events with a high spatial resolution and identification of charged particles by ionization sampling [2,3]. Furthermore, the principle of the TPC operation permits one to use effectively the detector itself in the mode detector-gas target-detector. A detailed description of the TPC is presented in the report [l]. Signals from the anode wire are splited in preamplifier, than they feed the fast flash ADC and Multistop TDC, which detect the time of incoming signals with an accuracy 2ns in the 16 mks period. A 6-bit FADC measures the charge of the signals from anode wires for a 64ns sampling period. In both converters there is a possibility to measure up to 256 different pulses at once. Such multi-pulses converters enable one to measure many close spaced particle tracks in the TPC detector. Pulses from both ends of the delay line, feed an appropriate preamplifier, income to a discriminator, which detects the time of the highest point of signals and then feeds MHTDC. The digitized time and charge signals are read-out to a computer via a CAMAC system. The TPC anode consists of several separated strips. Four electronic channels cooperate with each of the strips, three of them provide time information (MHTDC), the fourth is charge sensitive. At JINR Dubna are available two TPC, a big one and a much smaller one with three strips only. The small TPC aquisition software enables the perfomance of the following tasks: the trimming of parameters in each charge-sensitive channel, the transfer of data and their acquisition in the computer, the sorting of spectra, the monitoring of sorted time or charge spectra, the reconstruction of particle tracks. For checking the TPC electronics a special programable generator is used. It can simulate any combination of signals on the front of MHADC or MHTDC in both analogue and time channels. Diagnostic software for the rest of electronics enables the following tasks: the programing of a sequence of pulses from a 2-channel generator in the 256 time position, the checking of linearity of MHADC or MHTDC converters, the testing of acquisition in MHADC or MHTDC converters, the acquisition of data in MHADC or MHTDC converters. Using the diagnostic software, mentioned above, the following measurements have been done: charge transfer characteristics of MHADC (linear and nonlinear mode) and charge sensitive track, time transfer characteristic of MHTDC (linear mode) and measuring tracks, test spectra

19 PL9600990

of amplitude and time, measured in MHADC, test spectra of time measured in MHTDC, test acquisitions of amplitude and time pulses from external random generator. The charge transfer characteristics of 6-bit MHADC have a dead zone in the starting part and a saturation zone in the final part of the charge range. Thus nonlinear characteristic of MHADC enables the dynamic range to be extended to 8.5 bit, but with deterioration of the resolution. The charge transfer characteristics of the charge sensitive track have small nonlinearities, that however can be calibrated. For reconstruction of the energy spectra it would be better to have the linear transfer characteristics. The integral nonlinearities should not be larger than an error of particle energy, measured by the TPC detector. The calculations show that linearity of the MHADC and its charge sensitive channels are poor. Their dynamical ranges are also small. The integral and differencial nonlinearities distort information about the time the of incoming signals, which spoils the spatial resolution of the detecting system. On the other hand the transfer time characteristics of a 14-bit MHADC and time sensitive track are linear in a large dynamical range. References: [1] A.G. Artukh et al., 2-th. Int. Conf. on Rad. Nucl. Beams, August 19-21, p. 27, Belgium, Louvain (1991) [2] F. Sauli, Z. Phys. , C38 (1988) 339 [3] B.E. Bonner et al., Preprint BNL-42189 (1988) [4] Yu.A. Budagov et al., Preprint JINR, P13-88-927 (1988) [5] Yu.A. Budagov et al., Preprint JINR, 13-85-585, p. 85 (1985) [6] Yu.A. Budagov et al., Preprint JINR, 13-84-395 (1984) [7] Yu.A. Budagov et al., NIM, A234 (1985) 302 /( First External COSY Beam at the BIG KARL II Magnetic Spectrometer S. Igel, K. Kilian, G. Lippert, H. Machner, C. Nake, P. von Rossen Institut fur Kernphysik, Forschungszentrum Jiilich, Germany L. Jarczyk, S. Kistryn, J. Smyrski, A. Strzalkowski, P.A. Zolnierczuk Physics Institute, Jagellonian University, Krakow, Poland M. Drochner Institut fur Kernphysik, T.U. Dresden, Germany A. Budzanowski, L. Freindl, S. Kliczewski Institute of Nuclear Physics, Krakow, Poland A. Berg, G. Bolscheid, J. Ernst, C. Henrich, R. Jahn, R. Joosten, R. Maschuw, T. von Oepen, D.E. Rosendaal, K. Scho, R. Tolle Institut fur Strahlen- und Kernphysik, Universitat Bonn, Germany and the GEM and MOMO collaboration

A GEM detector system for the investigation of meson production, meson-nucleon interactions as well as pionic atoms properties was invented and developed in the Institut fur Kernphysik, Forschungszentrum Jiilich, Germany. The GEM system consists of the germanium wall (a stack of position sensitive germanium detectors) and magnetic spectrometer BIG KARL H. At the focal plane of the BIG KARL II magnetic spectrometer two sets of Multi-Wire- Drift-Chambers for measuring particles trajectories are positioned. These detectors are followed by the trigger hodoscope consisting of two, double-layer organic paddle-like scintillators for the time-of-night measurements to reduce background. Recently the first accelerated COSY (Cooler Synchrotron) proton beam was focused in the chamber placed at the entrance of the magnetic spectrometer BIG KARL II. The momentum of protons was 660 MeV/c and intensity was 2 X 106

20 PL9600991 particles per 300 ms burst. Repetition rate of the beam was 6 - 9 s. The beam was focused in a circle of 1.5 mm radius. The halo of the beam was measured with a set of 5 scintillators (the same as in the hodoscope) and was less than 1% at a 3 mm distance from the centre of gravity of the beam. The first on-line tests of the focal plane detectors and of the first two layers of scintillation hodoscope were also performed. The callibration measurements using the reactions pp —> dir+ and pd —> 3He x° are in progress.

Scattering and One-Nucleon Transfer in the 14C +14 N Interaction at Energy of E(14iV) = 116 MeV A. Budzanowski, YJEC. Chernievski1, E.N. Dovzhenko1, L. Glowacka2, E.I. Koshchy3 M. Makowska-Rzeszutko, Yu.G. Mashkarov3, V.V. Lutsenko1, Yu.G. Mashkarov2, A.V. Mokhnach1, W.Von Oertzen4, V.N. Pirnak1, O.A. Ponkratenko1, A.T. Rjidchik1, S.B. Sakuta5, R. Siudak, J. TurkTewicz2; T. Wilpert4 and V.A. Ziman1

institute for Nuclear Research, Kiev, Ukraine 2Soltan Institute for Nuclear Studies, Warsaw, Poland 3Kharkov State University, Kharkov, Ukraine 4Hahn-Meitner Institute, Berlin, Germany 5Kurchatov Institute of Atomic Energy, Moscow, Russia The elastic scattering, inelastic scattering and single-nucleon transfer cross sections in the collision of 116 MeV14 N ions with radioactive 14C target were measured using the Kiev isochronous cyclotron. The channels with radioactive nuclei often appear as exit ones in some nuclear reactions. For studies of such reactions it is necessary to know the effective optical potentials of the radioactive channels. The 14<7(14AT,14iV), (14iV,14C), (14JV,13C) and (14iV,13iV) nuclear reactions were analysed using the coupled reaction channels method. Reasonable agreement between measured and calculated cross sections was achieved. As an example the theoretical and experimental cross sections for one-nucleon transfer reaction to chosen excited states of 15iV are compared in Fig.l. The isotopic effects in the 14JV scattering and one-nucleon transfers for the carbon isotopes 12C,13 C and 14C were investigated. This interest was forced by the fact that 14C nucleus has a closed neutron shell that can strongly influence the reaction mechanisms in the 14C+14iV collision in a comparison with the same for the 12C and 13C isotopes.

1O1 I4C(I4N.ISC)I5N# 10 \ I4 u 1 E( N) = 116 MeV OT\ 1 JQ 10- B tot 10 • 1/2* 5/2'// Figure 1: Angular distributions for a 14 14 1S 15 10- \ the C( N, C) N* reaction for ^lO"4 both | and | excited states in b 15 io- N with theoretical CRC calculations (dashed lines) and with co- io- _ • herent sum of proton and neutron T 10 " transfers (solid line). 50 100 150

21 PL9600992 Detection System for the Study of Meson Production at the Energy Threshold A. Budzanowski1, P. Cloth2, A. Djaloeis2, M. Drochner 3'4, V. Drüke2., J. Ernst5, W. Erven4, D. Filges2, L. Freindl1, D. Frekers6, D. Grzonka2, J. Holzer4, R. Jahn5, L. Jarczyk7, K. Kilian2, S. Kliczewski1, J. Konijn 8, S. Kistryn7, D. Kolev9, T. Kutsarova10, B. J. Liebe łl, G. Lippert2, H. Machner2, H. P. Morsch2, C. Nake2, L. Pentchev10, H. S. Plendl12, D. Protic2, E. Roderburg2, P. von Rossen2, D. Schwierz3, R. V. Srikantiah13, J. Smyrski 7, A. Strzałkowski7, R. Tsenov9, P. Turek2, K. Watzlawik 2, P. A. Żołnierczuk7 and K. Zwoll4

1H. Niewodniczański Institute of Nuclear Physics, Krakow, Poland 2Institut für Kernphysik, Forschungszentrum Jülich, Germany 3Institut für Kernphysik, T. U. Dresden, Germany 4Zentralinstitut für Elektronik, Forschungszentrum Jülich, Germany 5Institut für Strahlen- und Kernphysik, Universität Bonn, Germany 6Institut für Kernphysik der Universität Munster, Germany 7Institute of Physics, Jagellonian University, Kraków, Poland 8NIKEF K, Amsterdam, The Netherlands 9Faculty of Physics, University of Sofia, Bulgaria 10Institute for Nuclear and Neutron Research, Bulgarian Academy of Science, Sofia, Bulgaria 11 George Mason University, Fairfax, Virginia, USA 12Florida State University, Tallahassee, Florida, USA 13Bhabha Atomic Research Centre, Trombay, Bombay, India

The hybrid detector system for the investigation of meson production and meson-nucleus interaction was developed and partially mounted at the COSY accelerator in the Forschungszen- trum Jülich (Germany). The system enabling the 4x detection consists of a germanium wall together with the magnetic spectrometer BIG KARL II (common name GEM) and of the two sets of Multi-Wire-Drift-Chambers (MWDC) coupled with a trigger hodoscope. This last device consists of two double-layer scintillation counters with a variable path of about 2 m in between. Each layer consists of 10 to 12 organic plastic scintillators which are similar in form to the paddles. Each paddle is 10 cm wide and 4 mm thick being connected via light guides to phototubes. The slit width between the paddles doesn't exceed 3 mm. The light diodes mounted on some scintillators and driven by a fast puiser enable time adjustment. In November 1993 the proton beam accelerated at COSY was extracted for the first time [1]. The 1.5 mm radius spot of the beam of some 2-106 particles per burst was achieved in the target place. The burst duration time was 300 ms with a 6-9 sec repetition period. The above described detection set-up was used to observe and establish the beam parameters. Reference: 1. A. Berg et al., IKP Annual Report 1993 (to be published)

22 PL9600993

Multifragmentation in the reaction 32S -f 58Ni at 30 AMeV A. Siwek1, A. Budzanowski1, H. Fuchs2, H. Homeyer2, W. Kantor1, G. Roeschert2, C. Schwarz2, A. Sourell2 and W. Terlau2

1 Institute of Nuclear Physics, Krakow, 2 Hahn-Meitner-Institut, Berlin. The decay of the compound nuclei formed in the reaction 32S + 58Ni at 30 AMeV bombarding energy was studied.1) The outgoing charged products were detected in the ARGUS detector which consisted of 123 phoswich type detectors (4.4° < 0 < 41.5°) and three semiconductor detectors (0 = 5.5°, 14.0° and 23.5°) which served as independent triggers. In the phoswich detectors a class of slow fragments (E < 7 AMeV for 7Li and E < 14.5 AMeV for 20Ne) with a charge higher than 2 was selected (HSF - heavy slow fragments). The fragments registered in the trigger detectors were separated into three classes according to the multiplicity of the registered HSF's. We thus denned the fragments corresponding to evaporation (with no HSF), fission (with one HSF) and multifragmentation (with two HSF's). The mass and velocity distributions of fragments from the three processes were analysed. In addition the polar-angle distributions and the azimuthal-angle correlations were studied for three-fragment emission. The experimental results were compared with predictions of three different models of multifragmentation: • the Berlin statistical multifragmentation model (GROSS),2) • the Copenhagen statistical multifragmentation model (CRACKER),3) • the sequential-fission simulations (sequential multifragmentation) (SMF).1) The first two models are modifications treating the same process - the quasi-instantaneous formation of fragments by critical density fluctuations close to the liquid-gas transition of excited nuclear matter. In order to introduce the entrance channel dynamics to the statistical models we made the calculations for eight different compound nuclei formed in the reaction and sumed them up with the weights calculated from the Mohring model.4) As an alternative scenario of multifragment emission we used simulations of two subsequent fissions preceded by light-particle evaporation. For the three models the dependence of the relative decay probabilities on excitation energy was extracted. In the case of the sequential fission simulations the excitation energy dependence was obtained by the adaptation of the theoretical results to the experimental data. The qualitative similarity of the three models seems to indicate that the phase spaces sampled by sequential fission and statistical multifragmentation are not too different. A significant difference between the models can be observed in mass and velocity distributions. Both theories of statistical multifragmentation yield the events with too low masses and too high velocities in comparison with the experiment, whereas sequential fission simulation gives a much better description underestimating the data only in low-mass region (Fig. la). The calculated azimuthal angle correlations and the polar angle distributions of HSF's are in good agreement with the experimental data. There is only a little difference between predictions of simultaneous break-up and sequential fission, slightly favouring the latter (Fig. lb). The calculations suggest that the emission of three heavy fragments is a mixture of the two processes with significant domination of the sequential fission.

23 MUL TIFRA CM E NT A TION MUL TIFRA GMENTA TION

CROSS Sr CRACKER GROSS — SF CRACKER

r 50 , MASS [a.m.u.] PHI3 [deg]

Fig. la. The mass distribution of the frag- Fig. lb. Relative azimuthal-angle distribu- ments with velocity v < 4cm/ns registered in tion between HSF registered in phoswich ar- semiconductor detector at three different an- ray and the fragment registered in one of the gles in coincidence with two HSF's detected trigger detectors at 5.5°, 14.0° and 23.5°. in the phoswich array. References: 1) A. Siwek, Ph.D. Thesis, INP Krakow 1994. 2) X. Zhang et al., Nucl. Phys. A461 (1987) 668. 3) H.W. Barz et al., Nucl. Phys. A448 (1986) 735. 4) K. Mohring et al., Nucl. Phys. A533 (1991) 333.

LIST OF PUBLICATIONS:

I. Articles:

1. A. Adamczak, Differential Cross Sections for Muonic Hydrogen Scattering on Hydrogen Molecules, Hyperfine Interactions 14 (1993) 1056;

2. S.P. Avdeyev, (W. Karcz) et al., FAS A- A 47r Detector Setup for the Investigation of Target Multifragmentation in Nucleus- Nucleus Collisions, Nucl. Instr. and Meth. A332 (1993) 149-156;

3. S.P. Avdeyev, (W. Karcz) et al., Elektronnaya apparatura i programnoye obespetshenye ustanovki 'FAZA', Pribory i Technika Eksperimenta 3 (1993) 104;

24 4. D.P. Beatty, (M. Palarczyk) et al., 16 Pion Double Charge Exchange on O at Tv = 300-500 MeV, Phys. Rev. C48 No 3 (1993) 1428-1430; 5. Z. Chyliriski, Gravity and Non-Extensive Nature of Mass, Acta Phys. Pol. B24 (1993) 1475-1479; 6. Z. Chylinski, E. Obryk, Internal Geometry of n-Body Systems and One-Particle States, Acta Phys. Pol. B24 (1993) 1179-1191; 7. S. Drozdz, J. Okolowicz, T. Srokowski, Coexistence of Hyperpolic and Nonhyperpolic Chaotic Scattering, Julich preprint KFA-IKP(TH)-1993-93; Phys. Rev. E48 (1993) 48-51; 8. J.D. Johnson, (M. Palarczyk) et al., Search for an 77 Bound State in Pion Double Charge Exchange on 18O, Phys. Rev. C47 No 6 (1993) 2571-2573; 9. P. Kaminski, S. Drozdz, M. Ploszajczak, E. Caurier, The Even-Odd Anomalous Tunneling Effect, GANIL preprint P-92-19; Phys. Rev. C47 (1993) 1548; 10. H. Machner, (A. Budzanowski, H. Dabrowski, I. Skwirczynska) et al., Quasi-Free Production of Pionic Atoms in Low-Lying States, Physica Scripta 48 (1993) 175-178; 11. R.S. Mayer, (H. Dabrowski, B. Fornal, L. Freindl) et al., Investigation of Pion Absorption in Heavy-Ion Induced Subthreshold n° Production, Phys. Rev. Lett. 70 (1993) 904; 12. N.N. Nikolaev, (A. Szczurek) et al., The Fermi Motion Effect in the Signal for Color Transparency in (e, e'p) Scattering, Julich preprint KFA-IKP(TH)-1993-21; Phys. Lett. B317 (1993) 287-292; 13. N.N. Nikolaev, A. Szczurek et al., Correlation Effects in the Final-State Interaction for Quasielastic (e,e'p) Scattering, Julich preprint KFA-IKP(TH)-1993-14; Phys. Lett. B317 (1993) 281-286; 14. E. Obryk, Reaktory wysokotemperaturowe - mozliwosci ich wykorzystania i perspektywy rozwoju, Archiwum Energetyki 22 (1993) 95 (in Polish); 15. J. Pluta, (P. Stefanski, H. Dabrowski) et al., Possible Observation of Medium Effects Using a Pion Correlation Technique, Nucl. Phys. A562 (1993) 365-388; 16. C. Schwarz, (A. Siwek, A. Budzanowski) et al., Projectile Break-up with Two Outgoing Intermediate-Mass Fragments in 26 MeV 32S+197Au, Z. Phys. A345 (1993) 29-35; 17. T. Srokowski, J. Okolowicz, S. Drozdz, A. Budzanowski, Fusion Cross Section from Chaotic Scattering, Phys. Rev. Lett. 71 (1993) 2867-2870;

25 18. A. Szczurek, Meson Cloud in the Nucleus and Search for u-d Asymmetry, Proc. of the Int. Conf. on Meson-Nucleus Interaction, Przegorzaly, May 14-19, 1993, in: Acta Phys. Pol. B24 (1993) 1833-1848; 19. A. Szczurek, J. Speth, Role of Meson Degrees of Freedom in Deep-Inelastic Lepton-Nucleon Scattering, Nucl. Phys. A555 (1993) 249-271;

II. Contributions to Conferences:

1. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al., The COMBAS Projectile Fragment Separator. Present and Future, Proc. 3rd Int. Conf. on the Radioactive Nucl. Beams, May 24-27 1993, Michigan, USA; Abstr. of Int. School-Sem. on Heavy Ion Phys., May 10-15, Dubna (1993) 163; 2. COSY-11 Collab., K. Kilian, (M. Ziolkowski) et al., Antiproton und Proton Induzierte Produktion von Mesonen am LEAR und am COSY, Abstr. Verhandlungen der DPG(VI) 28 (1993) 578; 3. S.I. Gogolev, (R. Wolski) et al., Energetic Particle Emission in the 16O-Induced Reaction on 27A1 at E/A=19.3 MeV, Abstracts of Int. School-Seminar on Heavy Ion Physics, May 10-15, 1993, Dubna, Russia (1993) 105; 4. M.G. Nagaenko, (M. Gruszecki) et al., Fragment-Separation Method. Ion Optics and Magnetic Structure of COMBAS, Proc. of Int. Workshop on Radioactive Nucl. Beams Produced by Fragment-Separation Technique, Varna, October 12-15 (1993) ; 5. E. Obryk, Nuclear Coal Synergism as an Option for Future Energy System, Proc. of the 2nd JAERI Symposium on HTGH Technologies, Tokaimura, Japan (1993) 377; 6. PS185 Collab., K. Kilian, (M. Ziolkowski) et al., Antihyperon-Hyperon Production am LEAR, Abstr. Verhandlungen der DPG(VI) 28 (1993) 579; 7. PS185 Collab., K. Kilian, (M. Ziolkowski) et al., Polarisationsdaten fur AA-Produktion in pp-Reaktionen des Experiments PS185, Abstr. Verhandlungen der DPG(VI) 28 II (1993) 579; 8. PS185 Collab., K. Kilian, (M. Ziolkowski) et al., Spinkorrelation und Singulett-Anteil in der AA Produktion, Abstr. Verhandlungen der DPG(VI) 28 (1993) 580; 9. PS185 Collab., K. Kilian, (M. Ziolkowski) et al., Der Dreiteilchenkanal AA7T0 in der pp-Wechselwirkung, Abstr. Verhandlungen der DPG(VI) 28 H (1993) 580; 10. PS185 Collab., K. Kilian, (M. Ziolkowski) et al., New Limits on CP and CPT in Hyperon Decays, Abstr. Verhandlungen der DPG(VI) 28 (1993) 717; 11. N.K. Skobelev, (R. Wolski) et al., Cross-Section Measurements of 6He-Induced Fission of Bismuth, Abstracts of Int. School-Seminar on Heavy Ion Physics, May 10-15, 1993, Dubna, Russia (1993) 93;

26 12. Yu.G. Teterev, (M. Gruszecki) et al., Radioactive Beams Diagnostic System of the Fragment-Separator COMBAS, Proc. of Int. Workshop on Radioactive Nucl. Beams Produced by Fragment-Separation Technique, Varna, October 12-15 (1993) 1; 13. W.A. Ziman, (M.H. Makowska-Rzeszutko) et al., Rassiejannyje i Odnonuklonnyje Pieriedaczi w Stolknowienijach 14C + 14N pri E(14N) = 118 MeV (in Russian); Int. Meeting: Jadiernaja Spektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23 Apriela (1993) 281;

III. Reports:

1. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al., Study of Properties of Ne-Al Neutron Rich Isotopes at and Near iV=20 Magic Shell Using Elastic Scattering in Inverse Kinematics, JINR Dubna Report E7-93-74 (1993); 2. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al., Magneto-Optic Structure of the COMBAS Fragment Separator, Scientific Report 1991-1992 in: JINR Dubna Report, p.262-264 E7-93-57 (1993); 3. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al., The COMBAS Projectile Fragment Separator, Scientific Report 1991-1992 in: JINR Dubna report, p. 260-261 E7-93-57 (1993); 4. S.P. Avdeyev, (W. Karcz) et al., Multifragmentation in 4He+Au Collisions at Relativistic Energies Studied with the 4TT- Setup FASA, JINR Dubna preprint E7-93-278 (1993); 5. J. Balewski, (M. Ziolkowski) et al., Status of the Preparation for the COSY-11 Installation, KFA Julich Annual Report 3 (1993); 6. P.D. Barnes, (M. Ziolkowski) et al., The PS185 Threshold Irregularity - A Detailed View, KFA Julich Annual Report 2 (1993); 7. B. Czech, Programowany sterownik urzadzen elektrycznych do 32 kW, Raport IFJ 1645/E (1993) (in Polish); 8. S. Drozdz, S. Nichizaki, J. Wambach, Chaos Driven Decay of Nuclear Giant Resonanses: Renote to Quantum Self-Organization, Illinois Preprint P-93-12-106 (1993); 9. A. Gorski, Chr.V. Christov, K. Goeke, Electromagnetic Nucleon Properties and Quark Sea Polarization in the Nambu-Jona- Lasino Model, Bochum Univ. preprint RUB-TPII-56/93 (1993);

27 10. M. Gruszecki, Spektrometryczne przetworniki analogowo-cyfrowe. (cz. II. Kodowanie interwałów cza- sowych). Stan obecny i perspektywy analogowych metod kodowania, Raport IFJ 1638/PL (1993) (in Polish);

11. D. Grzonka, (M. Ziółkowski) et al., Light Output of Twisted Scintillator Segments, KFA Jiilich Annual Report (1993);

12. H. Holtmann, A. Szczurek, J. Speth, Consistent Treatment of Pseudoscalar and Vector Mesons in Deep-Inelastic Scattering of Nucléons, Jülich preprint KFA-IKP(TH)-1993-33 (1993);

13. P. Kamiński, M. Płoszajczak, R. Arvieu, Quantum Tunneling in the Driven Lipkin N-Body Problem, GANIL preprint P-93-13 (1993);

14. S. Kopp, A. Szczurek et al., Final State Interaction Effects in Exclusive and Inclusive Quasi-Elastic Electron Scattering from 12C, Jülich preprint KFA-IKP(TH)-1993-20 (1993);

15. J. Majewski, (M. Ziółkowski) et al., Fast Pulse Integrator, KFA Jülich Annual Report 1 (1993);

16. N.N. Nikolaev, A. Szczurek, J. Speth, V.R. Zoller, Pions in the Light-cone Nucleón and Electromagnetic Form Factors, Jülich preprint KFA-IKP(TH)-1993-34 (1993);

17. N.N. Nikolaev, A. Szczurek et al., Multiple-Scattering Effects in the Transverse-Momentum Distribution from (e, e'p) Reactions, Jülich preprint KFA-IKP(TH)-1993-31 (1993);

18. J. Pluta, (H. Dąbrowski) et al., Possible Signature of Medium Effects with Pion Invariant-Mass Correlations, Rapport Interne Lnp-93-16 (1993);

19. I. Skwirczynska, L. Freindl, S. Kliczewski, M. Madeja, A. Budzanowski, W. Karcz, J. Szmider, R. Wolski, J. Czakański,

Heavy Ion Emission in Alpha-Induced Reaction on Silicon in the Energy Range Ea=24.9 - 27.85 MeV, Raport IFJ 1649/PL (1993);

20. A. Szczurek et al., Meson Cloud in the Nucleón and ü — d Asymmetry from the Drell-Yan Processes, Jülich preprint KFA-IKP(TH)-1993-13 (1993);

28 PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. A. Budzanowski,

"Nuclear Big Bang", Masurian School of Nuclear Physics, Piaski, 18-28 August 1993. "Big Bang in Nuclear Physics", XXXII Meeting of the Polish Physical Society, Krakow, September 1993.

2. 5. Drozdz,

"Modeling complex background spectra", Conference on Nuclear Spectroscopy and Nuclear Structure, Dubna, April 20-23, 1993. "Modeling complex nuclear spectra - regularity versus chaos", Mid-West Nuclear Theory Conference, Argonne, September 17-18, 1993.

3. A. Szczurek,

"The role of the meson cloud in deep inelastic scattering of leptons", Conference of Matter as Revealed with Electroweak Probes, Schladming, February 24 - March 5, 1993, Austria. "Strong form factors", Workshop Exclusive Reactions at High Momentum Transfer, Marciana Elba, June 22-23, 1993, Italy. "Meson-cloud of the Nuclear in Deep-Inelastic Scattering and the Drell-Yan processes", Meeting of German Physical Society, Mainz, March 22-26, 1993, Germany. "Consistent description of exclusive 12C(e,e'x) reactions", Meeting of German Phy- sical Society, Mainz, March 22-26, 1993, Germany.

SCIENTIFIC DEGREES

Ph.D. Theses:

1. Regina Siudak - "Multistep Direct Reaction Analysis of Inelastic Scattering and Charge- Exchange Processes at Intermediate Energies".

LECTURES, COURSES AND EXTERNAL SEMINARS:

A. Budzanowski "Selected Topics in Theoretical Physics" Lectures for students of physics at the Jagellonian University, Krakow. 5. Drozdz "Hadronic Matter Physics" Lectures for students of physics at the Jagellonian University, Krakow. A. Gorski (with S. Drozdz)

29 "Hadronic Metter Physics" Lectures for students of physics at the Jagellonian University, Krakow. 5. Drozdz 1. "Nuclear Chaotic Scattering" Seminar - University of Illinois, Urbana, September 15, 1993. 2. "Chaos Driven Decay of Nuclear Giant Resonance" Seminar - University of California, Berkeley, November 18, 1993.

INTERNAL SEMINARS:

1. Z. Majka: "Information on the subject of european forum of nuclear mechanisms". 2. R. Siudak: "MSDR model of preequilibrium reactions". 3. P. Kaminski: "Quantum tunneling in the SU(2) interacting fermion systems". 4. H. Holtman - KFA Julich, FRG: "Spin and flavour in the proton". 5. A. Gorski: "Electromangetic formfactors of nucleon in the Namub-Jona-Lasinio model". 6. H. Lenske - University of Giessen, FRG: "Relativistic mean-field theory of hypernuclei". 7. R. Broda: "Discrete gamma radiation in HI reaction studies - new regions of nuclear spectroscopy". 8. P. Kamiriski: "Quantum tunneling in the SU(2) models - even-odd effect". 9. J. Lukasik - Institute of Physics, Jagellonian University: "CHIMERA - microscopic description of intermediate energy heavy ion collisions". 10. A.T. Rudchik - Kiev Institute of Nuclear Researhch, Ukraine: "Current problems of heavy ion nuclear physics at low energy". 11. H. Fuchs - HMI Berlin, RFC: "Fire ball, hot spots and related problems in heavy-ion collisions in the Fermi energy domain". 12. A. Gorski: "Chiral solution model of the NJL type".

SHORT TERM VISITORS TO THE DEPARTMENT:

1. A. Artiuch - JINR Dubna, Russia. 2. A. Karnaukhov - JINR Dubna, Russia. 3. H. Holtmann - Forschungszentrum Julich, FRG. 4- E.J. Koschchy - Kharkov University, Ukraine. 5. V.K. Chernievski - Kiev Institute of Nuclear Research, Ukraine. 6. V.Z. Ziman - Kiev Institute of Nuclear Research, Ukraine. 7. A. Rudchik - Kiev Institute of Nuclear Research, Ukraine. 8. W. Protic - Forschungszentrum Julich, FRG. 9. P. Hamayer - Forscungszentrum Julich, FRG. 10. H. Fuchs - HMI Berlin, FRG.

APPENDIX:

In Annual Report 1992 the following items have been omitted page 33, Section: List of Publications, Subsection: Articles,

30 13. A.S. Demyanova, (M.H. Makowska-Rzeszutko) et al., Pieredacza tiazolych klastrov w reakcji 12C(4He,12C)4He, Yademaja Fizika, 55, No 10 (1992) 2731-2734 (in Russian). page 34, Subsection: Contributions to Conferences, 3. A.S. Demianova, (M.H. Makowska-Rzeszutko) et al., Pieredacza Tiasholych Klastrov w Reakcji 12C(4He,12C*)4He, Proc. of Conf. "Jadiernaja Struktura i Struktura Atomnovo Jadra", Alma-Ata (1992) 261 (in Russian).

31 Department of Nuclear Spectroscopy DEPARTMENT OF NUCLEAR SPECTROSCOPY:

Head of Department: Professor Andrzej Z. Hrynkiewicz Deputy Head of Department: Professor Jan Styczeń Secretary: Małgorzata Niewiara telephone: (48) (12) 37-02-22 ext.: 202, 477 e-mail: [email protected]

PERSONNEL: Laboratory of the Structure of Nucleus Head of the Laboratory: Professor Rafał Broda

Research Staff: Piotr Bednarczyk* Adam Maj Barbara Wodniecka Bogdan Fornal Marta Marszałek Paweł Wodniecki Marian Gąsior Witold Męczyński Jacek Wrzesiński Wojciech Królas* Tomasz Pawłat Kazimierz Zuber Małgorzata Lach Antoni Potempa

Technical Staff: Jerzy Grębosz Jan Jurkowski Mirosław Ziębliński Mieczysław Janicki Antoni Szperłak Laboratory of Applied Nuclear Spectroscopy Head of the Laboratory: Dr. Zbigniew Stachura

Research Staff: Kvetoslava Burdova Roman Kmieć Franciszek Maniawski Marian Cholewa Stefan Kopta Elżbieta Marczewska* Małgorzata Drwięga Janusz Kraczka Bogusław Rajchel Ewa Dryzek Wojciech M. Kwiatek Małgorzata Sowa Jerzy Dryzek Jadwiga Kwiatkowska Jagoda Urban

Technical Staff: Erazm M. Dutkiewicz Piotr Leśniewski Tomasz Nowak Luba Glebowa Ewa Lipińska Zbigniew Szklarz Roman Hajduk Janusz Łachut Andrzej SeUman Janusz Lekki Stanisław Łazarski * Ph.D. student Administration: Małgorzata Niewiara

33 GRANTS:

1. Prof. R. Broda grant No 224319203 (The State Committee for Scientific Research), "Heavy-ion reaction mechanism studied by discrete gamma-radiation" 2. Prof. A. Hrynkiewicz grant No 204579101 (The State Committee for Scientific Research), "PAC studies of hyperfine interactions in Hf and Ce compounds"

3. Prof. J. Styczen grant No 204519101/P01 (The State Committee for Scientific Research), "Properties of "hot" atomic nuclei studied by means of gamma rays"

4. Prof. J. Styczen grant No 204519101/P02 (The State Committee for Scientific Research), "Investigations of high-spin excitations and superdeformation in nuclei"

5. Dr J. Dryzek grant No 2P30202804 (The State Committee for Scientific Research), "Badanie rezonansowego wychwytu pozytonow w dele stalym" ("Studies of positron resonance trapping in solids") 6. Dr B. Rajchel joint grant with Mining Academy, Krakow, grant No 773269203 (The State Committee for Scientific Research), "Investigation of high-temperature corrosion in metals doped by the ion-implantation"

7. Dr Z. Stachura grant No 2P30204505 (The State Committee for Scientific Research), "Modyfikacja powierzchni cial statych i jej badanie z uzyciem wybranych metod spektroskopowych" ("Modification of solid surfaces and their investigation by methods of nuclear spectroscopy")

Dr J. Kwiatkowska and Dr. F. Maniawski also participate in following grants: grant No 201829101 at the Department of Structural Research, and grant No 223509102 at the Warsaw University (Bialystok branch)

34 OVERVIEW: PL9600994

The scientific activity of our Department in 1993 was as earlier continued predominantly in two research programs i.e. the nuclear structure and heavy-ion reaction studies by gamma detection techniques and condensed matter investigations with application of various atomic and nuclear spectroscopy methods. The short reports which follow include selected results from numerous scientific projects, seven of which were approved by the State Committee for Scientific Research and received special grants. Extensive studies were performed on some fp-shell nuclei. The experimental data obtained recently prove the 68Ni neutron-rich isotope to be a double closed-shell nucleus. While in 45Sc, the collective degrees of freedom seem to manifest pronouncedly. A collective band of states was observed in this nucleus up to possibly spin 39/2+ . The collective motion in heavier nuclei (rare earth and lead regions) was investigated with special consideration of superdeformed bands in 149Gd where the dynamic moment of inertia at high frequencies shows staggering which may be due to the C4 symmetry. The giant dipole resonance studies revealed, among others, the presence at low bombarding energies of the dipole gamma radiation (5 - 60 MeV) which is a bremsstrahlung type radiation due to nucleon-nucleon collisions. The perturbed angular correlation and Mossbauer spectroscopy techniques have furnished several new data on hyperfine interaction properties for some intermetallic and three-metal compounds. The Compton spectrometry studies of Ag single crystals shed some light on electronic structure in that metal. Properties and structure of some alloys were investigated with that method and also with the positron annihilation spectroscopy method. The successful use of the Van de Graaff accelerator, recently installed, has resulted in a number of works on trace element analyses in various parts of the human body (cooperation with a hospital) by the PIXE (proton induced X-ray emission) method. The role of ion implantation in changing surface properties of solids was studied by the RBS (Rutherford back scattering) measurements. The rich program for that year was to a great deal accomplished due to broad international cooperation which made it possible to perform several experiments with the use of multidetector gamma-arrays and other highly sophisticated instruments and facilities. In total, 95 publications with 44 in journals demonstrate the activity. Strong effort has also been devoted to the development of various instruments and detectors as well as to data storage and reduction. The present computer network allows one to perform the reduction of data from various multidetector systems (GASP, EUROGAM, OSIRIS, HECTOR). Much advanced has been the construction of: i) the AFM (atomic force microscope) which will enable both ultra-high resolution microscopy and investigation of mechanical properties of surfaces of solids in the atomic scale, ii) the RFD (recoil filter detector) for filtering the recoiled nuclei in heavy-ion fusion evaporation reactions for spectroscopic studies planned with the EUROGAM in Strasbourg. Worth mentioning is the upgrading of the old mass separator which is now used for surface modifications by the IBAD (Ion Beam, Assisted Deposition) technique, after the addition of an auxiliary ion beam. Two international meetings were organized in 1993: the XXVIII Zakopane School on "Con- densed Matter Studies by Nuclear Methods" and "High Resolution Compton Scattering as a Probe of Fermiology" attracting 90 and 55 participants respectively.

rof, Jan Styczen

35 REPORTS ON RESEARCH: PL9600995 The 208Pb -f- Ni collisions studied by discrete 7—ray analysis W. Krolas, R. Broda, B. Fornal, J. Gr§bosz, T. Pawlat M. Schramm1, H. Grawe1, J. Heese1, K.H. Maier1, R. Schubart2

In several previous reports [1] we presented a few initial results obtained from a complex analysis of the 7 radiation accompanying the collisions of 350 Mev 64Ni projectiles with the 208Pb target. One of the aims of this analysis was to obtain as complete as possible distribution of the final product nuclei, which would allow one us to inspect detailed features of the energy and mass transfer and of the N/Z equilibration process. This part of the analysis involved evaluation of the in-beam and off-beam coincidence data as well as of the measured radioactive decay 7 spectra and allowed to extract the production yields for more than 300 nuclei. The emerging picture is quite complex and clearly the interpretation of the results demands special efforts to extract the transparent information concerning specific features of the heavy ion deep-inelastic collisions. At the starting point of this interpretation work we present here few results, which display the quality of the obtained experimental material. In Fig. 1 the obtained product distribution is presented in N, Z frame for the heavy fragments localized around and below the 208Pb target nucleus. The projection of the complete distribution on the Z - atomic number axis is shown in Fig. 2. The lines drawn in a somewhat arbitrary way mark regions where various processes, from quasielastic A, through deep-inelastic B, to fusion-fision C play a dominant role. It has been earlier established [2] that in the energy range below 6.1 MeV/u the fusion process is supressed due to the requirements of an additional extra-push energy; small yields in the region C apparently correspond to the residual probability of the compound nucleus formation.

210.

85 200 Ebeam = 350 MeV

heavy fragments 80

A =165 70 Q stable nucleus 160 [Vj a = 10 units

HI ^Pb target

N 100 105 110 115 120 125 Fig. 1. Distribution of heavy fragments of the 208Pb + 350 MeV6ANi reaction.

36 105 f

104

t—4 CD

20 30 40 50 60 70 80 90 atomic number (Z)

Fig. 2. Element distribution of reaction products. Yields are given in arbitrary units. Target and projectile element numbers are marked by dashed lines. Thin lines are drawn to mark schematically contributions from different processes (see text).

The presented production yields refer to the secondary products which are formed from the primary excited fragments by a subsequent neutron evaporation. Since in the considered region of nuclei the charged particle evaporation can be neglected one can extract the average number of evaporated neutrons for each combination of exit channel partner nuclei with Z\ + Zi = 82 + 28 = 110. The sum of average masses of all Z\ and Zi products is smaller than the mass of the compound system and the difference must be attributed to the neutron evaporation. Fig. 3 shows the average number, obtained in this way, of evaporated neutrons as a function of the number of protons transfered from the 208Pb to 64Ni projectile. The correlation between the proton transfer and the energy transfer is evident.

References: [1]. W. Krolas et al., IFJ Krakow, An- nual Report 1992, p. 43, W. Krolas et al., Acta Phys. Pol. B24 (1993) 449, W. Krolas et al., Acta Phys. Pol. B (in press), [2]. R. Bock et al., Nucl. Phys. A388 (1982) 334. -6-4-2 0 2 4 6 8 10 12 14 16 18 number of protons transfered 1 Hahn-Meitner-Institut Berlin, Germany 2 Universitat Gottingen, Germany Fig. 3. Number of evaporated neutrons for given proton transfer. Lines are drawn to guide the eye.

37 PL9600996 High spin states in the 45Sc nucleus

P. Bednarczyk1, J. Styczeri, R. Broda, M. Lach, W. M^czyriski, G. de Angelis2, D. Bazzaco3, S. Lunardi3, R. Menegazzo3, L. Muler3 , C. Petrache2, C. Rossi-Alvarez3, G.F. Segato3, F. Scarlassara3, F. Soramel4

The nuclei in the /7/2 shell exhibit properties which reflect an interplay between dominant single-particle motion and collective degrees of freedom which become more and more important especially for the nuclei in the middle of the shell [1,2]. The experimental data for high spin states is still rather scarce due to an unsatisfactory efficiency and limited selectivity of the techniques used. Now available multidetector arrays and the use of Recoil Mass Spectrometer in reduction of the Doppler broadening, which enhance and improve considerably the data, can bring new insight into the excitation mechanism of high excited and high spin states. The present report is a continuation of the studies [3] which we have performed recently using the RMS and GASP at LNL. The level scheme of 45Sc reported in [3] is now extended up to I* = 39/2+ state, also additional transitions for the negative parity states have been found. The analysis of DCO ratios has allowed one to establish spin assignments for the most observed levels. In Fig. 1, plots of the angular momentum against the rotational frequency defined as a half of the 7-ray energy are shown, for three spin sequences in 45Sc. Striking is the smooth behavior of the moment of inertia for the positive parity A and B bands which points to their collective character, whereas negative parity "normal" /™,2 configuration states display a more irregular character typical for the single—particle states.

22 -i—i—r

' Band 0 17

negative parity states _ = 6 positive parity states _

0.5 1.5 0 0.5 1.5 Tito [MeV]

Fig. 1: The angular momentum versus rotational frequency plot for bands observed in the 45Sc nucleus

38 Ex[MeV) In fact, a shell model calculations performed for 51Cr [4] which is a cross conjugate nucleus to 45Sc reproduce well the sequence and excitation energies for the tentatively observed negative parity states (Fig. 2). The "staggering" of the dynamic moment of inertia (Fig. 3) for the band A at high angular frequencies resembles somewhat the staggering of the moment of inertia of heavy superdeformed nuclei [5]. This effect has been related to the influence of the C4 rotational symmetry at high angular momenta. A crude estimate obtained from the thick target measurement shows that the lifetimes for the positive parity A band • 13/2" above 15/2+ state are below 0.2 picosecond. . 11/2" Such lifetime limits imply that the high en- ' 9/2" ergy transitions are rather fast (more than

7/2- 15 WU). In order to determine this enhancement more precisely, an experiment concern- expcriment shell model ing the lifetime measurement of the high spin states in 45Sc nucleus with the DSAM tech- Fig. 2: The comparison between shell niques will be performed at LNL. model calculations and the observed negative parity levels. References:

[1]. J. Styczen et al., Nucl. Phys. A262 (1976) 317 [2]. J.A. Cameron et al., Phys. Lett. B235 (1990) 239 [3]. P. Bednarczyk et al., IFJ Ann. Rep. 1992 50 [4]. A. Yokoyama et al., Phys. Rev. C31 (1985) 1012 40 [5]. S. Flibotte et al., Phys. Rev. Lett. 71 (1993) 4292 30

1 Institute of Nuclear Physics, Krakow, Poland

10 and INFN, Laboratori Nazionali di Legnaro, Italy 2 INFN Laboratori Nazionali di Legnaro, Italy

0.4 0.5 0.6 0.7 0.8 0.9 1.0 I.J 3 Dipartimento di Fisica dell'Universita and rot. freqency (MeV) INFN, Padova, Italy 4 Dipartimento di Fisica dell'Universita and Fig. 3: The dynamic moment of inertia 2 INFN, Udine, Italy (j( ) = A^* ) of the positive parity collective band A in 45 Sc as a function of rotational frequency.

39 PL9600997 The N — 40 neutron subshell closure in the Ni nucleus

R. Broda, B. Fornal, W. Królas, T. Pawłat, D. Bazzacco1, S. Lunardi1, C. Rossi-Alvarez1, R. Menegazzo1, G. de Angelis2, P. Bednarczyk2, J. Rico2, D. De Acuña2, P.J. Daly3, R.H. Mayer3, M. Sferrazza3, H. Grawe4, K.H. Maier4, R. Schubart5

The proton Z = 40 subshell closure is clearly demonstrated by the well known level structure of the 90Zr nucleus [1], for which the lowest excitation is the 0+ state, the first 2+ state appears at 2.19 MeV and the energy favoured particle-hole (j?i/2<79/2) excitation produces the long-lived 5 isomeric state. Obvious difficulty to study similar features for the neutron number N = 40 comes from the fact that the nuclei in question lie very far from the stability line and are not easily available for spectroscopic investigation. Out of two possibilities, which can be considered as realistic, the extremely neutron defficient Z = N — 4080 Zr nucleus was found to be strongly deformed and does not show any trace of the shell closure signature [2]. The only other candidate with the proton closed shell is the N = 40 68Ni nucleus. It lies much closer to the stability line, but it is located on the neutron-rich side and cannot be produced by the fusion process. In fact, the only known excitation in 68Ni, the 1.77 MeV 0+ state was assigned using the 70Zn(14C,16O) reaction [3]. In our effort to search for excited states in 68Ni we used the deep-inelastic processes taking place in heavy ion collisions. Recently we exploited such processes to study the neutron-rich Ni isotopes produced in the 208Pb + 350 MeV 64Ni collisions [4]. The 7-7 coincidences measured with the OSIRIS array at the HMI Berlin allowed us to extend significantly the level schemes of A — 64 to 67 Nickel isotopes. The isotopic identifications were based on the observation of cross-coincidences between the 7-rays of two product nuclei present in the reaction exit channel. In that experiment

5-1

4.48 4.16 4- 3.85

(4+,3- 3- .+ 2.70

1 - 2033

o-J 0+

561 58 60 62 68Ni Nib3o0 Ni!322 Ni3344 "Nil3 6 « 40

Fig. 1. Systematics of selected states in even Ni isotopes and 6SNi results.

40 the production of 68Ni was clearly indicated, but no 7-ray could be positively identified with this isotope due to insufficient statistics. To improve the experimental conditions we performed at the INFN Legnaro a similar measurement for the 130Te + 64Ni system, using the much more powerful GASP multidetector array. The 275 MeV 64Ni beam bombarded the 1.2 mg/cm2 130Te target located in the array center and placed on a 14 mg/cm2 208Pb backing to stop all reaction products. The 7-7 coincidences were stored without any restriction on the multiplicity and the beam was pulsed with 200 ns repetition time in order to separate the prompt and delayed events. The scope of the experiment was much broader and the obtained data are analysed with emphasis on various spectroscopy and reaction mechanism aspects. Here we report this part of the analysis which led to the positive identification of the 68Ni excited states. Fig. 1 shows the systematis of even Ni isotopes and already includes the results obtained for 68Ni from the present analysis. In our search we were guided by a simple shell model expectation which predicts in 68Ni, similarly as in 90Zr, a likely appearance of a long-lived 5~ isomer as well as a significant increase of the 2+ excitation energy as compared to the lighter Ni isotopes. The scanning of the appropriate energy region of the 7^7 coincidence data revealed the cascade of two coincident transitions of 814 keV and 2033 keV energy, which were perfect candidates for the 5~ —> 2+ —• 0+ transition cascade in 68Ni. Both transitions were found to follow the 208 130 decay of the long-lived isomer (Ta/2 > 0.5/xs) and appeared in both, the Pb and Te target experiments with intensities, which matched the expected production yields of the 68Ni isotope. In an attempt to provide the final identification one has to realize that the long-lived isomer restricts the possibility to observe cross-coincidences to those events only, which correspond to the direct, prompt population of the presumed 2033 keV 2+ state. Nevertheless, the superior statistics of the GASP data for the 130Te + 64Ni system allowed one to establish the prompt coincidences between the 2033 keV line and several transitions of the Te isotopes with mass numbers A = 125 to 122. This pattern of Te partner products uniquely assigns the 2033 keV transition to the 68Ni nucleus, which is formed by a transfer of at least four neutrons to the 64Ni projectile and subsequent evaporation of one to four neutrons from the primary products. The high energy section of the prompt coincidence spectrum taken with the 2033 keV gate revealed the 1114 keV line; much weaker than the strong 814 keV isomeric transition, but clearly belonging to the nucleus. It establishes yet another state in 68Ni, lying 300 keV above the 5~ isomer. From the Fig. 1 systematics we assign tentatively this state as the 4+ excitation, although the 3~ assignment cannot be excluded. The progressing analysis is now directed towards a search for higher lying states in 68Ni + 2 and an attempt to locate the 8

References:

[1] L.P. Ekstrom and J. Lyttkens-Linden, Nucl. Data Sheets 67 (1992) 579 [2] C.J. Lister et al., Phys. Rev. Lett. 59 (1987) 1270 [3] M. Bernas et al., J. Physique Lett. 45 (1984) 851 [4] T. Pawlat et al., submitted to Nucl. Phys. A

1 Dipartimento di Fisica dell'Universita and INFN, Padova, Italy 2 INFN Laboratori Nazionali di Legnaio, Italy 3 Purdue University, West Lafayette, Indiana, USA 4 Hahn-Meitner-Institut Berlin, Germany 5 Universitat Gottingen, Germany

41 PL9600998 Spectroscopy of neutron-rich A=93-97 Zr nuclei B. Fornal, R. Broda, W. Krolas, T. Pawlat, D. Bazzacco1, S. Lunardi1, C. Rossi-Alvarez1, R. Menegazzo1, G. de Angelis2, P. Bednarczyk2, J. Rico2, D. de Acuiia2, P.J. Daly3, R.H. Mayer3, M. Sferrazza3

To explore yrast spectroscopy of the neutron-rich nuclei, which are not accessible by fusion- evaporation reactions, we performed an experiment, in which the target of 130Te (backed with Pb) was bombarded with a pulsed beam (200 ns repetition time) of 64Ni (12% above barrier) from the Tandem XTU at Laboratori Nazionali di Legnaro. The in-beam and off-beam 7-7 coincidences, taken with the multidetector system GASP, gave valuable information concerning the deep-inelastic reaction products with A~64 and A~130. For example, low lying excited states 2+, 5~ and 4+ in 68Ni have been identified for the first time revealing the double shell closure character of this nucleus [1]. The data include also intense 7-rays from the fusion-fission fragments; in particular from the Zr isotopes with A= 93-98, which are products of the symmetric fission. The quality of this data gives a very good opportunity to extract spectroscopic information in this poorly known area. Whereas the Zr isotopes with A<92 could be studied in fusion-evaporation reactions and, on the other hand, the Zr nuclei with A>98 were reached in fusion-fission processes [2,3], missing is any information about yrast excitations in 93Zr, 95Zr and 97Zr. Also in the even isotopes 94Zr and 96Zr the highest identified spins are only 6 and 8, respectively.

600

aD96- 500 gate: 1750 keV in 2r

400 C/)

450 650 850 1050 1250 1450 1650

Ey (keV) Fig. 1. Representative 7-7 spectrum for 9eZr product of the 130 Te + 272 Me V MNi reaction.

+ 96 Fig.l shows the spectrum associated with the gate on the 2 —*0+s transition in Zr. Clearly visible are 7-rays in 96Zr itself, among which one can recognize gammas depopulating known states as well as the new ones, presumably originating from the higher yrast levels. In addition, one can see 7-rays from the other Zr nuclei with A=92, 94 and 95; those are the exit channel reaction partners to the 96Zr associated with different numbers of evaporated neutrons. The coincidences between 7-rays from the different reaction partners, so called "cross-coincidences", happen to be very intense in the Zr case and they can serve as a powerful tool for assigning unknown transitions. In fact, by setting gates on a 7-transition in a specific nucleus, the intensity

42 PL9600999 pattern of the displayed cross-coincidence transitions from other nuclei is characteristic for that nucleus thus providing a unique isotopic assignment. We have just started the part of the data analysis concerning the fission products spectroscopy. In the first approach, we are going to study excitations in the mentioned 93~97Zr isotopes and then to extend these investigations to other fission products, which are otherwise hard-to-reach. References: [1] R. Broda et al., another contribution to this Ann. Rep. [2] J.L. Durell, Ada Phys. Pol. B24 (1993) 105. [3] M.A.C. Hotchkis et al., Nucl. Phys. A530 (1991) 111.

1 Dipartimento di Fisica dell'Universita and INFN, Padova, Italy 2 INFN Laboratori Nazionali di Legnaro, Italy 3 Purdue University, West Lafayette, Indiana, USA

Spectroscopy of neutron-rich sdf shell nuclei produced in deep-inelastic processes B. Fornal, R. Broda, R.H. Mayer1, I.G. Bearden1, Ph. Benet1, P.J. Daly1, Z.W. Grabowski1, I. Ahmad2, M.P. Carpenter2, R.V.F. Janssens2, T.L. Khoo2, E.F. Moore3

In an earlier study [1] of the 92Nb + 60Ni reaction, just above the Coulomb barrier, we found that thick target 7-7 coincidence measurements using a Compton-suppressed Ge detector array can yield useful information about the binary products of such heavy ion collisions. Similarly, the high quality 7-7 data, aquired in studies of superdeformed bands in Hg and Tl nuclei at the Argonne ATLAS accelerator, appeared to be a source of valuable spectroscopic information about light neutron-rich products of binary reaction of 34S, 36S and37 C1 beams on 160Gd thick target. We have therefore performed detailed analysis of lower multiplicity subset of these 7-7 data searching for new spectroscopic information on neutron-rich sdf nuclei, which are otherwise hard-to-reach. For many product nuclei near 160Gd, yrast 7-ray cascades were already well known up to high spins, but much less was known about 7-rays in the less accessible nuclei around36 S. During analysis, gates placed on known 7-rays in specific A~160 products selected individual reaction channels and identified coincident 7-rays in light product partners. For example, as shown for the 160Gd + 37C1 reaction in Fig.l(a), known 39C1 7-rays appeared in coincidence with yrast cascade 7-rays of 158Gd and gating on39 C1 transitions, (Fig. l(b)), sharply enhanced the prominence of the 39C1 coincidence peaks. Among those we have identified a new 695 keV 39 2 + transition in C1 depopulating probably the 7rd3/2("f7/2) 15/2 v=3 yrast state. Likewise, for the 160Gd + 36S reaction 7-rays of the 2n transfer product partners 158Gd and 38S were observed in coincidence. A new 849 keV yrast 7-transition in 38S, deexciting a state at 3674 keV was also found. It is very likely that this level is identical to the one located in the (t,p) study of 38S at 3690±16 keV and given a tentative V = 6+ assignment. In N=20 products 34S, 35P, 36S and 37C1 the 7-rays deexciting known yrast states up to I~6 were observed as well. Each isotone was produced with similar yields in at least two of the reactions studied. The present studies yielded also some information about the spectroscopy of the very poorly known 33Si and34 P N=19 nuclei. The34 P nucleus was found to be a product of 2 proton and 1 neutron transfer in the 160Gd + 37C1 reaction and 7-ray transitions in this nucleus could be

43 displayed by setting gates on 7-rays in the appropriate Dy-like partner products. Identification of a new 1876 keV 7-transition in 34P, feeding the known 1+ level at 429 keV, estabilishes a state at 2305 keV which is a good candidate for the yrast state of the type ^^\i2vhli with V — 3~ or 4~. The 2305 keV level located in the present work is almost certainly the same as the 2309±10 keV level populated in the (t,3He) reaction. Similarly, for the 160Gd + 36S reaction, inspection of the appropriate 7-ray coincidence spectrum gated on Dy-like products lines revealed a strong 1435 keV 7-ray that we interpret as a ground state transition in 2pln transfer product 33Si, deexciting the (7/2~) level first located at -1.47 MeV in the (13C, 14O) study. The present 7-ray analysis has shown that the spectroscopy of certain neutron-rich products of deep-inelastic heavy ion reactions can be explored. However, since the production method de- livers many product nuclei with rather low yields, the data analysis is often difficult. Obviously, the newer, larger 7-ray detector arrays open, in this respect, new possibilities.

1 1 i • • • 1 1 1600 o - 1400 - gates: 182 and 365 keV in 158Gd .

27 8 (a) 1200 - - 1000 - o 158Gd - c • 39CI 800 M C) C c 0 u•> a 600 (i c'•" • • COUN " 400 O 48 5 • 3 co 200 - ku J1 0 y win' (jK,i*fjiA»=rf- 1 1 1 1 1 1 400 I 1 I o 39 (b) gates: 410,485,638,1301 keVin CI 300 OO • • • • c c5 o o 158Gd a2 5 48 5 t '• J in 39 200 h o , oo • CI co NT S ID CO 1 O 100 — o „ 1.1 1 L III Li, . n I 0 P m I 1 < 1 I ' i m pp« 1i 1 1 1 1 1 0 200 400 600 800 1000 1200 1400

Ey [keV]

Fig. 1. Representative 77 coincidence spectra for 158Gd and 39Cl products of the reaction 160Gd +167 MeV37Cl. References: [1] R. Broda et al., Phys. Lett, B251 (1990) 245.

1 Purdue University, West Lafayette, Indiana, USA 2 Argonne National Laboratory, Illinois, USA 3 North Carolina State Univ., Raleigh, USA

44 PL9601000 Multi-particle excitations and identical bands in the superdeformed 149Gd nucleus S. Flibotte1, G. Hackman2, Ch. Teisen1, H.R. Andrews3, G.C. Ball3, C.W. Beausang4, F.A. Beck1, G. Bélier1, M.A. Bentley5, T. Byrski1, D. Curien1, G. de France1, D. Disdier1, G. Duchene1, P. Fallón6, B. Haas1, V.P. Janzen2, P.M. Jones4, B. Kharraja1, J.A. Kuehner2, J.C. Lisle7, J.C. Merdinger1, S.M. Mullins2, E.S. Paul4, D. Prévost1, D.C. Radford3, V. Rauch1, J.F. Smith4, J. Styczeń8, P.J. Twin4, J.P. Vivien1, J.C. Waddington2, D. Ward3 and K. Zuber8

Superdeformed excited bands in 149Gd have been studied using the 124Sn(30Si,5n)149Gd reaction . The beam was supplied by the tandem accelerator of the Daresbury Laboratory (U.K.). Gamma rays were detected in the EUROGAM multi-detector array comprising 44 large-volume HPGe Compton-suppressed detectors.

Eight superdeformed rotational bands belonging to this nucleus have been found [Fig.l]. Several excited bands have partners in neighboring nuclei which differ by up to four nucléons, with nearly identical dynamic moments of inertia and quan- tized 7 -ray phasing. These observations cannot be easily explained by theoretical models including an intrinsic scaling with mass of the moment of inertia. The moment of inertia of the yrast superdeformed band in149 Gd shows an unexpected staggering [Fig.2]. At high rotational frequencies the AI=2 rotational band is perturbed and two AI=4 rotational sequences emerge with an energy splitting of about 120 eV. The feature suggests the remnant 800 1000 1200 UOO 1600 y-roy energy (keV) of a quantum number associated with an invariance of the Hamiltonian under a ro- Fig. 1. The -y-ray spectra of the five ex- 149 tation of 90° around the rotation axis (C4- cited SD bands in Gd. symmetry).

CRN, Strasbourg, France McMaster University, Canada Chalk River Lab., Canada University of Liverpool, U.K. SERC, Daresbury, U.K. NSC, Berkeley, USA University of Manchester, U.K. "5S ÖT> ÖT~ Institute of Nuclear Physics, Rotational frequency (MeV) Cracow, Poland Fig. 2. Dynamical moment of inertia of the yrast superdeformed band in1 Gd.

Work is partly supported by the Pohsh KBN grant nr 204519101/p.02, published in Ph. Rev. Lett. 71 (93) 688 and Ph. Rev. Lett. 71 (1993) 4299.

45 PL9601001

First results from spectroscopy of 199At with the Recoil Filter Detector

M. Lach, J. Styczeri , W. M§czynski, K. Spohr1, H. Grawe1, J. Heese1, H. Kluge1, K.H. Maier1, R. Schubart1, J.C. Merdinger2

A not yet explored region of deformed nuclei exists for neutron numbers N < 126 and proton 186 188 numbers Z > 82. In previous work very low lying prolate deformed bands in . pD [1] and 196 198 likely oblate intruder states in > po [2] have been seen. This indicates that the transition region is close. As deformation is caused by the proton-neutron interaction the governing parameter is (126 - N)x(Z - 82). Therefore an attempt was made to establish excited states in 199At (Z=85) with the 175Lu (28Si,^n)199At reaction at E(28Si) = 141 MeV. The heavier odd isotopes of At are known. The experimental problem is that these nuclei are only produced with very low cross sections as fission of the compound nucleus dominates. The recoil filter detector (RFD) [3] identifies evaporation residues in coincidence with the 7-rays measured by OSIRIS and hereby selects the wanted events from the background. The cross section of 199At has been calculated from the data as 0.10(5)m6, while a PACE calculation gives 100m6 in total for fusion, and Coulomb excitation is very strong too. Fig. 1 shows a total projection of the 7-spectrum with and without i?FZ>-coincidences. A summed coincidence spectrum for 199At, as identified by X-ray coincidences, is shown in Fig. 2. The counting rate is too low to deduce a level scheme. But it is fairly clear that the 608 keV line is a crossover parallel to the cascade of the 236 and 372 keV transitions and the strongest 433 keV transition is coincident with the other lines. Unless these prompt transitions are on top of an isomer, therefore the first excited state of 199At has dropped to 433 keV (or even 372 or 236 keV) from a rather stable position above 600 keV in 201At and the heavier isotopes.

2.0x10 . X-Rays 199,, * Po 199 A At 1.5x10 © not yet ident.

200 400 600 800 1000 Energy (keV)

Fig. 1. Total •projection of 7-7-coincidences for the reactions of 141 MeV 28Si with 175Lu (lmg/cm2). The lower spectrum is in coincidence with the RFD, lines in 199At are marked by their energy. In the upper spectrum the otherwise dominant Coulomb excitation is suppressed by a window on the sum energy of the ball and requiring ball multiplicity between 1 and 11.

46 o o 10 r

0 :

-10b 0 200 400 600 800 Energy (keV)

Fig. 2: Summed spectrum in coincidence with 199At lines and the RFD.

The RFD worked well and reliably. Lowering the voltage and thereby the gain of the phot- multipliers and some other minor improvements led to a much more stable operation and better control of the threshold adjustments. Only the efficiency, that was 16% in this measurement, is still below the anticipated value of 30% to 50%. But the individual elements varied appreciably. The best elements would give a total efficiency of >25%. This shortcoming is mainly due to elevated noise between beam pulses caused by the scattered beam ( >1 hit per beampulse) and a smaller than expected signal height. In this experiment the energy of the recoiling nuclei was so low, that about 8% were stopped in the electron emitting 2 /xm Mylar foil. The detector foils will now be replaced by 0.5^m thick ones. The higher energy at the exit of the foils means larger signals, because the electronic energy loss is higher, and more than likely the design aim of >30% efficiency will be reached soon. A second version of the RFD is under construction for EUROGAM at Strasbourg, which has 100 times the efficiency for 7-7-coincidences. This efficiency and the clean spectra achieved with the RFD will allow one to measure cross sections of 10 fib. References: [1] J. Heese et al., Phys. Lett. B 302 (1993) 390. [2] D. Alber et al., Z. Phys. A339 (1991) 225. [3] J. Heese et al., EMI Bereich Schwerionenphysik Annual Report 1992, HMI-B507, ISSN 0944-0305, p. 90 and Proc. of the International Conf. on Nucl. Structure at High Angular Momentum, Ottawa and Chalk River May 1992, AECL-10613 Vol. 2 p. 439, and Ada Phys. Polonica B24 (1993) 61.

1 Hahn-Meitner Institut, Berlin 2 Centre de Recherches Nucleaires, Strasbourg

47 PL9601002 Search for Jacobi instability in hot and rotating 46Ti A. Maj, M. Kiciriska-Habior1, W. Krolas, J. Styczeri, J. Kownacki1, J.J. Gaardh0je2, T. Tveter2, Z. Zelazny1'2, M. Mattiuzzi3, F. Camera3, A. Bracco3, B. MiUion3

In a number of experimental studies in which the spectra as well as the angular distributions of 7-rays from Giant Dipole Resonance decay were measured, the predicted nuclear shape-change from prolate to oblate at specific temperature and angular momentum has been verified. At higher angular momenta, nuclei are expected to undergo another, so called Jacobi, transition from oblate shapes via triaxial to prolate ones. In this connection nuclei of medium-light masses attract a special attention since for them, contrary to the heavier ones, the critical angular momentum for such a shape-transition is predicted to be lower than the fission limit. An observation in an inclusive experiment of such a transition in the 45Sc nucleus has been recently reported by M. Kicinska-Habior and the Seattle group [1].

To investigate this problem further we have carried out an exclusive study of the GDR decay from hot and rotating 46Ti nucleus performed at the Tandem and Heavy Ion Booster accelerator 18 28 of the Niels Bohr Institute, Copenhagen. The employed reactions were O + Si at .Ef,eam = lOO 46 and 69 MeV, leading to the Ti nucleus at £'=80 and 61 MeV, and with lmax=Mh and 27h, respectively. The 7-rays emitted in the reaction were measured by the multi-detector array HECTOR, which consisted of 8 large volume BaF2 detectors located at different angles (see Fig. 1). HECTOR was also equipped with a multiplicity filter HELENA: 38 small BaF2 crystals covering 80% of the full solid angle. This high efficiency enabled one to select relatively narrow windows of the angular momenta of the decaying compound nucleus.

Helena

Fig. 1. The experimental setup used for the experiment.

48 OJ 100 U.V -O..WS! FoldS OJ Fold 4 B "" 0.1 .J • -0.1 1 -•.1 • • •••• -OJ "I ..Ml -OJ •••••fl -OJ 10 15 •0 -" OJ 100M«V>«D 0.1 FoldS OJ Fold 7 •.1 ^L n n • V»Oa>"TC Told 9 OJ Fold 10 0.1 • 0.1 o.o -0.1 -0.1 -OJ -OJ -OJ

. 2. Spectra of At angular distribution coefficient for different folds. The -ray energy is in MeV.

Fig. 2 shows the spectra of the A2 angular distribution coefficient for the high energy gamma rays from the reaction at 100 MeV. They were obtained by gating on different folds in the multiplicity filter. The behaviour of the spectra associated with low folds is in general agreement with that obtained by the Seattle group: the magnitude of the low energy component is similar and, moreover, there is a peculiar lack of change of the sign of A2- values around the GDR average energy (19 MeV). On the other hand the spectra gated by folds>8 (what corresponds to angular momentum of the compound nucleus l>28h) begin to show positive A2 values for the GDR high energy component. This makes the trend of the A2-spectra, though the statistics are rather poor, closer to the expectations for deformed nuclei. This observation might indicate a presence, at the bombarding energy of 100 MeV, of a low multiplicity component that is not related to the formation of the compound nucleus. The component can only be filtered out by means of a multiplicity filter. A more detailed data analysis as well as a comparison to the statistical model calculations are in progress.

We would like to thank Mrs. Andree Meens from CRN Strasbourg for preparing the Si target. This work was partly supported by the State Committee for Scientific Research under Grant No. 204519101/p.Ol. References [1]. M. Kicinska-Habior, K.A. Snover, J.A. Behr, C.A. Gosset, Y. Alhassid, N. Whelan, Phys. Lett. B308 (1993) 225

1 Instytut Fizyki Doswiadczalnej, Uniwersytet Watszawski, Warsaw, Poland 2 Niels Bohr Institute, Copenhagen, Denmark 3 Milano University, Milano, Italy

49 PL9601003 Entrance channel effects in GDR decay following heavy ion fusion Z. Zelazny1, J.J. Gaardh0je1, A. Maj, F. Camera2, A. Bracco2, M. Mattiuzzi2, T. Tveter1

In order to be selective in both excitation energy and spin a difference method has to be used. The idea is to produce in heavy-ion fusion reactions two compound systems with mass numbers differing by one neutron. The excitation energies are chosen so that they differ by the average energy removed by the first evaporated neutron. The 7-ray emmision from these two nuclei and from their daughters is measured and the resulting energy spectra are subtracted after normalization to the same number of fusion reactions. Determined in this way the difference spectrum contains gamma radiation from the first step of the CN decay. With the selective multiplicity filter HELENA we have been able to make full use of this idea, which requires that spectra that are subtracted correspond to the same angular momentum. The following three pairs of reactions have been investigated: 17'18O +144 Sm=161'162Yb , E*=39 and 51 MeV,

29,28Si + 128,130Te = 157,158Dy) E*=64 amJ 75 MeV) 48Ti + 113l114Cd=161,182Yb, E' = 64 and 75 MeV. As is shown in Fig. 1 the relative intensity of difference spectrum measured for an oxygen beam is very close to the value predicted by the statistical model.

48Ti-bearrr Fig. 1. Relative intensities of difference spectra (in % of the intensity of the total spectra corresponding to higher excitation) in the GDR energy range. Data are plotted as

-20 a function of the average ro- 20 30 40 50 60 70 tational angular momentum I of the selected bin.

For Si projectiles we observe a very distinctive dependence on spin: the difference yield decreases from close to the cascade value at low / to almost zero at higher / while for Ti induced reactions the intensity is close to zero at all covered angular momenta. This is in dramatic con- flict with statistical model expectations. In all three cases we produce very similar compound systems (N=91 and 92). It is a challenge to understand the reason for the lack of an extra GDR emission from an extra E* in cases of nearly symmetric projectile-target systems possessing high angular momentum. It is tempting to think about some preequilibrium process in these collisions which may have long relaxation times. In the near future we will complement some of the measurements by explicitly gating high-energy photon spectra with specific low-energy discrete transitions identified in the fusion residues using a Ge detector in order to make absolutely certain that we are dealing with pure fusion events.

1 Niels Bohr Institute, Copenhagen, Denmark 2 Milano University, Milano, Italy

50 PL9601004

Pre-fission 7-decay in hot superheavy 272Hs

T.S. Tveter1, J.J. Gaard^je1, A. Atac, B. Herskind1, W. Körten1, T. Rams0y1, G. Sletten1, Z. Żelazny1, J. Bacelar2, A. Buda2, H.v.d. Ploeg2, W. Krolas, A. Maj, A. Menthe3, H. Nifenecker3, J.A. Pinston3, F. Schussler3, A. Braceo4, F. Camera4, B. Million4, M. Pignanelli4

Measurements of neutron multiplicities from hot fissile nuclei at various initial excitation energies reveal that the number of pre-fission neutrons emitted increases with the excitation energy, while the number of post-fission neutrons stays approximately constant [1]. This result suggests that fission is a slow process, taking place only when the nucleus has been cooled to some lower excitation energy, contrary to statistical expectations. Since neutron evaporation is obviously able to compete favourably with fission at high temperatures, this should also be the case for GDR 7-ray emission. Recent experiments measuring 7-rays from fissioning systems confirm this idea: Both a pre-fission and a post-fission component can be discerned in the 7-spectra, at different 7-energies due to the different radii of the compound nucleus and the fragments [2]. The pre-fission GDR radiation offers insight into nuclear behaviour at extreme conditions with respect to spin and nucleón number, a region which has previously been closed to direct scrutiny. At the SARA Cyclotron Laboratory in Grenoble, the superheavy nucleus io|Hs has been synthesized employing the reaction 40Ar+232Th—>272Hs. A pilot experiment was carried through by the HECTOR collaboration in 1989, using beam energies of 6.8 and 10.5 MeV/,4 [3]. The main experiment was carried out in 1991, with beam energies of 10.5 and 15.0 MeV/A. The experimental setup included the 8 BaF2 HECTOR detectors, mounted in the plane perpendicular to the beam axis. An array of small BaF2 crystals defined the events in time and served as a common start for time-of-flight measurements. Four PPACs (Parallel Plate Avalanche Counters) were used for the detection of fission fragments. Due to the disappearance of shell effects at high temperature, hot thermalized fissile nuclei tend to decompose into two fragments of approximately the same mass. By gating at symmetric fission of very heavy systems formed using heavy projectiles, we can select events connected with complete fusion reactions and full thermalization.

Fig. 1. The normalized 7 -spectra 106 recorded in coincidence with symmetric 105 fission for the 15.0 and 10.5 MeV/A Vi 104 runs after subtraction of an exponen- 'S :iOMeV/u it»,ljf tial bremsstrahlung component, and the difference spectrum, representing the Diff. 102 pre-fission component. Bottom: ratio of the difference spectrum and the g 101 10.5 MeV/A spectrum. The arrows in- o 300 dicate the expected location of the pre- pre-fission post-fission fission component (*72Hs) and from the fission fragments.

51 PL9601005 Assuming that the excitation energy at which fission takes place is essentially independent of the initial excitation energy, the energy differential method [3] can be employed to obtain information about the earliest decay steps. We have normalized the coincident 7-spectra from the 15.0 and 10.5 MeV/^4 runs to the same number of symmetric fission events. The two total 7-spectra and their difference, corrected for bremsstrahlung, are displayed in Fig. 1. The difference spectrum shows a narrow distribution, centered at the 7-energy at which we expect the GDR radiation from the heavy composite system, N.o significant intensity is present in the energy region associated with fission fragment GDR radiation. This indicates that fission only takes place after cooling of the system down to an excitation energy below the one initially introduced by the 10.5 MeV/A beam. On the other hand, the difference between the total coincident 7-spectra from the 10.5 and the 6.8 MeV/yl runs (not shown here) reveals strong GDR contributions from both the superheavy compound nucleus and the fission fragments. The yields of pre- and post-fission GDR 7-rays at the three beam energies contain valuable information about the time constant for the fission process, which is related to the viscosity of nuclear matter. Our plans are to compare the 7-spectra extracted in coincidence with symmetric fission, with theoretical calculations performed with a modified version of the program CASCADE. In this way we will try to extract a lifetime for the hot fissile "gHs nuclei and the corresponding nuclear friction coefficient 7. This work was partly supported by the State Committee for Scientific Research under Grant No. 204519101/p.Ol. References: [1]. D.J. Hinde et al., Nucl. Phys. A502 (1989) 497 [2]. M. Thoennessen et al., Phys. Rev. Lett. 59 (1987) 2860 [3]. J.J. Gaardh0je and A. Maj, Nucl. Phys. A52O (1990) 575 Permanent addresses: 1 Niels Bohr Institute, Copenhagen, Denmark 2 KVI Groningen, The Netherlands 3 ISN Grenoble, France 4 Milano University, Milano, Italy

Rotational frequency dependence of orientation fluctuations M. Mattiuzzi1, A. Bracco1, F. Camera1, B. Million1, M. Pignanelli1, J.J Gaardh0je2, A. Maj, Z. Zelazny2, T. Tveter2

An interesting point that was found in a recent work [1] is the very different sensitivity of the GDR strength function and angular distribution to nuclear deformation. Analyses of the spectral distribution and of the size of the angular distribution can lead to different conclusions about the effective deformations of excited nuclei. This difference is expected to vary with the rotational frequency of the hot compound nucleus. We have started the study of the dependence of the effective nuclear deformation on rotational frequency in 176W at E*= 96.7 MeV. Making use of the multiplicity filter of the HECTOR detector array, high energy spectra associated to narrow spin intervals were measured. The analysis of the spectral shape and of the angular distribution is in progress. The final objective is the comparison of the effective deformations extracted from the two observables. References: [1]. F. Camera, A. Bracco, B. Million, M. Pignanelli, J.J Gaardh0je, A. Maj, Z. Zelazny, T. Rams0y, Nucl. Phys. A (in print)

52 1 Milano University and INFN, Milano, Italy 2 Niels Bohr Institute, Kopenhagen, Denmark PL9601006 Thermal and quantal fluctuations as probed by the GDR observables A. Bracco1, F. Camera1, M. Mattiuzzi1, B. Million1, M. Pignanelli1, J.J. Gaardh0je2, A. Maj, Z. Zelazny2, T. Tveter2

A study of the strength function and of the angular distribution of the high energy gamma rays from the giant dipole resonance in the hot rotating 110Sn nucleus at T ~ 2 Mev was made making use of the HECTOR array. The two GDR observables were obtained at different narrow angular momentum intervals of the compound nucleus. The simultaneous measurement and analysis of the two observables is expected to help to disentangle the different effects due to large amplitude thermal fluctuations from those due to small amplitude quanta! fluctuations. In fact, as shown in ref. [1] an increase of the apparent GDR width can be due to either one or both effects. In case the width increase is due to thermal fluctuations, that increase the effective nuclear deformation, the associated angular anisotropy also becomes larger. This is the case with the present data, shown in the figure, which for the first time demonstrate that the GDR intrinsic width remains unchanged and that the total width increase that occurs as a function of increasing rotational angular momentum arises almost solely from the GDR splitting due to increasing deformation.

0.3 = 43 0.2 0.1 0.0 ,f

V -0.1 -0.2 a -0.3 u 10 15 20 10 15 20 7 Energy (MeV) 7 Energy (MeV)

0.3 = 51 f 0.2 0.1 V C O 0.0 I u I V -0.1 en -0.2 -0.3 10 15 20 10 15 20 y Energy (MeV) 7 Energy (MeV)

Fig. 1. Comparison between the strength function and the 02(E-y) at temperature T~ 2 MeV for average spin 4$h (top row) and 51 ft (bottom row). The curves are the best fitting statistical model calculations and the width of the strength function at 51h is 1.5 MeV larger than at 43h.

53 D , PL9601007 Keierences: [1]. A. Braceo, F. Camera , M. Mattiuzzi, B. Million, M. Pignanelli, C. Volpe, J.J Gaardli0je, A. Maj, Z. Żelazny, T. Tveter, Nuci. Phys. A (in print)

1 MUano University and INFN, Milano, Italy 2 Niels Bohr Institute, Kopenhagen, Denmark

Ultradipole radiation in 12C-f24'26Mg collisions M. Kicińska-Habior1, K.A. Snover2, A. Maj, Z. Drebi2, D. Ye2, M. Kelly2

Photon production mechanism in heavy-ion collisions at projectile energies up to E/A=5- 6 MeV/u has been well understood in terms of the statistical decay of an excited compound nucleus taking into account the giant dipole resonance (GDR) built on excited states [1,2]. In the intermediate beam energy region {E/A > 20 MeV/u) the nonstatistical excess of high energy photon yield beyond the GDR region over the statistical model predictions called ultradipole radiation (UDR) or bremsstrahlung radiation occur and is well described by collisional models where photons are produced in first chance incoherent proton-neutron collisions [3]. At projectile energies E/A x 10 MeV/u UDR has been also observed with the 7-ray angular distribution implying a source moving at the nucleón-nucleón center-of-mass velocity [4,5]. It was found, however, that the yield of the UDR vary more strongly with the projectile-target combination than expected from scaling to the average number of the first chance p-n collisions [4,5]. At these low projectile energies the relative importance of the Fermi motion of nucléons in colliding nuclei and the Pauli blocking is expected to increase what can be manifested in the sensitivity of the UDR yield to the differences in the neutron-proton phase space distribution [4,6].

We have studied 7-ray emission in 12C+26Mg reaction at 6, 8.5 and 11 MeV/u and in 12C +24 Mg reaction at 11 MeV/u using 12C beams from University of Washington tandem linac. Gamma ray spectra at 40°, 55°, 90°, 125° and 140° with respect to the beam axis have been measured in a large Nal(Tl) crystal with plastic anticoincidence and lead shields. Coincidence 7-ray spectra have been also measured using a multiplicity filter consisting of 23 small Nal(Tl) crystals. We have chosen these reactions to study UDR at relatively low projectile energy for light targets and the mass asymmetric entrance channel, to check a influence of UDR on 7-ray angular distribution, to check the amount of UDR at projectile energy about 6 MeV/u in collisions providing to A ~40 nuclei previously studied in a more symmetric entrance channel [7] and also to look for 7-ray cross section dependence on difference of proton-neutron number in the target. Additionally, in 12C +24 Mg reaction an effective dipole charge is zero and possible contribution of the nucleus-nucleus bremsstrahlung vanishes. In this reaction the projectile and the target has isospin T=0 so the statistical contribution should be diminished due to the pure isovector character of the GDR excitation [8].

Measured inclusive 7-ray spectra and angular distribution coefficients a-y and a2 are shown in Fig. 1. In the top row preliminary statistical model CASCADE calulations are also shown (solid line). In the lower rows simple calculations assuming that the total cross section is described only by the a=croexp[ — E^/EQ] component with angular distribution isotropic in the nucleus-nucleus CM system are shown, where the slope parameter EQ is in agreement with UDR systematics [3].

It is clear that for E >30 MeV at two higher projectile energies, the positive ax coefficient is in good agreement with pure UDR mechanism. At the lowest projectile energy the statistical contribution has to be included. The a2 coefficient has a large negative value around mean GDR energy and it stays negative at energies above the GDR as it was observed earlier [7].

54 Multiplicity data up to fold> 2 show very similar behavior. It is intriguing that the ratio of the 7-ray yield for 26Mg and 24Mg targets is nearly constant with E-, energy above 2^=20 MeV and is equal 1.7, when the scaling factor corresponding to the average number of first chance n-p collisions is 1.03. More detailed calculations are in progress.

EproJ= 134.6 MeV Epro,= 134.6 MeV Epro]- 103.3 MeV 73.0 MeV io2

1O -g 10n°

10 ~3 4 io - r- ' •, -ir ••-ir- "•. -ir- »• -i • I I « -• I I * !i I I • !! I «ti ! "I I I I I I I I I It! itl I I I I I I • I I I 1T1 • i I i i i i I i«t iTi i • I i • i • t.m •- io2 26'Mg 26Mg 26Mg 6

w" 1

IO-4 i i ' I i ' i i I ilfi* ' ,' ' I 1 ' ' I—I—L t i i I. I. l 1. L->'' *' l" 1.0

0.5 5- 0.0

-0.5 +-H- I I I I -i f 4-H—I I I I III I. .1 I I I I I I -TH 0.50 H—H-++

0.25 Cd 0.00 •••„" v -0.25 iL V -0.50 -*-> i i I I I I I I I I i-l .{ .1. I 1 1 1 li 20 40 20 40 20 40 20 40

Er [MeV] Fig. 1. Measured "f-ray spectra and angular distribution coefficients a^ and a

This work was partly supported by the State Committee for Scientific Research under Grants No. 2 2396 9102 and 204519101/p.Ol. References: [1]. K.A. Snover, Ann. Rev. Nucl. Part. Sci. 36 (1986) 545 [2]. J.J. Gaardh0je, Ann. Rev. Nucl. Part. Sci. 42 (1992) 483 [3]. W. Cassing et al., Phys. Reports 188 (1990) 365 [4]. R. Vojtech et al., Phys. Rev. C40 (1989) R2441 [5]. C. Gosset et al., Phys. Rev. C42 (1990) R1880 [6]. M. Kicinska-Habior et al., Phys. Lett. B308 (1993) 225 [5]. M.N. Harakeh et al., Phys. Lett. B176 (1986) 297

55 1 Instytut Fizyki Doswiadczalnej, Uniwersytet Warszawski, Warsaw, Poland 2 Nuclear Physics Laboratory, University of Washington, Seattle, USA PL9601008

Electric quadrupole interaction at 181Ta in hexagonal HfPd3 compound B. Wodniecka, P. Wodniecki and A.Z. Hrynkiewicz

The HfPd3 compound was prepared by argon arc melting followed by 4 days of annealing at 1100 K in an evacuated and sealed quartz tube. The powder X-ray diffraction pattern confirmed the TiNi3-type structure of the investigated compound. The sample was neutron irradiated in order to produce the181 Ta probes and after 2 days of annealing at 1000 K the perturbed angular correlation (PAC) spectra were recorded in the temperature range 15 K - 1100 K. The least squares fits of the perturbation factor to the experimental spectra yielded two equal fractions ii of probe atoms exposed to the different electric field gradients corresponding to quadrupole frequencies UQ{ and asymmetry parameters r/i = 0, reflecting the existence of two nonequivalent axially symmetric 2a and 2c sites in the DO24 structure of the investigated sample. The room temperature spectrum for the HfPd3 sample and the measured temperature dependence of quadrupole frequencies, fitted using the formula

vQ{T) = uQ(0)[l-bT*'*], are shown in Fig.l. The fitted quadrupole interaction parameters are collected in Table 1. Particular note may be taken by the relatively very low value of the temperature dependence slope parameter b for the higher frequency component.

0.05 -

-0.05 800 1200 Tm [K]

Fig. 1. Room temperature PAC spectrum and the temperature dependence of quadrupole interaction frequencies for 181Ta in HfPd3 sample. Work is supported by the State Committee for Scientific Research (Grant No. 2 0457 91 01). The careful sample X-ray analyses of dr. A. Bajorek are gratefully acknowledged.

56 PL9601009

181 Table 1: The fitted quadrupole interaction parameters of Ta in HfPd3.

5 3 2 f I/Q(300 K) [MHZ] V uQ(0) [MHZ] 6[10- iif- / ] lattice site 0.47(1) 614(1) 0.0 615(1) 0.02(1) 2a 0.53(1) 30(1) 0.0 31(1) 0.9(2) 2c

1 oi lol PAC measurements at Ta in Hf2Pd and Zr2Pd tetragonal MoSi2-type phases. B. Wodniecka, M. Marszalek, P. Wodniecki, H. Saitovitch1, P.R.J da Silva1 and A.Z. Hrynkiewicz

In view of recent progress in the theoretical description of the electric field gradients in metals it seems important to enlarge the available base of experimental data. Temperature dependence of the electric field gradients (EFG) for most normal metal systems follows the T3/2 law, however, that is not the case if the transition metals are involved [1]. The temperature dependence of the electric field gradients in transition metal compounds was not studied extensively. The present PAC studies of Hf2Pd and Zr2Pd compounds start a systematic investigation of 181Ta quadrupole interaction in MoSi2-type intermetallic phases. This Cllf, family (space group D^ - I/mmm) occurs at A2B stoichiometry. The A atoms occupy the unique 4e (4mm) site and the B atoms the 2a (4/mmm) lattice positions. Most of the MoSi2 phases involve an element of the titanium group or a lanthanide as the A component and palladium or a member of the copper group as the B component [2]. The Hf2Pd sample was obtained by argon arc melting followed by 100 hours of annealing at 1100 K in an evacuated and sealed quartz tube. The powder X-ray analysis verified a single phase product of Cllj structure. The 181Ta probes were produced by neutron irradiation of the Hf2Pd compound. In order to remove the irradiation defects the sample was annealed for 2 days at 1000 K. The perturbed angular correlation (PAC) spectra were measured in the temperature range 15 K - 1100 K using the 4 BaF2 detector setup.

The (Zr 99Hf oi)2Pd sample was prepared and measured in Centro Brasileiro de Pesquisas Fisicas in Rio de Janeiro. The stoichiometric amounts of the respective constituent elements, including neutron irradiated Hf, were melted together in an argon arc furnace. The sample was then annealed for 48 hours at 923 K in vacuum. The PAC measurements for 181Ta probes were performed in the temperature range 15 K - 1123 K using the equipment with 2 BaF2 and 2 NaJ detectors with an experimental time resolution of 1.8 ns FWHM. All samples showed evidence of nonrandom orientation of the crystallites and the PAC data had to be fitted with free s2n parameters. The least squares fits of the perturbation factor

i=l n=0 to the experimental spectra measured for Hf2Pd and Zr2Pd compounds yielded in each case an electric interaction with a single quadrupole frequency VQ and asymmetry parameter 77 = 0, reflecting the existence of one axially symmetric probe site in the Cllf, structure of the investigated samples. The broadening of the EFG described by a Lorentzian distribution having a width 8 was for HfaPd sample of % 4.5% for lower measurement temperatures decreasing to less than 2% above 800 K. In the case of the Z^Pd sample this broadening was about two times larger.

57 The room temperature spectra for Hf2Pd and Z^Pd samples and the measured temperature dependence of the quadrupole frequencies are shown in Fig.l. The quadrupole interaction frequency values VQ at room temperature resulting from the fitting procedure were 305(2) MHz for Hf2Pd and 291(4) MHz for Zr2Pd. The corresponding EFG's are of about 0.5 xlO18 V cm"2. These almost identical values of vq reflect the chemical similarity of Hf and Zr and the very close lattice constants of both compounds [2]. The point charge model calculations of the ionic contribution to the EFG with the assumption of +4 charge on Hf and Zr atoms and 0 charge on Pd atoms yield the values of -2.1 xlO18 Vcm~2 and -2xl018 Vcm~2 for Hf2Pd and Z^Pd, respectively. Thus, the substitution of Zr 4e-sites by probe atoms in the Z^Pd sample was confirmed. As can be seen in Fig.l the decrease of the quadrupole interaction frequency with the measurement temperature is very fast for both Hf2Pd and Zr2Pd compounds and can not be well reproduced neither with T3/2 nor a linear function of the temperature in the whole measured range. The estimated slopes of both ^Q(T) curves are very similar and equal to as 5xlO~4 K"1.

R(t) 1 v [MHz] 1 Hf2Pd Q Hf2Pd 0.15 350 •

0.10 300 •

1\ 0.05 1 250 * • 0.00 200

Zr2Pd Zr2Pd 0.15 350 \

0.10 [ 300 * • • A , * 0.05 250

0.00 \ J XJ 200 •

10 20 30 40 50 60 200 400 600 BOO 1000 1200 tins] TIKI

Fig. 1. Room temperature PAC spectra and the temperature dependence of quadrupole inter- 181 action frequencies for Ta in Hf2Pd and Zr2Pd samples.

Work is supported by the State Committee for Scientific Researche (Grant No. 2 0457 91 01). The careful sample X-ray analyses of dr. A. Bajorek are gratefully acknowledged.

References: [1] H.C. Verma and G.N. Rao, Hyp. Int. 15/16 (1983) 207. [2] M.V. Nevitt, in Intermetallic compounds, eds. J.H. Westbrook, John Willey and Sons, Inc, New York, 1967. 1 Centio Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brasil

58 PL9601010 PAC studies of ion beam mixed Al-Sb multilayers P. Wodniecki, M. Uhrmacher1, F. Shi1 and K.P. Lieb1

Heavy ion irradiation of metallic multilayer is a new technique to produce intermetallic or amorphous phases by ion beam mixing. The PAC method is sensitive just to the neighbourhood of the probing atom. Different micro-phases arising during the irradiation can easily be detected already in an early stage if hyperfine interaction of inCd in these phases is known from separate control experiments. PAC studies of the Ni-Sb system [l] demonstrated that ion beam mixing can lead to crystalline intermetallic phases. Here we present the preliminary results for Al-Sb multilayer (four layers of Al and Sb with the total atomic stoichiometry 50:50). Experiments were performed at II. Physikalisches Institut der Universitat Gottingen using 900 keV Xe++ ions from IONAS ion implanter. mIn ions as a tracer were implanted at 400 keV into the Al/Sb multilayer of 200 nm thickness prior to Xe irradiations. PAC as well as RBS experiments were performed before and after each of ion mixing. The corresponding sequence of the obtained spectra is presented in Fig.l.

/yW^s-*****^^ L

1 1 1 1 f—4

100 200 300 t(ns) Fig. 1. PAC and RBS spectra for mIn doped Al/Sb multilayers mixed with 900 keV Xe ions.

Our former PAC studies of pure Al, Sb and AlSb crystalline phases allowed us to identify in "as implanted" (not Xe- irradiated) sample ss50% of nlIn probes situated in Sb lattice. The rest of luIn tracers exhibit the not perturbed angular correlation characteristic for the

59 PL9601011 cubic Al. Xe-irradiations performed at room temperature caused mixing of the layers leading to the subsequent dissappearance of both electric field gradients, characteristic for pure metal substrates in favour of a new, typical for the amorphous phase. After the Xe rradiation to the total fluence of 5xlO15 Xe/cm2 the RBS spectrum visualizes a homogeneous mixture of both metals while the corresponding PAC result indicates the formation of the amorphous phase in the whole sample. Further ion beam mixing experiments performed at low temperature are planned to confirm the result of XRD experiments [2], where the formation of crystalline Sb5oAl5o B3-phase was observed after the ion beam mixing at 77 K.

Work is supported by the German-Polish WTZ project X082.8 and the State Committee for Scientific Research (Grant No. 204579101).

References: [1] M. Uhrmacher, P. Wodniecki, F. Shi, T. Weber, and. K.P. Lieb, Appl. Phys., A57 (1993) 353. [2] F. Shi, W. Boise, K.P. Lieb, and J. Wilbrandt in press.

1 II. Physikalisches Institut, Universitat Gottingen, Germany

Xe-induced cavity formation in aluminium observed by PAC technique P. Wodniecki, M. Uhrmacher1, and K.P. Lieb1

The interaction of implanted gases with substitutional inIn probes in different metals was studied by Schumacher and Vianden [1,2]. It was shown that the gas implantation initiates the growth of large threedimensional vacancy clusters (usually called cavities) at indium impurity and the observed electric field gradient (EFG) is due to indium atoms situated at the inner surface of the cavities. We report on measurements performed at II. Physikalisches Institut der Universitat Gottingen, where an Al sample containing implanted inIn probes was irradiated with Xe ions of 700 keV. The sequence of PAC spectra (see Fig.l) demonstrates that also in this case the cavity formation take place, causing the EFG described by the hyperfine interaction parameters /^Q=143(1) MHz and 77=0.1. These values are close to the results of Schumacher [2] obtained for Al irradiated with Ar ions (VQ = 132.6(3) and 77=0.1). The fraction of luIn probes placed in cavities increased significantly (up to «50%) after subsequent annealing for 30 min at 200 °C.

60 I I I I I I I

I I I I I I

0.00 100 200 300 0.0 0.2 0.4 0.6 0.8 t(ns) frequency [GHz]

Fig. 1. PAC spectra with Fourier transforms for mIn doped Al irradiated with 900 keV Xe ions. In a check experiment we have annealed an aluminium sample at 400 °C after mIn implantation in order to remove the In-correlated radiation damage prior to the Xe irradiation. Then, the quadrupole frequency characteristic for the cavity in Al did not appear directly after xenon bombarding (as was observed for the not annealed sample) but after the additional thermal treatment in vacuum at 200 °C, which can be a hint that 111In probes migrate into the cavities created earlier from vacancies produced by Xe ions. The fraction of the discussed EFG was in this experiment much smaller («20%) than in the case of the not annealed sample, which indicates that the vacancies correlated with mIn implantation play a decisive role in the formation of cavities containing indium impurity.

Work is supported by the German-Polish WTZ project X082.8.

References: [1] R. Schumacher, and R. Vianden, Phys. Rev. B36 (1987) 8258. [2] R. Schumacher, PhD thesis, Institut fur Strahlen- und Kemphysik der Universitdt Bonn, (1991).

1 II. Physikalisches Institut, Universitat Gottingen, Germany

61 PL9601012 Electric field gradient and its temperature variation at in Zr2Fe and Zr2Co intermetallic compounds.

M. Marszalek, H. Saitovitch1 and P.R.J. da Silva1

Binary compounds formed between Zr metal and late transition metals (Fe, Co, Ni) have attracted recently a great deal of attention due to their unique physical properties; they'are able to absorb large amounts of hydrogen and easily form amorphous systems. In this paper we report a TDPAC study of Zr2X (X=Fe,Co) intermetallic compounds ( C16 crystallographic structure) performed at Centro Brasileiro de Pesquisas Fisicas. Samples of Zr2Fe and Zr2Co with a small addition of Hf (less than 2 at.%) containing radioactive 181Ta probe atoms were prepared by argon arc melting. A further heat treatment was necessary to obtain pure samples of the required crystal structure. A sample of Zr2Co was annealed for 72 hours at 923 K in an evacuated and sealed quartz tube. It is known [1] that Zr2Fe exists as a high temperature phase between 1050 K and 1250 K. Because of peritectoid decomposition of this phase at 1250 K a long annealing time (480 hours) at 1173 K was performed and the sample was next quenched to the liquid nitrogen temperature as fast as possible. TDPAC measurements were performed in the temperature range 14K-1150K using equipment with two BaF2 and two NaJ detectors with an experimental resolution of 1.8 ns FWHM. In order to avoid the decomposition of Zr2Fe, phase PAC spectra were taken from 20 K to room temperature and in the range of existence of the phase. Examples of G2(t) patterns obtained for investigated samples at room temperature are shown in Fig.l. together with the measured temperature dependencies of electric field gradient (EFG). In both cases we have observed only one strong asymmetric quadrupole interaction, according to one possible crystallographic position of the probe atom in the studied structure. The strength of the interaction was equal to 1039(8) MHz with asymmetry parameter 77=0.82 and 889(7) MHz with 77 = 1 at room temperature for Zr2Fe and Zr2Co, respectively. The measured temperature dependence of EFG showed alinear character. The parameters of the fit of VQ{T) = VQ(0)[1-O.T} relation to the experimental data are presented in Table 1.

MHz] Zr2Fe 1100

1000

900

800

ZraCo 1100

1000

900 > ^_

800

40 50 0 200 400 600 800 1000 1200 T[K] Fig. 1. Room temperature PAC spectra and the temperature dependence of quadrupole inter- 181 action frequencies for Ta in Zr2Fe and Zr2Co samples.

62 PL9601013

181 Table 2: The fitted quadrupole interaction parameters of Ta in Zr2Fe and Zr2Co samples.

compound J/Q(300 K) [MHZ] V uQ{0) [MHZ]

Zr2Fe 1039(8) 0.82 1125(5) 2.6(1) Zr2Co 889(7) 1.0 956(4) 2.2(1)

Work is partially supported by the State Committee for Scientific Research (Grant No. 2 0457 91 01) References [1] F. Aubertin, U. Gonser, S.J. Campbell and H.-G. Wagner, Z. Metallkde 76 (1985) 237. 1 Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brasil

FIDIAS - Fifteen Parameters Data Acquisition System J. Gre,bosz, W. Me.czyriski, M. Zie.blinski, W. Iwanski, M. Kajetanowicz, K. Korcyl

The FIDIAS, a new 15 parameters data acquisition system for single and multiparameter measurements at Krakow cyclotron has been developed. The system is composed of two main elements: A. hardware, in Camac and NIM crates, B. program, running on an IBM PC computer. A. The Hardware The hardware consists of: - up to 30 ADC in NIM crates, - system controller in a CAMAC crate, designed in the Electronics Division, - a CAMAC - IBM PC interface. The Hungarian ADCs, type EMG 38098, are used. They have the following features: double integration conversion method, result length set to 10, 11, 12 or 13 bits, maximum conversion time 80/rni (13-bit result), input range 0-10 V and integral nonlinearity smaller than 1.3*10~4. ADCs have been equipped with internal 8k x 16 bits memory where the histogram is auto- matically built from all conversion results. Maximum number of counts in a histogram channel is 65535. ADCs are divided into two groups: ADC converting coincidence events (max. 15) and ADC building single spectra (max. 15). ADCs and the system controller are connected by a separate bus. A pattern defining ADCs in the coincidence event is supplied to the controller with each event. A data compression based on the pattern is made. The result is transferred autonomously into an internal 4096 word FIFO memory. When more than the half of the memory is filled with data, an interruption to the IBM PC is generated. The computer reads a data block of an event by event type. The block length is 2048 words.

63 B. The Program The aim of program is to control the work of the system. Its main task is to read periodically the blocks of data from the hardware and store it on the EXABYTE magnetic tape. The program allows also for: - denning parameters of every ADC directly by the user - from the IBM PC, - collecting in a memory some coincidence spectra (projections) of chosen ADCs; these spectra can be shown on the screen, - transfer of a single spectrum from the ADC memory and displaying it on the screen, - evaluating of the single spectra and projections, - building pictures of two dimensional spectra (matrices); up to 32 matrices can be shown on the screen simultaneously - parameters of the matrices can be denned by the user at any moment, - all basic operations with the EXABYTE magnetic tape like rewinding, initializing opening and closing files, making a directory of the tape, etc., - all basic operations with Camac such as: resetting crates, single Camac commands, an infinite loop of single Camac command, denning longer sequences of Camac operations etc., important during the developing and testing of the system, - storing (and retrieving) the setup of the whole program on the disk. The program is written in an object oriented technique, in the C + + programming language. The communication with the user is based on menu and window environment.

Presently, the data processing capabilities of the system like the counting rate limit -both as trigger frequency and as Kilo words per second processed - versus the number of parameters handled are being extensively tested. This test is performed using 6 parameter events, generated from three Nal scintillator counters working in coincidence for different radioactive sources. Fig.l shows an example of two-dimensional coincidence spectra collected during the test.

s*.

Fig. 1. Two-dimensional gamma-gamma and gamma-time coincidence spectra measured with Nal scintillator counters and a 22Na source. 64 PL9601014 Development of data analysis software for UNIX systems applied to NORDBALL and EUROBALL data sets J. Wrzesinski*

The multidetector arrays (NORDBALL, EUROBALL) deliver large sets of coincidence data. With the new EUROBALL III instrument which will start to operate in 1996 it will be possible to collect approximately 1012 4-fold events in less than a week. We have therefore developed the program JUGGLER to handle such extreme data sets. It is a C package for off-line sorting of high-spin nuclear spectroscopy data adopted to a UNIX computer. The program is specially designed to sort data into large 3-D array (2048*2048*2048), but with a large flexibility, enabling a variety of sort functions in 1-2-D spectra, and corresponding file formats. The format of the 3-D array is based on that used by the program ANA [1]. Interactive communication with the program is made through a simple command language which is organised in a menu structure with a context oriented on-line help function. This facilitates easy and reliable application of the program. The task of analysis is handled in several independent steps: 1) Automatic calibration and gain matching of detectors including correction of gain shifts from the experiment. 2) Calibrating and filtering data (only good events and parameters, with energy dependent gating on time) and storing on tape in compressed format. 3) Sorting of compressed data in large 2-D and 3-D arrays. In a 2-D sort, different combinations of two parameters are available. In 3-D sort, a 7 — 7-7 cube is created. In both cases, gates on gamma-ray energy or extra parameter are possible. 4) Conversion of 1-2-3-D output data into formats suitable for the most commonly used analysis programs like SAP [2], GELIFT2 [3], ESCL8R [3], LEVIT8R [3] and TRIHAN [4]. These routines include format matching between VMS and UNIX systems. The program has been applied to sorting two sets of data from experiments performed at the EUROGAM detector array in Daresbury. Data sets of 1.8 and 2.9 Giga 3-fold events were obtained using the reaction 124Sn(48Ca,4-6n)168'167'166Yb at 210 MeV beam energy and 108Pd(48Ca,4n)152Dy, respectively. At a first replay of the data, calibration and gain matching coefficients were obtained requiring 28 and 43 hours sorting time, respectively. In the second step, the initial amount of 46 and 68 GBytes of data after filtering and calibration were compressed to 5.3 and 13 GBytes (compression factors: 8.7, 5.2), respectively. Then, 1 Giga of 3-fold events was sorted in 20 hours into 37-7-7 cube with 10243 ch on a Solbourne S4000DX UNIX computer. In the present case, 0.9 GBytes of disc space was used . We have tested the 3-D sort performance and found it strongly dependent on available disc space.

References [1] Program ANA: W. Urban. [2] Program SAP: F. Videbaek, A. Holm. [3] Programs GELIFIT2, ESCL8R, LEVIT8R: D.C. Radford. [4] Program TRIHAN: K. Shifter.

* This work was performed within the fellowship at the Niels Bohr Institute, Copenhagen, Denmark

65 PL9601015 Study of Sn-In alloys by positron annihilation J. Dryzek and E. Dryzek

Many experiments on alloys were performed using positron annihilation methods in order to detect the electronic structure or properties of vacancy type defects. However, sometimes one forgets about specific structures of the alloys which could influence the positron annihilation characteristics by creating new types of positron traps. It may be important in analysis of the behaviour of positron mean lifetime or S-parameter as a function of temperature. The interpretation of these results without taking into account the structure elements of the alloys could lead to the wrong conclusions. In our studies we prepared the Sn-In alloys which can exist at room temperature in four phases. Additionally, one eutectic and two peritectic points are also observed. Changes in the Doppler broadening spectra of the annihilation line were described by the classical line shape S-parameter defined as the ratio of the area under the fixed central channels to the total area under the annihilation line. Fig.l presents the results of measurements of the S-parameter at room temperature together with the phase diagram of the Sn-In alloys. The solid line in Fig.lb was drawn through the closed points measured for samples after long annealing and slow cooling so in such a case the number of defects was reduced . The dashed line in the Fig.lb was drawn through the open points which were obtained after deep plastic deformation of the samples (50% reduction of thickness). In such a case a great number of defects which can act as traps for positrons were produced. In Fig.l one can see that in the regions in where two eutectic or mixed phases exist in the alloy, there are no distinct differences between the annealed and deformed samples. The reason is that in the case of these alloys the positron traps can occur easily on the boundary between two phases or can be generated in the stress field. The differences between the two measurements are observed for the region where the alloy exhibits only one phase. This is obvious because in the annealing process the number of defects is reduced, and after the plastic deformation defects are generated so an increase of S-parameter should be observed.

The conclusion is that the results of positron Q) 212- annihilation measurements should be re-

\ ferred to the phase diagram and the struc- 200 ture of the investigated alloys. \ Liquid 1\ \ 157" ^150 \ \ U \ r \ \ ^ 5 \ 5 S.100 .... ^^ P \\ £ \ \\ \ \ 50 y i 0 Fig. 1: Phase diagram of Sn-In alloys (a). The S-parameter measured in the room tem- b) perature vs. concentration of In (b). The closed points present the measurements performed for samples after long annealing process, the open points for samples after deep plastic deformation.

20 '.0 60 80 100 Wt.% In

66 PL9601016

Mossbauer effect investigations of the short range order in the vicinity of magnetic transition in ErT2Sn2 (T = Ni, Cu) phases R. Kmiec, E.A. Gorlich1 and K. Latka1

The electronic properties of novel ternary compounds ErNiiSrii and ErCv.2Sri2 were investigated with the attention focused on the temperature region of the magnetic ordering transitions. The phases were found to crystallize with the CaBe2Ge2-type of structure (space group Pi/nmm). The samples are not free from a certain degree of disorder connected with the oc- cupation of 3d-transition metal and tin sublattices. This may eventually lead to the occurrence of the regions of the body-centered lattice of the T/iCr25i2-type rather than that of the above mentioned primitive one. Thermal processing was not effective in shifting the equilibrium either way. Magnetic susceptibilities of these compounds reveal regular Curie-Weiss behaviour in the temperature range 15K to 250K with the values of the effective magnetic moment hardly different from that of a free trivalent erbium ion [1].

G 10° " C 100 - o o : "m 0.99 - 8 0.98 - w B 0.98 - m a5 0.96: - \i •-•'/ g 0.97 - H ; \ // £ 0.94 : H 0.96 - CJ \w/ j> 0.92 '- ErCu Sn £ 0.95 - ErNi2Sn2 w 2 2

67 been performed down to 1.6K. At higher temperatures (T > T/v) spectra of both compounds show a similar character with two components in agreement with the presence of tin atoms in two crystallographicaly distinct sites. Each of the components presents a doublet which results from the coupling of u9Sn nuclear quadrupole moment with an electric field gradient originating from the distribution of charges in the crystal lattice around a given nuclear site. In the magnetically ordered state the overall shape of the ErNi2Sn2 spectrum does not change substantially while in the case of a copper compound, one of the spectral components splits further into two patterns. The different values of the angle between the main axis of the electric field gradient (originating from the crystal lattice) and the magnetic hyperfine field for the two above mentioned sub-components indicate a more complex, probably non-colinear spin arrangement in ErCu2Sn2. Moreover, although the Neel temperature of ErCu2Sn2 is distinctly lower than that of ErNi2Sn2 values of transferred hyperfine fields induced at tin nuclei ( of one of the two tin sites - that for which splitting into two sub-components is observed) are much larger for the former compound (4O(l)fc0e and 24(l)fcOe when extrapolated to T = 0) than any of the saturation fields (inferred from the lines broadening) in nickel compound (the larger is 5.3(5)ife0e, Fig.l). The observation of the hyperfine interactions of tin nuclei with the 119Sn Moflbauer effect (Fig.l) in the vicinity of the transition region allows one to trace the spin correlations and a short range magnetic order, taking full advantage of the sensitivity of this method to the local processes.

0.80 The correlation time of the Er3+ spin S fluctuations is substantially shorter than the char- 0.60 - acteristic precession time of 1195n nuclear moment in the effective hyperfine field Hhf at its •- 0.40 - site implies that the latter quantity attains its average value which is proportional to the average value of the spin < S >. The smallness ~ 0.20 - of the transferred hyperfine field Hhf results in n a mere broadening of the absorption spectrum. IV o 0.00 The careful and consistent analysis of the data x 5 10 15 w allowed to deduce the temperature dependence Temperature [K] of the excess spectrum widening (AT) for both components connected, respectively, with the Fig. 2: Mdfibauer absorption lines broade- lattice sites of tin found in the mng in ErNi2Sn2 as a function of temperature ™ structure variation of these compounds.

The dependance is well described under the assumption of the proportionality of the local 2 field Hhj to the two-spin correlation function: Ar oc< Si • S2 > (solid line in Fig.2). The least- squares fit brought the values of the effective erbium-erbium exchange integral of -0.96(5)meF and -1.15(ll)meF for the neighbourhood of each of the two tin positions in ErNi2Sn2 , respectively.

References: [1] E.A. Gorlich, R. Kmiec , K. Latka, A. Pacyna and A. Gleifiner, to be published in J. Phys.: Condens. Matter [2] E.A. Gorlich and R. Kmiec, accepted for publication in Ada Phys. Pol. A

1 Institute of Physics, Jagellonian University, Krakow, Poland

68 PL9601017 Mossbauer study of iron in axinite J. Kraczka, A. Pieczka 1, A. Hrynkiewicz and W. Zabiriski 1

Axinites form an accesory group of borosilicates that can be found in geological formations of various ages. The crystal structure of axinite was studied by many authors, e.g. Takeuchi [1] and others [2,3], and according to their results, there can be a "tetrahedral layer" distinguished. It is built of [B2Sig03o] groups with a six-member ring of [S1O4] and [BO4] tetrahedra connected to an "octahedral" layer. The latter is composed of Fe2+ and A13+(1) and A/3+(2) octahedra linked by distorted CaO$ and CaOs(OH) polyhedra. Mossbauer spectroscopy was applied to study the role of iron ions in axinite. The studied sample was collected in the Strzegom granite massif [4]. Testing various possibilities of spectra resolutions and their dependence on the mineral structure, it has been found that the resolution of the spectra into four quadrupole doublets, each two of them resulting from Fe2+ and Fe3+ ions, is the best one. The doublets of the octahedral Fe2+ differentiate cations of the second coordination shell (B3+, Al3+). Comparison of structural calculations and results of the Mossbauer measurement indicates that the doublet with the higher value of quadrupole splitting can be attributed to a structural arrangement with Al3+ in the Il-nd coordination shell while that with the lower value of Q.S. - to the presence of B3+ in the Il-nd shell. The doublet of Fe3+ with smaller isomer shift we allocate to the presence of iron ions in tetrahedral positions resulting from substitution:

[iV]St++ +[VI] R2+ =[IV] R3+{AijFe) +[Vl) R*+(Al,Fe). The other Fe3+ - doublet is caused by iron ions in the octahedral position. This occupancy reflects deprotonation of the structure:

v/ 3+ =t l R (Al,Fe) + O2~ and the above mentioned substitution. The following chemical formula of axinite, assuming the presence of 32(0, OH) ions, was calculated on basis of the chemical and Mossbauer data: (Ca3.9i3 iVao.o55 ^0.014) + {Fe\\00 Mno.622 Fel 156 A/0.125 M$ro.ii3 ^0.009 ^"0.004) Al2.ooo (S*7.893 ^0.107) (-81.679 -^0.321)

-5

Fig. 1: Mossbauer spectrum of axinite taken at room temperature.

69 PL9601018 Table 1. The best resolution of the Mössbauer spectrum of axinite. I.S.[mm/s](a - Fe) Q.S.[mm/s] S[%] Interpretation 0.14 1.60 8

0.59 1.62 5 [VI]Fe3+ 1.12 2.19 21 WFe2+(Al) 1.13 1.99 65 WFe2+(B)

References:

1. Y. Takeuchi, T. Ozawa, T. Ito, T. Araki, T. Zoltai and J.J. Finney, Z. Kristallogr. 140 (1974) 289

2. J.S. Swinnea, H. Steinfink, L.E. Rendom-Aiaz Miron and E. de la Vega, Amer. Miner. 66 (1981) 428

3. A.V. Astakhov, Yu.B. Voitkovskii, O.N. Generalov and S.V. Sidorov, Sov. Phys. Cristal- logr. 20 (1976) 471

4. J. Janeczek, Geol. Sudetica 20 (1985) 2

1 Academy of Mining and Metallurgy, Kraków

Site occupancy of iron in vesuvianites as studied by Mössbauer method J. Kraczka and W. Żabiński 1

Vesuvianite is an ortho-pyro-silicate of approx. formula Ca19(ylZ, Fe)w{Mg, 3+ 2+ [SÍOA\IÜ(O,OH,F)10 [1]. In its crystal lattice Fe and Fe ions can be distributed among at least three different sites, labeled: 5-coordinated B-site (tetragonal pyramid), 6-coordinated AlFe site (octahedron) and 8-coordinated C-site (square antiprism) [2]. Until now only few data concerning Mössbauer studies of iron in vesuvianites have been published and only Manning's and Tricker's reports [3,5] deserve notice. In this study several vesuvianite samples from different localities (Transvaal, Piz Longhin, Monzoni, Canzoccoli, Cziklowa, Telemark) have been investigated by means of the Mössbauer method. The first two samples represent so-called low-temperature ordered vesuvianites, the other four - high-temperature disorderd ones [4]. Due to the relatively small amount of iron in these minerals and the distribution of this element between several lattice sites a high quality proportional counter and relatively high number of counts per channel were necessary. Mössbauer parameters calculated for some spectra at room temperature and probable site occupancies are presented in Table 1. In most of the investigated samples Fe2+ ions occur only in subordinate amounts or are practically absent (Piz Longhin). Fe3+ ions are located predominantly in AlFe positions (CN 6). Some quadrupole doublets seem to be indicative of ferric as well as ferrous ions in B-sites (CN 6). No doublets due to Fe2+ or Fe3+ in C-sites (CN 8) have been observed. In the spectrum of vesuvianite from Transvaal, recorded at room temperature, out of 3 doublets (one due to a small Fe2+ content) a faint sextet of Zeeman splitting can be observed. In the spectrum of this mineral recorded at helium temperature ( due to the kindness of prof.

70 St. Hafner in his laboratory in Marburg ) this sextet is much more pronounced and is most probably due to a fine, submicroscopic admixture of an iron oxide mineral. In the Mossbauer spectrum of the same sample recorded after heating it for 20 hrs at 1073 K, the doublet coining from Fe2+ ions disappeared. However, no other distinct changes in the site occupancy of iron ions, suggested by EPR investigations, have been observed.

Table 1. Mossbauer parameters of some natural vesuvianites

Locality Iron content LS.(a - Fe) Q.S. S Interpretation (as FeO wt.%) [mm/s] [mm/s] {%] Ions Coord. Transvaal 2.88 0.34 0.58 24 Fe3+ VI 0.33 0.33 63 Fe3+ VI 1.14 2.69 13 Fe2+ V Monzoni 4.59 0.37 0.50 42 Fe3+ VI 0.38 1.08 25 Fe3+ VI 0.80 0.51 19 Fe2+ V 1.09 2.50 14 Fe2+ VI Canzoccoli 4.01 0.38 0.63 81 Fe3+ VI 0.80 0.41 4 Fe2+ V 1.04 2.60 15 Fe2+ VI

References:

1. W.A. Deer and R.A. Howie, J. Zussmann, An Introduction to the Rock-Forming Minerals, 2nd ed. Longmans (1992) 47

2. A. Yoshiasa and T. Matsumoto, Miner. Journal 13 (1986) 1

3. P.G. Manning and M.J. Tricker, Canad. Miner. 13 (1975) 259

4. F.M. Allen and Ch.W. Burnham, Canad. Miner. 30 (1992) 1

5. M.J. Tricker and P.G. Manning, J. de Physique C2 40 (1979) 477

1 Academy of Mining and Metallurgy, Krakow

71 PL9601019

Study of trace elements distribution in various tissue structures W.M. Kwiatek and E. Marczewska

Many papers have been written during the past ten years about TE study in cancer and normal tissues describing the use of different methods for detection of trace elements. Concen- tration of TE depends strongly on the sample measured. However, according to our knowledge, the role of TE in cancerous tissue is still not known. Therefore, we propose to perform an experiment which will hopefully give us more information about the relationship between the concentration of elements in different tissues. The developing industry localised near Cracow has become a serious danger for the health of it's inhabitants. The negative influence of air pollution on living organisms is seen not only in nature but also in humans. Therefore we want to analyse the trace element contents in the air. Such investigation will give information about the pollution level in the City. The pollution has an obvious negative influence on health and contributes to toxic the element concentration level in blood. It is interesting to check if the placenta plays an effective role in foetus protection against toxic metals. In order to study this problem, the trace element analysis of placenta tissues will be done by means of synchrotron microbeam. The determination of the concentration of trace elements in human cancerous tissues and in human placentas done by means of SRIXE at DORIS storage ring makes it possible to measure elemental distribution with a spatial resolution of around 20 /an. Such determination seems to be important due to the difference between the concentration of trace elements in normal and cancerous tissues. There are several questions to be answered.

-What occurs on the boundary of tissues? -What kind of correlations are observed between concentration of various elements? -What is the distribution of trace elements along the distance from the centre of the cancerous tissue to the normal tissue ?

We expect that the placenta investigations will give us the answers to the following questions: -What is the distribution of TE concentration along the distance between the mother-side and child-side of the placenta? -Which structures in placenta tissues work as filters for toxic TE, if they do? -What is the protection level of the foetus against the heavy metals?

With the synchrotron radiation, two-dimensional mapping will be done. All samples will be investigated histologically which should help to find the correlations from the medical point of view (correlation between the morphological and functional changes). In all biological experiments it is very important to keep always the same sample and target preparation technique. This diminishes the systematical errors which otherwise may occur. All cancerous samples will be obtained during surgical operations. The cut of tissue will be frozen, and then cut by a microtome into sections of 20-/xm thickness. That thickness is already sufficient for analysis. Two adjacent layers will be used for analysis, one for histological, treatment and the other for target preparation. The thin micro- target will be placed on 7.3/nn (1/3 mil) Kapton or other clean foil supported by a slide frame. Before targets mounting, the foils will be checked for impurities. In the same way the placenta samples will be prepared. In order to calculate trace element concentrations in investigated samples one should apply a technique of either external or internal standard, otherwise fundamental calculations should be done. In this study the external standard technique is proposed. A thin gelatine standard

72 PL9601020 containing various amount of different elements will be prepared according to the requirements of the "membrane preparation technique" described by Th. Brandenburg in his Masters Thesis. The 20 /im thick standard section will be analysed in advance using the TXRF technique. White-light Synchrotron Radiation Induced X-ray Emission (SRIXE) is an ideal technique for Trace Element (TE) analysis in "thin" samples. During the past few years it has been applied to biological research. The biological samples are mostly light-Z organic matrixes. This type of sample often requires a special selection of the experimental conditions for the measurements. An electron storage ring producing X-rays (i.e. Synchrotron Radiation) has many properties that makes it attractive for TE analysis. The advantages are: high photon brightness and flux, high degree of polarisation, and low divergence emission (small opening angle). These properties can be used for rapid non-destructive measurements with good spatial resolution, and very low Minimum Detectable Limit (MDL). The use of Total reflection X-ray Fluorescence Analysis (TXRF) with synchrotron radiation will help in thin standard investigation. The SRIXE work will be done on the beam line L at the DORIS X-ray storage ring at the HASYLAB in Hamburg, FRG. The experimental set-up fully described by S. Garbe et al (presented at HASYLAB User's Meeting in January 1993) seems to be adequate for the purpose of the proposed experimental work. Acknowledgements: This work is supported by the State Committee for Scientific Research (KBN), Poland as well as by the HASYLAB and DESY, Hamburg, Germany. Our thanks are extended to prof. A. Knochel's group from Hamburg.

Temperature and matrix effects in PIXE elemental analysis W.M. Kwiatek, J. Lekki and C. Paluszkiewicz1

Trace element determination using the PIXE technique is affected by two significant effects: - composition of a sample may change due to temperature effects introduced by beam heating (particularly true for biological samples) - in thick target, matrix dependent attenuation of X-rays and their energy dependent production cross sections require proper corrections introduced in computational procedures (particularly true for heavy matrices and light traces). The procedure is based on the use of FTIR (Fourier Transform InfraRed) and EBS (Elastic BackScattering) methods as complementary techniques for PIXE experiments. FTIR gives a rough estimation of sample chemical composition while EBS is used for the determination of the proper stoichiometry of major elements that form the sample matrix. The experimental set-up for PIXE/PIGE/EBS experiments is schematically presented in IFJ Ann.Rep. (1993) pp. 95-97. For this experimental work different samples were analysed. Those include IAEA Standard Reference Materials: A-13 (animal blood), H-8 (horse kidney), and Cl-1 (cabbage). All samples were prepared according to an external standard technique of pellets of 10 mm in diameter and 1 mm thick. Such thickness is big enough to stop a whole irradiating proton beam and decrease characteristic X-ray intensity. The exact sample preparation procedure followed the IAEA requirements for thick samples.

73 100 =

10: 00 I

I 1 = <

D 1 a: 0.1 \ j Jl .; I i - 1 1F 11= f m - • Elements: K, Ca. Fe. Zn

| romm temperature 600 C no correction 6 00 C corrected

Fig. 1. Elemental concentration ratio between A-13 and H-8 for K, Ca, Fe, and Zn.

The results show the importance of a multi-technique approach to the single sample measurement. As is shown in bar-graphs (above) the correction for matrix change is significant and gives different results in elemental concentration than simply using traditional calculation with the use of an external standard technique. The figures below show the results obtained.

10S

200 'I 4001' 600 800 Channel Number Fig. 2. The comparison of two normalized blood (IAEA A-13) PIXE spectra (higher spectrum corresponds to matrix change).

74 0.8-

0.6-

0.4-

0.2-

I I I I I I I I 500 1000 1500 2000 2500 3000 3500 4000 Wavenumbers Fig. 3. The comparison of two normalized blood (IAEA A-13) FTIR spectra (higher spectrum corresponds to matrix change).

1500n

1000-

c O O 500-

0.5 1.0 1.5 2.0 2.5 Energy MeV Fig. 4- The EBS blood (IAEA A-13) spectrum after matrix change.

A cknowledgement s: The authors wish to thank dr Boguslaw Rajchel for his help in EBS data taking and Erazm M. Dutkiewicz for his help in PIXE data analysis. Many thanks are given to the VDG group for their hard work during the measurements. This work has been supported by the State Committee for Scientific Research (KBN), Poland Account No. IFJ-0000202 and grant No. IFJ-0090267. 1. Jagellonian University, SLAFIBS, ul.Kaiasia 3, 30-060 Krakow.

75 PL9601021

Sample preparation procedure for PIXE, PIGE and RBS techniques applied for biological studies in Henryk Niewodniczanski Institute of Nuclear Physics

W.M. Kwiatek, E.M. Dutkiewicz, L. Glebowa, E. Marczewska, M. Sowa

Sample preparation technique plays an important role in the whole analytical procedure. The accuracy and reproducibility of the measurements depends on the chosen sample preparation technique. Since different sample types are used as well as analytical techniques it is important to follow always the same procedure while analysing a similar type of samples. This paper describes the sample preparation procedure applied mainly by the Trace Element Ana- lytical Group of the Henryk Niewodniczariski Institute of Nuclear Physics in Cracow, Poland.

There are several analytical techniques that are applied for biological studies and environmental problems in the Henryk Niewodniczanski Institute of Nuclear Physics. They include: PIXE (Proton Induced X-ray Emission), PIGE (Proton Induced Gamma-ray Emission), RBS (Rutherford Back-Scattering technique), EBS (Elastic Back- Scattering technique). In order to apply those techniques some sample preparation before analysis is required. The analyses are performed on ion beam (protons, alpha particles) obtained from 3MV Van de Graaff accelerator. During the analyses, targets are kept in the vacuum chamber and due to the applied technique a different electronic set is used.

By thin target one should understand a target which does not stop the irradiating beam. It means that the acceptable thickness depends on the ion beam energy and stopping power factor. The ion beam will pass through a light matrix much easier and therefore the target thickness for liquids and organic materials could be larger than for the other samples. In order to analyse liquids and thin (micrometers range in thickness) sections one has to use the support for the target.

Usually formvar (polyvinyl formal) film is used. Chloroform (CHCI3) or cyclohexanol are good solvents for formvar. The 2.5 % or 5 % formvar solution is good enough to be used for support preparation. In order to prepare a formvar film one has to lay a drop of the solution on double distilled water and spread it on the water surface. Next an aluminium frame is inserted into the water under the spread formvar and then pulled up on one side. Formvar will stick to the frame while being pulled up. The foil dries out in the air. The film prepared in this way is ready to be used for target backing after a few minutes. The usual thickness of formvar film ranges between 100 nm and 300 run. The foils of this thickness are transparent for ion beams.

In biomedical applications mostly human physiological fluids are subject to analysis. All samples such as blood or urine are very often analysed according to the so-called "thin samples procedure". In order to avoid any contamination those samples are taken directly to the tubes. Blood is taken to the tubes containing a few drops of blood conservant such as heparin. The known amount of the sample is mixed with yttrium nitrate Y(NOs)3 in the known ratio (usually 1:1) with the known yttrium concentration (usually 100 ppm). Yttrium is an element that practically does not exist in human organisms (natural concentration is below 10 ppb) and therefore it can be used as an internal standard during the analysis. Such a prepared sample is shaken for about 10 min. in order to ensure uniformity. In order to prepare a target one drop of a sample mixture is placed on the formvar film stuck to the frame. Then the target is placed in to the frame holder in the chamber. After target placing, the chamber is closed and pumped out. All water that exist in the target dries out and the sample is ready to be irradiated with

76 the ion beam. Sometimes a sample put on Formvar dries out in the air and then the second Formvar film is placed over the target to make a sandwich. Such a procedure is carried out in case when targets will be transported or irradiated several times.

Tissue sections are also recognized as thin targets. Commonly used tissues are taken from the body during the surgical operations. Then, with a clean sharp scalpel the tissues are trimmed to provide access to the structures and orientation required by the experiment. Usually samples are cut down to < 5 mm in at least one dimension. The trimmed tissues are frozen in liquid nitrogen (-196 °C). When completely frozen (it takes about 5 min) they are ready for cutting into sections. Usually sections of 10/xm to 30/xm are fully sufficient for the experiments. The sections are cut on a cryo-microtome and placed onto either Kapton, Mylar or Formvar film. In case of Kapton and Mylar it is important to keep the ratio target thickness to backing thickness as large as possible. By thick target, we understand a target, the thickness of which is large enough to stop the irradiating ion beam. Those samples do not require any specific backings to support them.

It is very important to have uniform targets. In order to ensure it the whole sample is homogenised. In case of biological samples they are dried in the air under a 200 W lamp or in the oven at a temperature of 100 °C. In case of blood or tissues they are dried in a refrigerator filled with silica gel (for about 5 days). In each case the drying time is determined by the dry mass factor. For example in the case of blood, the dry mass factor (the ratio of wet mass to dry mass) is 4.012 ± 0.002. When a sample is dry it is melted in the agate mortar and then pressed into a pellet of 10 mm in diameter and about 1 mm in thickness. Usually 100 mg of the sample powder is used and a pressure of 10 MPa is applied. Such a pellet is attached to the target holder with regular scotch tape. There is no risk of contamination or extra peaks originating from the tape since there is a thick target on it.

In the case of some samples (i.e. nails, hairs) before preparing targets they have to be washed out due to surface contamination. Pure distilled water and non-ionic detergent are used for cleaning the surface of those samples. When analysing minerals by PIXE/PIGE technique one has to take into account the grain sizes due to matrix effects. Sample preparation procedure for trace element analysis is a very significant part of the analysis. During sample preparation it is very easy to introduce contamination. Therefore a lot of care has to be taken in order to avoid it. A large advantage of PIXE/PIGE analysis is that for some bio-medical applications almost no sample preparation is required, thus reducing the risk of contamination.

References: [1] V. Valcovic, "Sample preparation techniques in trace element analysis by X-ray emission spectroscopy", IAEA-TECDOC-300.

77 PL9601022 Compton scattering studies of Ni - Cu alloy S. Kaprzyk1, J. Kwiatkowska, F. Maniawski

The development of the Korringa-Kohn-Rostoker coherent potential approximation (KKR- CPA) method and its further generalization [1] provided the means to calculate electronic structure of disordered substitutional alloys as reliably as that of pure elements. This made it worth- while to study such systems experimentally due to the prospect of comparing the results with the first-principle, parameter free theory. One of the most direct methods to probe electronic structure of materials is the Compton scattering technique [2]. The energy profile of Compton scattered X-rays or 7 rays, the so called Compton profile (CP) is related to the electron- momentum density in the material. The material chosen to be studied is the Ni-Cu alloy, often regarded as a typical representative of a binary substitutional alloy. It is a simple system with fee lattice for all compositions and expected complete solid solubility. At the same time the alloy possesses an interesting and complex band structure [3]. The specimens for the future Compton scattering studies are single crystals of the alloy of nominal composition 0.75Ni-0.25Cu grown by the Bridgman method. Phase diagram of the Ni —Cu alloy shows a gap of about 60°C between the liquidus and solidus line indicating that the liquid and solid phase can coexist in a wide range of temperature. This phenomenon causes that the conditions for single crystal growth are not favourable and thus big crystals difficult to obtain. Many attempts at growing the single crystal resulted in obtaining an ingot which consisted of four sizable grains the biggest of which was used to prepare the specimens. The crystals were oriented by the Laue X-ray diffraction method and the slices with the three principle orientations [100], [110] and [111] were cut by a spark erosion machine. The samples were all given the same shape of disks with $ = llmm and subsequently ground and chemically polished down to the thickness of 2mm. The Compton profiles of the specimens will be measured with the 7-ray Compton spectrometer at the Warsaw University Branch in Bialystok. Along with the sample preparation some theoretical calculations have been made for the alloy. The selfconsistent electronic structure calculations using the KKR techniques with the muffin-tin potential were performed allowing for relativistic nature of the core electron states. The momentum density was then determined and subsequently the Compton profiles generated for the three principle crystallographic directions. The calculations were made for various compositions of the Ni-Cu alloy. Some of the results are presented in Fig. 1 where one can see the effect of alloying on the Compton profile; here the profile of pure copper has been subtracted from the profile of the Ni —Cu alloy of given composition. This representation of the Compton profiles reflects the changes in the momentum density with alloying and the differences are expected to be directly related to the Fermi surface shape evolution for different compositions. The differences also vary with crystallographic dirrection. This anisotropy observed in the system indicates that the situation here is far from the free electron predictions. Morover, the pronounced peaks, if experimentally detected, will give unique information about electronic behaviour close to the Fermi level. The Compton scattering experiment performed on the single crystal is to serve this purpose.

78 CP Cui-»NI« - CP Cu CP Cu,-,NI, — CP Cu

along (1 OO) along (1 1 O)

Fig. 1: Changes in the Compton profile with alloying i.e. differenes between profiles of given composition of the Ni- Cu alloy and the profile of pure Cu, calculated for three crystallographic directions.

<->•>

In addition some new features on the Compton profile derivatives have been recently found by Kaprzyk, which correspond to the discontinuities in momentum density field resulting from the shape of the Fermi surface. These results can be verified experimentally if measurements are performed with a resolution better than O.lau in the momentum space which is just becoming feasible at some synchrotron laboratories.

References [1] S. Kaprzyk and A. Bansil, Phys. Rev. B42 (1990) 7358. [2] M.J. Cooper, Rep. Prog. Phys. 48 (1985) 415. [3] R. Benedek, R. Prasad, S. Manninen, B.K. Sharma, A. Bansil, P.E. Mijnarends, Phys. Rev. B32 (1985) 7650.

1 Academy of Mining and Metallurgy, Krakow, Poland

79 PL9601023 ?-{Co Construction of the Atomic Force Microscope (AFM) J. Lekki, U. Voss1, B. Cleff1 and Z. Stachura

Although the process of friction and wear mechanisms has been intensively investigated for a very long time, physical models of these effects are still not well developed, especially when one considers the models based on atomic scale interactions. This situation is mainly caused by the lack of reliable data, because the measurements of friction and wear basing on traditional techniques are averaged over large heterogeneous samples. Only by the reduction of the contact area (even to single contact in atomic scale), may more reliable data be produced as the measurement is betted controlled [1]. One of the most promising tools in this research field is the Atomic Force Microscope. Its operation principle is based on the measurement of the deflection of a cantilever with a sharp tip at one end, caused by the forces between the investigated surface and a tip. Since its invention in 1986 [2] many different constructions have been proposed [3]. In our construction the cantilever deflection is detected by a laser beam reflected from the cantilever surface with the use of the quadrant photodiode. This idea has proved to be successful in measuring both lateral and vertical forces, thus allowing direct microfriction and microadhesion measurements [4].

National Instruments AT-MIO16L9 National Instruments AT-AO6 Data Acquisition Boord Analog Output Board RTSI Bus Quadrant Diode Signals Scanning InchWorm 1 2 5 4 Z Coitrol X Y F M B C

Current to Voltage Converters & Amplifiers 1 2 3 4

HV Piezo HV InchWorm Controller Controller XYZ F M B C

"nn Quadrant Photodiode

nchWorm Stepping Motor Sconner & Fine Approoch

Laser Diode Sample

Atomic Force Microscope - Schematic Diagram

80 The coarse approach of the sample and scanning tip is realised using an Inch Worm stepping motor (Burleigh UHVL-025). This device assures controlled movement at distances up to 25 mm, in steps even as small as several nanometers. The scanning tip, laser diode and detecting quadrant diode are in fixed position, with the laser beam focused on the microfabricated cantilever (Park Scientific Instruments, dimensions 170 X 36 X 0.6 /zm with silicon nitride tip - radius of tip curvature about 500 A). The force constant of the cantilever is 0.1 N/m. The tip may be easily exchanged or replaced with another one characterized by different mechanical parameters. Fine Z adjustment and XY scanning of the tip over the investigated surface is performed by moving the sample relatively to the tip. The sample holder is held magnetically to a scanner, what assures its stable position and simple sample exchange. The scanner is constructed with the piezo tube divided into four quadrants (Staveley Sensors Inc., piezo displacement factor about 2-lO~10 m/V). Applying high voltage signals to the quadrants of the piezo tube one can perform very fine and well controlled movements of the sample in all three dimensions. The whole instrument is controlled by the IBM PC 486 microcomputer equipped with two data acquisition cards: AT MIO-16L-9 (multi I/O) and AT-06 (analog outputs) manufactured by National Instruments. Analog signals delivered by PC boards drive specialized high voltage amplifiers (up to +900 V for Inch Worm and ±400 V for scanning and fine approach system, optimized for large capacitance piezoelectric loads). Scanning of a picture 256x256 points takes several minutes. The control and data analysis program is written using Microsoft C 7.0 and runs in MS Windows 3.1 environment. Our setup is still under development - elements missing include elements of the scanning system (two additional HV amplifiers), details of the mechanics and antivibrational dumping system. Estimated time of first experiments is summer 1994.

Acknowledgements: AFM is developed in cooperation with the Institute of Nuclear Physics, University of Miinster, Germany. Work is supported by the State Committee for Scientific Research (KBN), Poland, Grant No. 2P30204505.

References [1] G.M. McClelland and S.R. Cohen, Chemistry and Physics of Solid Surfaces VIII, Eds. R. Vanselow and R.Howe, Springer Series in Surface Sciences, Vol.22, 1990. [2] G. Binnig, C.F. Quate, and Ch. Gerber, Phys. Rev. Let. 56 (1986) 930. [3] E. Mayer, Progress in Surface Science, Pergamon Press 1992, Vol.41, p. 3-49. [4] 0. Marti, J. Colchero, and J. Mlynek, Nanotech. 1 (1990) 141.

1 Institute of Nuclear Physics, University of Miinster, Germany.

81 PL9601024 WAFM - a Microsoft Windows control program for Atomic Force Microscope

J. Lekki, U. Voss1, B. Cleff1 and Z. Stachura

The code WAFM has been developed with the aim of software control of the Atomic Force Microscope and image processing of the measured data. The microscope setup is described in the previous report. The program is written entirely in Microsoft C 7.0, runs in MS Windows 3.1 environment and uses two specialized PC boards (AT-MIO-16L-9 and AT-AO6 from National Instruments) for analog output and input operations. Optimized software libraries delivered by the manufacturing company are responsible for high level control of analog boards, assuring minimization of interrupt latency, significantly present in the Enhanced mode of Windows. The structure of the program is typical for Windows application, and consists of the following modules: • Inch Worm (Coarse approach), • Quadrants (Option used during initial setting of the laser beam and quadrant diode geometry. Adjusting must be done by hand), • Data Collection (Scanning, fine approach), • Analysis (Filters, data evaluation tools), • File Operations (Data saving, loading etc.), • Setups (Most of the hardware parameters of AFM are software configurable). The coarse approach of the sample to a force sensor is based on an Inch Worm motor. There- fore three analog signals of a definite shape and timing must be delivered, which after HV amplification are supplied to the piezo motor. This task is performed entirely by software and its characteristics may be easily modified and optimized. The speed of approach is software controlled and is limited mainly by the response time of HV amplifiers. In the present application a motor speed of 100 steps per second was found to be sufficient. For the average single Inch Worm step of 2 /xm this frequency produces linear speed determining the approach time of only a few minutes for scan-sample distances in the range of 20-25 mm, thus assuring fast and convenient sample exchange. Additional safety measures are included into the procedure of coarse approach to avoid damage of the cantilever in close proximity of the sample. The fine approach is based on a software control of the piezo tube inner electrode voltage. This signal may be used also for the compensation of small Z-dimension scanning errors caused by the fact that tube scanners scan not a flat area, but the surface of a sphere. The image data collection is performed using a simple algorithm for position updating and acquisition of the normal and the lateral force values forming two rectangular maps constructed of up to 256x256 points. Every single pixel measurement consists of four voltage readouts and the subsequent summing and substracting of the appropriate signals. Data are displayed in real time using a 256 degree color scale corresponding to measured values and may be represented using different color palettes. Every measurement forms an independent window on the screen, therefore many experimental pictures may be simultaneously displayed and compared. Evaluation and image processing of the collected data is possible using several tools, such as dimensional and force calibration, zooming the region of interest, linear cut along a chosen direction, configurable convolution filters and FFT. Three dimensional data representation is foreseen and will be included in the future.

1 Institute of Nuclear Physics, University of Miinster, Germany.

82 PL9601025 Adaptation of the 75 kV INP ion implanter '

The ion implanter facility of the Institute of Nuclear Physics in Cracow was used, during many years, in different fields of research and technical application [1]. The ion engineering methods especially implantation, ion mixing, recoil implantation and ion etching were frequently used for the creation or modification of thin surface layers of material. Among all the ion engineering methods, based on the ion bombardment, the IB AD - Ion Beam Assisted Deposition technique allows for the most perspective and can give the complex surface layers with excellent e.g. mechanical, electrical, chemical or optical properties [2]. Adaptation work on the INP implanter to Ion Beam Assisted Deposition technique were performed. The ion implanter was adapted to IBAD technique by the connection of an additional ion beam line equipped with: a pumping system, hollow - cold - cathode ion source, all the systems to control material and electrical feedings of the ion source and a lens assembly for extraction and formation of the ion beam, modernized target chamber fitted out with a set of probes, the support of the auxiliary target and other control systems. In this new arrangement, the additional ion beam (noble gasses, energy from 5 keV to 45 keV) is used to sputter atoms out of the auxiliary target. These atoms are deposited onto the surface of the modified substrate with the deposition rate in the range of 1 nm/min to 10 nm/min and the layer thickness up to 1/zm. Simultaneously with deposition, the main ion beam from the implanter is employed in the ion bombardment of the growing layer (I/A ratio from about 10~3 to 1 or more ; A - number of deposited atoms, I - number of incoming ions in the same time). The geometry of the IBAD setup is shown in Fig. 1. As can be seen, the mass analysed, uniform ion beam from the implanter of almost all the elements, with the energy of ions selected ranging from 5 keV to 75 keV (or more, for multiple charged ions) can be used to influence dynamically the formation of sputter deposited substrate layer in a controlled way (i.e. number of bombarding ions / number of sputter deposited atoms ratio, energy of ions, vacuum conditions etc.). Any complex elemental, alloy or compound surface layer on the modified substrate can be produced by using this device. After adaptation, the new equipment was tested by:

1. growing, by sputter deposition, of the thin Ni layer on the Si < 111 > single crystal, 2. preparation of yttrium layer in Si < 111 > single crystal; by implantation of Y+ at the dose of 2 * 1016 ions/cm2 , with the energy of 45 keV,

3. creation, by means of IBAD method, thin Ni\-XYX layer on Si < 111 > single crystal, by sputter deposition of Ni atoms and simultaneous yttrium ions bombardment, at total dose of 2 * 1016 ions/cm2 , with the energy of 45 keV.

For sputtering of Ni target, a beam of AT+ ions with an energy of 45 keV was applied. In both cases, the parameters of the yttrium ions bombardment (ex. 2, 3) and the sputter deposition (ex. 1, 3) were similar. Rutherford Backs cat tering Spectroscopy method, using the beam of particles (protons or a particles) from the 3.0 MV Van de Graaff facility at the Institute of Nuclear Physics, can be applied to investigate the structure and elemental composition of the new surface layers [3]. The depth profiles of layers of the deposited Ni atoms and of the implanted Y+ ions were measured by detection of the a particles backscattered at an angle of 150°. In all cases, the Si < 111 > single crystals were bombarded by the a particle beam, with an initial energy of 1000 keV, in random direction. In Fig. 2 backscattering spectra for Si < 111 > single crystals with: the thin Ni film (2a), implanted Y layer (26) and the thin (about 20 nm) coating

83 of Nii^xYx (x = 0.15) (2c) formed by Ni and Y atoms by IBAD technique, are shown. First experimental a particles RBS spectra measured for the Si < 111 > single crystals with a surface layers created by IBAD technique, permits one to suppose, that after adaptation the INP two beam line ion implanter is a good tool for the formation of complex surface layers by IBAD technique.

The 75 kV INP ion implanter

Magnet Main ion bean line

Additional ion bean line

Fig. 1: The geometry of the IBAD setup.

10000

9000 RBS spectrum for Si < 111 > single crystal with thin (about 20 nm) Ni film 8000

7000 c c 6000 XICO o 5000

o 2000

1000

500 750 1000 1250 # Channel

Fig. 2a: RBS spectrum for Si < 111 > single crystal with the thin Ni film.

84 12000

RBS spectrum for Si <111> single crystal implanted 18 2 10000 by Y* at the dose 2*10 ions/cm with the energy 45 keV

c 8000 c (0 x: ^ 6000

tf> "c 4000 Si O O 2000 .A. 250 500 750 1000 1250 # Channel

Fig. 2b: RBS spectrum for Si < 111 > single crystal with the thin implanted Y layer. 16000

14000 RBS spectrum for Si <111> single crystal with thin (about 20 nm) Ni,.^ film 12000 created by the I BAD method d) c 10000 JC O 8000 Ni 0L.) a, 6000 o O 4000

2000

250 500 750 1000 1250 # Channel

Fig. 2c: RBS spectrum for Si < 111 > single crystal with the thin (about 20 nm) coating of Ni!.xYx {x = 0.15). References: [1] M. Drwi§ga, E. Lipinska, S. Lazarski, M. Wierba, Raport IFJ Nr 1656/AP (1993) [2] G. Dearnaley, NIM B50 (1990) 358 [3] S. Kopta, J. Lekki, B. Rajchel, J. of Rad. and Nucl. Chem. 172 (1993) 3

85 PL9601026 Creation of Li - Ni and Li - Mn coatings upgrading the high - temperature corrosion resistance of metals by IBAD method B. Rajchel1, M. Drwi^ga1, E. Lipinska1, J. Lachut1, A. Sellman1, M. Wierba1 S. Mrowec2, M. Danielewski2, I. Turek - Bednarska2

IBAD - Ion Beam Assisted Deposition of thin layers consisting of elements, alloys or compounds is a method in which the growing film is simultaneously bombarded with energetic ions [1], IBAD has become an advantegous method for controlled modifications of surface layers of metals, ceramics, composites and other materials. This technique is one of the most useful for production of up to few tens of fim thick adherent surface coatings with special physical, chemical, mechanical, optical and electrical properties. The highest degree of control of each process parameter is obtained with ion - beam - based systems in which the ion bombardment is independent of the deposition and both can be easily controlled. At the ion implantation laboratory of the Institute of Nuclear Physics there is a dual ion beam device with excellent parameters for the IBAD method. In this arrangement, layers are obtained by sputter deposition of atoms onto the substrate and simultaneous ion bombardment of the growing film by means of a mass analyzed ion beam. This system affords possibilities for controling the IBAD processes by accurate measurement and verification of the parameters of the two ion beams [2]. Providing, above all, the energy to a growing film by means of ion bombardment and the right selection of chemical and physical features of incoming atoms and ions, allows for variation of a lot of film properties like composition, structure, adhesion, intrinsinc stress, density, morphology, porosity, corrosion resistance and others. Recently the comprehensive, multidirectional investigations on high - temperature, oxygen - consuming and sulfur corrosion resistance of some metals and special alloys have been undertaken in the ion implantation laboratory in cooperation with several research centers in Poland and abroad. So far, the IBAD method was used to prepare Li-Ni and Li-Mn layers on Ni and Mn substrates, respectively [3]. A preliminary series of samples with different concentrations of Li atoms was performed by the proper choice of parameters of the two ion beams and other conditions during the IBAD process. In order to determine the exact composition of coatings, the non - destructive inspection was carried out by RBS (Rutherford Backscattering Spectroscopy), a nuclear method, adapted to material investigation (internal structure and composition). A 3 MV Van de Graaff accelerator was used to provide an adequate, analysing a particle beam. The oxidation behaviour of Li — Ni/Ni and Li — Mn/Mn test samples was studied at 1373 K in air or pure oxygen, by means of thermogravimetery. Electron microscopy method was used to define the morphology of layers. The data handling is carried out and the first results of investigation of high - temperature corrosion resistance of Ni and Mn specimens, modified by the IBAD method, will be published. References: [lj G.K. Wolf, Surf, and Coat. Tech. 43/44 (1990) 920 [2] B. Rajchel, M. Drwie,ga, E. Lipinska, M. Wierba, Proc. of the ECAART'3, Orlean (1993) [3] W.C. Hagel, Transactions of the Metallurgical Soc. of AIME, 233 (1965) 1184

1 Institute of Nuclear Physics, Krakow 2 Academy of Mining and Metallurgy, Krakow

86 LIST OF PUBLICATIONS: I. Books:

1. J. Gr§bosz, "Symphony in C++. Object Oriented Programming in C++", Oficyna Kallimach, Krakow, 1993 (in Polish).

II. Articles:

1. A. Andrejczuk, (J. Kwiatkowska, F. Maniawski) et al., Compton Profiles of Silver Single Crystal, Phys. Rev. B48 (1993) 15552; 2. A. Baczmariski, (F. Maniawski) et al., Calculation of the Rotation Rate Field on the Basics of Experimental Texture Data, Philosophical Magazine A67 No 1 (1993) 155-171; 3. R.C. Barber, (A. Hrynkiewicz) et al., Discovery of the Transfermium Elements, Pure and Appl. Chem. 65 No 8 (1993) 1757-1814; 4. P. Bednarczyk et al., First Observation of the Excited States in the Doubly Odd Nucleus 118Cs Identified Through 7-Recoil Coincidences, Z. Phys. A346 (1993) 325; 5. P.Bednarczyk, E.Bozek, B.Fornal, M.Lach, A.Maj, W. Mgczynski, T. Pawlat, J. Styczen, Cross Section Ratio for pn and d Emission as a Probe of Level Density for Light-Medium Nuclei, Acta Phys. Pol. B24 (1993) 451-452; 6. G. Bench, (M. Cholewa) et al., Applications of Energy Loss Contrast STIM, Proc. of 3rd Int. Conf. on Microprobe Technology and Applications, Uppsala, Sweden, June 7-12, 1992; Nucl. Instr. and Meth. B77 (1993) 175; 7. A. Bracco, (A. Maj) et al., Probing the Shapes of Hot Nuclei with the GDR, Nucl. Phys. A557 (1993) 237-246; 8. F. Camera, (A. Maj) et al., The Shape of Hot Nuclei and the Angular Distribution of Hard Dipole Photons, Acta Phys. Pol. B24 (1993) 437-440; 9. M. Cholewa et al., Channeling STIM and its Applications, Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala, Sweden, June 7-12, 1992; Nucl. Instr. and Meth. B77 (1993) 184; 10. M. Cholewa et al., The Use of a Scanning Proton Microprobe in AIDS Research, Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala, Sweden, June 7-12, 1992; Nucl. Instr. and Meth. B77 (1993) 282; 11. J. Dryzek, Resonance Trapping of Positrons in Solids, Acta Phys. Pol. A83 (1993) 293; Phys. Stat. Sol. (b)179 (1993) 15; 12. S. Flibotte, (J. Styczen, K. Zuber) et al., AI=4 Bifurcation in a Superdeformed Band: Evidence for a C4 Symmetry, Preprint of Univ. Strasbourg CRN 93-35; Phys. Rev. Lett. 71 (1993) 4299;

87 13. S. Flibotte, (J. Styczeri, K. Zuber) et al., Multi-Particle Excitations and Identical Bands in the Superdeformed 149Gd Nucleus, Preprint of Univ. Strasbourg CRN 93-36 (1993); Phys. Rev. Lett. 71 (1993) 688; 14. B. Fornal et al., Neutron Spectra from the 156Er Compound Nucleus Populated by 12C- and 64Ni-Induced Reactions, Phys. Rev. C48 (1993) 2072; 15. J.J. Gaardh0je, (A. Maj) et al., Atomic Nuclei at High Excitation Energy Studied with Giant Resonances, Acta Phys. Pol. B24 (1993) 139-172; 16. J. Heese, (W. M^czyriski, M. Janicki, J. Styczeri, J. Gr§bosz) et al., Development of a New Recoil Filter Detector for 7-Detector Arrays, Acta Phys. Pol. B24 (1993) 61; 17. J. Heese, (J. Gr§bosz, W.M§czynski, J. Styczeri) et al., Evidence for Low-Lying Prolate Bands in 188Pb and 186Pb, Phys. Lett. B302 (1993) 390-395; 18. K.M. Horn, (M. Cholewa) et al., Single Event Upset and Charge Collection Imaging Using Ion Microbeams, Nucl. Instr. and Meth. B77 (1993) 355; 19. A. Hrynkiewicz, Badania naukowe podstawowe i stosowane, Postepy Fizyki 44 (1993) 63-70; 20. A. Hrynkiewicz, Adiunkci bez habilitacji, Przeglad Akademicki 3 (1993) 6; 21. J.R. Hughes, (B. Fornal), et al., Collective Oblate Bands in 196Pb, Phys. Rev. C47 (1993) 1337; 22. S. KopJ^i, J. Lekki, B. Rajchel, Detection Ability and Elemental Contents Determination by Elastic Scattering of Light Ions and by Recoiling Nuclei Measurements, INP Report 1574/AP, J. Radioanal. Nucl. Chem. 172 No 1 (1993) 3-17; 23. VV. Krolas, R. Broda, J. Grgbosz, A. Maj, T. Pawlat et al., First Results of 208Pb +64Ni Collisions Studies, Proc. of the XXVII Zakopane School of Phys., in: Acta Phys. Pol. B24 (1993) 449; 24. M. Lach et al., Shell Model Yrast States in the 7V = 79 Nuclei 141Sm and 143Gd, Z. Phys. A345 (1993) 427-428; 25. G.J.F. Legge, (M. Cholewa) et al., High Resolution Imaging with Energy Ion Beams, Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala, Sweden, June 7-12 1992; Nucl. Instr. and Meth. B77 (1993) 153; 26. A. Maj et al., E* and I Selection Techniques for Hot Nuclei Studies, Acta Phys. Pol. B24 (1993) 429-432; 27. M. Marszalek, B. Wodniecka, P. Wodniecki, A. Hrynkiewicz, PAC Study of Compound Formation in the In/Pt System, Hypernne Interactions 78 (1993) 315; 28. M. Marszałek, B. Wodniecka, P. Wodniecki, A. Hrynkiewicz, PAC Measurements of In-Pt Intermetallic Compounds, Hyperfine Interactions 80 (1993) 1029; 29. R.S. Mayer, (H. Dąbrowski, B. Fornal. L. Freindl), et al., Investigation of Pion Absorption in Heavy-Ion Induced Subthreshold IIo Production, Phys. Rev. Lett. 70 (1993) 904; 30. D. Nissius, B. Fornal, LG. Bearden, R. Broda, et al., Yrast Isomers in Exotic N=81 Nucleus 151Yb Studied Using a Fragment Mass Analyzer, Phys. Rev. C47 (1993) 1929; 31. M. Piiparinen, (A. Maj) et al., Lifetimes of Yrast States in noCd, Nucl. Phys. A565 (1993) 671; 32. P. Rymuza, (Z. Stachura) et al., Deviation From First-Order Perturbation Theory Observed at Intermediate Relativistic Velocities for the Ionization of Highly-Charged Heavy Projectiles, GSI Scientific Report GSI-93-1 184; J. Phys. B26 (1993) 169-175; 33. A. Saint, M. Cholewa, G.J.F. Legge, PIXE Tomography, Proc. of 6th PIXE Conf., Tokyo, Japan, July 20-24, 1992; Nucl. Instr. and Meth. B75 (1993) 504; 34. W. Schmitz, (A. Maj) et al., Transition Quadrupole Moments of a Large-Deformation Intruder Band in 163Lu, Phys. Lett. B303 (1993) 230-235; 35. M. Schramm, (R. Broda, J. Grębosz, W. Królas, A. Maj) et al., 7-Decay of the Particle-Hole States with the Highest Spins in 208Pb, Z. Phys. A344 (1993) 363-367; 36. Th. Stöhkler, (Z. Stachuia) et al., Electron Capture Studies for Highly-Charged Bi-Ions, Rad. Effect and Defects in Solids 126 (1993) 319-323; 37. S.A. Stuart, M. Cholewa et al., Investigation of Isolated Chemical Vapour Deposited Diamonds Using STIM Tomography, Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala, Sweden, June 7-12 1992; Nucl. Instr. and Meth. B77 (1993) 234; 38. M. Uhrmacher, P. Wodniecki et al., Ion-Beam-Induced Atomic Transport and Phase Formation in the System Nic- kel/Antimony. Part II: Phase Formation in Mixed Multilayers Observed by XRD and PAC, Appl. Phys. A57 (1993) 353; 39. B. Wodniecka, M. Marszałek, P. Wodniecki, A. Hrynkiewicz, Electric Quadrupole Interaction at 181Ta in Tetragonal C16 Intermetallic Compounds, Hyperfine Interactions 80 (1993) 1039; 40. B. Wodniecka, P. Wodniecki, A. Hrynkiewicz, PAC Studies of Agln2 and Ag2ln Growth Kinetics at Ag-In Interface, Hyperfine Interactions 78 (1993) 323; 41. P. Wodniecki, B. Wodniecka, M. Marszałek, A. Hrynkiewicz, Hyperfine Interaction of mCd in Pd-In Intermetallic Compounds, Hyperfine Interactions 80 (1993) 1033; 42. P. Wodniecki, M. Marszałek, B. Wodniecka, A. Hrynkiewicz, Intermetallic Compound Formation at In-Pd Interface Investigated with 111In Local

89 Probes, Hyperfine Interactions 78 (1993) 319; 43. P. Wodniecki, M. Uhrmacher, Ion-Beam-Induced Atomic Transport and Phase Formation in the System Nickel/Anti- mony. Part HI: PAC Measurements in Intermetallic Ni-Sb Phases, Appl. Phys. A57 (1993) 469; 44. C.T. Zhang, (R. Broda, M. Lach) et al., 154 Energy Inversion of the /7/2 and hg/2 Neutrons in Yrast States of Yb, Z. Phys. A345 (1993) 327-328; 45. J. Zukrowski, R. Kmiec, J. Przewoznik, K. Krop, 155 Magnetism of GdMn2 - Gd Mossbauer Results, J. Magn. Magn. Mater. 123 (1993) 246.

III. Contributions to Conferences:

1. A. Andrejczuk, (J. Kwiatkowska, F. Maniawski) et al., Compton Studies of Ag, Proc. of the First Int. Workshop on High Resolution Compton Scattering as a Probe of Fermiology, Cracow, July 3-5 (1993) 150; 2. P. Bednarczyk, J. Styczen, R. Broda, W. M§czynski et al., Investigation of High Spin States in 45Sc with the Use of GA.SP and RMS, Ann. Report 1992 LNL-INFN Legnaro (1993) 26; Abstracts of Symposium on Perspec- tives in Nuclear Structure, NBI, Copenhagen, June 14-17 (1993) ; 3. A. Bracco, (A. Maj) et al., Thermal and Quantal Fluctuations as Probed by the GDR Observables, Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", Kellog Biological Station Gull Lake, Michigan, USA, August 17-21 (1993) 9; 4. R. Broda, Heavy-Ion Binary Reactions Viewed by Gamma Arrays-Spectroscopy of Neutron-Rich Nu- clei, Abstracts of the Midsummer Workshop on Nucl. Phys., Jyvaskyla, Finland, June (1993) ; 5. F. Camera, (A. Maj) et al., On Detailed Study of the GDR Lineshape at Finite Temperature, Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", Kellog Biological Station Gull Lake, Michigan, USA, August 17-21 (1993) 11; 6. M. Cholewa et al., A Study of Aluminium-Exposed Fish Using a Scanning Proton Microprobe, Proc. of 8th Australian Conf. on Nuclear Techniques of Analysis, Lucas Heights, NSW, Australia, November 17-19, 1993, (ISSN 0811-9422) (1993) 1; 7. M. Cholewa et al., Three Dimensional STIM Tomography and its Applications, Proc. of 8th Australian Conf. on Nuclear Techniques of Analysis, Lucas Heights, NSW, Australia, November 17-19, 1993, (ISSN 0811-9422) (1993) 2; 8. A.E. Gorlich, R. Kmiec, Hyperfine Interactions and Spin Correlations in ErT2Sn2 (T=Ni,Cu) Phases, The European Conf. "Physics of Magnetism '93 - Stongly Correlated Systems", June 21-24, 1993. Abstracts (1993) 38;

90 9. R.F. Garrett, (M. Cholewa) et al., EXAFS and Microprobe Analysis at the Australian National Beamline Facility, Proc. of 8th Australian Conf. on Nuclear Techniques of Analysis, Lucas Heights, NSW, Australia, November 17-19, 1993, (ISSN 0811-9422) (1993) 3; 10. K. Gromov, (A.W. Potempa) et al., Alfa-Gamma Sowpadienia pri Raspadie 225Ac—>221Fr, Int. Meeting: Jadiernaja Spektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23 Apriela (1993) 114; 11. J. Jedliriski, (B. Rajchel) et al., The Effect of Composition, Heat Treatment and Surface Modification by Ion Implantation on the Oxidation Behaviour of Aloys from Fe-Cr-Al System, Proc. of the 2nd ASM Conf. on Heat Treatment and Surface Engineering, Dortmund, Germany, June 1-3 (1993) ; 12. J. Jedlinski, (B. Rajchel) et al., Redistribution of Major and Minor Alloy Components in Scales Formed During Early Stages of Oxidation on FeCrAl Alloys Studies by Means of SIMS and SNMS, Proc. of the 2nd Int. Conf. on Microscopy of Oxidation, Cambridge, England, March 29-31 (1993); 13. J. Jedlinski, (B. Rajchel) et al., The Effect of Surface and Heat Treatment on the Oxidation Behaviour of the Fe-10Cr-4Al Alloy, Proc. of 12th Int. Corrosion Congress, Houston, Texas, September (1993); 14. R. Julin, (A. Maj) et al., Band Termination in 110Cd, Abstracts of the NBI Conf. "Perspectives in Nuclear Structure", Copenhagen, June 14-18 (1993) 2; 15. R. Kruk, R. Kmiec, K. Latka, K. Tomala, 119Sn Mossbauer Effect Investigation of UPdSn, The European Conf. "Physics of Magnetism '93 - Strongly Correlated Systems", Poznari, June 21-24 (1993). Abstracts (1993) 35; 16. K.P. Lieb, (P. Wodniecki) et al., PAC Studies of Ion-Mixed Metalic Multilayers, Proc. of XXVIII Zakopane School of Physics - "Condensed Matter Studies by Nuclear Methods", eds. E. Gorlich, K. Tomala (IPJU and INP, Cracow) (1993) 69; 17. A. Maj et al., GDR Exclusive Measurements, Abstracts of the NBI Conf. "Perspectives in Nuclear Structure", Copenhagen, June 14-18 (1993) 1; 18. A. Maj, W. Krolas, J. Styczen et al., GDR Decay in Hot 46Ti Studied by Means of the HECTOR Array, Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", Kellog Biological Station Gull Lake, Michigan, USA, August 17-21 (1993) 37; 19. W. Mqczyriski, K. Zuber, R. Broda et al., 9 Directional Polarization of the /in/2 Proton Pair in the g6 Dy83 Ground State from a Study of its Gamow-Teller Decay, Proc. of 6th Int. Conf. on Nucl. far from Stability and 9th Int. Conf. on Atomic Masses and Fundamental Constants, Bernkastel-Kues, 1992, (IOP Publ.Ltd) (1993) 695; 20. J.W. Mietelski, P. Macharski, M. Jasiriska, R. Broda, Radioactive Contamination of Forests in Poland,

91 Proc. of the Int. Conf. on Nuclear Analytical Methods in the Life Sciences, Prague, September 13-17 (1993) ; 21. J.W. Mietelski, P. Macharski, M. Jasinska, R. Broda, Distribution of Radioactive Contamination in Poland (1991), Int. Symposium of Remediation and Restoration of Radioactive-Contaminated Sites in Europe, Antwerp, October 11-15 (1993) ; 22. A.W. Potempa et al., Opriedielenie Granicznych Energij /?+-Spektrow Korotkozywuszczich Nuklidow Redkozem- lennych Elementow, Int. Meeting: Jadiernaja Spiektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23 Apriela (1993) 78; 23. J. Sajdimov, (A.W. Potempa) et al., 147 Schema Raspada Tb (T1/2 = 1.7 h), Int. Meeting: Jadiernaja Spektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23 Apriela (1993) 71; 24. Th. Stohlker, (Z. Stachura^ et al., Spektroskopie Hochgeladener Pb- und U- Ionen am Gastarget des ESR, Proc. of the Conf. EAS-14, April 1993, Riezlern (1993) 63; 25. T.S. Tveter, (W. Krolas, A. Maj) et al., Pre-fission 7-Decay in Superheavy Nuclei, Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", Kellog Biological Station Gull Lake, Michigan, USA, August 17-21 (1993) 58; 26. E. Wantuch, J. Gawlik, B. Rajchel, J. Stanek, J. Lekki. Wplyw szlifowania w polu magnetycznym na anizotropie, strukturalna warstwy wierzchniej przedmiotow hartowanych, Zbior prac XVI Naukowej Szkoly Obrobki Sciernej, Koszalin (1993) ; 27. J. Wawryszczuk, A.W. Potempa et al., 146 Raspad Tb, l+(T1/2=8 sek), Int. Meeting: Jadiernaja Spiektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23 Apriela (1993) 68.

IV. Reports:

1. U. Bechstedt, (T. Pawlat) et al., The Magnets for COSY. Review and Status, IKP Annual Report 1992, p.187 Jiil-2590 (1993) ; 2. G. Believ, (K. Zuber) et al., Fission et Decroissance des Bandes Superdeformees, Annual Report CRN 1992, Strasbourg, (1993) 35 ; 3. F. Bosch, (Z. Stachura) et al., Cross Section Studies for REC into High-Z Projectiles, GSI Nachrichten 08-93 (1993) ; 4. R. Broda et al., Yrast Isomers in Tin Nuclei from Heavy Ion Collisions and the yhn/2 Subshell Filling, IKP Annual Report 1992, (ISSN 03666-0885), Jiil-2726 (1993) 76 ; 5. C.N. Davids, (R. Broda, B. Fornal) et al., Experiments Using the Argonne Fragment Mass Analyzer, ANL Report PHY-7515-HI-93 (1993) ;

92 6. C.N. Davids, (R. Broda, B. Fomal) et al., Recent Results from the Argonne Fragment Mass Analyzer, ANL Report PHY-7469-HI-93 (1993) ; 7. M. Drwi§ga, E. Lipinska, S. Lazarski, M. Wierba, Implantator jonow IFJ i jego wykorzystanie w inzynierii jonowej, Raport IFJ 1656/AP (1993) ; 8. J. Dryzek, E. Dryzek, Aparatura do pomiaru poszerzenia dopplerowskiego linii pochodzacej z anihilacji pozytonow w materii, Raport IFJ 1634/PS (1993) ; 9. R.G. Henry, (B. Fornal) et al., First Gamma-Recoil Experiment at the FMA, Bull. Am. Phys. Soc. 38 No 2 (1993) 1049; 10. A. Hrynkiewicz, Zasady dozymetrii. Dawki i dzialanie biologiczne promieniowania jonizujacego, Raport IFJ 1639/PL (1993) ; 11. J. Kajfosz, 0 alternatywnej interpretacji szczegolnej teorii wzgl§dnosci, Raport IFJ 1625/PL (1993) ; 12. J. Kajfosz, Investigation of Clustering in Sets of Analytical Data, INP Report 1624/PL (1993) ; 13. T. Kandler, (Z. Stachura) et al., Charge Exchange Processes Utilized for Multi-Charge State Operation of the ESR, GSI Scientific Report GSI-93-1 (1993) 186; 14. B. Kharraja, (K. Zuber) et al., Degenerate Superdeformed Bands in 151.152Tb, their Interpretation and Possible Con- straints on the "Pseudo-Spin Orbital [200]!/2", Preprint Univ. Strasbourg CRN 93-37 (1993) ; 15. T.L. Khoo, (B. Fornal) et al., Superdeformation in the Mass of 190 Region, ANL Report PHY-7557-HI-93 (1993) ; 16. K. Krolas, B. Wodniecka, The Quadrupole Moment of the 2083 keV State of 140Ce Derived from PAC Measurements, INP Report 1644/PS (1993) ; 17. W. Krolas, R. Broda, J. Grebosz, A. Maj, T. Pawlat et al., Neutron and Proton Flow Between the Colliding 208Pb and 64Ni Ions, HMI Annual Report 1992, (1993) 245 ; 18. P.H. Mokler, (Z. Stachura) et al., Ground State Lambshift Measured for H-like U at the ESR, GSI Scientific Report GSI-93-1 (1993) 181; 19. P.H. Mokler, (Z. Stachura) et al., X-Ray Emission of H- and He-like Pb and U Ions Measured at the Gasjet of the ESR, GSI Scientific Report GSI-93-1 (1993) 182; 20. T. Pawlat, R. Broda, W. Krolas, A. Maj, M. Zie,blinski et al., High Spin States in Neutron Rich Ni Isotopes, HMI Annual Report 1992, (1993) 243 ; 21. Th. Stohlker, (Z. Stachura) et al., X-Ray Emission from Very-Heavy H- and He-Like Ions in Collisions with Gaseous and

93 Solid Targets, X'93, 16th Int. Conf. on X-Ray and Inner Shell Processes, Debrecen, July 12-16, 1993; GSI preprint GSI-93-59 (1993) ; 22. Ch. Theisen, (J. Styczen, K. Zuber) et al., Bandes Superdefonnees dans 149Gd, Annual Report CRN 1992, Strasbourg, (1993) 33 ; 23. Ya. Vavryszczuk, (A.W. Potempa) et al., Beta-Raspad 147ffTb. Niskospinovye Sostoyanya v 147Gd, JINR Dubna Report P6-93-275 (1993) .

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. R. Broda, J. Styczen, "The Midsummer Workshop on Nuclear" Physics, Jyvaskyla, Fin- land, June 1993; 2. R. Broda, A. Maj, "Perspectives in Nuclear Structure", Copenhagen, June 14-18, 1993; 3. R. Broda, W. Krolas, M. Lach, T. Pawlat, J. Styczen, "XXIII Mazurian Lakes Summer School on Nuclear Physics", Piaski, Poland, August 1993; 4. R. Broda, B. Fornal, "1993 Gordon Research Conference on Nuclear Chemistry", New London, New Hampshire, USA, June 1993; 5. M. Cholewa, W. M. Kwiatek, B. Rajchel, "European Conference on Accelerators in Applied Research and Technology", Orleans, France, August 31 - September 4, 1993; 6. E. Dryzek, J. Dryzek, "25th Polish Seminar on Positron Annihilation", Karpacz, June 7-11, 1993; 7. E. Dryzek, J. Dryzek, E. M. Dutkiewicz, W.M. Kwiatek, J. Kwiatkowska, J.Lekki, M. Marszalek, M. Sowa, Zb. Stachura, "XXVIII Zakopane School of Physics", Zakopane, Poland, May 8-15, 1993; 8. W. M. Kwiatek, "Nowoczene Metody Przygotowania Probek i Oznaczania Sladowych Za- wartosci Pierwiastkow", Poznari, April 27-28, 1993; 9. W.M. Kwiatek, "II Krajowe Sympozjum Uzytkownikow Promieniowania Syn- chrotronowego", Krakow-Mogilany, Poland, October 25-26, 1993; 10. J.Kwiatkowska, F. Maniawski, "First International Workshop on High Resolution Comp- ton Scattering as a Probe of Fermiology", Krakow, Poland, July 3-5, 1993; 11. R. Kruk, R. Kmiec, "The European Conference Physics of Magnetism 93 - Strongly Cor- related Systems", Poznan, Poland, June 21-24, 1993; 12. W.M. Kwiatek, "Workshop on Sample Preparation for Accelerator Based Analytical Tech- niques", Wieden, Austria, December 6-10, 1993; 13. J. Lekki, B. Rajchel, Z. Stachura, "Powierzchnia i struktury cienkowarstwowe", Raba Nizna, November 4-6, 1993; 14. A. Maj, "Gull Lake Nuclear Physics Conference on Giant Resonances", Kellog Biological Station, Gull Lake, Michigan, USA, August 17-21, 1993; 15. W. Me,czyriski, "Meeting on Auxiliary Detectors for EUROBALL and Electronics", CRN Strasbourg, May 26-28, 1993;

94 INVITED TALKS:

1. R. Broda "Heavy ion binary reactions viewed by gamma- arrays-spectroscopy of neutron- rich nuclei", The Midsummer-Workshop on Nuclear Physics, Jyvaskyla Finland, June 1993. 2. R. Broda "Gamma arrays as a new tool for complex heavy-ion reaction studies: reaction mechanism and prospects for spectroscopy", 1993 Gordon Research Conference on Nuclear Chemistry, New London, New Hampshire, USA. 3. B. Fornal "Heavy ion collisions from the perspective of gamma-ray studies", International School-Seminar on Heavy Ion Physics, Dubna, May 10-15, 1993. 4. W.M. Kwiatek "Trace element analysis using synchrotron radiation", Studsvick, Szwecja, January 1993. 5. W.M. Kwiatek "Wykorzystanie krakowskiego akceleratora Van de Graaff'a do PIXE" ("PIXE studies with Cracow Van de GraafF accelerator"), Poznan, April 27-28, 1993. 6. W.M. Kwiatek "Study of trace elements distribution in various tissues structures", Krakow-Mogilany, October 25-26, 1993. 7. W.M. Kwiatek "Sample preparation procedure for nuclear analytical techniques applied in H. Niewodniczanski Institute of Nuclear Physics", Wien, Austria,, December 6-10, 1993. 8. B. Rajchel "Application cyclotron beam in surface material studies", National Seminar on Cyclotron in Science and Technology, Ankara, May 3-6, 1993. 9. B. Rajchel "Use of cyclotron beams for trace element analysis", National Seminar on Cyclotron in Science and Technology, Ankara, May 3-6, 1993. 10. J. Styczeri "Recoil detection in in-beam gamma-ray measurements - the RFD", The Mid- summer Workshop on Nuclear Physics, Jyvaskyla Finland, June 1993. 11. J. Styczen "Nuclear spectroscopy studies in IFJ", NBI Copenhagen, February 1993.

SCIENTIFIC DEGREES:

1. Ph.D. thesis: Kvetoslava Burdova, "Badanie wybranych ukladow biologicznych przy uzyciu spektroskopii mossbauerowskiej" (Studies of selected biological systems using Mossbauer spectroscopy). Supervisor: Prof. J. Stanek. 2. Ph.D. thesis: Ewa Dryzek, "Badanie beta-brazow wanadowych metoda anihilacji pozytonow" (Studies of beta-vanadium bronzes using positron annihilation method). Supervi- sor: Prof. A. Hrynkiewicz.

LECTURES, COURSES AND SEMINARS:

1. R. Broda "Czy rzeczywiscie odkryto podwojny fonon 3~ w 208Pb? Wysokospinowe stany 207Pb" ("Was indeed the double octupole phonon in 208Pb discovered? High spin states in 207Pb"), seminar at Heavy Ion Laboratory - Warsaw University, February 1993. 2. R. Broda "Spektroskopia gamma dzisiaj - Eldorado fizyki jadrowej" (Gamma spectroscopy today - Eldorado of Nuclear Physics"), seminar at Krakow branch of PTF, October 1993. 3. R. Broda "Dyskretne promieniowanie gamma w badaniu reakcji cie.zkojonowych - nowe obszary spektroskopii jadrowej" (Discrete gamma radiation in HI reaction studies - new regions of nuclear spectroscopy"), seminar at Department of Nuclear Reactions, IFJ, Oc- tober 1993.

95 4. R. Broda "N/Z equilibration in HI collisions 58Ni + 208Pb experiment project", GASP-user meeting - Legnaro, November 1993. 5. M. Cholewa et al., "High Resolution Techniques Using Scanning Proton Microprobe (SPM)", ECAART-3, 3rd European Conference on Accelerators in Applied Research and Technology, Orleans, France, August 31 - September 4, 1993. 6. J. Dryzek, C. Wesselink, B. Cleff "Investigation of vacancies and precipitation processes of carbides in stainless steel made by positron annihilation methods", 25th Polish Seminar on Positron Annihilation, Karpacz, June 7-11, 1993. 7. E. Dryzek and J. Dryzek, "Measurement of Doppler broadening of annihilation line in Sn-In alloys", 25th Polish Seminar on Positron Annihilation, Karpacz, June 7-11,1993. 8. B. Fornal "Deep inelastic heavy ion reactions from the perspective of gamma-ray spectroscopy", seminar at Notre Dame University, USA, January 19, 1993. 9. A. Hrynkiewicz "Metody fizyczne w medycynie i ochronie srodowiska" ("Physical methods in medicine and ecology") - lectures for students at Jagellonian University, Krakow. 10. A. Hrynkiewicz "Seminarium magisterskie dla studentow V roku Specjalizacji Fizyki Me- dycznej i Ochrony Srodowiska Uniwersytetu Jagiellonskiego" - lectures for students of Health Physics at Jagellonian University, Krakow. 11. A. Hrynkiewicz "Nuclear Methods in Materials Research. Impurity Interactions in Dilute Alloys", Purdue University, West Lafayette, Indiana, USA, August 1993. 12. A. Hrynkiewicz "Nuclear Science and Perspectives of Atomic Energy in Poland", Chalk River Laboratories, Ontario, Canada, August 1993. 13. A. Hrynkiewicz "Hyperfine Interaction Studies in Materials Research", International School and Symposium on Physics in Materials Science Using Nuclear and Complementary Methods, Jaszowiec, September 1993. 14. A. Hrynkiewicz "Promieniotworczosci naturalne w srodowisku" ("Natural radioactivity in environment"), Uniwersytet Marii Curie-Sklodowskiej, Lublin, December 1993. 15. A. Hrynkiewicz "Warunki fizyczne powstania i rozwoju zycia we Wszechswiecie" ("Physical conditions of origin and development of life in the Universe"), seminar at Szczecin branch of PTF, December 1993. 16. A. Hrynkiewicz "Nuclear Science in Poland", Nuclear Research Center, Teheran, Iran, December 1993. 17. A. Hrynkiewicz "Hyperfine Interaction Studies in-Beam", Nuclear Research Center, Teheran, Iran, December 1993. 18. W.M. Kwiatek, J. Lekki et al., "Temperature and Matrix Effect in PIXE Elemental Anal- ysis" ECAART-3, 3rd European Conference on Accelerators in Applied Research and Technology, Orleans, France, August 31 - September 4 (1993). 19. A. Maj, T. Pawlat, B. Fornal, W. Meczynski "Poster - Pracownia Struktury Jadra", 32'nd PTF Meeting, 20-23.09.1993, Krakow. 20. W.M. Kwiatek "Promieniowanie synchrotronowe i analiza skladu pierwiastkowego metodami PIXE i SRIXE" ("Synchrotron radiation and PIXE and SRIXE elemental analysis"), lectures for students at Jagellonian University, Krakow 21. W. Krolas, R. Broda, J.Grebosz, A. Maj, T. Pawlat, M. Schramm, H. Grawe, J. Heese, H. Kluge, K.H. Maier, R. Schubart "Neutron and proton flow between the colliding 208Pb and 64Ni ions", XXIII Mazurian Lakes Summer School on Nuclear Physics, Piaski, Poland, August 1993. 22. J. Lekki, B. Rajchel, Z. Stachura et al., "Activities of the AGH - IFJ - IKP Surface Lab. at IFJ Krakow", Powierzchnia i Struktury Cienkowarstwowe, Raba Nizna, November 4-6, (1993).

96 23. A. Maj "Ekskluzywne pomiary rozkladow katowych wysokoenergetycznych fotonow probnikiem ewolucji ksztaltow j§der atomowych" ("Exclusive angular distribution measurements of high energy photons as a probe of nuclear shape evolution"), Warsaw Uni- versity, March 1993. 24. A. Maj "Giant dipole resonance studies at Copenhagen and Cracow", University of Wash- ington, Nucl. Phys. Lab., USA, August 1993. 25. A. Maj "Preliminary results of the HECTOR experiment on GDR in 46Ti", University of Milano, Mediolan, Italy, October 1993. 26. M. Marszalek "Intermetallic compounds formation in bilayer metallic systems", Centro Brasileiro de Pesquisas Fisicsa, Rio de Janeiro, Brasil and Universidade Sao Paulo, Sao Paulo, Brasil, 1993. 27. M. Marszalek "PAC study of intermetallic compounds", Federal Universidade de Rio de Janeiro, Rio de Janeiro, Brasil, 1993. 28. E. Pamula, J. Dryzek "Investigation of carbon fiber using Doppler broadening of positron annihilation radiation", 25th Polish Seminar on Positron Annihilation, Karpacz, June 7-11, 1993. 29. T. Pawlat, R. Broda, W. Krolas, A. Maj, M. Zieblinski, H. Grawe, K.H. Maier, J. Heese, H. Kluge, M. Schramm, R. Schubart "High spin states in neutron rich Ni isotopes", XXIII Mazurian Lakes Summer School on Nuclear Physics, Piaski, Poland, August 1993. 30. B. Rajchel "CRBS - A Program Simulating Dechanneling of Protons in Complex Crys- tals", ECAART-3, 3rd European Conference on Accelerators in Applied Research and Technology, Orleans, France, August 31 - September 4 (1993). 31. B. Rajchel, M. Drwiega, E. Lipinska "Adaptation of the 70 kV INP Implanter to IBAD Technique", ECAART-3, 3rd European Conference on Accelerators in Applied Research and Technology, Orleans, France, August 31 - September 4 (1993). 32. B. Rajchel "Metoda IBAD tworzenia cienkich warstw powierzchniowych. Badanie skladu stechiometrycznego cienkich warstw wiazka wstecznie rozproszonych czastek" ("Creation of thin surface layers by IBAD method), seminarium at AGH Krakow. 33. B. Rajchel "Zastosowanie wiazki jonow do badania skladu warstwy wierzchniej cial stalych" ("Determination of element distribution in surface layers by nuclear methods (RBS, NBA)"), seminar at AGH Krakow - SLAFBS. 34. Z. Stachura "Zasady dzialania mikroskopow ostrzowych. Wykorzystanie AFM w bada- niach trybologicznych." ("Tribological investigations using AFM and other microscopes based on the interaction of a sharp tip with surface"), seminar at Jagellonian University. 35. J. Styczen "The light lead isotopes studied with the use of the recoil filter detector", seminar at Warsaw University. 36. J. Styczen "Neutron activation techniques", lecture at Jagellonian University, Krakow. 37. P. Wodniecki "PAC studies of binary intermetallic compounds produced by alloying and ion-beam-mixing", seminar at II Physikalisches Institut der Universitat Gottingen.

INTERNAL SEMINARS:

1. St. Lazarski, W.M. Kwiatek "Aktualny stan prac przy akceleratorze Van de Graaff'a", (Status of the Van de Graaff accelerator) January 6. 2. M. Lach "Struktura stanow yrastowych jader 141Sm i 143Gd", (Structure of yrast states in 141Sm and 143Gd nuclei) January 13. 3. J. Kownacki (UW, Warszawa) "Spektroskopia jadrowana wiazce ci^zkich jonow w poblizu 100Sn", (Nuclear spectroscopy in the vicinity of 100Sn with heavy-ion beams) January 20.

97 4. Zb. Stachura "Wzbudzenia wieloelektronowe w zderzeniach atomowych", (Multielectron excitations in atomic collisions) January 27. 5. J. Kansy (US, Katowice) "Analiza wynikow eksperymentalnych uzyskiwanych metoda anihilacji pozytonow i efektu Mossbauera - prezentacja programow numerycznych", (Analysis of experiments performed with application of the positron anihilation and the Mossbauer effect methods - presentation of numerical codes) February 3. 6. K. Zuber "Superdeformacja w jadrach atomowych z obszaru A sinl50", (Superdeformation in nuclei from the A sin 150 region) February 10. 7. E. Dryzek "Badanie wanadowych brazow tlenkowych fazy beta przy pomocy metody anihilacji pozytonow" (Studies of beta-vanadium oxide bronzes using the positron anihilation method), February 17. 8. B. Rajchel "Zastosowanie metody IBAD do uzyskiwania wierzchnich warstw cial stalych" (Application of IBAD method for modification of surface layer properties.), February 24. 9. W. Me,czyriski "Poznawanie niedostejmego czyli badania struktur 188Pb i 186Pb przy pomocy detektora jader odrzutu" (Exploration of inaccessible - studies of nuclear structure of 188Pb and 186Pb with the recoil filter detector.), March 10. 10. F. Maniawski, St. Kaprzyk (AGH) "Badanie ge,stosci elektronow w przestrzeni p§dow przy pomocy rozpraszania Comptona" (Compton scattering studies of electron momentum density.), March 17. 11. B. Fornal "0 badaniu neutrono-nadmiarowych jader produkowanych w zderzeniach cie,zkich jonow" (Studies of neutron-rich nuclei produced in heavy-ion collisions.), March 24. 12. R. Kulessa "178m2Hf jako wysokospinowa tarcza do badarl reakcji jadrowych" (178m2Hf as a high spin target for nuclear reaction studies.), April 14. 13. W. Walus "Badanie struktury jadra przy pomocy wiazek radioaktywnych" (Studies of nuclear structure with radioactive beams.), April 21. 14. T. Pawlat "Wysokospinowe stany wzbudzone w neutrono-nadmiarowych izotopach Ni" (High spin excited states in neutron-rich Ni isotopes.), May 5. 15. A. Balanda (IF UJ, Krakow) "Fotony w reakcji p +115In przy energii protonow 50 MeV (GDR, bremstrahlung)" (Photons fromp"1" 115In reaction at 50 MeV proton energy (GDR, bremstrahlung).), May 12. 16. K. Grotowski (IF UJ Krakow) "Niestabilnosc jadra atomowego przy duzych wzbudzeniach" (Instability of a nucleus at high excitations.), May 19. 17. J. Jastrz§bski (SLCJ Warszawa) "Antyprotony - sonda powierzchni jadrowej" (Antiprotons - a probe of nuclear surface.), May 26. 18. V.A. Karnaukhov (JINR Dubna) "Multifragmentation in 4He + Au collisions at relativistic energy, studied with Air - setup FASA", July 14. 19. W. M§czynski "Sztuka pomiaru niskich aktywnosci", (Art of low activities measurement.), October 6. 20. B. Fornal "W poszukiwaniu izomerow ksztaltu" (Search for shape isomers.), October 27. 21. M. Samek (IF UJ Krakow) "Detekcja skorelowanych par e+ e~ w zderzeniach cie,zkich jonow" (Detection of correlated e~ e+ pairs in heavy ion collisions.), November 3. 22. W.M. Kwiatek, St. Lazarski, Zb. Stachura "Generator typu Van de Graaff'a w IFJ - jego stan techniczny i wykorzystanie" (Van de Graaff generator at INP - its technical conditions and applications.), November 10. 23. B. Rajchel "Dynamiczne formowanie warstwy wierzchniej metodami jonowymi" (Dynam- ical modification of surface layer using ion beam techniques.), November 17.

98 24. A. Bracco (Uniwersytet w Mediolanie) "Relaxation mechanisms of the collective GDR states in hot rotating nuclei", November 24. 25. Zb. Stachura "FIM, STM, SFM, AFM, ... - mikroskopy oparte na oddzialywaniu ostrza z powierzchnia" (FIM, STM, SFM, AFM ... - microscopes based on the interaction of a sharp tip with surface.), December 8. i78m2 + 26. R. Kulessa (IF UJ Krakow) » Hf (I = 16 , T1/2 = 31 y) jako tarcza do badan struktury 178m jadra" ( 2jjf (I=l6+, T1/2=31y) as a target for nuclear structure studies.), December 15.

SHORT TERM VISITORS TO THE DEPARTMENT: Angela Bracco (Italy) Bernd Cleff (Germany) Marco Cinausero (Italy) Gilles de France (France) Olaf Filies (Germany) Wolfgang Garske (Germany) Klaus Grewer (Germany) Peter Kleinheinz (Germany) Sergey Lebed (Ukraine) Boleslaw Pietrzyk (France) Yves Schutz (France) Ulrich Voss (Germany) Stephan Vollschlaeger (Germany)

99 Department of Structural Research PL9601027 DEPARTMENT OF STRUCTURAL RESEARCH

Head of Department: Prof. Jerzy Janik Deputy Head of Department: Assoc.Prof. Tadeusz Wasiutyriski Secretaries: W. Lisiecka and M.M. Mayer telephone: (48) (12) 37-02-22 ext.: 250 e-mail: [email protected]

PERSONNEL: Neutron Laboratory: Research Staff: Jerzy Janik, Professor, Jerzy Hubert, Assoc.Prof., Jan Krawczyk, Ph.D., Maria Massalska-Arodz, Ph.D., Jacek Mayer, Ph.D., Ireneusz Natkaniec, Ph.D., Ewa Sciesiriska, Assoc.Prof., Jan Sciesinski, M.Sc.,Eng., Waclaw Witko, Ph.D., Wojciech Zajac, Ph.D., Piotr Zielinski, Ph.D., Technical Staff: Jerzy Brankowski, M.Sc.,Eng., Andrzej Ostrowicz, M.Sc.,Eng., Janusz Sokolowski, M.Sc.,Eng., Eugeniusz Lisiecki, Tadeusz Sarga

Laboratory of Magnetic Research: Research Staff: Maria Balanda, Ph.D., Andrzej Pacyna, Ph.D., Tadeusz Wasiutynski, Assoc.Prof., Technical Staff: Waldemar Witek M.Sc.,Eng, Administration: Wladyslawa Lisiecka Maria Magdalena Mayer GRANT: Prof. J. Janik, grant No 2-0182-91-01, (The State Committee for Scientific Research), Research on time correlations of condensed matter properties in microscopic and real time scale.

101 OVERVIEW: The activity of the Department of Structural Research may be divided into three parts. The first part covers research on molecular motions in molecular crystals and liquid crystals in relation to their phase transitions. Studies concern either motions which can be treated as local motions of individual molecules, or those which have a collective character. One may notice an evolution of this research: from crystals and liquid crystals to glassy states, from ideal crystals to crystals with surface and interfaces, from the aspects characterized by euclidean geometry to those of fractals. In this field various kinds of relaxation phenomena were also studied. The second part of the activity covers the magnetic properties of crystals, both in microscopic and macroscopic scale. In this research one may notice an evolution as well: from the lattice of atoms and ions to the lattice of fluxons in a superconductor forming either a regular lattice or fluid or glass. A common feature of these two parts is the relaxational character of the dynamics. The third part of the research is devoted to macroscopic systems which reveal a polymorphism which is analogous in many respects to the polymorphism of microscopic systems (molecular and magnetic). This is an interdisciplinary domain which with the help of methods of the thermo- dynamics of nonequillibrium processes and/or of solving dynamical equations obtains phases characterized by various types of attractors. The evolution of such a system may be treated as a SKI generis relaxation process. In this part of our Department activity some philosophical extrapolations show up. Most of the experimental work of the Department was done by means of the following methods: neutron scattering, infrared spectroscopy, adiabatic and scanning calorimetry, X-ray diffraction, polarized microscopy and magnetometry. The method of neutron scattering plays a leading role in this research. In this respect of importance is the international collaboration with the I.M. Frank Neutron Laboratory of the Joint Institute of Nuclear Research at Dubna, Russia, with the Institute for Energy Technology at Kjeller, Norway, and with the Rutherford Appleton Laboratory, England. The majority of the research was done in cooperation with other groups in Poland. The most important are: the Chemical Physics Laboratory of the Chemistry Faculty of the Jagellonian University in Krakow, the Solid State Physics Laboratory of the Faculty of Physics of the Jagellonian University in Krakow, the Institute of Physics and Nuclear Technology of the Mining Academy in Krakow. The review of main studies in the year 1993 is following: The earlier studies of critical effect at the phase transition in Ni(NH3)6(NO3)2 were extended to neutron measurements with higher energy resolution. The same effect was also studied in Mg(NH3)6(NO3)2- The quasielastic neutron scattering method was used with the aim of obtaining information about various components of intramolecular motions of the reorientation type in liquid crystalline (nematic) di-etoxy-azoxy-benzene (PAP). A theoretical model which takes into account two such motions: motion of benzene rings coupled with ethoxy terminals and reorientations within the alkoxy terminals, fits very well to the QNS results. A detailed study of phase transition in cyclooctanol was completed. Evidence of two plastic phases, both transforming into glassy state, was obtained. An additional phase transition of a reversible character was discovered. Spectroscopic studies of xylenes in their para-, meta-, and ortho- configurations was continued with special attention paid to the dynamics of methyl groups. The temperature behavior of methyl torsion is different in every member of the family. In the field of magnetic studies the influence of the substitution of ions Fe3+ by the non 3+ magnetic ion Al in the rare earth orthoferrites (Er, Tb, Tm)Fei^xAlx0z was investigated. The aim was to establish the magnetic properties of these compounds and also the interaction between Re3+ and Fe3+ sublattices+. Another study was devoted to temperature dependence of the magnetic susceptibility of intermetallic compounds (Dy, Er, Ho)Ni2Ge2- Also some new compounds of the type: (Ce,Tm)2Fen(H,D)x were studied in order to establish the Curie

102 PL9601028 PL9601029 temperatures and the effective magnetic moments. The study of magnetic relaxation in superconducting EUBO.ICUZOT-1 and YBaiCu^O^ with praseodymium ions substituted in place of rare earth was completed. The measurements were performed via observation of diamagnetic susceptibility time dependences. The distribution of pinning energy of fluxons in the studied substances were obtained and compared with those known for the other superconductors.

Prof. Jerzy Janik REPORTS ON RESEARCH: Evidence of Fast Reorientational Motions of Alkoxy Terminals in the Nematic Phase of Di-ethoxy-azoxy-benzene R. Podsiadly, J.M. Janik, T. Stanek Faculty of Chemistry of Jagellonian University, Krakow, Poland J.A. Janik Institute of Nuclear Physics, 31-342 Krakow K. Otnes Institute for Energy Technology, Kjeller, Norway

Quasielastic neutron scattering experiments performed in the nematic phase of the second member of the PAA series i.e. for H.$CtO.C%K$.0C-iH%, show a large excess of the quasielastic component, when compared with a model in which the reorienting units are benzene rings rigidly coupled with rigid ethoxy groups. We show that this excess can be explained when a second motion — interconformational jumps in the terminals around the O (ethoxy) axis are included.

Magnetisation of TmFe(1_x)Ala;O3(a; < o.i) A. Bombik, B. Lesniewska Department of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, 30-059 Krakow. A.W. Pacyna, W. Witek Institute of Nuclear Physics, 31-342 Krakow.

The investigation of the TmFe(1_x)Alx03 system was undertaken as a continuation of previous research [1] dealing with the influence of nonmagnetic substitutions on the physical properties of rare-earth orthoferrities. The first experiments were limited to a rather low content of non-magnetic ions. Measurements of powdered samples were performed using a magnetic electrobalance, in a magnetic field H=450 Oe at both increasing and decreasing temperatures. A typical magnetisation dependence on temperature for investigated compounds is shown in Fig.l. It has been found that for all examined samples magnetisation depends strongly on the amount of the substitute (x), the magnetic field and the history of the sample. All characteristic temperatures are visible and can be precisely determined from the differential net curve. All characteristic points: Tc - compensation temperature, Tti , Tt2 - temperatures of begining and ending of the spin reorientations process respectively are summarised respectively in Tab.l.

103 PL9601030

50 100 150 200 250 TEMPERATURE(K)

Figure 1: Magnetisation at H 450 Gs. Curve labeled by FC-ZFC results from a subtracting FC and ZFC curves.

X T«[K] Tti[K] Tt2[K]x 0.00 7 ± 1 79 ± 1 93 ± 1 0.03 12 ± 1 81 ± 1 98 ± 1 0.06 19 ± 1 85 ± 1 102 ± 1 0.10 27.5 86 ± 1 112 ± 1 As can be shown, substituting Fe3+ ions by non-magnetic Al3+ ions causes a noticeable increase in all characteristic temperatures and the broadening of the spin reorientation region. References: [1] A. Bombik, A.W. Pacyna and W. Witek, Acta Phys. Pol., A85 (1994) (in press).

Gold Substitution and Superconductivity in YBa2Cu3O7_£ J. Stanek, A. Szytula, Z. Tomkowicz institute of Physics, Jagellonian University, Krakow A. Bajorek, M. Balanda Institute of Nuclear Physics, 31-342 Krakow.

In this work we report on the properties of Au-substituted YBa2Cu3O7_£, where gold was partially substituted for Y, Ba and Cu respectively. Au is one of the few elements which increase critical temperature Tc of transition into a superconducting state. The initial interest of other researchers in Au-substitution was to study the influence of Au crucible used to grow single crystals of YBa2Cu307_i. It has been stated that gold introduced to the compound from the crucible was located in the Cul position of the crystal lattice. In our studies gold was introduced in the form of a very fine powder of AU2O3 and mixed with other powders, weighted in the proper proportion. The samples in the form of tablets were subjected to sintering in oxygen with a number of intermediary crushing. The final temperature of sintering was about 950°C and after that the samples were cooled in oxygen at a rate of l°/min. The whole process was repeated several times for newly weighted components and some preparation conditions were changed, i.e. the number of intermediary crushing, final temperature and the rate of cooling. The samples were studied by X-ray diffraction, DC electric resistance method, AC and DC magnetic susceptibility and Mossbauer effect method on 197Au. The samples showed high quality X-ray diffraction patterns with no impurity peaks up to about 10% gold substituting the corresponding component. Generally, the quality of patterns for Au-substituted samples was

104 better than for non-substituted samples. The most interesting finding in our studies was the distinguishing behaviour of (Yi_xAux)Ba2Cu3O7_$ samples which have the best superconducting properties. The smallest transition width (0.6 K) and the highest Tc (92.3 K) were observed for the sample with x = 0.05. The increasing of lattice constant c with x value shows that Au goes into the structure. The lattice constants a and b remain unchanged. An intergrain critical current was measured by means of AC susceptibility method. The value of about 160 A/cm2 has been obtained at liquid nitrogen temperature. The lower critical field value Hci observed by means of magnetic balance at liquid helium temperature was about 500 Oe. The Mossbauer spectra (Fig.l) point out that all gold in (Yo.95Au0.o5)Ba2Cu307_i is incorporated into the structure. This result is in agreement with those from other methods which show that (Yi_xAux)Ba2Cu3O7_£ samples seem to be most homogeneous. Metallic gold component is seen only in Mossbauer spectra of Y(Bao.96Auo.o4)2Cu307_£ and YBa2(Cuo.97Auo.03)307-$. The valence of incorporated gold is 3+ for all measured samples. The samples were next deoxy- genated by annealing for 3 hours in argon at 600°C and the Mossbauer spectra were measured again. As a result of deoxygenation all incorporated gold was reduced to monovalent. Such a change of valence, but for YBa2(Cu0.977Auo.o23)307-i, was interpreted earlier by Eibschutz et al.[l] as a proof that gold is located in the Cul position of the lattice. Thus, in our case, excess copper atoms could go into the ytrium sublattice or into the vacancies in the ytrium plane. By varying preparation conditions we obtained an additional (Yo.95Auo.o5)Ba2Cu307_£ sample which, although having a sharp transition into a superconducting state, was composed of two phases being in nearly 1:1 proportion with very similar, nearly overlapping X-ray diffraction patterns. Fig.2 presents a part of the pattern where the third additional peak appears which may be connected with the second oxygen poor phase or with a new phase. A new phase of YBa2Cu307_6 was recently observed by infrared measurements [2]. It is possible that gold is a catalizator in the process of forming a new phase. Further studies are in progress.

- (YAu) -annealed 1\(\C1

" (CuAu) l\ -annealed | Hfir 0.5-

.1. ... i,. . i . -10-5 0 5 10 15 -10 -5 0 5 10 15 Velocity (mm/s) Velocity (mm/s)

197 Figure 1: The Au Mossbauer spectra of (Yo.95Auo.o5)Ba2Cu307_« at 4.2 K marked as (YAu) and of YBa2(Cu0.97Au0.03)3O7_s marked as (CuAu) for obtained samples and for the same samples after annealing in argon (3h/600°C). The weak single line in the lower part of the figure origins from the metallic gold.

105 10000

3100 3tS0 3Z00 3250 3100 33.50 3A.00 ANGLE 29

Figure 2: Part of the X-ray diffraction pattern (CuKa) measured for (Yo.95Auo.o5)Ba2Cu307_5 sample obtained according to the special treatment (open circles). For comparison also a part of a pattern for (Yo.92Auo.o8)Ba2Cu307_$, having a typical YBa2Cus07 structure, is included (dashed line).

References: 1. M. Eibschiitz, M.E. Lines, W.M. Reiff, B. van Dover, J.V. Waszczak, S. Zahurak, R.J. Felder, Appl. Phys. Lett. 62 (15), 1827 (1993). 2. K.L. Borth, F. Kleimann, Z. Phys. B91, 419 (1993).

LIST OF PUBLICATIONS: I. Articles:

1. R. Podsiadly, J.A. Janik, J.M. Janik, K. Otnes: "Quasielastic scattering of neutrons by liquid crystal substance with flexible molecules", Liquid Crystals 14 (1993) 1510. 2. P. Zielinski, A. Fuith, W. Schranz, I. Rychetsky, H. Warhanek: "Strain anomaly and orientational disorder in the tetragonal phase of KHF2", Phys.Rev. B47 (1993) 8453. 3. P. Zielinski and K. Zabinska: "Green functions in crystals and thin layers with long range interactions", Phys. Rev. B47 (1993) 16447. 4. P. Zielinski and K. Zabinska: "Dynamics and phase transitions in crystals and thin layers with dipolar interactions", Phys. Rev. B48 (1993) 5505. 5. V. Spasojevic, D. Rodic, P. Nordblad, A. Bajorek: "Magnetic susceptibility of the semimagnetic semiconductor Hgi-xMnxS", J. Magn. Magn. Mater. 118 (1993) 152. 6. V. Kusigerski, M. Mitric, V. Spasojevic, D. Rodic, A. Bajorek: "Measurements and calculation of magnetic susceptibility of low-concentrated semimagnetic semiconductor GdxY2-xO3", J. Magn. Magn. Mater. 128 (1993) 369. 7. V. Spacejovic, D. Rodic, A. Bajorek, A. Szytula: "Magnetic susceptibility calculation of Cd1_!rMna!5", J. Magn. Magn. Mater. 128 (1993) 375. 8. M. Balanda, A. Bajorek, A. Szytula, Z. Tomkowicz: "Flux creep in Pr-substituted systems — A comparative study of Eu1-xPrxBa2CuA06 ", Physica C 205 (1993) 280.

106 9. S. Niziol, R. Zach, D. Fruchart, A. Bombik, A.W. Pacyna and R. Pruchard: "New magnetic properties of (Co1-.xMnx)2P", J. Magn. Magn. Mater. 127 (1993) 103. 10. P. Barta, S. Niziol, M. Zagorska, A. Proii and A. Pacyna: "Low temperature magnetic properties of poly(3-alkylthiophenes) and poly(4,4'-dialkyl-2,2'-bithiophenes)", Synthetic Metals 55-57 (1993) 5003. 11. M. Massalska-Arodz: " Dielectric relaxation in the glass phase of a liquid crystal", Phys. Rev. B47 (1993) 14552. 12. Ch. Selbman, W. Witko, W.D. Koswig: "Studies of Thermooptical Switching Properties of Glass Forming Calamitic Liquid Crystals", Proc of 28 Freiburg Arbeitstagung Fliisig Kristalle, ed. S. Baur and G. Meier, Freiburg 1993. 13. V.K. Fedotov, A.I. Kolesnikov, V.V. Sinicyn, E.G. Ponyatovskii, I. Natkaniec, J. Mayer, J. Brankowski, A.V. Belushkin: "Izlutchenie vodoroda v sverchprovodiashtchei keramike metodom nieuprugovo rasseyania neitronov", Fizika Tverdovo Tela 35 (1993) 189-197. 14. V.K. Fedotov, A.I. Kolesnikov, V.I. Kulakov, E.G. Ponyatovskii, I. Natkaniec, J. Mayer, J. Krawczyk: "Izlutchenie angarmonizma kolebanii atomov miedi i kisloroda v ytrevoy keremike metodom neuprugovo rasseyania neitronov", Fizika Tverdovo Tela 35 (1993) 310-319. 15. I.V. Markichev, I. Natkaniec, E.F. Sheka: "Method of Multicomponent Systems Basic Spectra Construction: Zero Coefficient Correlation Criterion", Zh. Strukt. Khimii 34 (1993) 44-53. 16. I.V. Markichev, I. Natkaniec, E.F. Sheka: "Construction of Basic Vibrational Spectra of a Multicomponent System. 1. Aerosil", Zh. Struk. Khimii 34 (1993) 54-63. 17. I.V. Markichev, I. Natkaniec, E.F. Sheka: "Construction of Basic Vibrational Spectra of a Multicomponent System. 2. Silica Gel", Zh. Struk. Khimii 34 (1993) 64-76. 18. I.V. Markichev, A.Yu. Muzychka, I. Natkaniec, E.F. Sheka: "Postrojenie basisnych spektrov kolebanii mnogokomponentnoi sistiemy. 3. Aerogel", Zh. Strukt. Khimii 34 (1993) 29-38. 19. E.F. Sheka, I.V. Markichev, V.D. Khavryutchenko, I. Natkaniec: "Sravnitelny analiz kole- batelnych spektrov dispersnych kremniezemov i ich komponentov", Zh. Strukt. Khimii 34 (1993) 39-51. 20. E.F. Sheka, I. Natkaniec, V.D. Khavryutchenko, P. Nechitailov, A.Yu. Muzychka, V.M. Ogenko, I.V. Markichev: "Kolebatelnaya spektroskopia dispersnych kremniezemov. Niey- prugoye rasseyanie neitronov", Zh. Fiz. Khimii 67 (1993) 38-46. 21. E.F. Sheka, I. Natkaniec, I.V. Markichev, V.D. Khavryutchenko: "Vibrations of disperse silicas", Phonon Scattering in Condensed Matter VET, Eds. M.Meissner and R.O.Pohl Springer Series in Solid State Sciences, 112 (1993) 303-305. 22. J. Kalus, J. Wolfrum, F. Worlen, K. Holderna-Natkaniec, I. Natkaniec, M. Monkenbush, M. Prager: "Internal rotation-phonon coupling in lattice dynamics of p-xylene", Phonon Scattering in Condensed Matter VII, Eds. M. Meissner and R.O. Pohl Springer Series in Solid State Sciences, 112 (1993) 521-523. 23. E.F. Sheka, I. Natkaniec, I. Markichev, A. Chuyko, V. Khavryutchenko V. Ogenko: "Vi- brations of Dispersed Silicas: A Comparative Study", React. Kinet. Catal. Lett. 50 (1993) 221-226. 24. A.I. Kolesnikov, V.V. Sinitsyn, E.G. Ponyatovsky, I. Natkaniec, L.S. Smirnov: "Neutron scattering studies of vibrational spectrum of high density amorphous ice in comparison with Hi and VI", J. Phys. Condensed Matter 6 (1994) 375-382.

107 II. Contributions to Conferences:

1. T. Wasiutynski: "Modulated Crystal with Multipole Interactions", XXEH Conference on Dynamical Properties of Solids, Lunteren, 26-30 Sep. 1993. 2. M. Massalska-Arodz: "Statistical self-similarity", Janik's Friends Meeting, Kalatowki 1993. 3. M. Massalska-Arodz: "Searching of the statistical self-similarity in the topological defect pattern of liquid ceystal", Physical Methods in Material Science, Jaszowiec 1993. 4. M. Massalska-Arodz: "Dielectric relaxation of statistically self-similar materials", 2nd Conference of Liquids, Florence. 5. I. Natkaniec, S.I. Bragin, J. Brankowski, J. Mayer: " Multicrystal Inverted Geometry Spectrometer NERA-PR at the IBR-2 Pulsed Reactor", Proc. International Collaboration on Advanced Neutron Sources ICANS XII, RAL Abingdon 1993 (in press). 6. I. Markichev, E. Sheka, I. Natkaniec, A. Muzychka, V. Khavryutchenko, Y. Wang., N. Herron: "Density of vibrational states of thiol capped CdS particles. Inelastic Neutron Scattering", 3rd International Conference on Surface X-ray and Neutron Scattering, Dubna 1993, Physica B (in press). 7. I. Markichev, E. Sheka, N. Goncharova, I. Natkaniec, A. Muzychka, V. Chukalin, V. Khavryutchenko, E. Nikitina: "Density of vibrational state of silicone nitride", 3rd Inter- national Conference on Surface X-ray and Neutron Scattering, Dubna 1993, Physica B (in press). 8. K. Holderna-Natkaniec, I. Natkaniec: "Study of internal vibrations of dl-camphene by IINS method", XX International Conference on Low Temperature Physics Eugene, Oregon 1993, Physica B (in press). 9. K. Holderna-Natkaniec, I. Natkaniec, S. Habrylo, J. Mayer: "Comparative neutron scattering study of molecular ordering in d-camphor and dl-borneole", XX International Con- ference on Low Temperature Physics Eugene, Oregon 1993, Physica B (in press). 10. I. Natkaniec, L.S. Smirnov, A.I. Solovev, S.I. Bragin: "Neutron scattering studies of ammonium dynamics and phase transition in K(l-x)(NH4)(x)SCN at 10K", XX International Conference on Low Temperature Physics Eugene, Oregon 1993, Physica B (in press). 11. L.S. Smirnov, V.A. Goncharova, E.L. Gromnitskaya, G.G. Ilina, I. Natkaniec, A.I. Solovev, O.V. Stalgorova: "The acoustic and neutron scattering investigations of NH4SCN phase diagram", XXXI Annual Meating EHPRG, Belfast 1993. 12. A.N. Ivanov, I. Natkaniec, L.S. Smirnov: "The Titanium-Zirconium high pressure cell for neutron scattering", XXXI Annual Meating EHPRG, Belfast 1993. 13. I. Natkaniec, L.S. Smirnov, A.I. Solovev, S.I. Bragin: "Neutron scattering studies of la- ticce dynamics and phase transitions in K(l-x)(NH4)(x)SCN", International School and Symposium on Physics in Materials Science, Jaszowiec 1993. 14. V.D. Khavryutchenko, I. Natkaniec, E.F. Sheka: "Computation chemistry as the necessary component of the inelastic neutron scattering spectroscopy of adsorbed molecules and surfaces", International School and Symposium on Physics in Materials Science, Jaszowiec 1993. 15. L. Bobrowicz, K. Holderna-Natkaniec, M. Mroz, I. Natkaniec, W. Nawrocik, W. Wojtowicz: "Neutron scattering studies of phase transitions in protonated and deuterated ammonium hydrogen sulphates", International Seminar on Protonic Conductors, Dubna 1993. 16. W. Witko: "Studies of Thermooptical Switching Properties in Glass-Forming Liquid Crys- tals", Freiburg 1993. 17. A. Bombik, A.W. Pacyna, W. Witek: "Phase transitions in ErFei-xAlxO3 systems", Abstracts of the European Conference Physics of Magnetism 93, Poznan.

108 18. M. Balanda: "Magnetic relaxation studies of Pr-substituted superconductors of the 123 and 124 structures", Abstracts of the European Conference Physics of Magnetism 93, Poznari. 19. M. Godlewska, A. Kocot, E. Sciesiriska, J. Sciesiriski: "Infrared study of 4-n-pentylphenyl- 4'-n-heptyloxythiobenzoate (7S5) ", II National Conference on Molecular Spectroscopy, Wroclaw 1993.

III. Reports:

1. P. Zielinski: Green functions in microscopic models of surface and interfaces, INP Rep. no 1632/pf. 2. M. Massalska-Arodz: Zjawisko relaksacji w ukladach nieuporzadkowanych, INP Rep. no 1626/ps. 3. L. Bobrowicz, A. Kartusiak, W. Nawrocik, J. Wasicki, I. Natkaniec "Neutron Scattering in 1,3-Cyclohexanadione", International Seminar on Structutal Investigations at Pulsed Neutron Sources, E3-93-65, JINR, Dubna 1993, pp 307-314.

SCIENTIFIC DEGREES: Maria Balanda — Ph.D. degree INTERNAL SEMINARS:

1. W. Zajac: Reorientation within the ether methyl group of PMMA. 2. J. Chrusciel: Dielectric relaxation in liquid crystalline phases of n55. 3. J. Janik: Critical effects in neutron scattering. Experimental results from JINR Dubna. 4. H. Piekarzowa: Efekt organizacyjny jako szczegolny przyklad synergii. 5. S. Taczanowski: Termodynamiczno-informacyjne determinanty podejmowania decyzji i ich implikacje aksjologiczne. 6. J. Chrusciel: Quasielastic neutron scattering in liquid crystalline phases of 855.

7. M. Balanda: Magnetic relaxation in high Tc superconductors. 8. J. Krawczyk, M.Massalska-Arodz and R.Podsiadly: 2nd Liquid Matter Conference. 9. W. Witko: Science in Berlin - its successes and troubles. 10. T. Wasiutynski: Dynamical Properties of Solids, impressions from the conference in Lunteren. 11. W. Otowski: Dynamics of the Ceo molecule from a point of view of dielectric relaxation research. 12. H. Kresse: Short range correlations in liquid crystals. 13. W. Witko: Thermoelectrooptical effects in liquid crystals. 14. T. Wasiutynski: Relaxation phenomena in glassy states. 15. M. Massalska-Arodz: Dynamics of complex systems: holistic model. 16. E. Sciesinska: Spektroskopowe badania polimornzmu substancji cieklokrystalicznej 755.

109 SHORT TERM VISITORS TO THE DEPARTMENT:

1. Jan van Loef, Reaktorcenter Delft, Holland 2. K.H. Michel, Universiteit Instelling Antwerpen, Belgium 3. Ivar Svare, Trondheim University, Norway 4. Ludmila Czernienko, Kiyev University, Ukraine 5. Aleksander Chalyi, Kiyev University, Ukraine 6. Peter Kleboe, Oslo University, Norway 7. Tonnod Riste, Institute for Energy Technology in Kjeller, Norway 8. Arne Skjeltrop, Institute for Energy Technology in Kjeller, Norway 9. W. Weidlich, Stuttgart University, Germany 10. Werner Press, Universitat Kiel, Germany 11. Horst Kresse, Universitat Halle, Germany 12. Siergiej Briagin, Joint Institute of Nuclear Research in Dubna, Russia

110 Department of Theoretical Physics PL9601031

DEPARTMENT OF THEORETICAL PHYSICS

Head of Department: Prof. J. Kwieciński Deputy Head of Department: Assoc.Prof. L. Leśniak Secretary: E. Pagaczewska telephone: (48)-(12)-37 02 22 ext.: 270 e-mail: [email protected]

PERSONNEL:

Research Staff

Piotr Bochnacki M.Sc. Piotr Bożek Ph.D. Wojciech Broniowski Ph.D. Marcin Cerkaski Ph.D. Piotr Czerski Ph.D. Wiesław Czyż1 Professor Wojciech Florkowski Ph.D. Krzysztof Golec-Biernat Ph.D. Andrzej Horzela Ph.D. Edward Kapuścik2 Professor Marek Kutschera Assoc.Professor Leonard Leśniak Assoc.Professor Jan Kwieciński Professor Andrzej Małecki Assoc.Professor Marek Płoszajczak Professor Stanisław Zubik M.Sc. Piotr Żenczykowski Assoc.Professor Robert Kamiński research student

Administrât ion

Ewa Pagaczewska M.Sc., Eng.

1 also at the Institute of Physics Jagellonian University, Chairman of the Sc. Counc. there, Chairman of the Sc. Counc. of the Nicolas Copernicus Astronomical Center 2 also at the Krakow Pedagogical University

111 GRANTS:

1. Prof. E. Kapuscik grant No: 2 0342 91 01 (The State Committee for Scientific Research), The Meaning of the Galileo Relativity Principle in Quantum Mechanics. 2. Assoc.Prof. M. Kutschera grant No: 2 0204 91 01 (The State Committee for Scientific Research), Dense and/or Hot Hadion Matter. 3. Prof. J. Kwiecinski grant No: 2 0198 91 01 (The State Committee for Scientific Research), Structure ofHadrons Studied in Particle and Nuclear Interactions. 4. Prof. J. Kwiecinski grant No: 2 P302 062 04 (The State Committee for Scientific Research), Analysis of Lepton Inelastic Scattering on Nucleons and on Atomic Nuclei. 5. Prof. J. Kwiecinski grant No: F0408 (British - Polish Joint Research Collaboration Programme), Proton Structure and Small x Physics. 6. Prof. J. Kwiecinski grant No: 3159 (Cooperation in Science and Technology with Central and Eastern Euro- pean Countries), Theory and Deep Inelastic Processes in QCD.

OVERVIEW: Research performed at the Department of Theoretical Physics concerns various theoretical problems of general physics, low, intermediate and high energy nuclear physics, elementary particle physics and astrophysics. Both formal problems as well as the more phenomenologically oriented ones are being considered. Department of Theoretical Physics actively collaborates with other departments of our Institute as well as with several scientific institutions in Poland and abroad. The research program is formally grouped into the following four main subjects:

1. the role of the Galilean relativity principle in classical and quantum mechanics, 2. dense and/or hot hadronic matter, 3. structure of hadrons studied in particle and nuclear interactions, 4. analysis of inelastic lepton scattering on nucleons and on atomic nuclei. These are the titles of the approved proposals by the State Committee for Scientific Research. The details of the results obtained in various fields are listed below in the abstracts. Besides pure research, members of our Department are also engaged in the graduate and undergraduate teaching program. At present one research student is working for his PhD and one for his M.Sc.

Prof. Jan Kwiecinski

112 PL9601032 PL9601033 PL9601034 REPORTS ON RESEARCH:

Intermittency in High Energy Collisions P. Bozek and M. Ploszajczak 1 1 GANIL, Caen, France The intermitent multifractal cascade was studied. It was used as a model of the multiparticle production cascade with a specific modelling of the hadronization effect. This model has basically the same structure if used as a model of the hadronization or as a model of the infrared cut-off in the QCD cascade. It has also the interesting feature that the fluctuations are enhanced at small scales according to some universal, but no longer selfsimilar pattern [1]. The perturbative QCD in the double logarithm approximation follows this universal pattern. Reference: 1. P. Bozek and M. Ploszajczak, Zeit. Phys. C59 (1993) 585 Instabilities and Fluctuations in Heavy Ion Collisions P. Bozek and M. Ploszajczak 1

1 GANIL, Caen, France The developement of the instabilities in the early phase of the intermediate energy heavy ion collision was modelled. This model was used for the calculation of the production cross sections for the subthreshold meson production. This allows to reproduce, using two free parameters, the production probabilities for the pion, kaon and eta mesons at subthreshold energies and also the differential cross section versus the pion kinetic energy [1]. The development of the instabilities in the expanding anisotropic nuclear matter was studied. The changes of the instability rates due to the geometry and the dynamics of the fragmenting nuclei could allow for an experimental signal of an unusual geometry of the fragmenting nuclei. Reference: 1. P. Bozek and M. Ploszajczak, Fluctuations in the Heavy Ion Collisions, GANIL preprint P-93-20 (1993)

Multiscaling in the Hadronization in High Energy Collisions P. Bozek and M. Ploszajczak 1 1 GANIL, Caen, France We study the multiscaling in the fluctuations of multiparticle distributions at small scales. Similarly to the multiscaling effect, recently found in multifractal models, we analyse the dependence of the strength of the fluctuations on the low density cut-off in the cascade. The effect changes the scaling behaviour and leads to stronger dependence of the scaled factorial moments on the resolution than the power law. This could be an explanation of the behaviour observed recently in the experimental 3-dimensional data on the scaled factorial moments. The multiscaling analysis allows to restore the universality in the processes with different cut-offs and could be used in the analysis of the experimental data [1]. Reference: 1. P. Bozek and M. Ploszajczak, Z. Phys. C59 (1993) 585

113 •iiniiiiiiiii iwiiiiiiiigiiiiiii Hiniiiini PL9601035 PL9601036 PL9601037 The Even-Odd Anomalous Tunneling Effect P. Kaminski, S. Drozdz, M. Ploszajczak 1 and E. Caurier 2 1 GANIL, Caen, France 2 CRN and Univ. of Strasbourg, Strasbourg, France The analysis of the interacting fermion models with the SU(2) symmetry indicates the different behaviour of the splittings of opposite-parity lowest-energy eigenstates for even and odd numbers of fermions. The imaginary time-dependent mean-field approach reproduces the average results only. For the odd particle numbers, an introduction of the universal logarithmic term to the action integral is needed. The even-odd effect appears in a wide class of models with the SU(2) symmetry and is connected with the crossing of the energy surfaces of opposite-parity states for an odd number of fermions [1]. Reference: 1. P. Kaminski, S. Drozdz, M. Ptoszajczak and E. Caurier, Phys. Rev. C47 (1993) 1548 r * The Analysis of the Charged-Fragment Correlations using a Fragmentation-inactivation Binary Model R. Botet * and M. Ploszajczak 2 1 Lab. de Phys. des Solides, Univ. Paris-Sud, Orsay, France 2 GANIL, Caen, France The fragmentation-inactivation binary model of the fragmentation at the transition line between the "oo-duster" phase and the "shattering" phase is applied for analyzing the nuclear multifragmentation data of ALADIN Collaboration for average charged-particle correlations in 600 MeV/u gold induced reactions on various targets. A constant break-up kernel, independent of the sizes of the daughter fragments, is used. By adjusting the strength of the inactivation probability function to the correlation between the mean-size of the largest cluster and the composed particle first moment, we find that the remaining charge correlation data is correctly reproduced by the fragmentation-inactivation binary model [1], Reference: 1. R. Botet and M. Ptoszajczak, Phys. Lett. BS12 (1993) 30 I Energy Dependence of Intermittency in Nuclear Reactions at Intermediate Energies Bao-An Li 1 and M. Ploszajczak 2 1 Hahn-Meitner Inst., Bereich Schwerionenphysik, Berlin, Germany 2 GANIL, Caen, France Using a hadronic transport model we study the beam energy dependence of intermittency in intermediate energy heavy-ion collisions by analysing the reduced scaled factorial moments of pion distributions in both pseudorapidity and kinetic energy. It is found that the anomalous dimension obtained from analysing pion pseudorapidity distributions decreases rapidly as the beam energy increases from about 0.5 to 3.0 GeV/nucleon. On the contrary, the anomalous dimension extracted from analysing pion kinetic energy distributions is almost independent of the beam energy [1]. Reference: 1. Bao-An Li and M. Ptoszajczak, Phys. Lett. B317 (1993) 300

114 PL9601038 PL9601039 PL9601040

JVC-Counting Rules and the Axial Vector Coupling Constant of the Constituent Quark W. Broniowski, M. Lutz 1 and A. Steiner 2

1 Department of Physics, University of Washington, Seattle, WA 98195, USA 2 Institute of Theoretical Physics, University of Regensburg, D-8400 Regensburg, Germany

The notion of constituent quarks has been useful in various models of hadronic structure and in the description of low-energy spectroscopy. It is generally assumed that these objects are Dirac particles, i.e. have no anomalous magnetic moment, and their axial vector coupling constant, gA, equals 1. Recently Weinberg argued why constituent quarks should behave as Dirac particles [1] in the limit of number of colors, Nc going to infinity. The analysis was based on the Adler-Weisberger sum rule. We have reanalyzed [2] the axial vector coupling of the constituent quark in the large-Nc limit and pointed out mechanisms which yield 1 - g^ ~ JV°. These mechanisms come from high-energy contributions to the sum rule. We have also pointed out that low-energy models (Nambu-Jona-Lasinio, Gell-Mann-Levy) also yield 1 - g^ ~ JVC° if vector-meson couplings are present. The numerical value of gx is around 0.8, which is welcome by phenomenology. A similar study has also been done for the magnetic moment [2]. References: 1. S. Weinberg, Phys. Rev. Lett. 65 (1990) 1181, 2. W. Broniowski, M. Lutz and A. Steiner, Phys. Rev. Lett. 71 (1993) 1787

r-. Low-Energy Sum Rules and Large-Nc Consistency Condition W. Broniowski

Recently, there has been a renewed interest in the large-iVc (number of colors) limit of QCD, which followed the derivation of the large-Nc consistency conditionsby Dashen and Manohar [1]. These conditions reconcile the large-Nc limit of QCD with hadronic physics, and indicate the special role of the baryon decuplet states. We have discussed [2] in detail these issues starting from the point of view of the low-energy sum rules. We show that using the Adler-Weisberger or the Drell-Hearn-Gerasimov sum rule one can very straightforwardly obtain the results of Refs. [1]. The crucial point of this derivation is the special role of the A resonance, and the correct Nc counting of the remaining contributions to the cross sections which enter the sum rules. References: 1. R. Dashen and A. V. Manohar, Phys. Lett. B315 (1993) 425, 438 2. W. Broniowski, Univ. of Regensburg preprint TPR-93-39 (1993)

Nuclear Collective Motion within O(N—1) Invariant Dynamics M. Cerkaski and I.N. Mikhailov 1

1 Joint Institute for Nuclear Research, Laboratory of Theoretical Physics, Head Post Office, P.O.B.79, Moscow, Russia

Assuming an O(N — 1) symmetry for the interaction term in the iV-body Hamiltonian we find a closed subsystem of equations describing the collective motion in a classical way. When studying, in the group geometric way, the mutual correspondency of the O(N-l) invariant

115 PL9601041 PL9601042 approach with the Sp(6,R) collective model we find that the nucleons move along trajectories determined by an effective one-body time-dependent harmonic potential being a function of the collective variables. The relation between the equations for the collective motion and the system of equations found elsewhere for the second order moments of the Wigner distribution function is discussed. A class of stationary solutions to the collective equations of motion leads to the cranking model with the selfconsistency relations depending on the O(N-l) scalar part of the potential.

Collective Modes in a Slab of Interacting Nuclear Matter: The Effects of Finite Range Interactions W.M. Alberico l, P. Czerski, A. De Pace * and V.R. Manfredi 2

1 Dipartimento di Fisica Teorica deU'Universita-Torino, Italy and INFN, Sezione di Torino, Italy 2 Dipartimento di Fisica delTUniversita-Padova, Italy and INFN, Sezione di Padova, Italy

We consider a slab of nuclear matter and investigate the collective excitations, which develop in the response function of the system. We introduce a finite-range realistic interaction among the nucleons, which reproduces the full G-matrix by a linear combination of gaussian potentials in the various spin-isospin channels. We then analyze the collective modes of the slab in the 5 = T = 1 channel: for moderate momenta hard and soft zero—sound modes are found, which exhaust most of the excitation strength. At variance with the results obtained with a zero range force, new "massive" excitations are found for the vector-isovector channel [1]. Reference:

1. W.M. Alberico, P. Czerski, A. De Pace and V.R. Manfredi, Collective Modes in a Slab of Interacting Nuclear Matter: The Effects of Finite Range Interactions, to be published in Z. Physik A

Spatial Dependence of Meson Correlation Functions at High Temperature W. Florkowski 12 and B.L. Friman 13

1 GSI Darmstadt, Germany 2 INP Krakow, Poland 3 Institut fur Kernphysik, TH Darmstadt, Germany

The spatial dependence of meson correlation functions at high temperature is studied in perturbative QCD, keeping only the lowest order term. We obtain analytic results for the static correlation function in this approximation. Problems connected with the regularization of the divergent expressions are discussed in detail. The meson screening mass is determined 2 2 2 from the form of the correlation function at large distances. We obtain mJcr = 2\Ar T + M , which agrees with the results of Eletskii and Ioffe for massless quarks (M = 0). Finally, the correlation function in the temporal direction is briefly discussed. For massless quarks we find the corresponding screening mass macr = 2vT.

116 PL9601043 PL9601044 Soft Photon Production in the Boost-Invariant Color-Flux Tube Model W. Czyz x and W. Florkowski

1 Institute of Physics, Jagellonian University and INP Krakow, Poland Starting from the classical expressions for emission of radiation we calculate soft photon production in the boost-invariant color-flux tube model. In the center-of-mass system of the initial tube we find that for large energies {yfs ~ 20 GeV) the production of photons with frequencies: 20MeV < u> < 50MeV, and emitted perpendicularly to the collision axis is strongly enhanced; it exceeds considerably production of photons given by the Low limit. For the emission more collinear with the collision axis and for decreasing u> the effect becomes weaker and, eventually, in the limit u> = 0 we recover precisely the Low formula. We also find that for smaller energies (y/s ~ 5 GeV) the emission of photons is well reproduced by the Low formula. Gener- ally speaking, the observed enhancement is related to the existence of a large, i.e. extended in time, region of photon emission. This, in turn, results from the time dilation accompanying the space-time evolution of tubes. Strong time dilation effects follow from the boost-invariance of our model and, for large s, considerably enhance radiation of soft photons. By the same token, this enhancement decreases with decreasing s, because dilation decreases.

Polarization of Incident Electron Beam and e-p Scattering Cross Sections K. Golec-Biernat

The influence of the polarization of an incident electron beam on certain e-p scattering cross sections is studied. It is shown that photoproduction and bremsstrahlung cross sections are not affected by the initial electron polarization in the Born approximation. The DIS case is also considered [1]. Reference: 1. K.Golec-Biernat, Polarization of Incident Electron Beam and e-p Scattering Cross Sections, HI Note, DESY Hamburg, Hl-06/93-302 (1993)

Gluons from Logarithmic Slopes in the NLL Approximation K. Golec-Biernat

We make a critical, next-to-leading order, study of the accuracy of the "Prytz" relation, which is frequently used to extract the'gluon distribution at small x from the logarithmic slopes of the structure function Ft. We find that the simple relation is not genarally valid in the HERA regime, but show that it is aleasonable approximation for gluons which are sufficiently singular at small x. Reference:

1. K.Golej^iernat, Gluons from Logarithmic Slopes of F2 in the NLL Approximation, HI Note, DESY Hamburg, Hl-10/93-313 (1993), submitted for publication in Phys.Lett. B

117 PL9601045 PL9601046 PL9601047 Small-a? Data Analysis by the Global Fit Method K. Golec-Biernat, M.W. Krasny 1 and S. Riess 2

1 IFJ and LPNHE, University Paris VI and VII, Paris, France, 2 Institute of Experimental Physics, University of Hamburg, Germany

The possibility of tracing shadowing corrections with hot spot scenario in the proton structure functions in deep-inelastic scattering is studied. The small x region of HERA is analyzed with reference to the experimental setup of the HERA colider. The global fit method is used. Reference: 1. K. Golec-Biernat, M.W. Krasny and S. Riess, Small-x Data Analysis by the Global Fit Method, in preparation

Implications of Scaling Violations of F2 at HERA for Peturbative QCD A.J. Askew 2, K. Golec-Biernat, J. Kwiecidski, A.D. Martin a, and P.J. Sutton 2

1 Department of Physics, University of Durham, England, 2 Department of Physics, University of Manchester, England

We critically examine the QCD predictions for the Q2 dependence of the electron-proton deep-inelastic structure function i^x, Q2) in the small x region, which is being probed at HERA. The standard results based on next-to-leading order Altarelli-Parisi evolution equations are compared with those that follow from the BFKL equation, which corresponds to the ressumation of the leading log(l/a;) terms. The effects of parton screening are also quantified. The theoretical predictions axe confronted with each other, and with existing data from HERA. Reference: 1. A.J. Askew, K. Golec-Biernat, J. Kwieciiiski, A.D. Martin and P.J. Sutton, Implications of Scaling Violations of F2 at HERA for Peturbative QCD, report INP 1653/PH (1993), submitted for publication in Phys. Lett. B

Galilean Covariance in Classical and Quantum Mechanics P. Bochnacki, A. Horzela, E. Kapuscik \ J. Kempczyriski 2 and A. Radosz 3

1 INP and Krakow Pedagogical University 2 Institute of Theoretical Physics, Warsaw University, Warsaw, Poland 3 Institute of Physics, Wroclaw Technical University, Wroclaw, Poland

We have continued to study the properties of the Galilean covariant formulation of classical mechanics as well as its consequences for Galilean covariant formalism of quantum mechanics. The fundamental concept of Galilean covariant single particle dynamics is based on the rejection of the notion of force laws which, as non-covariant expressions of the forces in terms of a particle position and velocity, can not describe acting forces (except of the constant one) in a covariant way. In our approach acting forces are considered as physical objects possessing their own time evolution and they may be expressed in terms of force laws in only one, chosen reference frame. It means that for a complete and consistent description of a physical system a new degree of

118 PL9601048 PL9601049 freedom has to be introduced and that we are to describe a particle always together with its environment. The formalism admits Lagrangean and Hamiltonian formulations with technical aspects which are similar to that of one dimensional field theory, but its interpretation needs new ideas. In particular many physical quantities, identified within standard, non-covariant approach, must be distinguished in the new formalism. The differences between covariant and non-covariant formalisms are seen in the easiest way in the framework of the covariant canonical formalism which gives unexpected results. The most important of them is a different shape of the uncertainty principle (caused by the fact that the canonical and mechanical momenta must be distinguished) and the different Galilean transformation rule for the total and kinetic energies. The connection between covariant and non-covariant formalisms can be analysed in the framework of Dirac's theory of constrained systems which shows how the covariant formalism reduces to the standard one in a reference frame in which the force law is satisfied. Physical Theories in Discrete Space-Time A. Horzela, E. Kapuscik 1 and Ch.A. Uzes 2 1 INP and Krakow Pedagogical University 2 University of Georgia, Athens, 30602 Georgia, USA The aim of the research is the formulation of quantum mechanics in the configuration space given by the finite, discrete set of allowed positions. In such a space the quantization can not be given by the standard canonical procedure and becomes canonical only in the limit in which the spacing of the allowed positions tends to zero. In contradistinction to any discretization of the physical theory defined primarily on a continuum our approach realize the concept of the physical theory defined from the very beginning on a discrete set. Such an approach demands new mathematical methods to be used. The algorithms based on the theory of discrete Fourier transforms allows to perform theoretical investigations as well as numerical calculations. Scalar Meson Dynamics R. Kaminski, L. Lesniak and J.P. Maillet 1 1 Division de Physique Theorique, IPN, Orsay, France Coupled channel analysis of the -Kit and KK interactions in the IG(JPC) = 0+(0++) states has been performed using a separable potential formalism [1]. A system of the Lippmann- Schwinger equations with relativistic propagators has been solved. The decay parameters of three resonances found in the analysis have been evaluated and compared with experimental data. The /o(975) resonance can be interpreted as a KK bound state. The root mean square radii of the corresponding KK wave functions have been calculated for the different data sets and compared with radii evaluated in the nonrelativistic approach. Their values (about 0.7 fm) are roughly 10 % smaller than the values found in the nonrelativistic analysis [2]. The parameters of the 7T7T and KK threshold interactions have been calculated. The scattering lengths have been compared with experiments and other determinations. The real part of the KK scattering length is about -1.65 fm and the imaginary part about 0.6 fm. The irw scattering length (0.17 m"1) is in agreement with the experimental value. Analogous calculations have been performed in the / = 2 TTT channel where a nonresonant behaviour of the scattering amplitude was found. References: 1. R. Kaminski, L. Lesniak and J.-P. Maillet, Relativistic Effects in the Scalar Meson Dynamics, Orsay preprint IPNO/TH 93-31 (1993) 2. F. Cannata, J.-P. Dedonder and L. Lesniak, Z. Phys. A 343 (1992) 451

119 PL9601051 PL9601052 PL9601053 Nuclear Symmetry Energy and Structure of Dense Matter in Neutron Stars PL9601050 M-Kutschera

Consequences for neutron star matter of the behaviour of symmetry energy which results in disappearing of protons at high densities are explored. It is shown that interactions responsible for disappearance of protons tend to separate protons and neutrons at lower densities. Two separation mechanisms are considered: a bulk separation of protons and neutrons and formation of a neutron bubble around a single proton. The latter one corresponding to trapping of protons in the neutron background bubbles is more likely to occur in neutron star matter. In this case protons form polarons which are localized. High Density Behaviour of Nuclear Symmetry Energy M. Kutschera

There exists profound discrepancy in the high density behaviour of the nuclear symmetry energy obtained in realistic variational many-body (VMB) calculations and in relativistic mean- field (RMF) calculations. While the symmetry energy decreases to negative values in the former approach it increases monotonically in the latter one. The origin of this discrepancy is discussed and it is argued that VMB prediction is more reliable. It is shown that vanishing of the symmetry energy implies proton-neutron separation instability in dense matter. Polarized Neutron Matter with Skyrme Forces M. Kutschera and W. Wojcik 1

1 Institute of Physics, Krakow University of Technology, ul. Podchorazych 1, 30-084 Krakow, Poland

It is shown that Skyrme forces with a commonly used parameter t% < 0 lead to instability of polarized neutron matter. This instability has a form of the ferromagnetic spin ordering. There is, however, no ground state and the system displays a singular behaviour. Physically consistent description of polarized neutron matter requires that the exchange parameter x2, which was neglected in spin-saturated systems, is in the range -5/4 < x2 < — 1. We find that Skyrme forces with x2 in this range provide very good parameterization of realistic neutron matter calculations. QCD Expectations for Deep Inelastic Scattering at Small x J. Kwiecinski

The QCD expectations concerning the small x limit of parton distributions where x is the Bjorken scaling variable are reviewed [1,2]. This includes discussion of the evolution equations in the small x region, the Lipatov equation which sums the leading powers of ln(l/x) and the shadowing effects. Phenomenological implications of the theoretical expectations for the deep inelastic lepton-hadron scattering in the small x region which will be accessible at the HERA e-p collider are described. We give predictions for structure functions F2 and FL and discuss specific processes sensitive to the small x physics such as deep inelastic diffraction and jet production in deep inelastic lepton scattering. A brief review of nuclear shadowing in the inelastic lepton nucleus scattering at small x is also presented [1].

120 PL9601054 PL9601055 References: 1. J. Kwiecinski, Small x Physics, in: Proc. of the 32nd Schladming Winter School "Substructures of Matter as Revealed with Electroweak Probes", Schladming, Austria, 24-th February-5th March 1993; Lecture Notes in Physics 426 (1993) 215, eds. L. Mathelitsch and W. Plessas (Springer- Verlag, 1993) 2. J. Kwiecinski, QCD Expectations for Deep-Inelastic Scattering at Small x, in: Proc. of the Work- shop: "HERA - the New Frontier for QCD", 21-26 March 1993, St. John's College, Durham, United Kingdom; J. Phys. G19 (1993) 1443

QCD Predictions for Deep Inelastic Structure Functions at HERA A.J. Askew 1, A.D. Martin 1, J. Kwiecinski and P.J. Sutton 2

1 Department of Physics, University of Durham, Durham, England 2 Department of Physics, University of Manchester, Manchester, England

In [1] the perturbative QCD is used to predict the deep-inelastic electron-proton structure 3 functions FT,L(^,Q2) in the small x region (x ss 10~ ) from an experimental knowledge of the behaviour at larger x. Theoretical calculations are based on the kx factorisation theorem together with the gluon distribution obtained from solving the BFKL equation. Shadowing corrections are quantified. In refs. [2,3] we study the general properties of the BFKL equation which sums the leading log(l/a;) terms and propose modifications to the infrared region. In particular we study the theoretical uncertainties in the predictions and show, in the HERA 2 2 x regime, that the effective slope A, denned by F2(x,Q ) - Ffg(x,Q ) = Cx~ , is a remarkable stable prediction of perturbative QCD, where Ffg is a suitably denned background. Numerical predictions for the deep inelastic electron-proton structure functions at small x are presented and confronted with recent HERA measurements. References: 1. A.J. Askew, A.D. Martin, J. Kwiecinski and P.J. Sutton, Phys. Rev. D47 (1993) 3775 2. A.J. Askew, A.D. Martin, J. Kwiecinski and P.J. Sutton, Properties of the BFKL Equation and Structure Function Predictions for HERA, Durham University preprint DTP/93/28 (1993) 3. A.J. Askew, A.D. Martin, J. Kwiecinski and P.J. Sutton, A Structure Function Test of the QCD Lipatov Behaviour at HERA, Durham University preprint DTP/93/38 (1993) (to be published in Modern Physics Letters)

Report of the Working Group on Radiative Corrections at HERA B. Badelek 1, S. Bentvelsen 2, P. Kooijman 2, J. Kwieciriski, H. Spiesberger 3 and W. von Schlippe 4

1 Institute of Experimental Physics, Warsaw University, Warsaw, Poland 2 NIKHEF, Amsterdam, The Netherlands 3 Institute of Physics, Bielefeld University, Bielefeld, Germany 4 Queen Mary and Westfield College, London, England In inclusive deep inelastic lepton nucleon scattering, the radiative "tails" originating from processes at Q2 values from the interval Q^ea* > Q2 > 0 contribute to measurements at Q2 —

121 II PL9601056 PL9601057 PL9601058

tne knowledge of the structure functions in this Q2 interval is necessary. We revise and compare existing parametrizations of structure functions and their extrapolations into the yet unexplored very low Q2 regions and discusss the resulting uncertainties for leptonic radiative corrections. The unfolding procedures to determine structure functions from observed cross sections by the experiments NMC, ZEUS and HI are confronted with each other. Reference: 1. B. Badelek, S. Bentvelsen, P. Kooyman, J. Kwiecinski, H. Spiesberger and W. von Schlippe, Report of the Working Group on Radiative Corrections at HERA; Proc. of the Workshop "HERA - the New Frontier for QCD", 21-26 March 1993, St. John's College, Durham, United Kingdom, J. Phys. G19 (1993) 1671

ii Shadowing in Deuteron and the New F*/F% Measurements B. Badelek 1 and J. Kwiecinski

1 Department of Physics, Uppsala University, Uppsala, Sweden and Institute of Experimental Physics, Warsaw University, Warsaw, Poland

The quantity 2i*2i(a;, Q2)lF%(%,Q2) — 1 is calculated in the region of low x and low- and moderate Q2 relevant for recent NMC and E665 measurements as well as for the expected final results of the precise NMC analysis of their low x data. The calculations include nuclear shadowing effects and a suitable extrapolation of the structure functions of free nucleons to the low Q2 region. The theoretical results are in a good agreement with the NMC data. The shadowing correction to the experimental estimate of the Gottfried sum is quantified. Reference: 1. B. Badelek and J. Kwiecinski, Shadowing in the Deuteron and the New F%jF\ Measurements, Uppsala preprint TSL/ISV-93-0090 (1993)

'\°\ J/H? Coherent Production on Nuclei by High Energy Mesons or Photons L. Lesniak

The distorted wave Born approximation has been used to describe an effective cc pair nuclear absorption in the J/$ coherent meson or photoproduction reactions on nuclei [1]. This effect has been neglected in earlier analyses of experimental data. The best fit value of the effective J/$- nucleon total cross section is

W KK Scattering Length and the Nature of the /0(975) Meson F. Cannata 1, J.-P. Dedonder 2 and L. Lesniak 1 Dipartimento di Fisica and INFN, Bologna, Italy 2 Laboratoire de Physique Nucleaire, Universite Paris 7 and Division de Physique Theorique, IPN, Orsay, France In extensive studies of coupled channel effects at the KK threshold we have explored

122 PL9601059 PL9601060

the possibility that the KK attraction is due to the coupling to a channel different from the TTT channel [1]. So this requires to study three channels: TTTT , KK and a so-called exotic channel. We have studied various possibilities including the one where the bare exotic state is at Eex = 975 MeV or at Eex = 1950 MeV. We favour the solution at 1950 MeV which corresponds to a pole structure like the one of the molecular picture for the /o(975) [2]. In view of alternative findings [3], we also study the solution at 975 MeV for the bare exotic state which leads for the /o(975) meson to a pole structure of a conventional Breit-Wigner resonance in the energy variable , We find that our solution corresponding to the molecular picture leads to a rather large KK scattering length whereas the low mass exotic solution at 975 MeV displays a large cancellation in the KK scattering amplitude at low energies. This cancellation arises because of the coalescence of poles and zeroes of the 5 matrix. References: 1. F. Cannata, J.-P. Dedonder and L. Lesniak, Z. Phys. A - Atomic Nuclei 343 (1992) 451 2. J. Weinstein and N. Isgur, Phys. Rev. D41 (1990) 2236 3. D. Morgan and M.R. Pennington, Phys. Rev. D48 (1993) 1185

Weak Hyperon Decays -1 P. Zenczykowski :

1 INP Krakow and Guelph University, Guelph, Canada

A simple explanation of the difference in the values of the apparent f/d ratios for the S- and P- wave amplitudes of nonleptonic hyperon decays was proposed [1] (experimentally (f/d)s = -2.6, {f/d)p — -1.9). The argument was formulated in the framework of the standard pole model with 56,0+ ground-state and 70,1~ excited baryons as intermediate states for the P- and S-waves respectively. Under the assumption that the dominant part of the deviation of (f/d)p from - 1 is due to large quark sea effects it was shown that the naively expected equality of (f/d)s and {f/d)p is lifted by the SU(3) symmetry breaking in energy denominators of S- wave amplitudes. A new relationship between these two f/d ratios was derived: (f/d + l)s = (1 + x)/(l - x) * (f/d + l)p (x = i,/AB K 0.33; 6, - strange-nonstrange quark mass difference; A^ - mean spacing of (56,0+) and (70,1~) baryons), which is in excellent agreement with experiment ( — 1.6 ss 2 * (-0.9)). It was also pointed out that for weak radiative hyperon decays the signs of the asymmetries calculated in the SU(3)-symmetric approach [2] are unchanged by the consideration of the SU(3)-symmetry breaking in energy denominators.

Nonleptonic Decays of Charmed Baryons ?z

P. Zenczykowski *

1 INP Krakow and Guelph University, Guelph, Canada

Quark and pole models of nonleptonic decays of charmed baryons were analysed from the point of view of their symmetry properties. In the first paper on the subject [3] symmetry properties of parity conserving amplitudes were discussed at length. It was shown that the symmetry structure of the dominant (due to ground-state intermediate baryons) contribution to the parity conserving amplitudes differs from the structure hitherto employed in the symmetry approach [5]. The structure given in ref.[5] must therefore be considered incorrect. It was also pointed out that the "subtraction" of sea quark effects in hyperon decays leads to an estimate of W-exchange contributions in

123 charmed baryon decays that is significantly smaller than naively expected on the basis of SU(4). Furthermore, an SU(2)w constraint questioning the reliability of the factorization technique for parity conserving amplitudes was exhibited. Differences of symmetry structures of current algebra and pole model predictions for the parity violating amplitudes were also analysed [4]. A simple technique generalizing the expressions of current algebra to the case of flavour symmetry breaking in the intermediate state was applied to sum the contributions from all intermediate excited l/2~ baryons of given charm. The technique permits easy discussion of departures from current algebra for any value of Ac/Ao; (Ac-charm-noncharm mass difference, Au - l/2~ -l/2+ mass difference). It was found that in the pole model the symmetry structure of parity violating amplitudes of charmed baryon decays into an octet baryon and a pseudoscalar meson consists of two pieces: (i) a term proportional to the standard current algebra expression but much smaller and of opposite sign and (ii) a term proportional to the factorisation contribution, interfering with it destructively. The full pole model was aplied to the description of available data [4], and compared with the predictions of current algebra [3]. Decays whose measurements should provide good discrimination between the pole model and current algebra were singled out. References: 1. P. Zenczykowski, Weak Hyperon Decays: Quark Sea and SU(3) Symmetry Breaking, Report INP 1647/PH (1993) 2. P. Zenczykowski, Phys. Rev. D44 (1991) 1485 3. P. Zenczykowski, Quaik and Pole Models of Nonleptonic Decays of Charmed Baryons, Report INP 1643/PH (1993) 4. P. Zenczykowski, Nonleptonic Charmed Baryon Decays: Symmetry Properties of Parity Violating Amplitudes, Report INP 1655/PH (1993) 5. J.G. Koerner, G. Kramer, J. Willrodt, Phys. Lett. 78B (1978) 492; Z. Phys. C2 (1979) 117; J.G. Koerner, M. Kramer, Z. Phys. C55 (1992) 659; J.G. Koerner, H.W. Siebert, Ann. Rev. Nucl. Part. Sci. 45 (1991) 511

124 LIST OF PUBLICATIONS: I. Articles:

1. A.J. Askew, J. Kwieciriski, A.D. Martin, P.J. Sutton: QCD Predictions for Deep Inelastic Structure Functions at HERA Phys. Rev. D47 (1993) 3775 2. B. Badelek, S. Bentvelsen, P. Kooijman, J. Kwiecinski, H. Spiesberger, W. von Schlippe: Report of the Working Group on Radiative Corrections at HERA J. Phys. G: Nucl. Part. Phys. 19 (1993) 1671 3. Bao-An Li, M. Ploszajczak: Energy Dependence of Intermittency in Nuclear Reactions at Intermediate Energies Phys. Lett. B317 (1993) 300 4. R. Botet, M. Ploszajczak: Patterns of Fluctuations in Disaggregatiming Systems Lecture Notes in Physics 415 (1993) 303 5. R. Botet, M. Ploszajczak: The Analysis of the Charged Fragment Correlations Using a Fragmentation-Inactivation Binary Model Phys. Lett. B312 (1993) 30 6. P. Bozek, M. Ploszajczak: Multiscaling in the Hadronization in High Energy Collisions Z. Phys. C59 (1993) 585 7. W. Broniowski, T.D. Cohen: Response of Nucleons to External Probes in Hedgehog Models. I. Electromagnetic Pola- rizabilities Phys. Rev. D47 (1993) 299 8. W. Broniowski, T.D. Cohen: Response of Nucleons to External Probes in Hedgehog Models. II. General Formalism Phys. Rev. D47 (1993) 313 9. W. Broniowski, T.D. Cohen: The Structure of the Pion and Effective Electric Currents in Soliton Models of the Nucleon Phys. Rev. D48 (1993) 2299 10. W. Broniowski, M. Lutz, A. Steiner: JVc-Counting Rules and the Axial Vector Coupling Constant of the Constituent Quark Phys. Rev. Lett. 71 (1993) 1787 11. M. Cerkaski, I.N. Mikhailov: Nuclear Collective Motion within the 0(N - 1) Invariant Dynamics Annals of Phys. 223 (1993) 151 12. W. Czyz: Interaction of a Quark with the Perturbative Vacuum Acta Phys. Pol. B24 (1993) 483 13. W. Czyz, J. Turnau: Quark in a Magnetic Vacuum Acta Phys. Pol. B24 (1993) 1501 14. A. Horzela, E. Kapuscik: Another Treatment of the Relation Between Classical and Quantum Mechanics Annales de la Fondation Louis de Broglie, 18 (1993) 155 15. A. Horzela, E. Kapuscik, Ch.A. Uzes: Comment on the paper: "Introductory Gauge Invariance", by R. Barlow [Eur.J. Phys. 11 45-46 (1990)] Eur. J. Phys. (1993) 190 125 16. A. Horzela, E. Kapuscik, Ch.A. Uzes: Comment on the paper: "Magnetic Monopoles, Galilean Invariance, and Maxwell's Equa- tions", by F.S. Crawford [Am. J.Phys. 60, 109-114 (1992)] Am. J. Phys. 61 (1993) 471 17. P. Kaminski, S. Drozdz, M. Ploszajczak, E. Caurier: Even-Odd Anomalous Tunneling Effect Phys. Rev. C47 (1993) 1548 18. M. Kutschera, A. Kotlorz: Maximum Quark Core in a Neutron Star for Realistic Equations of State Astrophys. J. 419 (1993) 19. M. Kutschera, W. Wojcik: Proton Impurity in the Neutron Matter: A Nuclear Polaron Problem Phys. Rev. C47 (1993) 1077 20. J. Kwieciriski: QCD Expectation for Deep-Inelastic Scattering at Small x J. Phys. G: Nucl. Phys. 19 (1993) 1443 21. L. Lesniak: J/$ Absorption Effects in the Coherent Production on Nuclei Phys. Lett. B302 (1993) 140 22. A.J. Askew, J. Kwieciriski, A.D. Martin, P.J. Sutton: A Structure Function Test of the QCD Lipatov Behaviour at HERA Modern Physics Letters A8 (1993) 3813. II. Contributions to Conferences:

1. W. Florkowski: Emission of Soft Photons in the Boos-Invariant Color-Flux Tube Model, to be published in the Proc. of the Krakow Workshop on Multiparticle Production: Soft Physics and Fluctuations, Krakow 1993, R.C. Hwa ed., World Scientific 2. W. Florkowski, B.L. Friman: Screening and Dynamic Masses of Mesons in the Nambu- Jona-Lasinio Model, to be published in the Proc. of the Conference on Many Body Physics, Coimbra 1993, World Scientific 3. W. Florkowski, B.L. Friman: Meson Screening Masses in the Nambu-Jona-Lasinio Model, to be published in the Proc. of the XXXIII Krakow Summer School of Theoretical Physics: QCD Vacuum, Non-Perturbative Methods and Correlation Functions, Zakopane 1993, W. Czyz ed., Acta Phys. Pol. B 4. J. Kwieciriski: Small x Physics (An Introductory Theoretical Review), Proc. of the XV Int. Warsaw Meeting on Elementary Particle Physics, Kazimierz, Poland, 25-29 May 1992, eds. Z. Ajduk, S. Pokorski, A.K. Wroblewski, World Scientific, 1993 5. J. Kwieciriski: Small x Physics, Proc. of the 32. Int. Universitatswochen fur Kern- und Teilchenphysik, Schladming, Austria, 24 Feb.-5 March 1993, "Substructures of Matter as Revealed with Electroweak Probes", eds. L. Mathelitsch, W. Plessas, Springer-Verlag, Lecture Notes in Physics 426 (1993) 215 6. L. Lesniak: J/* Coherent Production on Nuclei by High Energy Muons or Photons, Contribution to the XIII International Conference "Particles and Nuclei", Perugia, Italy, 28 June - 2 July 1993, Books of Abstracts, vol.1, p.149 7. F.Cannata, J.P. Dedonder, L. Lesniak: KK Scattering Length and the Nature of the fo(975) Meson. Contributed paper No 118 to the Int. Europhysics Conf. on High Energy Physics, Marseille, July 22-28, 1993. 8. R. Kamiriski, L. Lesniak, J.P. Maillet: Coupled Channels Analysis of the f0 Mesons. Con- tributed paper No 119 to the Int. Europhysics Conf. on High Energy Physics, Marseille, July 22-28, 1993.

126 III. Reports:

1. Y. Abe, B.G. Giraud, M. Ploszajczak, E. Suxaud: Atomic Nuclei: A Laboratory for the Study of Complexity GANIL preprint P-93-06 (1993) 2. A.J. Askew, K. Golec-Biernat, J. Kwiecinski, A.D. Martin, P.J. Sutton: Implications of Scaling Violations of F2 at HERA for Perturbative QCD Institute of Nuclear Physics preprint INP 1653/PH (1993) 3. A.J. Askew, J. Kwiecinski, A.D. Martin, P.J. Sutton: Properties of the BFKL Equation and Structure Function Predictions for HERA Univ. of Durham preprint DTP/93/28 (1993) 4. B. Badelek, J. Kwiecinski: Shadowing in the Deuteron and the New F£ /F% Measurements Univ. of Uppsala preprint TSL/ISV-93-0090 (1993) 5. R. Botet, M. Ploszajczak: Fragmentation-Inactivation Binary Model - A New Model of Kinetic Sequential Fragmen- tation GANIL preprint P-93-14 (1993) 6. P. Bozek, M. Ploszajczak: Fluctuations in the Heavy Ion Collisions GANIL preprint P-93-20 (1993) 7. W. Broniowski: Low-Energy Sum Rules and the Large-iVc Consistency Conditions Technical Report Univ. of Regensburg TPR-93-39 (1993) 8. W. Czyz, W. Florkowski: Soft Photon Production in the Boost-Invariant Color-Flux Tube Model Institute of Nuclear Physics preprint INP 1640/PH (1993), to be published in Zeit. Phys. C 9. W. Florkowski, B.L. Friman: Spatial Dependence of the Finite-Temperature Meson Correlation Function Institute of Nuclear Physics preprint INP 1618/PH (1993), to be published in Zeit. Phys. A 10. W. Florkowski, B.L. Friman: Screening of the Meson Fields in the Nambu-Jona-Lasinio Model Institute of Nuclear Physics preprint INP 1622/PH (1993) 11. R. Kaminski, L. Lesniak, J.-P. Maillet: Relativistic Effects in the Scalar Meson Dynamics IPN Orsay preprint IPNO/TH 93-31 (1993) 12. P. Kaminski, M. Ploszajczak, R. Arvieu: Quantum Tunneling in the Driven Lipkin N-Body Problem GANIL preprint P-93-13 (1993) 13. M. Kutschera: Nuclear Symmetry Energy and Structure of Dense Matter in Neutron Stars Institute of Nuclear Physics preprint INP 1641/PH (1993) 14. M. Kutschera: High Density Behaviour of Nuclear Symmetry Energy Institute of Nuclear Physics preprint INP 1642/PH (1993) 15. M. Kutschera, W. Wojcik: Polarized Neutron Matter with Skyrme Forces Institute of Nuclear Physics preprint INP 1654/PH (1993)

127 16. J. Kwiecidski: Small x Physics Institute of Nuclear Physics preprint INP 1620/PH (1993) 17. E.N. Nikolov, W. Broniowski, K. Goeke: Electric Polarizability of the Nucleon in the Nambu-Jona-Lasinio Model Ruhr-Univ. Bochum Technical Report RUB-TPII-55/93 (1993) 18. P. Zenczykowski: Quark and Pole Models of Nonleptonic Decays of Charmed Baryons Institute of Nuclear Physics preprint INP 1643/PH (1993) 19. P. Zenczykowski: Weak Hyperon Decays: Quark Sea and SU(3) Symmetry Breaking Institute of Nuclear Physics preprint INP 1647/PH (1993)

PARTICIPATION IN CONFERENCES AND WORKSHOPS: P. Boiek: 1. Interdisciplinary Workshop on Statistical Description of Transport in Plasma, Astro- and Nuclear Physics, Les Houches, France, February 1993. W. Broniowski: 1. Electromagnetic Polarizabilities in Hedgehog Models, University of Regensburg, Regens- burg, Germany, January 1993, 2. Nc Counting Rules and g\ of the Constituent Quark, Institute of Physics, Ljubljana Uni- versity, Ljubljana, Slovenia, April 1993, 3. Nc Counting Rules and the Axial Vector Coupling Constant of the Constituent Quark, Institute of Theoretical Physics, Bochum University, Bochum, Germany, May 1993, 4. Low-Energy Sum Rules and the Large-iVc Limit, talk at the Session "Chiral Symmetry in Hadrons and Nuclei" of ECT, Trento, Italy, Sept. 1993 and at the Institute of Theoretical Physics, Bochum University, Germany, October 1993, 5. Linear Response in Chiral Soliton Models, talk at the Session "Structure of Nucleons" of ECT, Trento, Italy, October 1993. P. Czerski: 1. The Equation of State for Nuclear Matter , University of Padova, Padova, Italy, March 1993, 2. Collective Modes in a Slab of Interacting Nuclear Matter, University of Padova, Padova, Italy, March 1993. W. Czyi: 1. Theory and PHOBOS, Workshop on Heavy Ions Interactions at Brookhaven and the PHO- BOS Experiment, High Energy Physics Department, INP Krakow, November 1993. W. Florkowski: 1. Screening Masses of Mesons in the Nambu-Jona-Lasinio Model, Institute of Physics, Jag- ellonian University, Krakow, March 1993, 2. Convective Stability of the Relativistic Hydrodynamic Flow, Institute of Physics, Jagel- lonian University, Krakow, March 1993, 3. Screening of the Meson Fields in the Nambu-Jona-Lasinio Model, High Energy Physics Department, INP Krakow, April 1993; XXXIII Summer School of Theoretical Physics, Zakopane, June 1993,

128 4. Soft Photon Production in the Boost Invariant Color Flux Tube Model, Krakow Workshop on Multiparticle Production - Soft Physics and Fluctuations, Krakow, May 1993 - invited talk. K. Golec-Biernat: 1. Shadowing at Small x, 32 Internationale Universitatswochen fur Kern - und Teilchen- physik: "Substructures of Matter as Revealed with Electroweak Probes", Karl-Franzens Universitat Graz, Schladming, Austria, February 24 - March 5, 1993, 2. Small x Physics at HERA, High Energy Physics Department, INP Krakow, March 1993. A. Horzela: 1. Galilean Covariance in Classical and Quantum Mechanics, Department of Physics, Uni- versity of Georgia, Athens, USA, March 1993, 2. On the Galilean Covariant Generalization of the Harmonic Oscillator Lie Algebra , III Wigner Symposium, Oxford, UK, 5-11 Sept. 1993, 3. On the Connection Between Classical and Quantum Mechanics , Frontiers in Fundamental Physics, Olimpia, Greece, 25-30 Sept. 1993. E. Kapuscik: 1. Physics without Physical Constants , Frontiers in Fundamental Physics, Olimpia, Greece, 25-30 Sept. 1993, 2. Galilean Covariance Revisited, Frontiers in Theoretical Physics, Edirne, Turkey, 15-21 Dec. 1993. M. Kutschera: 1. Maximum Quark Core Inside a Neutron Star for Realistic Equations of State, Institute of Physics, Jagellonian University, Krakow, April 1993, 2. Properties of Dense Hadronic Matter, Workshop on Research Programme of the Institute of Nuclear Physics, Krakow, May 1993, 3. The Equation of State of Dense Nuclear Matter, Topical Workshop on Meson Production in Nuclear Collisions, GSI Darmstadt, Germany, May 1993 - invited talk, 4. Galactic Physics I, Institute of Physics, Jagellonian University, Krakow, November 1993. J. Kwieciiiski: 1. QCD Expectation for Deep Inelastic Scattering at Small x, Workshop on HERA - the frontier for QCD, held at St. John's College, Durham, England, 21-26 March 1993 - focal talk, discussion leader, 2. QCD Expectations for Deep Inelastic Scattering and their Phenomenological Exploration at HERA, LPTHE Orsay, France, July 1993, 3. International Europhysics Conference on High Energy Physics, Marseille, France, July 1993, 4. Structure Functions at Low x, DESY Theory Workshop: "Quantum Chromodynamics", Hamburg, Germany, 29.09 - 1.10.1993. L. Lesniak: 1. Structure of the /o Mesons , Topical Workshop on Meson Production in Nuclear Collisions, GSI Darmstadt, Germany, May 1993 - invited talk, 2. Studies of the /o Mesons , Krakow Seminar of Nuclear Physics and its Applications, Institute of Physics, Jagellonian University, May 1993,

129 3. «/y# Coherent Production on Nuclei by High Energy Mesons or Photons, XIII Int. Conf. "Particles and Nuclei", Perugia, Italy, June 1993, 4. Aspects of /o Mesons, Int. Conf. on High Energy Physics, Marseille, France, July 1993, 5. Interactions of the J/# Mesons in Atomic Nuclei at High Energies, High Energy Physics Department, INP Krakow, November 1993. M. Pioszajczak: - invited talks 1. Fluctuations in Nuclear Fragmentation, Krakow Workshop on Multiparticle Production - Soft Physics and Fluctuations, Krakow, May 1993, 2. Fluctuations in Multiparticle Dynamics , n TAPS Workshop, Guardamar, Spain, June 1993, 3. Revue sur les outils nouveaux dans la recherche de la multifragmentation , Colloque GANIL, Pradet (Var), France, June 1993, 4. Fluctuations in the Fragmentation Process, XXIII Mazurian Lakes Summer School on Nuclear Physics, Piaski, Poland, August 18 - 28, 1993, 5. Fragmentation - Inactivation Binary Model - a New Model of Kinetic Sequential Fragmen- tation, Int. Workshop on Dynamical Features of Nuclei and Finite Fermi Systems, Sitges, Spain, September 13 - 17, 1993, 6. Quantum Tunneling in the Driven Lipkin N-Body Problem, Workshop on Large Amplitude Collective Motion, Institute for Nuclear Theory, University of Washington, Seattle, USA, November 1993. P. Zenczykowski: 1. Weak Radiative Hyperon Decays - Rare but Important Processes, invited talk at the Joint Theoretical and Experimental Wine-and- Cheese Seminar, Fermilab, USA, April 2, 1993, 2. Weak Radiative Hyperon Decays and Hara Theorem, invited talk at the E761 meeting, St.Petersburg Nucl. Physics Institute, Gatchina, Russia, October 19, 1993, 3. The Neutrino Affair: the Position of MSW, Institute of Physics, Jagellonian University, Krakow, November 1993, 4. Weak Decays of Charmed Baryons, Institute of Physics, Jagellonian University, Krakow, November 1993.

LECTURES AND COURSES: W. Broniowski 1. How Stiff are Hadrons ?, lectures for physics students at the Institute of Physics, Regensburg University, Regens- burg, Germany, January 1993, 2. Electromagnetic Polarizabilities of Hadrons, lectures for graduate students at the Institute of Physics, Ljubljana University, Ljubljana, Slovenia, April 1993. W. Czyi 1. Quantum Mechanics, lectures for graduate physics students at the Institute of Physics, Jagellonian University and Institute of Nuclear Physics.

130 E. Kapuscik 1. Introduction to Nuclear and Elementary Particle Physics , lectures for physics students at the Krakow Pedagogical University, Krakow 1993, 2. Classical Electrodynamics, lectures for physics students at the Krakow Pedagogical University, Krakow 1993, 3. General Properties of Space-Time, lectures for teachers of physics at the Krakow Pedagogical University, Krakow 1993. M. Kutschera 1. Introduction to Theoretical Astrophysics, lectures for students of physics at the Jagellonian University, Krakow, 1993, 2. Introduction to Physical Cosmology, lectures given at the 1993 European School of High Energy Physics, Zakopane, 12-25 September 1993. 3. Are Protons in a Neutron Star Core Polarons ? lecture given at the Institute of Physics, Jagellonian University, Krakow, January 1993. J. Kwieciriski 1. Recent Developments in Particle Physics , advanced lectures for physics teachers at the Krakowy Pedagogical University, 2. Small x Physics, lectures given at the 23nd Schladtning Winter School: "Substructures of Matter as Re- vealed with Electroweak Probes", Schladming, Austria, 24th Feb. - 5th March 1993. M. Pioszajczak 1. Fluctuations and Correlations in Heavy-Ion Collisions, Institute of Theoretical Physics, University of Catania, Catania, Italy, 27 February - 12 March 1993.

INTERNAL SEMINARS:

1. A. Blin (University of Coimbra, Portugal): Temperature Effects in the Lipkin and the Dicke Models 2. P. Bozek : Subthreshold Meson Production 3. P. Bozek : The Effect of the Cut-Off on the Multiparticle Correlations 4. O. Boyarkin (University of Grodno, Byelorussia): Probing Physics Beyond the Standard Model 5. W. Broniowski: Low-Energy Sum Rules and Nc —> oo Limit 6. M. Cerkaski: Rotational Nuclear Bands within Unitary U(3) Model 7. Z. Chylinski: Passive and Active Interpretation of Space Time Symmetries 8. P. Czerskv. The Equation of State for Nuclear Matter 9. W. Czyk Interactions of Light and Heavy Quarks with Paramagnetic Vacuum

131 10. W. Florkowski: Screening Masses of Mesons in the Nambu-Jona-Lasinio Model 11. W. Florkowski: Convective Stability of the Relativistic Hydrodynamic Flow 12. 5. Giller (University of Lodz): The Meaning of Periodic Orbits in the Quantization of Hamilton Classical Systems 13. St. Glazek (University of Warsaw): Renormalization of Hamiltonians 14. A. Gorski: Chiral Soliton Model of the Nambu-Jona-Lasinio Type 15. B. Hiller (University of Coimbra, Portugal): Static and Dynamical Properties of Mesons in the Nambu-Jona-Lasinio Model 16. M. Jezabek: Is It Worth to Construct a New Accelerator e+e~ ? 17. R. Kamiriski: Relativistic TTTT Interactions in the s-State 18. E. Kapuscik: Another Look at Maxwell's Electrodynamics 19. M. Kutschera: Maximum Quark Core Inside a Neutron Star for Realistic Equations of State 20. J. Kwiecinski: Nuclear Shadowing in Inelastic Lepton-Deuteron Scattering 21. L. Lesniakr. Searches for t-Quark 22. A. Maiecki: Unitarity Constraints of Diffraction 23. A.D. Martin (University of Durham, U.K.): Deep Inelastic Scattering 24. H. Patka: The Search of Higgs Particles in Experiments at LEP 25. M. Ploszajczak. Fluctuation in Nuclear Fragmentation 26. Ch.A. Uzes (University of Georgia, Athens, USA): Quasi-Canonical Approach to Quantum Mechanics 27. B. Wosiek: A Study of Correlation Integrals in Proton-Nucleus and Nucleus-Nucleus Interactions 28. 5. Zubik: What is the Value of the Nuclear Incompressibility Coefficient ? 29. P. Zenczykowski: Weak Nonleptonic Decays of Charmed Baryons

VISITORS TO THE DEPARTMENT:

1. Prof. J.-P. Maillet - Division de Physique Theorique, Institut de Physique Nucleaire, Orsay, France, April 1993 2. Dr. 0. Boyarkin - Department of Theoretical Physics, University of Grodno, Byelorussia, June 1993 3. Prof. A.D. Martin - Department of Theoretical Physics, University of Durham, England, June, September, October - December 1993 4. Prof. Ch.A. Uzes - Department of Theoretical Physics, University of Georgia, Athens, USA, August/September 1993

132 5. Dr. A. Blin and dr. B. Hiller- Department of Theoretical Physics, University of Coimbra, Portugal, September 1993 6. Dr. P.J. Sutton - Department of Theoretical Physics, University of Manchester, England, October - December 1993 7. Dr. A.J. Askew - Department of Theoretical Physics, University of Durham, England, October - December 1993 8. Dr. S. Riess - Department of Experimental Physics, University of Hamburg, Germany, November/December 1993 9. Dr. J. Kurzhoffer and dr. A. de Roeck- DESY, Hamburg, Germany, December 1993

133 Department of High Energy Physics PL9601061 DEPARTMENT OF HIGH ENERGY PHYSICS (High Energy Physics Laboratory)1

Head of the Department: Professor Tomir Coghen Deputy Heads: Professor Roman Hotyriski, Dr. Grzegorz Polok Secretaries: E. Bukala, D. Filipiak, D. Krzyszton and M. Mielnik telephone: (48) (12) 33-33-66 e-mail: [email protected]

PERSONNEL: Sub-department of Electronic Particle Detectors (EPD) Research Staff (26): Head: Professor Krzysztof Rybicki, [email protected] Grazyna Bak-Zalewska, Ph.D. [email protected] Andrzej Bozek, M.Sc. - research student [email protected] Pawel Briickman, M.Sc. - research student [email protected] Alfred Budziak, M.Sc. - research student [email protected] Michal Dziadus, M.Sc.Eng. [email protected] Szymon Gadomski, M.Sc. - research student [email protected] Lidia Gorlich, Ph.D. [email protected] Leszek Hajduk, M.Sc. [email protected] Zbigniew Hajduk, Ph.D. [email protected] Pawel Jalocha, M.Sc. [email protected] Bartlomiej Kisielewski, Ph.D. [email protected] Mieczyslaw Krasny, Assoc. Professor KRASNY@CHOPIN .IFJ.EDU.PL Wojciech Krupiriski, M.Sc. - research student [email protected] Tadeusz Lesiak, Ph.D. [email protected] Janusz Martyniak, M.Sc. - research student MARTYNIAK® CHOPIN.IFJ.EDU.PL Jerzy Michalowski, Eng. MICHAL0WSKI@CH0PIN .IFJ.EDU.PL Stanislaw Mikocki, Ph.D. [email protected] Ewelina Mroczko, M.Sc. [email protected] Zbigniew Natkaniec, M.Sc. Eng. [email protected] Grazyna Nowak, Ph.D. [email protected] Henryk Palka, Ph.D. [email protected] Grzegorz Polok, Ph.D. [email protected]?J.EDU.PL Maria Rozariska, Assoc. Professor ROZANSKA® CHOPIN.IFJ.EDU.PL Michal Turala, Professor (Deputy Director) [email protected] Jacek Turnau, Assoc. Professor TURNAU@CHOPIN .IFJ.EDU.PL Mariusz Witek, Ph.D [email protected]

Technical Staff (2): Andrzej Florek Boguslaw Florek

'Address: ul.Kawiory 26 A, 30-055 Krakow, Telephone: 48 (12) 333366, Fax: 48 (12) 333884, Telex: 322294

135 Experiments and International Collaborations of EFD:

DELPHI (e+e- interaction at LEP Em « lQOGeV), CERN; Geneva HI {e~p interaction 30 GeV x 820 GeV at HERA), DESY, Hamburg CRYSTAL BALL (e+e- interactions at DORIS, E^ ss lOGeV), DESY, Hamburg NA32 (ir-Cu interactions at 200 GeV), CERN, Geneva, ATLAS (Preparation of the experiment at the LHC 7 TeV x 7 TeV), CERN, Geneva

Sub-department of Experimental Elementary Particle Physics (EEPP) Research Staff (20):

Head: Professor Andrzej Eskreys [email protected] Jerzy Bartke, Professor [email protected] Przemysiaw Borzemski, M.Sc. [email protected] Wojciech Burkot, Ph.D. [email protected] Janusz Chwastowski, Ph.D. [email protected] Tomir Coghen, Professor [email protected] Jan Figiel, Assoc. Professor [email protected] Ewa Gladysz-Dziadus, Ph.D. [email protected] Jerzy Halik, M.Sc.Eng. [email protected] Zbigniew Jakubowski, Ph.D. [email protected] Marek Kowalski, Ph.D. [email protected] Bronislaw Niziol, Ph.D. Krystyna Olkiewicz, Ph.D. [email protected] Bogdan Pawlik, Ph.D. [email protected] Krzysztof Piotrzkowski, M.Sc. - res. student PIOTRZKOWSKI® CHOPIN.IFJ.EDU.PL Maciej Przybycieii, M.Sc. [email protected] Piotr Stefanski, Ph.D. [email protected] Piotr Stopa, Ph.D. STOPA@CHOPIN .IFJ.EDU.PL Maciej Zachara, Ph.D. [email protected] Leszek Zawiejski, Ph.D. [email protected]

Technical Staff (6): Lucyna Antosiewicz Bogdan Dabrowski [email protected] Piotr Jurkiewicz, M.Sc.Eng. [email protected] Maria Pieczora Anna Stobierzanin-Aleksandrowa Wojciech Wierba, M.Sc.Eng. [email protected]

Experiments and International Collaboration of EEPP: ZEUS (e~p interactions 30 GeV x 820 GeV at HERA), DESY, Hamburg E665 (/x+p interactions at 500 GeV, TEVATRON), Fermilab, Batavia, USA NA35/NA49 (heavy ion interactions on nuclear targets at 60 and 200 GeV/nucleon, SPS), CERN, Geneva ALICE (preparation of the experiment with ultrarelativistic heavy ions at the LHC 3 A TeV x 3 A TeV), CERN, Geneva

136 Geneva ALICE (preparation of the experiment with ultrarelativistic heavy ions at the LHC 3 A TeV x 3 A TeV) CERN, Geneva NA22-EHS (TT+, K+,p - p interactions at 250 GeV, SPS), CERN, Geneva WA59 (i/, v interaction at 10 - 200 GeV, SPS^ CERN, Geneva

Sub-department of High Energy Nuclear Interaction (HENI) Research Staff (12):

Head : Professor Roman Hoh/nski [email protected] Anna Dabrowska, M.Sc. [email protected] Alina Jurak, Ph.D. Dariusz Kudzia, M.Sc. Eng. [email protected] Andrzej Olszewski, Ph.D [email protected] Monika Szarska, Ph.D. [email protected] Adam Trzupek, Ph.D\ [email protected] Barbara Wilczynska, Ph.D. [email protected] Henryk Wilczynski, Ph.D. [email protected] Wladyslaw Wolter, Assoc.Professor [email protected] Barbara Wosiek, Assoc.Professor [email protected] Krzysztof Wozniak, Ph.D. [email protected]

Technical Staff (7):

Maria Brozyna Kazimiera Chudoba Janina Czajka CZAJKA@CHOPIN .IFJ.EDU.PL Witold Kita Marianna Kowalczyk Anna Lasa [email protected] Anna Polarska

Experiments and International Collaborations of HENI: JACEE (Composition, energy spectra and nuclear interactions of cosmic rays in balloon-borne emulsion chambers) KLMM (16O,28 5i,32 5 - emulsion interactions at 15, 60 and 200 GeV/nucleon) BNL-Brookhaven, CERN - Geneva KLMT ( ir~ - emulsion interactions at 525 GeV) Fermilab, Batavia, USA PHOBOS (Preparation of the experiment at the Relativistic Heavy Ion Collider 100A GeV x 100A GeV) Brookhaven, USA.

137 Electronic and Computing Group Staff (13):

Head: Assoc. Professor Piotr Malecki MALECKIOCHOPIN .IFJ.EDU.PL (Deputy Director) Jerzy Andruszków, M.Sc. Eng. [email protected] Krzysztof Cetnar, M.Sc. [email protected]' Witold Daniluk, Eng [email protected] Edward Górnicki, Eng. [email protected] Zofia Kawula [email protected] Andrzej Kotarba, M.Sc.Eng. [email protected] Bogdan Madeyski, Eng. [email protected] Paweł Małota [email protected] Arkadiusz Moszczyński, M.Sc. Eng. [email protected] Krzysztof Oliwa, Eng. [email protected] Andrzej Sóbala, M.Sc. [email protected] Artur Wolak, M.Sc. [email protected]

Participation in ZEUS, ATLAS and NA35/NA49 Collaborations.

Theory Group Research Staff (5):

Head: Professor Kacper Zalewski [email protected] Piotr Białas, Ph.D. [email protected] Stanisław Jadach, Assoc. Professor [email protected] Marek Jeżabek, Professor JEŻ[email protected] Zbigniew Was, Assoc. Professor [email protected]

Participation in HI, ZEUS, ATLAS, DELPHI Collaborations.

Mechanical and Thermal Computing and Engineering Group Staff (11):

Head: Dr. Krzysztof Pakoński [email protected] (on leave of absence, the group is presently headed by M.Stodulski, M.Sc.Eng.) Jacek Błocki, Dr.Eng. [email protected] Marian Despet Kazimierz Gałuszka, M.Sc.Eng. Jan Godlewski, M.Sc.Eng. [email protected] Marian Lender, M.Sc.Eng. LEMLER@CHOPIN .IFJ.EDU.PL Marek Stodulski, M.Sc.Eng. [email protected] Zdzisław Stopa Andrzej Strączek Mieczysław Stręk Tadeusz Wojas

138 Participation in DELPHI, HI, ZEUS, ATLAS, PHOBOS and also in R&D of LHC accelerator.

Administration: Mrs. Ewa Bukala, Mrs. Danuta Filipiak, Mrs. Danuta Krzyszton, Ms. Maria'Mielnik, M.A.

GRANTS: A. From the State Committee for Scientific Research (KBN)

1. Prof. K. Zalewski Grant No. 203809101, 1991-93 " Predictions of Standard Model for new-generation accelerators ". 2. Prof. R. Holynski Grant No. 203419101, 1991-94 " Composition, energy spectra and nuclear interactions of cosmic rays ". 3. Prof. A. Eskreys and Prof. K. Rybicki, together with Prof. J. Zakrzewski of the Warsaw University Grant No. 204209101, 1991-93 " Project HERA - experiments ZEUS and HI ". 4. Dr A. Zalewska, together with Prof. R. Sosnowski and Dr K. Doroba of the Institute of Nuclear Studies, Warsaw Grant No. 209639101, 1991-93 " Participation in DELPHI experiment ". 5. Prof. J. Bartke, together with Prof. E. Skrzypczak of the Warsaw University Grant No. 204369101, 1991-94 " Collisions of relativistic nuclei ". 6. Prof. R. Holyriski Grant No. 203799101, 1991-94 " Study of nucleus-nucleus interactions at highest accelerator energies ". 7. Prof. S. Jadach Grant No. 223729102, 1992-94 " Predictions of Standard Model for future colliders ". 8. Assoc. Prof. J. Figiel Grant No. 2P30204104, 1993-94 " Investigation of muon-nucleon and muon-nucleus interactions at the TEVATRON (experiment E665) ". 9. Prof. T. Coghen Grant No. 2P30215104, 1993-95 " Participation in the PHOBOS experiment: study of correlations and fluctuations of low

pt particles produced in heavy ion interactions in the future RHIC collider at BNL ". 10. Dr Eng. K. Pakonski Grant No. 3P40700604, 1993-96 " Technology of manufacturing extremely stiff thin shells made of carbon-carbon composites ".

139 11. Prof. M. Turala, together with Prof. D. Kisielewska of the School of Mining and Metal- lurgy, Krakow, and Prof. J. Krolikowski of the Warsaw University Special grant No. 115/E - 343/SPUB - 206/93, first part of the three-years' project " Preparation of the physics programme and detectors for studying proton-proton interactions at 16 TeVin the LHC collider ". B. From the Polish-German Foundation

1. Prof. A. Eskreys and Prof. K. Rybicki, together with Prof. D. Kisielewska of the School of Mining and Metallurgy, Krakow, and Prof. J. Zakrzewski of the Warsaw University Grant No. 506/92, 1993-95 " Experiments ZEUS and HI at the HERA collider in DESY ". 2. Prof. J. Bartke, together with Prof. E. Skrzypczak of Warsaw University Grant No. 565/93/LN, 1993-95 " Experiment NA49 with ultrarelativistic heavy ions at the CERN SPS ".

OVERVIEW: The Department originated from a group of cosmic ray and high energy physicists created by the late Prof. M. Mifsowicz in the early fifties. This group consisted of people originally employed and housed in the Academy of Mining and Metallurgy. In 1955 some of them were transferred to the so-called Krakow Branch of the High Energy Physics Department of the In- stitute of Nuclear Studies in Warsaw, which rapidly increased in number and in 1970 became a Department in the Institute of Nuclear Physics in Krakow. The Department is located in a separate building in the campus of the Academy of Mining and Metallurgy, which facilitates the close collaboration with research groups from the latter as well as with the theorists from the Jagellonian University. Joint weekly seminars represent a more than 30-years old tradition of this high energy physics community, where theorists from the Department of Theoretical Physics of our Institute also play an important role. On April 5, 1993 the first anniversary of the decease of Prof. Mi§sowicz, who for 37 years was the leader of the high energy physics community in Krakow, agreement was signed by representatives of the Academy of Mining and Metallurgy, the Jagellonian University and the Institute of Nuclear Physics to honour his name by forming the M. Mifsowicz Centre for High Energy Physics in Krakow. In 1993, the research in the Department continued to cover a variety of problems of experimental and theoretical high energy elementary particle physics: hadronic and leptonic interaction with nucleons and nuclei, mainly characteristics of particle production, including heavy quark physics, e+e~ interactions and tests of the Standard Model (also evaluation of radiative corrections), ultrarelativistic heavy ion interactions and search for the quark-gluon plasma, as well as spectra, composition and interactions of high energy cosmic ray particles. Research and development of apparatus for high energy physics experiments at future accelerators such as LHC or RHIC were also carried out. The experiments in which the Department participates are mainly carried out within the framework of large international collaborations formed at leading laboratories where large accelerators have been or will be constructed: the European Centre for Nuclear Research CERN in Geneva, DESY in Hamburg, Brookhaven National Laboratory and Fermilab, Batavia in the USA, with relatively more engagement in European laboratories. In 1993 this work brought the publication of further very interesting results from the e+e~ experiment DELPHI at CERN and gave first physics results from the e~p experiments HI and ZEUS at DESY. Important results

140 which the reader can find in the following pages have also been obtained by other experiments and our theorists. An important part of the activity of the Department was teaching and training of students both from the University and the Academy of Mining and Metallurgy on the master's and PhD level. This is possible owing to the vicinity of the Department site to the university campus. In addition to the staff listed above some task teams working on certain projects, e.g. DELPHI, ZEUS and the future ATLAS experiment also include people belonging to various departments of the Institute of Nuclear Physics and other institutions forming the M. Mie,sowicz Centre for High Energy Physics. On December 31, 1993 the staff of the Department was 106, including 6 PhD students. J Prof. T. Coghen

141 REPORTS ON RESEARCH: PL9601062 The DELPHI experiment at LEP 1 The DELPHI Collaboration 2

Kraków DELPHI group: P. Briickman, A. Budziak, Z. Hajduk, P. Jalocha, K. Korcyl, W. Krupiriski, W. Kucewicz, T. Lesiak, J. Michałowski, B. Muryn, G. Polok, H. Pałka, K. Rybicki, M. Witek, A. Zalewska physicists, engineers and technicians contributing to the project: A. Adamski, J. Błocki, M. Despet, A. Florek, B. Florek, K. Gałuszka, T. Gdański, J. Godlewski, P. Gruszecki, W. Sosnowski, M. Stodulski, Z. Stopa, A. Strączek, M. Stręk, M. Turała

DELPHI (Detector for Electrons, Leptons, Photons and Hadrons Identification) is one of four multi-purpose detectors installed at the LEP accelerator at CERN. It serves to study e+e~ interactions at the energies close to the mass of the Z° boson. In 1993 LEP was working since May till November. During this time about- 800,000 Z° events have been collected by the DELPHI detector. Data corresponding to 16.3723 pb^1, 9.4294 pb'1 and 9.4753 pb—1 have been taken at the Z° peak, 2 GeV below the peak and 2 GeV above the peak, respectively. It is expected that the Z° energy scan and high precision measurements of the beam energy performed this year should give a reduced error of 5 MeV for both the Z° mass and the Z° width determinations. A total number of about 2,200,000 Z° particles has been collected by DELPHI since the LEP startup in 1989 till the end of 1993. The analysis of the data taken since 1990 till 1992 resulted in about 20 publications and in tens of conference contributions. They cover a wide range of physics: precise tests of the electroweak interactions, search for new particles, e.g. Higgs bosons and excited quarks, tests

'work of Polish groups partially supported by the giant 2 09 63 91.01 of the State Committee for Scientific Studies 2Iowa State University, Ames, USA, Univ. Instelling Antwerpen, Wilrijk, Belgium, ULB-VUB, Brussels, Belgium, Univ. de l'Etat Mons, Mons, Belgium, University of Athens, Athens, Greece, University of Bergen, Bergen, Norway, Università di Bologna and INFN, Bologna, Italy, Collège de Prance, IN2P3-CNRS, Paris, France, CERN, CH-1211 Geneva 23, Switzerland, Centre de Recherche Nucléaire, IN2P3 - CNRS/ULP, Strasbourg, France, Institute of Nuclear Physics, N.C.S.R. Demokritos, Athens, Greece, Last, of Physics of the C.A.S., Praha, Czechoslovakia, Università di Genova and INFN, Genova, Italy, Institut des Sciences Nucléaires, IN2P3- CNRS, Université de Grenoble 1, Grenoble, France, Research Institute for High Energy Physics, SEFT, Helsinki, Finland, Joint Institute for Nuclear Research, Dubna, Russian Federation, Universität Karlsruhe, Karlsruhe, Germany, Institute of Nuclear Physics, Krakow, Poland, Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil, Lab. de l'Accélérateur Linéaire, IN2P3-CNRS,Orsay, France, University of Lancaster, Lancaster, UK, LIP, Lisboa, Portugal, University of Liverpool, UK, LPNHE, IN2P3-CNRS, Universités Paris VI et VII, Paris, France, University of Lund, Lund, Sweden, Université Claude Bernard de Lyon, IPNL, IN2P3-CNRS, France, Universidad Complutense, Madrid, Spain, Univ. d'Aix - Marseille II - CPP, IN2P3-CNRS, Marseille, France, Università di Milano and INFN, Milan, Italy, Niels Bohr Institute, Copenhagen, Denmark, Charles University, Praha, Czechoslovakia, NIKHEF-H, Amsterdam, The Netherlands, National Technical University, Athens, Greece, University of Oslo, Oslo, Norway, University of Oxford, Oxford, UK, Università di Padova and INFN, Padua, Italy, Pontificia Univ. Católica, Rio de Janeiro, Brazil, Rutherford Appleton Laboratory, Chilton, UK, Università di Roma II and INFN, Rome, Italy, Centre d'Etude de Saclay, France, Istituto Superiore di Sanità, INFN, Rome, Italy, Universidad de Santander, Santander, Spain, Inst, for High Energy Physics, Serpukow, Russian Federation, University of Ljubljana, Ljubljana, Slovenia, University of Stockholm, Stockholm, Sweden, Università di Torino and INFN, Turin, Italy, Università di Trieste and INFN, Trieste, Italy, Università di Udine, Udine, Italy, University of Uppsala, Uppsala, Sweden, IFIC, U. de Valencia, Valencia, Spain, Institut für Hochenergiephysik, Österr. Akad. Wissensch., Vienna, Austria, Inst. Nuclear Studies and University of Warsaw, Warsaw, Poland, University of Wuppertal, Wuppertal, Germany.

142 PL9601063 of quantum chromodynamics, studies of the quark hadronisation processes. A growing interest in heavy flavours physics could be observed. Almost a half of the DELPHI publications and conference contributions in 1993 concerned the latter topics. The Krakow group participated in two studies of baryons containing the 6 quark, namely the Aj, and the H(>. They are discussed below as separate contributions. Apart from the data analysis, the Krakow DELPHI group has helped during the data taking period and was co-responsible for three subdetectors: the Microvertex Detector, the Inner Detector and the Ring Imaging Cherenkov detectors (RICH). The data acquisition, the safety of the detector, the quality of the data and the data processing had to be controlled during runs. The Krakow group had more than 50 shifts, participating in first three kinds of controls. Last year was crucial for the Microvertex Detector. An almost completely rebuilt detector should be installed in the experiment in 1994. This is a part of an even bigger upgrade forseen in 1995. The Krakow group has contributed to the Microvertex project by testing some of silicon detectors, building reinforcement bars for one of its layers, working on the data acquisition and the online analysis programs and working on the detector simulation programs. The group took also part in running the actual Microvertex Detector and preparing it for the data taking. A description of.the detector upgrade and more informations concerning the work for it is given below as a separate contribution. The Inner Detector is a common responsibility of the DELPHI group from the NIKHEF Institute in Amsterdam and of the Krakow DELPHI group. Our group was preparing both the detector and the data acquisition programs for running, took shifts during runs and helped in the calibration of the detector using collected data. The Inner Detector is very useful for studies of the accelerator background. Results of these studies are described in a separate contribution. In 1993 the Forward RICH detector has been completed and has been working with an efficiency of about 50 % averaged over the whole period of the data taking. The Krakow group has contributed by helping in preparations of the detector for runs, by working on the detector programs and the data and by building the special setup for tests of elements of the RICH detectors outside the experiment. The Forward RICH detector is presented below in a separate contribution.

Measurement of A& production and lifetime in Z° hadronic decays T. Lesiak

This analysis was devoted to a study of the production rate as well as of the lifetime of the A& baryon. Its results have been presented at the XXVII International Conference of High Energy Physics in Marseille [1] (August 1993) and are intended to be published in Physics Letters B. Part of the analysis was done in Krakow as the continuation of earlier study based on a smaller amount of data [2]. The A(, particle, made from the u, d and 6 quarks is believed to be the lightest of baryons containing the b quark. Better knowledge of its properties would provide deeper understanding of the quark fragmentation and of the weak decay of the b quark. The Aj, candidates were searched for demanding two high-momentum particles from its semileptonic decay: the lepton itself (with p\ > 3 GeV) and the A0 (with p^ > 4 GeV), where the baryon number of the latter was opposite to the charge of the former (the so called right-sign pairs; by wrong-sign pairs we understand pairs with the same sign of the lepton charge and the baryon number of A0). Due to large mass of the b quark only leptons with high transverse momentum (pf > 0.6 GeV) with respect to the jet containing the lepton and A0 were selected.

143 This study needed tracking devices of the DELPHI detector (the microvertex, the inner detector, the time projection chamber, the outer detector and the forward tracking chambers) and the RICH detectors used to identify protons from the A° decays. The data taken between 1990 and 1992 amount to a total number of 1 134 000 hadronic events. Lepton detection was based on the muon drift chambers and on the high-density projection chamber. Muons and electrons were selected with the efficiences of (90±l) % and (80±3) %, respectively. A0 hyperons were tagged by their decay into proton and pion yielding secondary vertices formed by pairs of oppositely charged particles. A sample of (2000 ±43) A0 —• pir decays for the A0 momentum greater than 4 GeV has been collected. The selection efficiency of A0 was found to be equal to (16 ± 3) %. Selected leptons and A0 baryons were then coupled demanding that the invariant mass of the lepton-A0 pair was between 2.0 and 6 GeV. This was intended to get rid of the background coming from the semileptonic decays of B meson and of the Ac baryon as well as from accidental combinations. The (pir) invariant mass distribution for the right- and wrong-sign combinations for muon and electron channels, respectively are shown in Fig. 1. We observe an excess of (92 ± 15(stat.) ± 15(syst.)) entries in the right-sign combinations (after subtracting the corresponding entries in the wrong-sign combinations) in the range 1.106 GeV < M^ < 1.126 GeV. Prom this value

Delphi 1990+91+92 data ~O 50 ihd MM 7 IT "o 50 F_ n mx* a) ; b) n \.\\% N « I 40 40 -

in 30 w 30 0) A" At" «> Ae I 20 I 20 [ A ' " 10 10 Liu ri i i I i i i • I • i i i I i i • i 1 • iTi 0 0 1.1 1.125 1.15 1.175 1.2 1.1 1.125 1.15 1.175 1.2 m(p TT) (GeV/cl) m(p n) (GeV/c2)

™(j 50 O 50 - \ c) I 4°

^m" 30

"c 20

0 1.1 1.125 1.15 1.175 1.2 1.1 1.125 1.15 1.175 1.2 m(p n) (GeV/c2) m(p n) (GeV/c*)

0 Figure 1: Distribution of the pr invariant mass for A 1 candidates correlated to high pt muons and electrons in the same jet. and from the total efficiency of (3.8±0.9) % and (2.4±0.5) % for the muon and electron channels, respectively, we determine the product of the probability of the fragmentation of the 6 quark into A{, baryon and the branching fraction for the decay A& —• \°lviX as:

f{b -* A*) x BR(Ab -> A%X) = (0.32 ± 0.06 ± 0.08) % (this result is obtained assuming lepton universality; the results in the muon and electron chan-

144 I PL9601064 nels are 0.30 db 0.06 ± 0.08 and 0.35 ± 0.09 ± 0.09, respectively). The measurement of the A;, lifetime was based on the reconstruction of the secondary vertices formed by the lepton, the A0 and particle of the opposite charge to that of the lepton (this particle was assumed to be a pion resulting from the A+ -* A°n+X decay). The A& momentum estimate needed to compute the lifetime from the measured decay length was obtained by the 'residual- energy' technique described in ref. [3]. For the lifetime analysis only the muon sample has been used and 44 decays have been reconstructed out of 147 right-sign A°/i events. A maximum likelihood fit to the lifetime distribution of these 44 decays resulted in the lifetime value for the At of rAfc = (0.68±S;|S ± 0.13) ps. Thus the A;, lifetime is shorter than that of B mesons, for which r « 1.6 ps. This indicates the presence of the W exchange diagram in addition to the spectator one.

References

[1] F. Bianchi, U. Gasparini, T. Lesiak, P. Zalewski: "Measurement of beauty baryons production and lifetime in in Z° hadronic decays", DELPHI 93-88 PHYS 192, contribution to the XXVII International Conference of High Energy Physics, Marseille, August 1993. [2] DELPHI collaboration, "Measurement of A& production and lifetime in Z° hadronic decays", Phys. Lett. 31 IB (1993) 379. [3] DELPHI Collaboration, "A measurement of B mesons production and lifetime using D- lepton events in Z° decays". Zeit. Phys. C 57 (1993) 181.

Production of the S& hyperon at LEP B. Muryn

The search of "beauty" baryons seems to be very important since it provides a knowledge on the hadronisation mechanism and extends spectrum of known hadrons containing "beauty" quark b. An observation of the the A^ baryon via its semileptonic decay and A°-lepton correlations was a stimulation for a similar analysis of Ef, hyperons using mainly their semi-inclusive decays [1],

Here muon fi was emitted in b —» cpv transition and the charge symmetric reactions with E+ production were also investigated. We have looked for E±s decaying both inside and outside of the Vertex Detector (VD). In the first case only the S± decay products could be measured by VD. In the second case the S± track itself was searched for in VD. Tracks having three VD hits not associated with measurements done by other tracking detectors were considered as 3* candidates. In both cases the tracking detectors outside the Vertex Detector provided measurements of the E^ decay products. In the next step only events with lepton originating from Sj, decay were selected. This was possible due to standard cuts on the energy and transverse momentum of leptons calculated with respect to the flight line of the 3^ baryon. Such a sample has been analysed and divided according to two types of S^-lepton correlations. Events with S and lepton having the same

145 1 PL9601065 signs of the electric charge (right combination) were taken as good H& candidates, whereas those with opposite signs ( wrong combination) were considered to be a background. The comparison of both samples shows that they are different (see Fig. 1, a and b). For the right charge combination one can see a peak at the E* mass position (see Fig. 1 a). The corresponding mass distribution for the wrong charge combination (background) does not show such a property (see Fig. 1 b). This difference can be explained by E& hyperon production.

~ 9 9 \ ' L r P.(A)> 1.2 GeV 3 ;jt 7 i. r——i (~ji-).(?.^*) M(Z./i)> 2 GeV 7 L mm (r.^).(r./i-) \. 6 r m 5 r 4 r 1 'Ii 3 B 2 - i—i 1W 2 9m i I • r If l.n , n 1 0 1.05 '/./' i./i 7.2 /.2J U 1.35 1.4 1.45 1.5 ' '05 1.1 1.15 1.2 1.25 1.3 US 1.4 1.45 1.5 M(\n) (CeVlc2) M(\x) (GcV/c!)

Figure 1: a,b

References

[1] S. Plaszczynski, P. Roudeau, A. Stocchi (LAL Orsay)( B. Muryn (Krakow), Search for Strange-B baryon production at LEP, DELPHI 93-92, contribution to the XXVII Interna- tional Conference on High Energy Physics, Marseille, August 1993.

Upgrade of the Microvertex Detector J. Blocki, P. Bnickman, T. Gdanski, J. Godlewski, P. Jalocha, W. Kucewicz, J. Michalowski, B. Muryn, H. Palka, A. Zalewska

The DELPHI Microvertex detector provides high precision measurements of track position in the plane transverse to the beam. It evolved from a two layered detector installed for the Delphi start-up in 1990, to the three layered set-up with a smaller diameter beam pipe, in operation since 1991 till now. Its ability to measure three points on a track precisely and close to the primary vertex, is of great benefit in the reconstruction of tracks and vertices and enables detailed studies of heavy quarks and a r lepton. The present Microvertex detector measures tracks with polar angles above 45° with respect to colliding beams. The DELPHI Collaboration decided in 1992 to increase tracking capabilities of the whole detector and to extend them down to small polar angles. These changes are vital in order to meet requirements of physics program of high energy phase of LEP (LEP200). The main physics motivation is to improve the b quark tagging capabilities and to increase the efficiency of the searches for Higgs bosons. The modifications concerning the silicon tracker include : • rebuilding of the Microvertex detector by replacement of single sided silicon detectors by double sided detectors allowing track reconstruction in space and an extension of the layers to cover polar angles down to 25° (the Forward Microvertex Detector or FMD) • the addition of three layers of silicon detectors covering the angles between 15° and 25° (the Very Forward Tracker or VFT)

146 The Krakow DELPHI group participates in the FMD part of the upgrade. The FMD project proceedes in two stages. In the first stage, which will be ready for 1994 runs, the outermost layer and the closest layer are being equipped with double sided detectors and the length of the closest layer is extended from 22 cm to 28 cm. A schematic view of the FMD'94 is shown in a Fig. 1. In the second stage (to be operational in 1995) , the middle layer will be equipped with double sided detectors and the length of both outer and inner layers will be extended from 24 cm to 48 cm .

-5

-0

—5

Figure 1: A schematic vue of the barrel part (FMD) of the upgraded (1994) Microvertex detector (plotted from the database)

The use of double sided detectors arranged in long layers required thorough tests and strict selection criterias to be applied on the quality of the detectors used. The selected detectors had to pass acceptance criteria based on parameters of the detector which are vital for a performance of the set-up. The criteria included limits on the total leakage current from the active area, the depletion voltage, the coupling capacitance, the resistivity of polysilicon resistors, the number of pinholes in in the coupling oxide and the number of defective channels in the active area. More than 100 detectors have been tested in four collaborating laboratories, and 30 of them in Krakow. A special attention has to be paid to the mechanical construction of the detector, to achieve the precision close to the intrinsic precision of the silicon. The detector modules should be rigid enough and the amount of the material introduced by the construction should be minimal. The second constraint is especially important in the case of the closer layer support because this layer measures the first point on the track. The supports for the closer layer modules have been designed and constructed in Krakow. The stiffening of the modules was achieved via V-shaped kevlar beams which ensure the module deflection of 2.2 /xm per a gramm of load, while the additional material constitues 0.1% Xo . The hardware contribution of the Krakow group to the upgrade includes also redesign and construction of voltage supplies as well as participation in the assembly of modules. In parallel to hardware efforts, we were active in a software development needed for the new detector for data taking in 1994. The Monte Carlo simulation program has been adapted to the new set-up, the database for the detector has been coded and the on-line software has been changed accordingly.

147 PL9601066 The Synchrotron Radiation measurements in the Trigger Layers of the DELPHI Inner Detector Z. Hajduk, M. Witek

Trigger Layers (TL's) axe 5 cylindrical, concentric MWPC with 192 sensitive wires per plane and the cathodes made of solid copper foil of 17.5 /zm. The electronics can measure charge collected by wires using FADC (flash-analogue-to-digital-converter) which samples input pulse every 75 ns. Thus the electronics has some crude time measuring properties. Studying the old literature [1] on proportional counters sensitivity to gamma rays, we find that TL's are ideally suited to photon detection (in X-rays range) having walls of relatively heavy material which serves as converting medium for photons and being thin enough to allow knocked electrons escape into the gas volume. LEP synchrotron radiation has critical energy of 100 keV with mean energy around 60 keV. We have used TL's as synchrotron radiation monitor to set absolute scale for Monte Carlo programs used by machine people to estimate the synchrotron radiation background. The data have been taken at the end of physics run with stable beam conditions. We have taken runs with fully random trigger running synchronously with LEP BCO changing position of 8 m horizontal collimators. Data have been written to tape using the standard DELPHI data acquisition system. To make the Inner Detector less sensitive to possible minimun ionizing particles accompanying photons we have risen the proper thresholds in electronics in such way that efficiency for MIP's has dropped to 20-25%. The detectors have been run on full nominal voltages. We believe this arrangement to have good efficiency for photons since the ionization should be an order of magnitude higher than for MIP's. Later the data have been analysed by standard Inner Detector monitoring program modified to be sensitive to pointlike events. We have estimated that the efficiency of our detector to X-rays in LEP region is around 0.2 % per layer. Once again, the boosting factor quoted in literature [1] for multilayer photon counter is estimated to be around 4 for five layers counter. Recently we have used an EGS [2] program to evaluate the efficiency of our setup to X-rays by Monte Carlo method. We have obtained a value of 1.2 % which is slightly higher than the previous one. This difference can be easily explained by the fact that the Monte Carlo method has taken into account the real spectrum emitted by LEP and different incident angles of incoming photons. Thus for further calculations we have taken the value of 1.2% as Trigger Layers efficiency for synchrotron radiation photons seen at TL's radii. Figure 1 shows a comparison between measured and simulated [3] frequencies. The character of changes is very well reproduced. The higher values of measured frequencies (exceeding those of Monte Carlo) can be attributed to the fact that the MC program has been using idealized orbit which crosses magnetic field of the quadrupoles at 'zero' angle. The real orbit hardly does that and so the passage through quadrupoles consists another source of synchrotron radiation. The timing properties of the Trigger Layers have been used to estimate the contribution to the background from various places along the beam pipe where photons can be scattered and reflected. The measurement has been done with a single positron beam. Figure 2 shows the results. 'DIRECT ' line indicates time of the photons arriving together with the beam (drift time in th TL's is around 150 nsec). Another line shows expected arrival time of the photons reflected from the collimators laying 'downstream?. We see that appearing maxima of the spectrum correspond to different position of the reflecting collimator. From the presented results we see that Trigger Layers proved to be very useful tool for the monitoring, calibration and timing measurements of synchrotron radiation background.

148 K Kr«et photons - MC • Seotterad photons - MC « Trigger tay»r» - manured

Cottmatort qpaung (

Figure 1: Frequencies of the synchrotron radiation photons; measured and simulated (MC).

T»B» Ottlttifen •( »R photon h TL (unl -7»rw«!

4 r nil 1 L. II n /[pi kfil • til nK [SJI i it 4 M ••

m - » r 1 •-"•nJL_( 10 ,4 M M li •< «.

t u r Jll . ...nrt L ^ M *• ii N M to ID m •

10 r 1 I J iitn. . . JTIl . II . kjl I It H 10 I tt » OflECf MJmHctfo&xvr&nam dosed, M"""v-fl?v. *****

Figure 2: Time distribution of the synchrotron radiation photons for different settings of the collimators.

149 PL9601067 References

[1] E. Fünfer, H. Neuert - Zahlrohre und Szintillationzahler, Verlag G. Braun, Karlruhe 1946. [2] The EGS4 - code system - W.R. Nelson et al. SLAC - 265 Dec 1985 [3] Georg von Holtey - Monte Carlo simulations of synchrotron background at LEP ( private communication).

The FRICH detector A. Budziak, A. Florek, B. Florek, J. Michalowski, G. Polok

FRICH (Forward (Backward) Ring Imaging Cherenkov) is a part of the particle identification system of the DELPHI detector [1], [2]. It is used for a hadron identification over most of the momentum range up to 40 GeV/c by Cherenkov angle reconstruction. The RICH system covers almost the full solid angle. It consists of two end-cap detectors (together reffered to as FRICH) and a detector of cylindrical geometry in the central region, the Barrel RICH. Forward RICH covers the polar angles 15° < 0 < 35° and 145° < 0 < 165°. Geometry of Forward RICH is totally different from the Barrel RICH but exploited principles are exactly the same. Cherenkov photons in Ultra Violet (UV) range from both liquid and gaseus radiators are detected by Time Project Chamber sensitive to single photons. The RICH counters are not stand-alone instruments. They rely on tracking detectors for the determination of particle momenta, as well as for the measurement of track coordinates. In the case of Forward RICH the necessary particle tracking information is obtained from the forward tracking chambers. Up to 0 = 20°(160°) central tracking detectors are contributing significantly to particle information. From the photon coordinates measured in the TPC plane, emission angles with respect to particle tracks are reconstructed. For a given particle momentum, various mass hypotheses are tested against the observed number of photons and the distribution of Cherenkov angles of individual photons. Geometrically both (forward and backward) detectors are placed ±1720 mm from interaction point (front faces) and extend 940 mm along beampipe. The full description of the design of the detector and of its readout system can be found in the references [1], [2]. The Kraków group has a substantial contribution to the construction of the FRICH. Photon detectors (drift boxes), main vessels and support tubes were designed, prototyped and produced by the Kraków group. Our group has also been involved in a prototype work for the single photon sensitive TPC and many solutions found in Kraków are now in general use. Details concerning the construction of these parts of the FRICH can be found in [2]. In 1993 the main hardware effort of the Kraków group was the production of a test drift box for the RICH detectors. The test box has been contracted in Kraków and then equipped and tested at CERN. This device simulates in a smaller scale one sector of the RICH detector. It consists of a photon detector, a pocket for the multiwire proportional chamber, a high voltage degrader-vessel and a calibration system. A drift volume of the photon detector has a lenght of 170 mm. It is closed by quarc windows, 5 mm thick. They enable a penetration of the UV photons starting from a wave length of 160 nm. Dimensions of the pocket for the chambers have been adjusted to enable tests of the multiwire proportional chambers used in the experiment with a full access to their preamplifiers. The calibration system provides the UV photons of a known wave length in a region of the photon detector. Apart from the tests of the chambers the test box will serve for studing different gas mixtures, drift velocities and calibration systems.

150 In 1992 one quarter of the FBICH was installed and took first data. In 1993 FRICH was fully operational and data for about 400k Z° events were taken. Some preliminary results have been presented on a few conferences and schools ( e.g. Dallas 92, BARI 93). The fact that the magnetic field (1.2 Tesla) in the Forward RICH is not parallel to the electric field responsible for drifting and a conciderable background due to the secondary processes in a material of the end-plates of the barrel detectors seriously complicate the FRICH data analysis. Measurements of the resolutions in Cherenkov angle based on high energy muons from the reaction e+e~ —v fi+fi~ indicate both for liquid and gas radiators that values close to the simulated prediction will be obtained once alignment and calibration procedures become perfect. In each of the two radiators media the number of detectable photons is about 8 for tracks at /3 « 1. In analysing multi-track hadronic Z° events in real data, the true particle identification is in general unknown. Fig.l from [2] shows preliminary results of the data analysis for hadronic Z° decays, obtained with the liquid radiator. A clean separation between pions, kaons and protons is realized. Obtaining a better calibration of the Forward RICH, a better alignment and a more efficient reconstruction of charged tracks in the forward regions of DELPHI require further studies. Solving these problems will allow us to really use the 1993 Forward RICH data for the particle identification.

mean Cerenkov angle - liquid

Figure 2: Liquid radiator data: mean Cherenkov angle as a function of particle momentum. The angles shown are the unambiguous result of a set of robustified least squares estimates. The fit used photons in a 5

References

[1] W. Adam,..., A. Budziak, A. Florek, B. Florek, K. Gahiszka, J. Michalowski, K. Pakonski, G. Polok, M. Stodulski, Z. Stopa, M. Turala et al., Performance of the Forward RICH Detector System at DELPHI - IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 40, NO.4 AUGUST 1993, 583-588 [2] W. Adam,..., A. Budziak, A. Florek, B. Florek, K. Gahiszka, J. Michalowski, K. Pakonski, G. Polok, M. Stodulski, Z. Stopa, M. Turala et al., The Forward Ring Imaging Cherenkov detector of Delphi, CERN-PPE/93-154, Nucl. Instr. and Meth. ...

151 PL9601068 The HI Experiment at HERA The HI Collaboration 1

During 1993 the HI experiment collected about 530 nb'1 of high quality data at electron- proton collider HERA in DESY/Hamburg. The data from 1992 corresponding to an integrated luminosity of 22.5 nft"1 has been analysed and the results presented in eleven publications [1]- [11], three of which were restricted to detector performance. In the next entry of this report we present results of the HI collaboration on the first measurement of the proton structure function and soft parton distributions [6],[11] in the low x region. Also the topic of multi-jet rates in deep-inelastic scattering (DIS) will be covered [10]. Members of the HI Krakow group have participated in the analysis of data and significantly contributed to activities of the following physics working groups: • DIS working group • heavy quark group • radiative corrections group They have also participated in the HI run shifts. The Krakow contribution to physics analysis and the HI detector upgrade covers several topics: • Preliminary studies of local parton density fluctuations ("hot spots") at low x, based on the ideas of Muller [12], have started with the data collected in 1993. The clear signature of the "hot spot" process is the production of a high energy jet in the particular kinematic region. The event topology with the associated jet very close to the beampipe in the proton beam direction represents a real experimental challenge. Using the simulated data, detailed studies of the selection and identification criteria for this process have been performed. The contribution of beam induced and photoproduction background has been estimated. In the restricted kinematic region we observe in the 1993 data more jets indicating the Lipatov behaviour than in Monte Carlo simulation. Prospects for tests of Lipatov behaviour in DIS and (with more statistics) a direct search for "hot spots" are very promising. This problem was vividly discussed during a workshop (1-6.12.1993) organized in our institute by the Department of Theoretical Physics and the Hi Krakow group. This workshop was generally devoted to theoretical and experimental aspects of low x physics at HERA. Physicists from Krakow, DESY, Durham and Warsaw, participated in this meeting. • The gluon distribution in proton at small x can be extracted from DIS data using the measurement of heavy flavour production. The possibility of charm particles detection

'Krakow HI group: L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. MikockiyE. Mroczko, G. Nowak, K. Rybicki and J. Turnau. engineers and technicians contributing to the project: E. Banas, A. Cyz, B. Dulny, M. Dziadus, J. Godlewski and W. Janczur. Participating institutions: Antwerpen Univ., Univ. of Birmingham, Brussels Univ., CEN Saclay, Davis Univ., DESY, Dortmund Univ., Ecole Polytechnique (Palaiseau), ETH (Zurich), Glasgow Univ., Hamburg Univ. (1. and 2. Institute), Heidelberg Univ., Inst. of Nuclear Physics (Krakow), Institute of Physics (Prague), Institute of Experimental Physics (Kosice), DESY - Institut fur HEP Zeuthen, INFN Roma, Kiel Univ., Lancaster Univ., Liverpool Univ., Lund Univ., Manchester Univ., ITEP (Moscow), Lebedev Physics Institute (Moscow), MPI (Miinchen), LAL Orsay, P.& M. Curie Univ. (Paris), Queen Mary and Westfield College (London), RWTH Aachen (1. and 2. Institute), Rutherford Appleton Lab., SLAC (Stanford Ca), Wuppertal Univ., Zurich Univ.

152 by tagging an electron from their semileptonic decay has been studied. Electron identification method based on electromagnetic shower characteristics in the HI liquid argon calorimeter and dE/dx information from tracking detectors has been developed. Further optimalization of the detection technique and studies of b quark decays are foreseen. • In 1993 the LAL-Krakow project of the topological second level trigger has been pursued. The contribution of the Krakow group included Monte Carlo tests of the trigger efficiency, the upgrade of the trigger simulation program to real, working conditions of the HI detector, as well as the design and preliminary programming of the trigger monitor system.

Deep Inelastic Scattering at Low x The data collected with the HI detector in 1992 during the first year of HERA running correspond to an integrated luminosity of 22.5 nb~l . The HI detector description can be found in the previous Annual Report. The analysis of the neutral current deep inelastic e-p scattering (NC-DIS) allows the first measurement of soft parton distributions in proton [6],[11] and studies of the hadronic final states [10]. At HERA, where 26.7 GeV electrons collide with 820 GeV protons, one can study NC-DIS of an electron off the proton constituents carrying a very small fraction x of the proton momentum. For the first time values of the x Bjorken in the range x % 10~4 — 10~2 can be measured in the DIS regime (Q2 > bGeV2). The proton structure function can be probed at distances which are ten times smaller than those previously accessible in the fixed target experiments. The kinematics of the inclusive neutral current reaction ep —y eX at fixed centre of mass energy y/s is determined by two variables usually taken as x, the Bjorken scaling variable and Q2, the negative four-momentum squared from the electron to the proton. According to the relation Q2 = sxy both are related via the relative energy transfer y. In the NC-DIS events the final state consists of the scattered electron and the hadronic final state . The HERA experiments simultaneously measure the scattered electron and reconstruct the hadronic final state therefore the kinematic variables can be determined using either energy and angle of the scattered electron or of the hadronic system or a combination of both. In this analysis the event kinematics is calculated by two methods which are very different with respect to systematic uncertainties and therefore allow an important cross-check of the final result. In method I we use the electron variables ( the energy and the polar angle of the scattered electron ) and in method II the mixture of the hadron measurement of y and the electron measurement of Q2. These methods differ substantially not only in the dependence on systematic effects but also in the size of radiative corrections, in the event selection and in the accessible kinematic range of

This analysis is restricted to the low x region and to 5eV2 < Q2 < 80eV2. In the Q2 region under consideration the scattered electrons are detected in the backward electromagnetic calorimeter (BEMC). The events were triggered by requiring an energy cluster with more than 4 GeV deposited in the BEMC and no time of flight veto from the scintilator hodoscope TOF installed behind the BEMC. In total we have recorded ss 5 X 105 events which are dominated by beam-induced background and photoproduction. A clean sample of DIS candidates is selected offline using more stringent criteria on the scattered electron candidates, the suppression of beam induced and photoproduction background. The final data sample comprises about 1000 events. In the region of low Q2 (Q2 << M2) the cross section for NC-DIS is expressed in terms of the structure function F^ and the photoabsorbtion cross section ratio of longitudinally and

153 transversely polarized photons, R = d2a

The ratio R(x, Q2) has not yet been measured at HERA and we have chosen R values according to the QCD prescription [13]. In the quark-parton model the structure function F2 can be expressed in terms of parton distribution in the proton. The F2 values measured with the help of method I and II are presented in Fig.l for two Q2 values, together with data points from the N-MC [14] and BCDMS [15] fixed target muon proton scattering experiments. The global systematic error of 8% is not shown in the figure. Both methods give consistent results. The high x points agree well with the available fixed target data, giving a cross check of the absolute normalization 2 with an accuracy of about 20%. A unique F2 in the full range of x and Q is obtained by taking 2 F2 values with smaller systematic error. The x dependence of F2 is shown in Fig.2 for four Q 2 values. We observe a clear rise of F2 with decreasing x. The Q dependence of F2 is shown in 2 2 2 Fig.3 for Q > 10eF . For constant values of x, F2 increases slowly with Q in agreement with scaling violation expected from perturbative QCD. Similar results have been obtained by the 2 ZEUS collaboration. The F2(x,Q ) evolution at small x reflects the assumptions made on the shape and the evolution of the gluon distribution as the sea quark distribution at low x is driven by the gluon density. Since the small x region is unexplored experimentally, extrapolations of presently proposed parton distributions in this range vary rapidly. The measured structure 2 function F2(x,Q ) in Fig.2 and 3 is compared to several structure function parametrization fitted to recent low energy data. Our data are consistent with the GRV [16] and the MRSD- [17] parametrizations. For the GRV parametrization small x partons are radiatively generated according to the Altarelli-Parisi evolution equations, starting from the "valence like" quark and 2 gluon distributions at Qo = 0.3eF . For MRSD- parametrization the small x evolution of the 2 x gluon density ( at Qo = 4eF ) is assumed to be singular with a characteristic x~ , A ~ 0.5 behaviour ( Lipatov behaviour). The range of validity in x for the Lipatov behaviour is unknown. Both ( GRV and Lipatov type) parametrizations predict large densities of gluons in the region of 2 small x. If F2(x, Q ) grows sufficiently fast at low x, HERA will allow to test QCD in the domain of high parton densities, where the new effects such as screening and saturation may become detectable. Assuming validity of Altarelli-Parisi evolution equations in our kinematic range and neglecting the quark contribution in this evolution, we have extracted a first estimate of the gluon distribution in the proton at small x (Fig.4). The experimental estimate of the gluon 2 distribution G(x,Q0), at Qo = 20eF , rises with decreasing x. The observed x dependence, with large experimental uncertainty, is consistent with the expectation based on the Lipatov evolution. The search for the new QCD effects, such as screening and saturation, damping the fast increase of the parton density may be possible with further accumulation of high quality data at low x. One could assume that the large gluon density increase does not develop uniformly over the full transverse size of the proton, but is localized instead in small regions, the so called "hot spots". For the hot spots we expect large saturation effects that may become detectable at HERA. The search for hot spots of soft partons is a great experimental challenge with interesting theoretical consequences and will be studied with the HI data. The analysis of the hadronic final states for values of Q2 up to 500 GeV2 and in the range of the invariant mass W of the hadronic system between 70 and 230 GeV has been performed. The detailed description of the event selection and background suppression can be found in [10]. Multi-jet production in this new kinematic region of DIS has been observed (Fig.5). The jets were reconstructed using the JADE algorithm, requiring jet-jet masses above 10 GeV or more (depending on W). Between 10% and 20% of events contain 2+1 jets (2 high pt jets and proton remnant). The data are in good agreement with QCD expectations, especially with the MEPS model based on first order matrix elements and additional parton shower evolution describes

154 the jet characteristics in satisfactory way without any further adjustment of parameters.

1 I I I H—M IIIH| 1—I I IIHH 1—I I-IH1I 2 = 15 • Q Q* = 30 CeV* 3 - • eledron o mixed [

• NMC • 0 2 [ } BCDMS 1 - A A fill Q 1 ' 0 a —i 1114444) ^ I II Hill 1- 1 1 tltllj 1 1 iflffrl fO~3 tO~2 10~f 10° X Figure 1: Measurement of F2(x,Q2) for two values of Q2. The full circles correspond to method II (mixed variable measurement). The error bars show statistical and systematic errors in quadrature. In addition all points have a normalization uncertainly of 8%. Data points of the fixed target muon-proton scattering experiments NMC and BCDMS are shown for comparison.

9* = t.S CtV , «* = is c«v*

-- HKS if — URS cr- CTCQIUS —• CRY -- oou

10-' to-* to-'

Figure 2: The measured structure function F2(x,Q2) for different values of Q2, compared to several structure functions parametrizations which are fitted to recent low energy data. The error bars show statistical and total errors obtained by adding the statistical and systematic errors in quadrature. In addition, all poits have a normalization uncertainty of 8%.

155 to1 • 1'AMM 'SttSJ - *»*«* A • IU) _ • 1*0,0024 ' 111) - CTC9IK3 s - - e«f 10 '•" •

to4 •

—, — to3 — •— ±. 10*

_ .-.^—« to' 4 ! r to' J

to-' roo Q'/CV'

Figure 3: The measured structure function F2(x,Q2) for different values of x, compared to several structure functions parametrizations which are fitted to recent low energy data. The eeror bars show statistical and total errors obtained by adding the statistical and systematic errors in quadrature. In addition all poits have a normalization uncertainty of 8%.

--- MRSDO' MRSD- CTEQU CTEQZL ••— CRV 10

CJ)

to-3

Figure 4: The gluon distribution function G(x,Q2) at Q2=20GeV2. The inner errors are the statistical errors, the full bars represent the systematic and statistical errors added in quadrature. The curves represent different parametrizations of G.

156 HI Q* < SO GcV Q- > 100 GcVJ 1.0 1 I • T -0.0 rTrnrrn i . (1-1) ;cl» • (2-1) jets • (2-1) jets » (S3-1) jet. » (S3-1) jol$ MEPS recon. - MEPS recon. - - MEPS hadrons . MEPS hadroni" MEPS pertonj MEPS partonj

,()•!) Jets • .(2-1) jell J T(S3-1) jets - MSPS - - CDM PSVTQ ~ HERVfiC

0.050.0 0.05

Figure 5: Functions of N + 1 jets (Rjv +1) vs the cut variable of the jet algorithm for 12

References

[1] HI Collab., T. Ahmed et al., Phys. Lett. B298 (1993) 469-478 [2] HI Collab., T. Ahmed et al., Phys. Lett. B299 (1993) 385-393 [3] HI Collab., T. Ahmed et al., Phys. Lett. B299 (1993) 374-384 [4] HI Collab., I. Abt et al., Phys. Lett. B314 (1993) 436-444 [5] HI Collab., I. Abt et al., Nucl. Phys. B396 (1993) 3-26 [6] HI Collab., I. Abt et al., Nucl. Phys. B407 (1993) 515-535 [7] HI Calorimeter Group., B. Andrieu et al., DESY preprint 93-047 (1993) [8] HI Calorimeter Group., B. Andrieu et al., DESY preprint 93-078 (1993) [9] HI Collab., I. Abt et al., DESY preprint 93-103 (1993) [10] HI Collab., I. Abt et al., DESY preprint 93-137 (1993) [11] HI Collab., I. Abt et al., DESY preprint 93-146 (1993) [12] A. H. Muller, Nucl. Phys. B (Proc. Suppl.) 18C (1990) 125 [13] G. AltareUi, G. Martinelli, Phys. Lett. 76B (1978) 98 [14] NMC Collab., P. Amandruz et al., Phys. Lett 295B (1992) 159 [15] BCDMS Collab., T. Ahmed et al., Phys. Lett. 298B (1993) 485 [16] M. Gliick, E. Reya and A. Vogt, Z. Phys. C53 (1992) 127 M. Gliick, E. Reya and A. Vogt, Phys. Lett. 306B (1993) 391 [17] A.D. Martin, W.J. Stirling, R.G Roberts, Phys. Lett. 306B (1993) 145, ibid. 309B (1993) 492

157 f I The HEGRA experiment PL9601069

The HEGRA (High Energy Gamma Ray Array) detector is a ground-based array for the detection of ultra high energy cosmic radiation 2. It is located at Roque de los Muchachos (2240 m altitude) at La Palma island (Canary Islands, Spain). During 1992-1993 the collaboration has installed a novel type of air Cerenkov detector matrix, named AIROBICC. The matrix consists of hemispherical, 20 cm diameter photomultipliers observing light disk from extended air showers with angular acceptance of 1 sr. The incident shower direction is determined with high precision from the individual timing signals due to very sharp time definition of the light front and the large diameter of the Cerenkov light disk. The radial light structure contains information of the shower developement as a function of altitude. In 1993 first performance results from a 7 x 7 submatrix were obtained Data from the first run period have shown that the most of the expected performance has been achieved 3 and confirmed basic predictions of Monte Carlo air shower simulations 4. Fig. 1 shows the time structure of the particle cloud and of the Cerenkov light for the same shower. As predicted one observes for the light front a much more reduced time spread. The physicists from Institute of Nuclear Physics participated in Monte Carlo simulations and in studying 7-hadron discrimination possibilities of AIROBICC detector 5.

112 ...... 1 ' ' O' I ' ' ' ' . o ; §10 o o o o - 8 o .-o o - Scintillator signals o ° -o'' o o 9"o o o 3 o o° o o o c q o° o o. - o°°o &l o.. - oo 0® o - -) c )° ° s O Oi?P O Cerenkov signals w # • o &&' "" ° c * rg}6 O °, t.. • -• • 5 0 1 40 80 120 160 200 Distance of shower axis [m] Fig. 1: Time structure of the particle cloud and the Cerenkov light of an air shower 3. 1M. Rozariska in the collaboration with Universities of Hamburg, Kiel, Madrit, Wuppertal, Max-Planck Insti- tute for Physics and Astrophysics - Munich and Institute of Physics - Yerevan. 2F. Aharonian et al., Status and upgrade of the HEGRA air shower experiment at La Palma, Proc. XXIII ICRC 4 291 (1993). 3A. Karle et al., First Running Experience with the Novel Wide Angle Air Cerenkov Matrix Detector AIRO- BICC, Proc. XXIII ICRC 4 666 (1993). 4S. Martinez et al., Monte Carlo simulation of the HEGRA array performance, Proc. XXIII ICRC 4 742 (1993). SF. Arqueros, S. Martinez and M. Rozariska, 7/proton discrimination in cosmic rays (1013 — 1016eVr) using EAS information from electrons and air Cernkov light, Proc. XXIII ICRC 4 738 (1993).

158 PL9601070 The ACCMOR collaboration (NA32 experiment terminated in 1986)

A study of A+ decays into pK ?r+, pK 7r+7r° and pK 7r+7r°7r° Amsterdam-Bristol-CERN-Krak6w6-Munich-Rutherford-Valencia collaboration

The paper7 is based on the results of a high-precision charm experiment performed at the CERN SPS. The experiment used a negative 230 GeVjc beam and a 2.5mm Cu target. Charm decays were reconstructed with a sophisticated silicon vertex detector and a large-acceptance spectrometer. We have collected a clean sample of 121 A+ —• pK~ir+ decay vertices8 and we have studied the effective mass distribution of the subsystems pK~, pr+ and K~TT+ . A joint fit to these distributions yielded the subresonant structure of pK~ir+ state. The results are shown in Table 1, in which the subscript "nr" denotes the non-resonant i.e. the genuine three- body decay and the branching ratio for the second channel has been corrected for the unseen K*°(S92) -> K°K° decay mode. In the same experiment we have observed some secondary pK~T+ vertices with a visible mass mvia below the A+ mass m\. In order to separate statistically the channels with various numbers of neutral secondaries, we have used the neutral mass mo defined as:

where p"" is the visible transverse momentum with respect to the direction of the parent A+. A joint fit to mvi, and m0 distribution yielded fractions of events with one, two or even three 7r°'s in the final state. The results are also listed in Table 1.

Table 1: Branching ratios with respect to the total A+ —» pK x+ channel

Final state No of events Branching ratio (PK-T+)nT 70.5+?^ 0.56^;^ ± 0.05 PK*°(S92) 38.8±S"g 0.351°•{£ ± 0.03 A++(1230)iir- 14.0±|-» 0.1212;°* ± 0.05 47 A(1520)TT+ 11 q+ 0.091°;^ ± 0.02 ii y pK-ir+T0 66.-6 -3.±6.84 0.73 ±0.12 ±0.05 pK-TT + TT0*0 15.0 ±6.9 0.16 ±0.07 ±0.03 ptf-Tr+TrW0 8.4 ±4.6 0.10 ±0.06 ±0.02

6A. Boiek (Ph.D thesis), Z. Hajduk, H. Palka, K. Rybicki and M. Witek 7Physics Letters B 311 (1993) 247 8A particle symbol stands for particle and antiparticle i.e. any reference to a specific state implies the charge- conjugate state as well

159 1 PL9601071 Spin Alignment of Z>*+(2010) Mesons Produced in 230 GeV/c TT'CU Interactions K. Rybicki and R. Rylko9

The paper10 is also based on the results of the ACCMOR collaboration which collected a 11 + clean sample of 127 D*+(2010) -* D°ir+xi decays with a subsequent D° decay into K~w or K~ir+ir+ir~. The D° decay vertices were reconstructed in a sophisticated silicon vertex detector and in a large-acceptance spectrometer with a good hadron identification. The angular distribution of the D*+ decay has been fitted to the form:

+ where 0 is the angle between the D* momentum in the laboratory frame and the ir*xt momentum in the D*+ rest frame, while r\ is the D*+ alignment parameter. The fit to the angular distribution yields for the whole sample: ± °-01 The spin alignment is consistent with zero for such Feynman x and transverse momentum cuts as were possible in our sample. This is the first result on the spin alignment of hadronically produced charmed mesons. It has been used to test the statistical approach to spin counting suggested by Donogue12. This approach gives a simple relation between the spin alignment parameter and the production cross sections of vector and pseudoscalar mesons. The result shown in Eq.(3) corresponds to:

+ ,°}r \n^ = 0.83+g-i 10J ± 0.01

'Now at Queen Mary and Westfield College, University of London. 10Acta Physica Polonica B 24 (1993) 1049. 11A particle symbol stands for particle and antiparticle i.e. any reference to a specific state implies the charge- conjugate state as well. "Physical Review D 1£ (1979) 2806. "ACCMOR collaboration, Z. Phys. C 5 (1991) 555.

160 PL9601072 ATLAS experiment at LHC1

FromlNP Krakow: J. Błocki, J. Chwastowski, A. Czermak, S. Gadomski, J. Godlewski, Z. Hajduk, W. Iwański, M. Kajetanowicz, J. Kapłon, K. Korcyl, P. Malecki, Z. Natkaniec, A. Moszczyński, J. Olszowska, W. Ostrowicz, A. Sóbala, M. Tárala, A. Wolak

The ATLAS collaboration is a group of more than 80 institutes and universities2 preparing an experimental programme and a large spectrometer for the studies of proton-proton interactions at energy of 14 TeV (center of mass) at the LHC accelerator at CERN [1]. The Kraków groups from the Institute of Nuclear Physics and the Faculty of Physics and Nuclear Techniques are taking part in this programme. The preparatory works include: • simulation studies of physics processes, designing of the spectrometer and simulation of its performances, prototyping work on detectors, electronics and programing, • participation at CERN R&D programme on development of detectors for LHC experiments, in particular in the following projects: - RD6 "Integrated high-rate transition radiation detector and tracking chamber for the LHC" [2], - RD11 "Embedded architecture for second level-triggering in LHC experiments (EAST)" [3], - RD20 "Development of high resolution Si strip detectors for experiments at high luminosity at the LHC" [4], - RD28 "Development of gas micro-strip chambers for high radiation rate detection and tracking" [5].

References

[1] ATLAS Int. Note, GEN-NO-004, March 1993 [2] CERN/DRDC/90-38, CERN/DRDC 91-55 (Oct. 1991), CERN/DRDC/93-46 (Nov. 1993) [3] CERN/DRuC/gO-oô, CERN/DRDC 92-11 (March 1992), [4] CERN/DRDC 91-11, CERN/DRDC 92-28 (May 1992), CERN/DRDC 93-30 (Aug. 1993) [5] CERN/DRDC 92-30 (1992), CERN/DRDC/93-34 (Aug. 1993)

'Work supported in part by Polish State Committee for Scientific Research, grants 2 0906 91 01 and 115/E- 343/SPUB-206/93 2Univ. Alberta, Inst. Alma-Ata, NIKHEF Amsterdam, LAPP Annecy, ANTU Athens, Athens Univ., Univ. Barcelona, HEP Lab. Bern, Univ. Bermingham, Univ. Bratislava, Cambridge Univ., Univ. Clermont-Ferrand, NBI Copenhaghen, Univ. Calabria, INP Krakow, FPNT Krakow, INR Debrecen, Univ. Dortmund, Univ. Edinburgh, Florence Univ., INFN Frascati, Freiburg Univ., CERN Geneva, Univ. Geneva, Univ. Glasgow, IN2P3-CNRS Grenoble, IIT Haifa, Univ. Hamburg, Univ. Heidelberg, SEFT Helsinki, Innsbruck Univ., Univ. Jena, Kobe Univ., IEP Kosice, Univ. Lancaster, LIFEP Lisbon, Univ. Liverpool, QMWC Univ. London, RHBNC Univ. London, Univ. College London, Lund Univ., Univ. Madrid, Manchester Univ., Mannheim Univ., CPPM Marseille, Meulbourn Univ., Milan Univ., Univ Montreal, ITEP Moscow, FLAN Moscow, MEPI Moscow, Moscow Univ., Univ. Munich, MPI Munich, Univ. Neijmegen, LAL Orsay, Oslo Univ., Oxford Univ., Paris VII Univ., Pavia Univ., Pisa Univ., Prague Univ., LHEP Protvino, Univ. Rio de Janeiro, Univ. 'La Sapienza' Rome, Univ.'Tor Vergata" Rome, RAL Lab., DAPNIA Saclay, CST Saratov, Univ. Sheffield, Siegen Univ., MSI Stockholm, Stockholm Univ., IFMO St. Petersburg, NPI St. Petersburg, ANSTO Sydney, Tel-Aviv Univ., Univ. Tokyo, Univ. Uppsala, Univ. Valencia, Univ. Vancouver, Univ. Victoria, IHOAW Vienna, WIS Rehovot, Univ. Wuppertal.

161 B-physics in ATLAS PL9601073 S. Gadomski

Collider experiments at LHC will be able to see large numbers of bb events. Due to the higher center of mass energy the signal-to-background ratio is more favorable then in fixed target experiments, K ir~, B° -> K ir~ and B° -> K K~. This background can not be reduced by means of secondary vertex reconstruction. One year of operation at low luminosity should bring of the order of 3100 signal events. With a total background of around 8200 events it is possible to measure the asymmetry in B-decays and provide an independent measurement of CP-violation [2]. 1

Figure 1: Reconstructed (TZ+T ) mass for signal (dark region) and signal plus background (white region).

References

[1] S. Gadomski, P. Eerola, N. Ellis, D. Froidevaux, Workshop on B Physics on Hadron Accele- rators, Snowmass, Colorado, June 21-July 2, 1993 [2] The ATLAS Collaboration, CERN/LHCC/93-53, 15 October 1993.

162 PL9601074 A Vertex Detector for LHC Experiments J. Blocki, S. Gadomski, J. Godlewski, M. Turala, A. Wolak

The prime goal of experiments at the LHC will be to search for Higgs particles and other exotic phenomena, but this accelerator will produce also large quantities of particles containing 6and i-quarks. Such processes will represent a substantial background for Higgs search however, on the other side, they are interesting on their own. Due to the finite lifetime of B mesons, b and <-jets will be characterised by the separation from primary interaction point and as such could be identified with the help of a precise vertex detector. The ATLAS group has recognised the potential of heavy flavours tagging right from the begining: a conceptual design of the central part of the ATLAS Inner Detector includes high precision tracking layers made out of silicon microstrips and pixels - Fig. 1 [1]. On the other hand it was also clear that severe operational conditions at the LHC (very high radiation levels) will require new detectors and electronics (special RfeD programme) and that, in addition, some compromises will be necessary between performances and the lifetime of the detector.

400 800 BOO 1000

Figure 1: Conceptual design of the ATLAS vertex tracker.

Several simulation studies have been done to understand better the influence of the geometry, detector parameters and the amount of material on the impact parameter resolution of a vertex detector - Fig. 2 [2]. From these studies as well as from the general analythical considerations a few strong recommendations follow: - the first detector layer has to be very precise and it shall be placed as close as possible to the interaction point (beam line), - the amount of material of the first detector layer (and a beam pipe) shall be kept at minimum, - the angular accuracy of the whole tracking system should be very high (of the order of hundreds microradians) to allow for high precision extrapolations. Using such constrains the Krakow group has proposed a gas cooled silicon strip vertex detector for LHC, which could replace pixel detectors - Fig. 3 [3]. The design is based on 60 x 60 mm2 detector units with 50 /«n readout pitch assembled into self supporting "bridges". The power dissipated by the readout electronics (2 mW/channel) can be effectively cooled by the gasous helium (the temperature uniformity of the order of a few °C can be reached). According to our judgement such solution minimises the mass of the detector.

163 I I * H Htl :::::::::::::: '..^gt^/K^^L ::::::"• -A"?^«4J->c:....j. K?^_i i r T i )f ltfcim.iaitpolnt.oi 1s£ . . •-. » * lit C i 20Mm. loM point oii r- A- 10«m, la»l point o|f 10 - 20um, ioWioint ojf

! ! ; -i + *• v.;;T ,-, ; vr; ••;••;••;• l; . , ; -2 10 19 20 25 30 35 10 ,..,! . , I I I INNER RADIUS (cm) 10 102 103 P [GeVl Figure 2: Impact parameter resolution of a vertex detector as a function of detector geometry and spatial resolution of individual layer (a.) and particle momenta for 90° tracks. Different curves are for different amounts of material in the first double layer: 0.5, 1.0, 2.0 and 3.0% per layer (respectively upwards) (b.).

878 195

Figure 3: Conceptual design of gas cooled silicon strip vertex detector (a.) and a single detector module (b.).

Recently a new layout for barrel part of the ATLAS Inner Detector has been presented [4]; it includes a vertexing layer at the radius of 6 cm from the beam pipe. The performance of such solution would be superior against the ones proposed up to now but the lifetime of detectors and electronics will be limited to a few years. However that period of time will be sufficient to accumulate a significant number of interesting physics events so the construction of this detector is justified.

References

[1] The ATLAS Inner Detector, ATLAS Int. Note, GEN-NO-004, March 1993 [2] J.-C. Chollet, S. Gadomski at al, ATLAS Int. Note, PHYS-NO-019, May 1993 [3] J. Blocki, S. Gadomski, J. Godlewski, K. Pakonski, M. Turala; Presented at Int. Symposium on Silicon Detectors, Hiroshima, May 1993 [4] S. Gadomski, S. Roe and P. Weilhammer; ATLAS Int. Note, INDET-NO-035, Nov. 1993

164 PL9601075 Development of silicon detectors and VLSI electronics RD20 Collaboration From Krakow: A. Czermak, P. Grybos, W. Dabrowski, M. Idzik, J. Kaplon, M. Kajetanowicz, S. Moszczyriski, A. Skoczen, M. Turala

The Krakow group is involved in designing and testing of silicon microstrip detectors and VLSI electronics for RD20 collaboration [1]. Last year the Krakow group has continued investigating of test structures designed within this project [1], [2], [3]. To be able to explain some of the experimental observations the ToSCA (Two-dimensional Semiconductor Analysis) simulation program has been lernt and applied. Fig. 1 obtained by means of using ToSCA shows electron and hole densities near the Si/ SiOi interface of n-side detector (a simple model of one-strip detector was used). One can see accumulation layer of electrons interrupted in neighbourhood of strip edges by field plates potential and inversion layer of holes in the same region.

Elektronendichte Loecherdichte

Figure 1: Electron and hole densities. Some of the n-side detector test structures (with field plate strip isolation) have been irradiated with 7 rays from mCo source at the Institute of Oncology in Krakow. The electrical parameters of these test structures, before and after irradiations, have been measured with the help of an Alessi probe-station, HP4145B Semiconductor Parameter Analyser and HP4284A LCR Meter. Some unexpected results on leakage currents have been observeed. The ToSCA program was used to explain the observed behaviour of the detectors [3]. The contribution of Krakow group to development of RD20 electronics [4], [5] and cooling systems [6] is reported elsewhere.

References [1] RD20 Status Report , CERN/DRDC 93-30 [2] S. Moszczynski, M. Turala, et al., CERN/PPE/93-137, Submitted to Nucl. Instr. and Meths. S. Moszczynski, et al., RD20 Technical Note TN/25 A. Czermak, M. Kajetanowicz, J. Kaplon, S. Moszczynski, et al., RD20 Technical Note TN/23 [5] M. Kajetanowicz, J. Kaplon, RD20 Technical Note TN/24 [6] J. Blocki, J. Godlewski, K. Pakonski, RD20 Technical Note TN/26

165 Transition radiation tracker PL9601076 ATLAS, RD6 and RDll Collaborations From Krakow: K. Cetnar, G. Ciechanowska, Zb. Hajduk, St. Jagielski, P. Jurkiewicz, B. Kisielewski, A. Kotarba, P. Malecki, Zb. Natkaniec, J. Olszowska, W. Ostrowicz

A considerable activity of physicists and engineers from our Institute concerned the research and development project of the transition radiation datector, the important part of the future Inner Detector of the ATLAS experiment. The work concentrated on three subjects: the design and construction of the test system for the readout electronics, the design and construction of the second level trigger model system and on the analysis of the data collected during the test run of the TRT prototype. SECOND LEVEL TRIGGER FOR TRT DETECTOR. We have contributed to the hardware design and construction of a level two trigger system for Transition Radiation Tracker [1]. The system has been based on special commercial image processor (Max-Video) [2] running feature extraction algorithm (feature - a physical variable on which a trigger decision is based). The algorithm [3] was based on histogramming technique which was looking for an absolute maximum on the event image in the detector. In collaboration with CERN and the Weizmann Institute we have designed and build two parts of the system. The general configuration is presented on the Fig. 1. We have constructed, debugged and finaly run the HIPAD [4] interface and DATA COLLECTOR.

Dais fas fflPJL ROUTER DAQ

TAPE HIPP!

ROI teotu* HIPAD Mix-Video

Figure 1: Structure of the second level trigger system for TRT

Presented structure has been sucessfully tested with the TRT prototype detector during '93 autumn test run at the SPS accelerator. TEST SYSTEM FOR FRONTEND TRT ELECTRONICS. We have built and run a test system for TRT frontend electronics, called 'daughter boards' (ROB - on the Fig. 2). One board covers 32 channels of the detector. It contains the analogue part, set of discriminators, the digital communication electronics and the slow control part used for card initialisation and control. All electronics is build with ASICs to minimise the space. Our test system hardware was build in the VME standard. The control software (device drivers, application programs) has been written for the OS-9 environment. The test system is composed of following blocks (see Fig. 2): • analogue switch and control ('analog card') • read-out unit - the heart of the system ('readout card')

166 • slow control board (built by MPI-Munich; 'TRDS controller')

Figure 2: Test system for frontend electronics of TRT detector.

The system allows to test functionality of the cards and perform their calibration. Parame- ters, like pedestals, offsets, noise, crosstalks can be adjusted. A software based on pulled down menus has been written to make the tester operational. The results are presented in tables or histograms form.

TEST RUN OFF-LINE DATA ANALYSIS.

Distribution of number of high hlto per track as •IWM siaoi BlM«» 1414 Htm MM 07 Mm amo 0.28 J 0.6 |-

0.2 '- |- —I 0.8 — 0.4

0.1S Mil l 0.3 0.1 -, - 0.2 [ 0.05 r h 0.1 :. ... i k- ...... :, 4- i .... i .... e e 10 is <) 8 10 18 Hunker •! Mb Mumbtr o< httr Electrons SO OeV Plon*S0O«V Figure 3: Distributions of hits for electron and pion tracks.

167 PL9601077

The TRT detector prototype has been tested at the SPS electron and pion beams in the fall 1993. The data collected during this run have been analysed by us and the preliminary results presented at the RD6 collaboration meeting in Dec. 93. The analysis allowed for the test of the readout channels efficiency, overall DAQ functional test as well as for some analysis of the track reconstruction and electron/pion identification efficiency. The track reconstruction efficiency was satisfactory and the pion/electron rejection factor - due to the TR (transition radiation) effect - has been estimated at the value about 5.

References

[1] Status Report CERN/ DRDC/ 93-46. [2] MaxVideo hardware reference manual - DATACUBE, Inc August, 1992. [3] A. Gheorge, Z. Natkaniec et al, EAST note # 92-17 CERN May 92. [4] fflMAX - User Manual L. Levinson, Z. Natkaniec et al, EAST note #93-04.

Modelling of local/global architectures for second level triggering at the LHC experiment RDll Collaboration From Krakow: Z. Hajduk, W. Iwanski, K. Korcyl

A local/global architecture for a second level trigger has been chosen for modelling [1]. The proposed architecture is based on a FEAST concept [2]. The basic building block of the proposed system contains one or two TMS320C40 processors serving as a feature-extractor (feature - a physical variable on which a trigger decision is based) and a boards-manager. In case of one processor both tasks are performed by single processor This particular piece of hardware has been chosen due to its computing power and 6 communication links which can support high speed data transfers between different processors. Former studies [3] shown that the data from events accepted by level-1 trigger should be stored on the FEAST board i.e. data are transferred from the front-end electronics to the T2-bufFer immediately after every positive Tl decision. The boards can communicate and exchange the data via links provided by level-2 trigger processors. In such a way a 'sliding window' can be formed in order to cover fully the Re- gion_of_Interest i.e the detector part where level-1 trigger gave positive notation. The full system will form a 'mesh' covering the surface of detector. The other links of the processors serve as communication pathes with global part of the system, the read-out and connection to the third level. We have used as modelling tool a MODSIM II [4] 'object oriented' language. The board components has been constructed as objects having some limited resources which could have been granted only to one event in a given time instant. In such a way a queing of events is realised. Then within one object the resources have different priorities and demand for free resource of higher priority can interrupt an action of the resource currently used, thus the interrupt system was implemented. From such a single block a more complicated system has been build containing a matrix of N * N boards. The system has been fed with randomly incoming events having average frequency of 100 kHz (Fig. la). The number of 'regions of interest' was also randomly generated according to the distribution from Fig. lb. Whole system was completed by adding

168 a simple switch conducting the data to the T2 global level processors having fixed (2msec) processing time. Described construction allowed for easy modification of the board configuration and simple changes in number of used components. Ex. one of the variable parameters was the size of the 'farm' used as the feature extractor (one, two or more DSP's). We have investigated the following issues: • average and peak occupancy of the FIFO's, units, links, buffers and processors • average and peak 'live time' of the event in the system i.e. time from positive Tl decision until readiness of the event for global processing for one or two processors i.e board management and feature extraction in one processor or seperate CPU's (Fig. lc, Id) • average and peak processing time for 1 or two processors on the board i.e board management and feature extraction in one processor or seperate CPU's (Fig. le, If). The following conclusions can be drawn from our studies: • processing units should be built as farms of several processors to decrease significantly local queues • efficient management of T2 buffer is very important • MODSIM II has proven to be very handy tool for behavioural simulations of quite complicated systems.

StnuMcnraauln • tocdtfoM wcNtocbra bwed on FWST gonafit

• n (on a/Locolfmcmmiguu-lDSP Figure 1: MODSIM II simulation results

References D. Crosetto et al: LHC Workshop, Aachen, 1990 P. Clarke, Z. Hajduk, K. Korcyl, W. Iwanski et al: EAST note # 93-11 CERN August 93 G. Appelquist, W. Iwanski: EAST note # 92-27, FERMI note # 13, CERN November 1992 [4] CACI Products Company - MODSIM II Reference Manual

169 The ZEUS Experiment at HERA 1 Hill nrTTo n 11 i .• 1 I ilium mil III mil III niiillllliin ZEUS Collaboration z PL9601078

Group from the Institute of Nuclear Physics includes: P. Borzemski, J. Chwastowski, A. Eskreys, K. Piotrzkowski, M. Przybycien, M. Zachara, L. Zawiejski (physicists) and J. Andruszk6w, B. Da.browski, W. Daniluk, P. Jurkiewicz, A. Kotarba, K. Oliwa, W. Wierba (engineers and technicians)

HERA (Hadron Electron Ring Anlage , located at DESY in Hamburg, is the first and unique accelerator colliding proton and electron beams at very high energy {sfs = 314GeF). It started operation in 1992. This year's running was very succesful, experiments have collected about 600nb~1 of integrated luminosity i.e. 20 times more than in 1992. ZEUS Luminosity Monitor has been designed and built by the Krakow team which includes groups from the INP and from the Nuclear Physics Faculty of the Academy of Mining and Metallurgy3. Thus, the main responsibility of the Krakow group is the maintenance of this detector and the luminosity measurement itself. The experience gathered during the first running period allowed for some important improvements and modifications implemented during the 1992/1993 winter shut down. The most important steps in the development of the luminosity measurement are:

• Installation of the position detector for the electron calorimeter, which allows better understanding of the systematic errors in the luminosity measurements and provides a very important tool in the analysis of the photoproduction processes. • Implementation of the new, more complete and relialable online display of the luminosity measurement used by the ZEUS experiment and by the accelerator crew for optimization of the electron beam orbit. • Further development of software necessary for the precise offline luminosity calculation. 1Polish ZEUS groups activity is partially supported by the State Committee for Scientific Researches (grant No 204209101) 2Participating institutions: Argonne National Laboratory, University and INFN (Bologna), Universitat Bonn, Bristol University, Brookhaven National Laboratory, Calabria University and INFN (Cosenza), Columbia Univer- sity, Institute of Nuclear Physics (Krakow), Dept. of Physics and Nuclear Technology of the Academy of Mining and Metallurgy (Krakow), Jagellonian University (Krakow), DESY (Hamburg), DESY-Zeuthen (Zeuthen), Uni- versity and INFN (Florence), INFN (Frascati), Universitat Freiburg, University of Glasgow, Hamburg University (I. and II. Institutes of Physics), Imperial College London, University of Iowa (Iowa City), Institut fur Kern- physik (Jiilich), Korea University (Seoul), Louisiana State University (Baton Rouge), Univer. Autonoma Madrid, University of Manitoba, McGill University (Montreal), Moscow State University, NIKHEF (Amsterdam), Ohio State University (Columbus), University of Oxford, University and INFN (Padova), Pennsylvania State University (University Park), Univ. 'La Sapienza' (Rome), Rutherford Appleton Laboratory (Chilton,Didcot), University of California (Santa Cruz), Universitat-Gesamthochschule Siegen, Tel-Aviv University, University of Tokyo, Tokyo Metropolitan University, University and INFN (Torino), University of Toronto, University College London, Vir- ginia Polytechnic Institute (Blacksburg), Warsaw University, Institute for Nuclear Studies (Warsaw), Weizmann Institute (Rehovot), University of Wisconsin (Madison), York University (North York) 3s. INP Annual Reports 1991, 1992

170 • Design and construction of the new electronics for the photon position detector to be installed during the present shutdown. • Design of the new, more reliable scheme for the calibration of the calorimeters, based on the light pulser with laser diode; this system will be also implemented during this winter shutdown. Members of the Krakow ENP group have been taking part in the ZEUS run shifts. They have also contributed to the development of the general ZEUS online and offline software. Our physicists have actively participated in the physical analysis of the collected data and have significantly contributed to that of the photoproduction processes. Many aspects of the deep inelastic scattering, photoproduction processes and searches for new particles have been studied by both HERA experiments: ZEUS and HI. Results of the ZEUS physics analysis, based mainly on the data collected in 1992, have been published in 7 papers. New interesting data concerns mainly the deep inelastic scttering processes (DIS) in the new kinematic range available at HERA collider. Results on the study of the proton structure, similar for both experiments, are presented in this Report by group working for the HI Collaboration. Here we would like to review briefly on the analysis of a special subsample of the ZEUS DIS events.

Observation of Events with a Large Rapidity Gap in Deep Inelastic Scattering at HERA 4 ZEUS Collaboration M. Derrick et al. 5

The dominant mechanism of DIS is the scattering of the incident lepton from a coloured quark (see Fig. la). The colour transfer between the struck quark and the proton remnant is responsible for populating the rapidity interval between them with final state hadrons. Such a picture predicts that DIS events observed at HERA should have substantial energy deposits at angles close to the proton direction. Indeed, the energy flow distributions found for those events are consistent with this prediction [1,2]. In this paper the ZEUS Collaboration reported on the first observation of a class of DIS events in which the hadronic energy deposit closest to the proton beam direction is observed at a large angle. These events exhibit a sizeable difference between the pseudorapidity, r\ — —lntan(9/2), of the smallest detector angle/footnote In the ZEUS coordinate system the polar angle 6 is measured with respect to the z axis pointing along the proton beam direction. (9 = 1.5°, r\ — 4.3) and the pseudorapidity of the hadrons observed closest to the proton direction. These events are not described by standard QCD based fragmentation models [3]. Theit general characteristics are compatible with those expected from difractive dissociation with pomeron exchange. The present understanding of the pomeron nature is poor despite a wealth of data [4]. It has been suggested that the pomeron may have a partonic structure which could be probed in hard diffractive dissociation [5]. The concept of the pomeron structure function has been studied in terms of perturbative QCD [6,7-13]. It has been suggested that the pomeron structure could be probed with a virtual photon at HERA [5,14,15] and that the experimental signature of a

*Phys. Lett. B315 (1993) 481 5INP authors: P. Borzemski, J. Chwastowsld, A. Dwuraany, A. Eskreys, Z. Jakubowski, B. Niziol, K. Piotrzkowski, M. Zachara, L. Zawiejski

171 pomeron exchange wotdd consist of a quasi-elastically scattered proton, well separated in rapidity from the remaining hadronic system as illustrated in Fig. lb. The events described here have such a rapidity gap.

Fig. 1: (a) Schematic diagram describing particle production in deep inelastic electron proton scattering, (b) Schematic diagram describingparticle production by diffractive dissociation in a deep inelastic ep interaction. W is the center of mass energy of the y*p system and Mx is the invariant mass of the hadronic system measured in the detector. N represents a proton or low-mass nuclear system, (c) Schematic view of the ZEUS calorimeter and central tracking. Overlaidis an event with a large rapidity gap. Tracks are detected in the central tracking chamber and energy deposits are obseved in the calorimeter. The electron is detected in the rear direction (RCAL).

The data were collected during fall 1992 and the sample used in this analysis corresponds to an integrated luminosity of 24.7 nb'1. The ZEUS detector has been described elsewhere [16]. The hermetic uranium-scintillator calorimeter (CAL), the central tracking detector and the vertex detector were the main components used for this analysis. They are shown schematically in Fig. lc. The kinematic variables used to describe DIS events are the following: Q2, the negative of the squared four-momentum transfer carried by the virtual photon, 7*,

172 Q> = -f = -(k - k')2, where k and k' are the four-momentum vectors of the initial and final state electrons, respectively; y, the variable which describes the energy transfer to the hadronic final state,

y = (q.P)/(k.P), where P is the four-momentum of the incoming proton; x, the Bjorken variable,

x = Q2/{2q.P) = Q2/ys, where s is the center-of-mass energy squared of the ep system; and W, the center-of-mass energy of the 7*p system,

W2 = (q + Pf = Q2(l - x)/x + M2,

where Mp is the mass of the proton. The kinematic variables can be determined from either the leptonic or hadronic system. Studies have shown [17] that it is sometimes advantageous to used a mixed set of variables. Here we use the so called "double angle" method [18]. The relevant quantities will be denoted by the subscript DA.

i—i—•—i—i—i—.—Y~'—i—'—'—•—r / RCAL. BCAL FCAL • ZEUS dolo o Monte Corto • ZEUS doto m Monte Carlo

-1 10 +++++ -2 H, 10

10 o -2 8

Fig. 2: (a) The fraction / of events for which 99% of the hadronic energy is contained within the pseudorapidity

interval -3.8 < -r\ < rjc.t as a function of r/cut, for data and for MC events, (b) Distribution of J?mo*, the maximum rapidity of a calorimeter cluster in an event, where a cluster is defined as an isolated set of adjacent cells with summed energy higher than 400 MeV, for data and for MC events. The boundaries of the calorimeter are indicated. Values of v-max > 4.3 may occur when particles are distributed in many contiguous cells around the beam hole of the FCAL. The data selection procedure used for the isolation of the DIS sample and the Monte Carlo method used to determine the detector acceptance and the possible background are described in [18]. Final sample of the deep inelastic events consists of 1441 events. Most of the characteristics of that sample are similar to those of the Monte Carlo (MC) neutral current DIS events generated with HERACLES [19] (the hadronic final state was simulated using ARIADNE [20] for the QCD cascade and JETSET [21] for the soft processes). In one importatnt aspect, however, the data differs from MC. In the data we observe a substantial number of events with low energy deposited in the forward calorimeter (FCAL) in contrast to the MC expectations.

173 Fig. 2a shows for both data and MC the fraction of events, for which 99% of the hadronic energy measured in the calorimeter is contained within -3.8 < r\ < 77^, as a function of r^. The lower limit of of 77 = —3.8 is denned by the inner edge of the rear calorimeter (RCAL). In almost all MC events, the full calorimeter acceptance is required to measure 99% of the deposited energy. However, in the data we observe a clear excess of events for which 99% of the deposited energy is contained within a smaller angular range, corresponding to 77^ < 3. To study these events further, we define r\rnax as the maximum pseudorapidity of all calorimeter clusters in an event. The distribution of r)max is shown in Fig. 2b both for data and MC. A clear excess of events in the data sample is observed for rjmax < 1.5. We denote events with Vmax < 1-5 as events with large rapidity gap. This corresponds to requiring a rapidity gap of at least 2.8 units. After estimation of the number of backround events an excess of 78 ± 10 remains, corresponding to 5.4% of the DIS sample. Deep inelastic interactions due to diffractive virtual photon-proton scattering (j*p) are expected to produce events with a large rapidity gap in the final hadronic state. In the tripple pomeron exchange one expects a flat rapidity distribution of the recoiling diiFractive state. For fully contained diffractive states the r)max variable is related to the rapidity distribution of the hadronic state. In the region of 77max < 1.5 in Fig. 2b, the measured distribution is indeed flat. We have then looked into inclusive properties of the large rapidity gap events. We divide the DIS events into two samples, one with r)max < 1.5 and the other with r\max > 1.5. In Fig. 3 we present for both samples the correlation between the invariant mass Mx of the observed hadronic system and the total available energy WDA in the ~f*p system. A feature of the events with a large rapidity gap is that Mx is small compared to WDA and is typically smaller than 10 GeV.

ZEUS O < 1 -5 > "I -5 TOO

50 -

O t • . i... • ' "*»..•••• <". , i . . . ,__) , . 0 50 100 150 200 250

Fig. 3: Correlation between the invariant mass Mx of the hadrons observed in the calorimeter and the invariant mas, WDA, of the y'p system. Events with a large rapidity gap, r)max < 1.5, are shown as solid dots, and events with r)ma* > 1.5 are shown as crosses.

There are also other inclusive distributions shown in the paper. Their shapes are suggestive of a difltactive interaction between a highly virtual photon and the proton, mediated by the exchange of the pomeron. The selection criteria limit the acceptance for the diffractive-like

174 events. Since we have made no corrections for acceptance, the 5.4% for DIS events should be considered a lower limit for diffractively produced events.

References

[1] T. Ahmed et al., Phys. Lett. B298 (1993) 469. [2] M. Derrick et al., Z. Phys. C59 (1993) 231. [3] B. Andersson et al., Phys. Lett. B94 (1980) 211; B. Anderson et al., Phys. Rep. 97 (1983) 31; B.R. Weber, Nuci. Phys. B238 (1984) 492; Y.I. Azimov et al., Phys. Lett. B165 (1985) 147. [4] K. Goulianos, Phys. Rep. 101 (1983) 169; Nuci. Phys. B, Pore. Suppl. 12 (1990) 110. [5] G. Ingelman and P.E. Schlein, Phys. Lett. B152 (1985) 256. [6] E.L. Bergef et al., Nuci. Phys. B286 (1987) 704. [7] L.V. Gribov et al., Phys. Rep. 100 (1983) 1. [8] J. Bartels and G. Ingelman, Phys. Lett. B235 (1990) 175. [9] E.M. Levin and M. Wiisthoff, DESY 92-166, FERMELAB-Pub-92/334. [10] M.G. Ryskin, Sov. J. Nucl. Phys. 53 (1991) 668. [11] G. Ingelman and K. Prytz, Z. Phys. C58 (1993) 285. [12] N.N. Nikolaev and B.G. Zakharov, Z. Phys. C53 (1992) 331. [13] J.C. Collins et al., Phys. Lett. B307 (1993) 161. [14] R. Donnachie and P.V. Landshoff, Phys. Lett. B191 (1987) 309. [15] K.H. Streng, Proc. HERA Workshop, Vol.1 (1987) p. 365; CERN-TH-4949 (1988). [16] M. Derrick et al., Phys. Lett. B293 (1992) 465. [17] S. Bentvelsen et al., Proc. Workshop on Physics at HERA, Vol. 1 (1991) p. 23. [18] M. Derrick et al., Phys. Lett. B303 (1993) 183. [19] A. Kwiatkowski et al., Proc. Workshop on Physics at HERA, Vol. 3 (1991) p. 1294. [20] L. Lonnblad, LU TP-89-10 (1989). [21] T. Sjostrand, Comput. Phys. Commun. 39 (1987) 347; T. Sjostrand and M. Bengtson, Comput. Phys. Commun. 43 (1987) 367.

175 PL9601081 PL9601080 FNAŁ £665 Experiment The inelastic fi+p and /x+-nucleus interactions

The E665 Collaboration6 The INP group: A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik, P. Stopa7 The group led by J. Figiel has been, continuing investigations of muon-nucleon (nucleus) interactions at 490 GeV. In 1993 the reduction process of the data of the 1990 run (fi+b,Ca interactions) was completed and of the 1991 run (/x+Z?2,J2 interactions) was well advanced. In particular our group was involved in software development and studies of systematic errors. Other activity of growing importance to which our group contributed significantly was the analysis of various physical subjects using processed data. The following problems were studied : a) The Bose - Einstein Correlations in muon - nucleon interactions [1] b) Measurements of the ratio crnjav in inelastic muon - nucleon scattering at very low x and Q2 [2] c) Perturbative QCD effects in deep — inelastic muon scattering and determination of strong coupling constant a,(Q2) [3,4] d) Production of charged hadrons in muon - deuterium and muon - xenon interactions, nuclear effects in lepto - production of hadrons [5,6] e) Production of neutral strange particles in muon - nucleon scattering [7] In 1993 7 papers were prepared of which 2 have been already published and 4 have been accepted for publication. Some of them are presented briefly below.

Q2 Dependence of the Average Squared Transverse Energy of Jets in Deep — Inelastic Muon — Nuclepn Scattering with Comparison to QCD Predictions The E665 Collaboration In the parton model of deep - inelastic muon - nucleon scattering, a virtual photon interacts with a single quark within the nucleon. The experimental signature in the photon - nucleon centre of mass system is a forward jet of particles resulting from the struck quark and a backward jet coming from remnants of the nucleon. Perturbative Quantum Chromodynamics (PQCD) corrections introduce processes with two current partons with transverse energy relative to the virtual photon direction. To the first order this energy is proportional to the strong coupling constant a,. As it cannot be measured directly we measured instead the average transverse energy of jets as a function of four momentum transfer Q2 of the scattered muon. It turned out that, on average, this is a good measure of the parton final state. So it was possible 2 to deduce from the single process the dependence of a3 on Q . As can be sean from Fig.l our results are compatible with PQCD predictions and the other measurements.

"Albert-Ludwigs -Universitat Freiburg i. Br.,Germany, Argonne National Laboratory, Argonne IL USA, Uni- versity of California, San Diego, CA USA, Fermi National Accelerator Laboratory, Batavia, IL USA, Harvard University, Cambridge, MA USA, University of Illinois, Chicago, IL USA, Institute of Nuclear Physics, Kraków, Poland, Department of Nuclear Physics and Technique, Academy of Mining and Metallurgy, Kraków, Poland, University of Maryland, College Park, MD USA, Massachusetts Institute of Technology, Cambridge, MA USA, Max-Planck-Institut fur Physik Munich, Germany, Northwestern University, Evanston, IL USA, University of Washington, Seattle, WA USA, University of Wuppertal, Wuppertal, Germany, Yale University, New Haven, CT USA, 7work of Kraków group supported partly by the grant 2P30204104 of the State Committee for Scientific Reseach

176 PL9601082

* R, -b l • £655 JET ANALYSIS » cc mo»3 splitting b) • 0IS(k) © OIS(M) O '. T decoys

A o'e" evt shopes a «*e" evt shapes i O r(Z->-hod) $ «'«" evt shop«s

.UJ.L . '""''2 :^ 10 10 10 10 10 ' 1 1 Q1 (GeV') Q (GeV )

2 Fig.l: a) at(Q ), the point are the data, the line shows the PQCD prediction, 2 b) as(Q ), E665 data compared with other experiments

Production of charged hadrons by positive muons on Deuterium and Xenon at 490 GeV [5,6] The E665 Collaboration The hadrons produced in lepton - nucleon interaction originate mainly from parton fragmentation. This is non - perturbative strong process for which there is no satisfactory theory. That is why it is important to study it experimentally. This experiment is specially suited for this purpouse because of nearly complete reconstruction of hadronic final state up to CMS energy W = 30 GeV. The results for (i D interaction may be summarised a following: a) The average charged multiplicity increases approximately linearly with In (W2), the width of the distribution is proportional to its average. b) With increase of energy W the " plateau " in rapidity distribution develops. c) The positive, short range correlation between backward and forward multiplicities and two- particle correlation are observed. For the ft+Xe interaction the distributions of hadrons are modified due to possible reinteractions in the Xe nucleus. The most striking nuclear effect is the excess of hadrons (mainly positive) in the backward hemisphere whereas no significant increase is found is the central region. This suggests presence of the intranuclear cascade but very weak multiple projectile ( = photon dissociated into hadronic state) scattering. The collisions inside the nucleus produce the " knock out " protons some of which can be observed as so called "gray" tracks. There is of course positive correalation between number of collision and multiplicity of grey tracks, which enables more detailed study of nuclear effects in hadron production. This is demonstrated in Fig.2, where the ratio of multiplicities in (i+Xe

177 and fi+D in function of rapidity is shown for events without and with grey tracks. Clearly the nuclear multiplication of hadrons is rather weak for no = 0.

Ratio CuXe) / ) U|

10 = 0

charged

• 1111111111111 u 111111111111 ii 1111111111111 2 ,JD 4

Fig.2 The ratio of charged particles densities as a function of CMS rapidity y* in /i+le and interactions for two subsamples of fi Xe interactions: without (TIG — 0) and with grey tracks (na ^ 0).

We tried also to compare hadron production in two subsamples of fi+Xe interactions: one in which the shadowing of the per- nucleon cross- section is observed (see previous Annual Report) (XBJ < 0.02) and second - where it is negligible (XBJ > 0.02). This comparison may give insight into the mechanism of shadowing in lepton - nucleus interaction. Very preliminary results are presented in Fig.3. Surprisingly, the effect of nuclear cascading is weaker in the non- shadowing sample then in the shadowing one. The investigation of this subject is being continued.

• 11111111 1.4 |_' ' ' ' 1 ' ' ' ' 1 i • • * . 1 , , , . 1 , . . , 1 1 1 1 IJ A • shad. i Cv, 1.2 L f 1 o non—sh. i 1111 1 X °-B 1 M °-« 0.6 o o c o 0 X 0.4 # * • • 0.2 i o j

0 !•••••-• *-«- -0.2 * -Ę -0.4 §-.... •.I.I.III i. , i , 1,,,. 1,,,, l . , , , 1 , , , , 1 , , . ,~ -5 -4 -2 -1 3

Fig.3. Difference of charged particles densities in n+Xe and fiD interactions as a function of CMS rapidity y* in shadowing (black circles) and non - shadowing regions (open circles).

178 References PL9601083

[1] M.R. Adams et al., An Investigation of Bose-Einstein Correlations in Muon-Nucleon Inter- actions at 490 GeV, Phys. Lett. B308, 418 (1993).

[2] M.R. Adams et al., Measurement of the ratio

Experiments with Ultrarelativistic Heavy Ions at CERN )<<>'•

Our participation in experiments with ultrarelativistic heavy ions at CERN can be described in three points: 1. Continuation of data analysis from the experiment NA35 at the SPS The NA35 Collaboration involves the following laboratories: Athens (Univ.) - Bari (INFN and Polit.) - Berkeley (LBL) - CERN - Kraków (INP) - Darmstadt (GSI) - Frankfurt (Univ.) - Freiburg (Univ.) - Marburg (Univ.) - Munich (MPI) - Warsaw (Univ. and INS) - Zagreb (IRB). This experiment, in which the 2 m long streamer chamber placed in a magnetic field served as the main detector which was supplemented with a set of calorimeters, took data with oxygen and sulphur beams of 60 and 200 GeV/nucleon at the SPS in the years 1986-92. A time projection chamber (TPC) was added to the set up at the later stage, allowing to obtain significantly higher statistics and precise momentum analysis also for particles emitted into the forward hemisphere. Data analysis from the streamer chamber and the TPC is still being continued, focussed on different aspects of nuclear collisions. In 1993 two papers were published by the Col- laboration, five presented at the Quark Matter Conference in Borlange, Sweden, and one submitted for publication. Below we present results of the investigation of intermittency.

2. Preparation of the experiment NA49 at the SPS This experiment aims to study interactions of lead ions at 160 GeV/nucleon, which should be accelerated in the SPS by the end of 1994. Approved in 1991, and using mostly new apparatus with large TPC 's as principal detectors, the NA49 experiment is being prepared by the collaboration with has evolved from NA35, with a few newcomers (KFKI Budapest, Univ. of Birmingham, Univ. of Washington in Seattle). Our contribution to NA49 is threefold : a) development of electronics and programming for low-voltage power supply system for the TPC 's ;

179 PL9601084 b) construction of the mechanical manipulator/extractor for handling the TPC readout plates for the Main TPC ; c) computer simulation of the TPC performance. Preparation of the heavy ion experiment ALICE at the LHC The Letter of Intent for ALICE was submitted to the LHC Committee on March 1, 1993. In view of many questions from the referees, extensive simulation activities are still going on. In particular, in Kraków the performance of the TPC is being studied by computer simulation within the RD-32 programme. A short account of a part of this work is given below.

Our participation in the NA35/NA49 experiments is supported by the grant from the State Com- mittee for Scientific Studies (KBN), Nr. 204369101 (the grant manager is Prof. E. Skrzypczak of Warsaw University), and since recently also by the allocation Nr. 565/93/LN from the Polish- German Foundation, granted to Prof. J. Bartke.

CERN Experiment NA35 The NA35 Collaboration, from Krakow: B. Wosiek, J. Bartke, E. Gładysz, M. Kowalski, P. Stefański

An Investigation of Intermittency in Proton-Gold, Oxygen-Gold, Sulphur-Gold and Sulphur-Sulphur Interactions at 200 GeV per Nucleon8

The intermittency phenomenon is investigated in proton-gold, oxygen-gold, sulphur-gold and sulphur-sulphur collisions at 200 GeV per nucleon. The data were taken with the NA35 streamer chamber detector at the CERN SPS. The data samples were carefully cleaned from double-countings of tracks. Using the Fritiof event generator and the GEANT detector simulation package contaminations from photon conversions, particle decays and secondary interactions were determined. Such contaminations are shown to have a sizable effect on the observed intermittency signal and the necessary corrections have been applied. Two methods are adopted to study intermittency. The first method uses factorial moments Fq, for which a modified definition is employed to eliminate the effects from the non-uniform single particle distributions and from correlations between the kinematical hadron variables. The second method uses correlation in- GHP tegrals Fq . One of their advantages over the Fq moments is the fact that they have smaller statistical errors what allows to extend the analysis to smaller cell sizes in phase space. The correlation integral of the order q is denned as [1]

HP m F? (v) = (Nq(v))/(N™ (v)}

where Nq(v) denotes the total number of g-tuples in an event within a cell of volume v. For normalization, JVJlorm, the number of q-tuples of uncorrelated particles is counted in fake events which are constructed from the experimental data sample. For each fake event it was required that all N particles are taken from N different randomly chosen real events. The averaging () is performed over the whole event (fake event) sample. The superscript GHP refers to the symmetrized integral for which one requires that all q particles are within a cell of volume v.

J. Bachler et al., accepted for publication in Z. Phys. C

180 The analysis is carried out in three-dimensional (y,pr, ) phase space. For each reaction we start with the phase space volume V = Ay • Apr • A, where Ay = 2.0, Apr = 1.995 GeV/c and A = 2ir. The number of g-tuples is counted in movable phase space cells of size v in real and fake events and correlation integrals are calculated according to (1). The data are compared with the Monte Carlo (MC) simulations for which we have used the Pritiof event generator with the additional incorporation of Bose-Einstein correlations [2]. Fig.l shows corrected FjfHP moments for negative particles for q = 2 and q = 3. They are plotted as a function of the total number of three-dimensional cells M3 — V/v. On the left (right) hand side plots for the data (MC) are shown. A clear evidence for fluctuations can be seen in all reactions. The moments differ from unity and increase with decreasing size of the cell (i.e. with increasing M3). A somewhat stronger and earlier rise is seen for pAu data. For nucleus-nucleus (AA) collisions the effect is weaker and long range correlations seem to be suppressed. No significant differences are seen between OAu, SAu and SS collisions. The observed reduction of the correlations for AA collisions as compared to pAu data is however not as strong as expected in superposition models [3]. Thus, to explain AA results some collective effects are required and BE interference is an obvious candidate.

10* 10"

Fig.l Log-log plots of FS>HP VS. Af3 for negative Fig.2 Log-log plots of F?HP vs. Jlf3 for (-, -) hadions. and (+, —) pairs. To investigate the importance of BE correlations we compare (Fig.2) the correlation integrals for like sign and unlike sign pairs (results for SAu reactions are not shown, since only negatively charged particles were measured). A strong rise of F2HP for (—) pairs contrasts with almost flat moments for (H—) pairs and favours the explanation by BE interference effects. HF From the data on the moments Fq and F^ and their comparison with the MC simulation (which included Bose-Einstein correlations) the following main physics conclusions are drawn: Basically, the analysis in terms of factorial moments lead to the same physics results as the analysis of correlation integrals, however, the latter exhibit the observed effects more clearly. For negative hadrons the moments rise with decreasing cell size, thus showing nonstatistical fluctuations. This rise is stronger for the third than for the second order moments. The correlations are weaker for AA collisions than in pAu data, however the effect decreases much more slowly than (dN~/dy)'1 which would be expected in superposition models.

181 PL9601085 We observe no significant effect of nonstatistical fluctuations for (H—) pairs. A Monte Carlo version of the Pritiof model, which approximately incorporates the BE correlations describes the data reasonably well. From a comparison of the second correlation integral for (H—) and (—) pairs we conclude that the observed correlations are probably due mostly to the Bose-Einstein interference. Consistency between data and MC simulations supports the BE interpretation. References: 1. P. Lipa et al., Phys. Lett. B285, 300 (1992) 2. K. Kadija and P. Seyboth, Phys. Lett. B287, 363 (1992) 3. A. Capella et al., Phys. Lett. B230, 271 (1989)

Calculation of Space Charge Distortions in ALICE TPC

Marek Kowalski

In Time Projection Chambers working in the environment of high particle densities ( large multiplicities and/or high event rates ) one of the possible sources of the distortions of tracks is the build-up of positive charge from the primary ionization in the drift volume. The reason is that the drift velocity of positive ions is by 3-4 orders of magnitude lower than for electrons what leads to the permanent presence of the positive charge and thus to the extra electric field, affecting drift of the electron swarm to readout chambers. This can be particulary harmful for heavy ion collider experiments like STAR at RHIC or ALICE at LHC. The detailed calculation of the space charge effect is therefore very important. In order to calculate the above distortions one has to solve the Poisson equation in cylindrical coordinate system: 2) = p(R,z), where $ is the potential, p is charge density and drift is along the z-axis. The charge density can be obtained from the y — pt distribution taken from Monte Carlo.

I I I 50 100 150 200 250 100 150 200 250 z. cm z, cm

182 PL9601086 The Figure shows radial (a) and azimuthal (b) distortions for ALICE TPC filled with the

Ne/CH4/CO2 88/10/2 mixture which is considered in ALICE Letter of Intent as the primary choice. The calculations have been done for the highest luminosity L = 2*1027 cm"2 s"1 which corresponds to the event rate of 11.6 kHz. One should notice that these distortions scale linearily with the luminosity, for event rate of 5 kHz they are smaller by a factor of ~2. In order to reduce them one can also use gases with small Z and/or higher drift velocity of positive ions. The validity of above calculations has been checked using data from the NA49 TPC 1993 test run. The TPC has been irradiated with the muon beam. The space charge resulted as the effect of opened gate which allowed the leaking of positive ions from the gas multiplication process to the drift volume. Results of calculation reproduce the order of magnitude and the general behaviour of the data, better description requires more detailed knowledge of gas parameters.

BNL 868 Experiment9 The KLMM Collaboration10 from Kraków: A. Dąbrowska, R. Hołyński, A. Olszewski, M. Szarska, B. Wilczyńska and W. Wolter

Interactions of 10.6 GeV/n Gold Nuclei in Nuclear Emulsion

In 1992 the Brookhaven AGS accelerated for the first time a beam of gold ions, delivering nuclei with kinetic energy of 10.6 GeV/n to the target areas. We exposed a number of stacks of BR-2 nuclear emulsion to these nuclei. Here we present the analysis of 461 interactions [1], for which the angles of emission of all charged particles and charges of multicharged projectile fragments have been measured.

The number of released protons from the gold projectile is defined as np = Zj^n — (2 • Na + Y^N %F)' The Np and Zp denote the number and charges of the projectile fragments with Z>3 and Na is the number of alpha particles emitted from the projectile nucleus. In order to test the dependence of the fragmentation of a projectile nucleus on the energy of the projectile we have compared our results with those obtained at lower energies, <1 GeV/n [2]. The fractional yields of fragments with Z>3 at the two energies are compared in Fig. 1. At first sight it appears that these yields are nearly identical. There is however a significant difference at Np = 0, such that at the higher energy nearly 10% of the interactions have no fragments, whereas the low energy projectiles are essentially never completely disrupted. Also, the mean charge of the fragments from the high energy projectiles is 20.3±0.6, which is significantly less than 28.3±0.9 for the fragments at the low projectile energies. The fractional yields of alpha particles are compared in Fig. 2. It is three times less likely to have no alpha particles at high energy interactions than at lower energy, but twice as likely to produce between 3 and 6 alphas. On the other hand, copious alpha particle emission, Na > 7, although relatively rare, appears to be independent of the projectile energy. As a consequence of the above differences in the fragmentation of a projectile into multicharged fragments, the fractional yields of released protons also show a significant energy dependence (see Fig. 3). At low energy 48% of all the interactions have very few, np < 4, protons released, to compare with only 16% of such events

'This research has been partially supported in Poland by State Committee for Scientific Research, grant No 203799101. 10Participating institutions: Institute of Nuclear Physics, Kraków, Poland; Department of Physics and As- tronomy, Louisiana State University, Baton Rouge, LA, USA; University of Minnesota, Minneapolis, MN, USA; Institute of Theoretical and Experimental Physics, Moscow, Russia.

183 at the high energy. The high energy interactions have also consistently higher yields of events with rip > 30. A special case of nucleus fragmentation is a fission of a nucleus, where just two heavy fragments are emitted. The fission of gold nuclei have been studied and the striking result is an almost complete suppression of fission of the gold nuclei in the high energy interactions [3]. In Fig.4 we show the yields of a fission seen at lower energies compared to that observed for the high energy projectiles. It can be seen that there is a suppression of fission by more than an order of magnitude. Concluding, the breakup of the projectile gold nuclei at the energy of 10.6 GeV/n is appreciably more severe than that observed at the lower energies. Although on the average a similar number of fragments is produced, their mean charges are smaller at high energy interactions. Similarly, more alpha particles and released protons are observed in these energetic interactions and, finally the fission of the gold nuclei, relatively frequent at lower energies, becomes largely suppressed at the high energy.

0.5 - x 2 0.25 o E£ I.OAGeV EC I.OAGeV ! 0.4 O f 0.2 • E- 10.6AGeV o O # E-10.6A6eV g 0.3 - | 0.15 - 1 O o OJ H- 0.1 PI 0.05 •!!•:»• rt> . 1 ? a « # : , 0 2 4 0 4 a 6 N,8 12 N. Figure 1. The fractional yields of fragments Figure 2. The fractional yields of alpha parti-

NF with Z > 3. cles at the two energies.

tO0.48 O E< t.OACeV 1 •o °-2 • E-10.6AG8V 7> ^ 0.15

a h >no l yiel d

U -2

fractio n • ••• • -•:•!•• ,i t 1 20 4D 60 80 10 - 1 io E[Gev/n]

Figure 3. Fractional yields of released protons Figure 4. Fractional yield of fission events as at the two energies. a function of incident energy.

References

1. M.L. Cherry et al., Inst. of Nuci. Phys., Kraków, Poland, Report No. 1637/PH, June 1993, in press in Z. Phys. C (1994). R. Hołyński, Proc. 10th Inter. Conf. on Ultra-Rel. Nucleus-Nucleus Collisions, Borlange (1993), to be published in Nuclear Phys. A (1994). 2. C.J. Waddington and P.S. Freier, Phys. Rev. C31 388 (1985).

3. C.J. Waddington et al., Proc. 23rd ICRC, Calgary, Vol.2;203 (1993).

184 PL9601087 FNAŁ - experiment 667 The KLMT Collaboration1

From Kraków: A. Dąbrowska, R. Hołyński, A. Jurak, M. Szarska, B. Wosiek and K. Woźniak

Measurements of 525 GeV pion interactions in emulsion2

Measurements have been made of inclusive T~ interactions in emulsion at 525 GeV, the highest available fixed target energy. We present the 525 GeV results2 together with a comparison with the earlier pion and proton data. The ratio of the dispersion of multiplicity distribution of shower particles n5 to its average value is constant at all energies for both protons and pions. The KNO scaling appears to hold for T~-emulsion collisions in the energy range 60-525 GeV. The shower particle pseudorapidity distributions are independent of the beam energy in the target fragmentation region and in the projectile fragmentation region. Both the multiplicity and pseudorapidity distributions of shower particles measured at 525 GeV agree well with the FRITIOF model predictions. The multiplicity distributions of heavily ionizing particles {Nh), mostly target fragments, do not vary significantly with the energy. 5 A/ A 4.5 V 40 L n" (525 GeV)-Em v 35 3.5 - 30

20 2.5 - 15 2 - 10

I I I ł f I I I I I I I I I t 1.5 10 20 30 40

Fig.l The mean multiplicity {nt) of shower particles Fig.2 The dependence of the average pseudorapi- as a function of Nh- dity on Nh-

The dependence of the shower particle multiplicity (nt) on Nh approaches saturation as the number of heavy tracks exceeds about 20 (see Fig.l). The shower particle pseudorapidity distributions shift toward lower values with increasing Nh- In consequence the average pseudorapidity decreases with increasing Nh, as it is shown in Fig.2. For large Nh this dependence, however, seems to level off. Thus, one can conclude that for interactions characterized by the high values of N^ i.e. violent target nucleus disruption, the multiparticle production process becomes independent of the target fragmentation.

1 Participating institutions: Institute of Nuclear Physics, Kraków, Poland; Louisiana State University, Baton Rouge , LA, USA; Lebedev Physical Institute, Moscow, Russia; Physical Technical Institute, Tashkent, Uzbeki- stan. 2M.L. Cherry et al., to be published in Phys. Rev. D.

185 PL9601088 1 \r.' CERN - EMU07 experiment The KŁM Collaboration 2

From Kraków: A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski, M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek and K. Woźniak Particle production in interactions of 200 GeV/nucleon oxygen and sulfur nuclei in nuclear emulsion Oxygen and sulfur nuclei with energies of 200 GeV/nucleon from CERN SPS interacted in nuclear emulsions and were scanned with minimum bias criteria so that essentially all the interactions were detected. Approximately 1000 interactions of each projectile were analyzed [1]. Results on the multiplicity distributions, the pseudorapidity distributions and the fragmentation of the projectile and target nuclei were presented. These results concentrated on obtaining a global description of the inelastic interactions by analyzing inclusive data sample. In addition the subsamples of interactions characterized by different degrees of centrality were also studied.

It is shown that the mean number of intranuclear nucleon-nucleon collisions, {Ncoii), calculated from a superposition model, is a useful parameter to organize the data. We have found that the normalized particle multiplicity is a function of the number of intranuclear collisions only and depends neither on the mass of the projectile nor on its energy (see Fig.l).

20 40 60 80 100 120

Fig.l The dependance of the normalized mean Fig. 2 The inclusive pseudorapidity distributions

multiplicity {NT)/((Nr)pp) on (NcoU) for oxygen of shower particles, produced in proton (stars), (open squares) and sulfur (solid squares) interac- oxygen (open squares), and sulfur (solid squares) tions in emulsion at 200 GeV/n. The published interaction in emulsion. [2] data for oxygen interactions in emulsion at 14.5, 60, and 200 GeV/n are shown by stars. The inclusive pseudorapidity distributions of shower particles, N,, produced in proton, oxygen and sulfur interactions in nuclear emulsion are shown in Fig.2. The increase of particle production with increasing mass of the projectile is evident over the entire range of pseudorapidity. However, a more detailed analysis of pseudorapidity distributions has shown that the angular distributions of shower particles from oxygen and sulfur projectiles are essentially the

same for groups of events characterized by similar values of (Ncou). The universal dependence of the scaled multiplicity on the number of nucleon-nucleon colli-

sions, observed in a wide range of (Ncou), together with other results presented in [1] strongly supports the superposition models.

'This research has been partially supported in Poland by State Committee for Scientific Research, grant No 203799101. 2Participating institutions: Institute of Nuclear Physics, Kraków, Poland; Louisiana State University, Baton Rouge, LA, USA; University of Minnesota, Minneapolis, MN, USA.

186 References: 1 1. A. Dąbrowska et al., Phys. Rev. D47, 1751 (1993). PL9601Ó89 2. M.I. Adamovich et al., Raport LUIP 9103 (1991).

Comparison of particle production in nucleus-nucleus /1 collisions with predictions of the Venus Monte Carlo model A comparative analysis of the particle production in 200 GeV/nucleon oxygen and sulfur interactions in emulsion has been done [1,2] using the Venus 4.02 Monte Carlo model. The data samples contain about one thousand inclusive interactions for each projectile. For each interaction the forward charge flow, Qp, was determined from the measurements of angles and charges of projectile fragments. The charge flow distributions can be directly compared to the Monte Carlo predictions. To improve the agreement for large Qp values, the uncertainties in charge measurements of heavy projectile fragments were taken into account in the model calculations of Qp [2]. The uncertainties were assumed to have a gaussian shape with the widths of 0.3-0.5 and 0*3-0.7 for oxygen and sulfur interactions respectively. A resulting good agreement is shown in Fig.l. 0.28 i r 0.28

4 8 12 8 16 24

charge flow, Qf charge flow, Q, Fig.l Charge flow distributions for a) 16O and b) 32S - interactions in emulsion. Solid line - experimental data, dotted line - Venus model predictions with uncertainties of charge measurements included. The relation between the forward charge flow and the number of intranuclear nucleon-nucleon collisions was calculated from the Venus model for both oxygen and sulfur interactions in emulsion. Using this relation we compared the measured multiplicity of produced charged particles in interactions characterized by different degrees of centrality with the model predictions. The results are presented in Fig.2.

fWV/

• , i 1 400

300

200 _ o • V o - • 100 - 8 "0-Em

n '.iii 1 1 • .i., 30 60 90 120 30 60 90 120

Fig.2 Comparison of the Monte Carlo predictions (open circles) and the experimental data

(solid circles) of the dependence of (Nx) on (Ncoii).

187 PL9601090

Prom Fig. 2 we see that the relation between the mean multiplicity and the corresponding number of intranuclear collisions is well reproduced by the Monte Carlo simulations, except for the largest values of (Ncon) where multiplicities predicted by the model are slightly larger than the measured ones. References: 1. A. Dąbrowska et al., Phys. Rev. D47, 1751 (1993). 2. R. Holyński et al., 23rd ICRC, vol.4, 9 (1993).

Multifractal analysis of nucleus-nucleus interactions

We have performed a multifractal (G-moment) analysis of 14.6-200 GeV/nucleon nucleus- nucleus and 200-800 GeV proton-nucleus interactions from KLM and Fermilab E-90 and E-508 emulsion data, including explicit corrections for the finite statistical sample [1]. The corrected slopes of the G-moments for protons, 16O,28 Si, and32 S nuclei show only slight evidence for departures from random behaviour. The case of 32S - AgBr, the heaviest system that has been investigated, is the most interesting from the point of view of having the smallest statistical uncertainty in the derived slope parameters. Only this system shows convincing evidence for nonrandom behaviour. Given the size of the uncertainties for all investigated systems, the results of the fractal analysis are not inconsistent either with results of intermittency analyses for nucleus-nucleus collisions [2,3] or with the nonrandom behaviour previously reported for leptonic and hadronic collisions. It should be emphasized that for central nucleus-nucleus collisions, the fluctuations are small and are dominated by statistical background. It is therefore a crucial and rather difficult task, often dependent on the detailed analysis method, to disentangle dynamical and statistical fluctuations. We have shown that because of the effects of statistical noise, the fractal analysis is not as sensitive as the intermittency analysis for detecting non-statistical fluctuations.

References: 1. K. Sengupta et al., Phys. Rev. D48, 3174 (1993). 2. R. Hołyński et al., Phys. Rev. Lett. 62, 733 (1989); Phys. Rev. C40, R2449 (1989). 3. B. Wosiek, INP Preprint 1553/PH (1991).

188 PL9601091 BNL - Experiment PROBOS at RHIC 1 The PHOBOS Collaboration2 From Krakow: A. Białas, A. Budzanowski, T. Coghen, W. Czyż, J. Godlewski, R. Hołyński, J. Kotuła, H. Lemler, P. Malecki, A. Olszewski, K. Pakoński, H. Palarczyk, M. Stodulski, A. Trzupek, H. Wilczyński, B. Wosiek, K. Woźniak and K. Zalewski

The PHOBOS experiment [1,2,3] will explore the rich physics program for the collisions of the beams of gold nuclei at Relativistic Heavy Ion Collider (RHIC) in Brookhaven. This will be the first accelerator, where the beams of heavy ions will collide at relativistic energy (100 GeV/nucleon each). It will open a new area of research - the physics of strongly interacting matter at extreme energy densities. In such conditions the creation of the Quark Gluon Plasma (QGP) is expected. There are several sensitive observables to probe the existence of the QGP. The PHOBOS detector is designed to study a number of this specific signatures like e.g. structures in the pt distributions, multiparticle correlations, abundant production of some species of particles and other. Some of these observables can be investigated on an event-by-event basis, the other will be obtained from the inclusive high statistics measurements.

Multiparticle Paddle spectrometers Trigger counters Time of flight array

High 7j trigger counters

Ring multiplicity detector Magnet yoke Pole piece Vertex detectors and coil

Fig.l The overall view of the PHOBOS detector (upper part of the magnet is not drawn to show the details of the multiparticle spectrometer). The PHOBOS experiment will focus on the precise measurements of the particles produced in the central region, where the search for QGP should be most promissing. These measurements

'Supported in part in Poland by State Committee for Scientific Reasearch, grant No 2P302 151 04 2Participating institutions: From USA: Brookhaven National Laboratory, Massachusetts Institute of Tech- nology, University of Illinois at Chicago, University of Maryland, Yale University; From Danmark: Niels Bohr Institute, University of Copenhagen; From Poland: Institute of Nuclear Physics, Jagellonian University.

189 with the limited phase space acceptance will be complemented with information about the global event features. The multiplicity and the emission angles of the particles will be measured in a very wide pseudorapidity interval (-5.5 to 5.5) by the vertex and multiplicity detectors. In the central region of rapidity (between 0 and 1.5) the charged and decaying neutral particles will be identified and their momenta will be precisely measured in the two-arm spectrometer placed in the magnetic field. We have chosen the conventional magnet with 2 Tesla magnetic field, since it can produce more uniform field in a wide area. The planes of silicon with pads or strips will be used as the active elements everywhere except the TOF and trigger counters. Mechanical structure and cooling system

The PHOBOS detector can be divided into three groups: multiparticle two arm spectrometer, vertex detector and ring multiplicity detectors. Each type of detectors requires a rigid mechanical structure ensuring precise and stable location of silicon planes and an efficient cooling system which will keep front-end electronics and detectors at constant temperature. The Krakow group of the PHOBOS collaboration is responsible, among others, for designing and manufacturing of both mechanical structures and cooling systems. Intensive studies have been performed to prepare the documentation of the design. The present design of mechanical structures and cooling systems is presented in Conceptual Design Report [3] (see also Fig.l). Finite Element Method has been used to calculate the rigidity of supporting structures and the efficiency of cooling systems. Bending stiffness of the spectrometer base plate is the most crucial among the mechanical issues. Acceptable deflection of 0.5 mm over the distance of 1500 mm requires extremely high concern in the design and the selection of the material of the plate. From various light materials considered for a spectrometer base plate, carbon-epoxy composite has the best mechanical properties and is planned to be used.

PHOBOS STRIP DETECTORS PHOBOS PAD DETECTORS tempera I u re i in stagnant air temperatures in stagnant air Ql- lOfl W/m.v-ZOI/mln Q.I- (10 w/m. v- ZZ 1/min

« MM A M N IN iii lit IM IM position across deUctor position across detector Fig.2 Comparison of the measured and calculated temperatures for two kinds of the PHOBOS silicon detectors. The front-end electronics of spectrometer and vertex detectors is cooled with water while that of ring multiplicity detectors with moving air. The water cooling system consists of two closed circuits. The circuit cooling front-end electronics is working at pressure lower than the atmospheric one to avoid water leakage. The cooling system is designed to absorb heat emitted from electronics and magnet as well, and to keep the silicon detector temperature at about 20°C. The results of the heat flow calculations have been compared with the experimental data obtained for specially built models of cooling frames with pad and strip detectors (Fig.2). The

190 presented diagrams indicate, that the special attention has to be payed to the pad detector design.

The Monte Carlo simulations

In the central collisions of two Au nuclei at RHIC energies we expect very large number of particles produced in the primary interaction. As they traverse the material surrounding the interaction point a number of secondary interactions occurs in which several times more background particles is produced - most of them in the magnet yoke and coil. The Monte Carlo simulations using the GEANT simulation package were performed in order to check the capability of track recognition and identification of the particles in the spectrometer. We have used the central events produced by HIJET Monte Carlo event generator and normalized all results to a "standard" event with dnch/dy=1000 at y=0, what corresponds to about 14000 primary particles. First we have studied the occupancy (i.e. the number of the particles hitting a detector plane divided by the number of channels in this plane). In most planes we have managed to keep the occupancy close to 3% - the value that should ensure an efficient and reliable pattern recognition. Only in some planes in their parts closest to the beam pipe occupancy was much higher - up to maximum of 12%. Those parts of the spectrometer will be still usefull for the events with lower multiplicity. The results of the analysis of the trajectories of particles with different momenta and ra- pidities, produced at three positions of the interaction point (-10, 0, 10 cm) (Fig.3), were used to optimize the geometry of the spectrometer. The final positions and dimensions of the silicon planes in the spectrometer were chosen to obtain the highest acceptance and best momentum resolution, without exceeding the planned cost.

Fig.3 Examples of the trajectories of particles with different momenta produced at vertex position = 0 cm. For the optimized spectrometer layout we have determined the geometrical acceptance for measuring and identification of different particle species. Our results (Table 1) were scaled to 106 "standard" events (such that dnch/dy=l000 at y=0). We assume, that a particle is measured when it traverses sufficient number of planes to accuratelly determine its momentum. Using the measured values of dE/dx we can identify pions and kaons with momenta up to 550 MeV/c, protons up to 950 MeV/c. The TOF measurements can increase those limits to 1200 MeV/c and 2000 MeV/c respectively.

191 Particle Measured Identified by dE/dx Identified by dE/dx or TOF 7 7 7 TT* 5.4xl0 3.1X10 4.8X10 K± 2.4X106 0.9X108 1.9X108 p and p 2.2xlO6 1.5xlO6 1.9X106 K°, 8.2xlO3 5.9xlO3 6.4xl03 A 3.7xlO3 3.0xl03 3.7xlO3 A 3.0X103 3.1X103 2.6X103 c£(1020) 5.7xlO3 0.8 xlO3 4.4xl03

Table 1. Numbers of various particles measured and identified, for 106 standard events.

The measured and identified particles will have rapidity in the range 0-1 (pions up to 1.8). ± ± The lowest pt that can be observed are: 20 MeV/c for T , 60 MeV/c for K and 80 MeV/c for p and p. The phase space regions, where PHOBOS spectrometer will identify particles can be seen in Fig. 4.

1 — o) O ex 0.8 —

0.6 —

0.4

0.2 ijijjii1 1 1 i1 iiiiii! 1 1 1 1 1 !! n i,'i I ! ! ! IH|l|l •i ! ! ! ; 1111111 11111111111111 0.5 1 1.5 2 y Fig.4 The kinematical regions, where the particles will be measured and identified (using dE/dx information only): a) w^,b) p and p.

References: 1. "A Letter of Intent to Study Very Low pt Phenomena at RHIC" - PHOBOS Collaboration, 1992 2. "Proposal to Study Very Low pt Phenomena at RHIC" - PHOBOS Collaboration, 1992 3. "PHOBOS Conceptual Design Report", PHOBOS Collaboration, 1993.

192 JACEE Experiment" PL9601092 From Kraków: R. Hołyński, B. Wilczyńska, H. Wilczyński and W. Wolter

Cosmic ray composition, energy spectra and nuclear interactions are studied by the JACEE Collaboration with emulsion chambers exposed to cosmic radiation in balloon flights at high altitude. Both primary cosmic ray particle and products of its interaction are recorded in the chamber. Primary particle charge and energy are measured, thus elemental composition and spectra can be obtained at energies in the 1-100 TeV/nucleon energy range.

1 Cosmic ray spectrum

Cosmic ray energy spectrum spans many orders of magnitude: from MeV region to 1O20 eV. The intensity of cosmic radiation falls with energy according to E~21 power law below 1015 eV and E~32 above 1016 eV. The break in the energy spectrum around 1015 - 1016 eV is called the 'knee'. While at low energies the cosmic ray flux is large enough for use of small detectors (spectrometers, calorimeters, etc.) to collect data, spectra of individual elements cannot be determined at energies above about 1014 eV due to insufficient data statistics which can be accumulated during lifetime of an apparatus. It has long been expected that the knee in cosmic ray spectrum may be due to some important change in cosmic ray acceleration mechanisms and/or propagation conditions in the Galaxy, when one mechanism becomes less effective and the other takes over. Therefore detailed cosmic ray study at energies 1012 -1015 eV is of critical importance to our understanding of acceleration and propagation of cosmic ray particles. Presently available experimental data on spectra of individual elements cover only the region well below the knee. The highest energy data on composition and spectra presently available are those provided by JACEE [1]. Summary of JACEE data on proton spectrum [2] is shown in Fig.l. JACEE-1 to JACEE-6 denote the emulsion chambers exposed to cosmic radiation in balloon flights in the U.S.A., while JACEE-7 and JACEE-8 are the chambers from long duration balloon flights Australia - South America. As the statistics increased, the steepening of the spectrum was increasingly evident at energy above 4-1013 eV. Spectra of heavier elements [3] tend to flatten in this energy region, as shown in Fig.2. This is in a rough agreement with expectations for cosmic ray acceleration in supernova remnants: as proton spectrum gets cut off, the fraction of heavier nuclei should increase with energy before the heavier nuclei consecutively reach their limiting energies. However, present data show no sign of spectral cutoff of Helium nuclei up to 1014 eV/nucleon. Clearly, the data is not sufficient to draw definite conclusions. In December 93/January 94 new JACEE emulsion chambers were exposed to cosmic radiation in long duration balloon flights in Antarctica. New data from these chambers will significantly increase our statistics, and will extend the experimental spectra to higher energies.

2 High energy interactions

A special effort was devoted to heavy particle decay study. Among the interactions detected so far two events were found which contain secondary vertices with almost identical, characteristic topology: a singly charged particle track undergoes a kink, with four photons apparently emitted

'Participating institutions: Institute for Cosmic Ray Research - University of Tokyo, Hiroshima University, Kobe University, Kobe Women's Junior College, Kochi University, Okayama University of Science, Waseda Uni- versity, University of Alabama in Huntsville, Louisiana State University, NASA Marshall Space Flight Center, Universitu of Washington, Institute of Nuclear Physics - Kraków. This research was partially supported by Polish State Committee for Scientific Research, grant No. 203419101.

193 JACEE 1-6

_-i.n±oos *~f=^~I 10' JACEE 7-8

U rT-r ..

I IO»

10* W* W« Energy (GcV)

Figure 1: Differential energy spectrum of protons from the kink and converting into electron pairs near the emission point. Interpretation of these vertices as nuclear interactions is very unlikely; most probably they are due to bottom particle decays [4]. The two decay vertices are shown schematically in Fig.3. In both events one of secondary particles, denoted particle 1 in each event, decays into neutrals and one charged particle, which in turn undergoes another apparent decay within the detector. The four photons which convert into electron pairs were undoubtedly emitted from decay vertex of particle 1 in each event, not from primary interaction vertex. A virtually complete transverse momentum balance among the decay products is observed in both decay vertices. Analysis of the decays indicates that the decaying particles are most probably bottom particles in both events. The photons convert into electron pairs very early, within 0.38 and 0.59 conversion length, respectively in the two events. In case there were just four photons emitted in each decay, the observed conversion distances would be unusually small. More photons emitted from the decay vertices would make it difficult to explain a possible (weak) decay mode of a heavy particle into one charged particle and many photons. The decays obviously proceed via the weak interaction, since particle 1 decaying via strong or electromagnetic interaction would not leave a visible track, while particles 1 are observed

103 r 10 rŁ67 He (JACEE 1-8)

•t-h TJ1102 N 'E 1-5 X .,

I 10 ii i I 1 ENERGY 10 (TeV/n) 100 .2 1 TeV/n 10 50

Figure 2: Differential energy spectra of heavier elements

194 Eo- 50T«y/n

-120-83 -40 40 80 120 X(pm) 200X(pm)

Figure 3: Projection of decays of particle 1 in the two events to travel before decay 23.4 ram and 7.9 mm, respectively in the two events. The two decays discussed were found in a sample of 15 high energy interaction events, so they appear to be relatively common. On the other hand, all known decay modes of heavy particles [5] with topologies resembling the observed one have small branching ratios. Thus the events discussed may be examples of a new decay channel of a bottom particle.

References

[1] S. Swordy, Rapporteur talk at the 23rd International Cosmic Ray Conference, Calgary, July 1993. [2] K. Asakimori et al., Proc. 23rd ICRC, Calgary 1993, vol.2, p.21. [3] K. Asakimori et al., Proc. 23rd ICRC, Calgary 1993, vol.2, p.25. [4] H. Wilczyński et al., Proc. 23rd ICRC, Calgary 1993, Vol.4, p.29. [5] Particle Data Group, Review of Particle Properties, Phys. Rev. D45 Part 2 (June 1992).

195 1 Theory Group PL96Ó1093

In the year 1993 research activity of the particle physics theory group was continuation of the projects already performed in 1992. Altogether twenty seven papers and conference contributions were published or prepared for publication in this year (thirteen were published in international journals). Main subjects which were discussed are: (a) effects of the photon and gluon emission in electron-positron, electron-proton and proton-proton collisions, (b) production and decay mechanism of heavy quarks and heavy leptons (c) comparison of the new experimental data with the predictions of Standard Model and its extensions. Below, we shall present the most important results grouped by subjects. The corresponding papers were often quoted, in particular at the international conferences and in the publications presenting new experimental data, proposals for forthcoming accelerators or experiments (asymmetric B-factory, ATLAS, 500 GeV e+e~ collider). A general reveiw of heavy flavour physics has been given in the plenary talk "Heavy flavours (theory)" on International Europhysics Conference on High Energy Physics by K. Zalewski. In the papers (Z. Phys. C57 (1993) 115 and Z. Phys. C59 (1993) 117) the problem of finiding the most general, consistent with conservation laws, distributions in complicated particle decays is solved. The paper (Z. Phys. C59 (1993) 399) suggests, that when an atomic nuclues is struck by a very energetic projectile the energy absorbed by the nucleus is limitted. When this limit is approached a kind of phase transition occurs: the nucleus gets rid immediately of all the surplus energy. The paper (Z. Phys. C59 (1993) 677) shows that an Isgur-Wise function, in very good agreement with experiment can be simply obtained from the MIT bag model. The paper (Phys. Lett. B314 (1993) 74) clarifies the relation of intermittency to finite size scaling in the Ising model. The repport (CERN-TH 7058/93) exposes the origin of the discreappancy between two methods of calculating the decay constants of heavy mesons.

Quantum theory of quarks and leptons predicts existence of the t quark of the mass mt = 110 - 200 GeV. This is more than masses of W and Z bosons of weak interactions. One expects that this mass, the biggest dimensional parameter of presently most fundamental theory of interactions, may play exceptionally important role in future theory explaining numerical value of all quark and lepton masses. Precise measurement of this parameter will form one of the main goals of planned 500 GeV e+e~ collider. The lifetime of t quark is probably shorter than time necessary for formation of the bound states it. That is why methods designed for measurement of b and c quark masses cannot be used. This problem as well as measurement 2 of the QCD running coupling constant as(Q ) was discussed in articles by M. Jeżabek Phys. Rev. D48 (1993) R1910 and Z. Physik C59 (1993) 669 as well as in other six publications and contributions to conferences. 2 It has been also pointed out (Phys. Lett. B301 (1993) 121) that running of as(Q ) may indicate existence of supersymmetric particles. QCD corrections to semileptonic decays of polarised quarks have been calculated. Some results of this work (preprint TTP 93-32) are presented in fig. 1. These results can be used for processes involving polarised top quarks as well as polarised charmed and beautiful A baryons from Z° decays. One of important aspects of LEP I scientific program are precision tests of the Standard Model. The idea is to measure and calculate certain observables to such a precision that effects of radiative corrections can be tested. This seemingly uninteresting name covers very deep test of the Standard Model. In calculation of radiative corrections one has to take into account effects due to quantum structure of theory and also renormalization. Papers, Phys. Rev. D47 (1993) 2682 and Phys. Rev. D47 (1993) 3733 include study of matrix elements for Bhabha scattering. In Comp. Phys. Commun. 76 (1993) 361, new version of the T decay library was published.

196 It is now being implemented together with PHOTOS into the Monte Carlo program KORALZ (see not yet published reports CERN-TH.7033, CERN-TH.7075) which is widely used by LEP experiments. These papers form final steps in developing Monte Carlo algorithms used by the LEP I experiments for high precision tests of the Standard Model. This long term project was started by S. Jadach nearly ten years ago.

-0.4 0 0.2 0.4 0.6 0.8 0.2 0.4 0.6 0.8 Fig. 1 The asymmetry functions for bottom quark, a,=0.2, e=0 and 0.35 : a) QCD corrected (Xb(x) - solid - and Born cc°\x) - dashed lines; b) ab(x)^\x) for the transitions b -* c (e = 0.35) - solid - and b —> u (e = 0.0) - dashed line. This abstract does not have ambitions to present all papers published in the year 1993 in theoretical physics group. We refer the interested reader to the complete list of publications. In the year 1993 Marek Jeżabek received the scientific title of Professor. Two Ph. D. thesis, by P. Biatas (superviser K. ZaleWski) and W. Płaczek (superviser S. Jadach) were defended. Z. Was gave lectures on the European School of High Energy Physics in Zakopane, Poland.

197 PL9601094 Engineering and Technical Support of High Energy Physics Experiments J. Blocki, M. Despet, A. Florek, B. Florek, K. Gałuszka, J. Godlewski, J. Kotuta, M. Lemler, J. Michałowski, K. Pakoński, M. Stodulski, Z. Stopa, A. Strączek, M. Strck

The ATLAS Experiment Design study of the supporting structure and rail systems for suspension of the inner detector inside the cryostat of the barrel calorimeter were performed. In addition, a method of suspension of the polyethylene moderator from the cryostat wall was proposed. Thanks to a fellowship from Commission of the European Communities this work was carried out at NIKHEF in Amsterdam.

The DELPHI Experiment Silicon detector modules of the upgraded DELPHI microvertex tracker had to be stiffened. After carrying out numerical calculations, V-shaped kevlar beams which are directly glued to microstrip detector modules were proposed. Two dummy models of the module were made. Their stiffness was checked experimentaly. Thirty of such kevlar beams were manufactured.

The PHOBOS Experiment A conceptual design of the mechanical structures positioning and fixing the PHOBOS silicon detectors was continued. Numerical simulations of both the spectrometer base plate deflection and heat transmission from the front-end electronics to the cooling water were carried out. Calculated deflection of a carbon-epoxy composite plate of 5 mm thick reinforced with webing is presented in Fig.l. Prototypes of the spectrometer cooling frames as well as the pad and strip detectors were made and tested to verify calculated temperature distribution in the detectors.

RD20 - Gas Cooling for Silicon Strip Detectors A gas cooling method of silicon strip detectors has been developed. Based on it, a concept of a silicon vertex detector has been proposed. The calculations of temperature distributions and mechanical deformations of a detector module have been performed using Finite Elements Analysis. Thermal measurements with air and helium as a cooling agents have been performed. A temperature distribution throughout a detector module (Fig.2) and the results of mechanical measurements and simulations show that it is possible to cool a specially designed Silicon Vertex Tracker by a gas flow.

Carbon/Carbon Composites for Special Applications The main aim of the project is to develop a method of manufacturing thin shell elements made of a special carbon material. Such elements should have high stiffness, good reproducibility of mechanical properties, high radiation hardness and, in addition, low coefficient of thermal ex- pansion. With the help of researchers from School of Mining and Metallurgy some carbon/carbon composite samples in the form of thin plates were produced. Different types of carbon fibres and fabrics were used. The elastic properties of these samples were tested using a simple bending method and ultrasonic method which connects wave propagation velocity with the material elasticity. This work is supported by the State Committee for Scientific Research (grant no. 3 P407 006 04).

198 Design Study of the Large Hadron Collider (LHC) In the framework of the LHC project led by the Mechanical Technology Division at CERN mechanical properties of superconducting wires have been studied. Basing on the unidirectional fibre composite material theory a method which allows to establish all the elastic properties of a superconducting wire was proposed. For a Ti-Nb/Cu wire some numerical calculations using the ANSYS code were carried out.

AM BY* 1 .4 UMIV VEftSXOM JAM *0 1**3 OtilOlOS »ŁOT MO. I VOST1 STRESS 6TEP-1 XTER-1 Of D 4LOBAŁ DH1C -O.431B-63 I24B-03 aSMmC -<1.--o3. I9B-05 BC SYMBO LA XV —1 yIVv -O.-i S DXBT-Q.C 17714 xr -0.3 yp -o.* •r -o.o AMCS-tO I34B-O3 Bji|| »o>7«E-0. 3 I«1B-O3 i^^K ••• 13VB-03 B^» 0.3 I9B-OS

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Fig.l Deflection of the PHOBOS base plate

u ISr TEMPERATURE DIFFERENCE (DETECTOR - GAS) 0) u o — air. 1- m/s, 1.4 mW/ch g O-helium. 7m/s. 13mW/ch direction of gas flow

a v a

I , . . .1 ,. . . I i .... I • II i I . i i i I i i i i I i ml i i I I I 0 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500

Position along the modelmm

Fig.2 Comparison of air and helium cooling efficiency

199 LIST OF PUBLICATIONS:

I. Articles:

1. ACCMOR Collab., S. Barlag, (A. Bożek, Z. Hajduk, H. Pałka, K. Rybicki, M. Witek) et al., Charmed Pair Correlations in it~ - Cu Interactions at 230 GeV/c, Phys. Lett. B302 (1993) 112; 2. ACCMOR Collab., A. Bożek, (Z. Hajduk, H. Pałka, K. Rybicki, M. Witek) et al., A Study of A+ Decays into pK~ir+, pK'n+ir0 and pK-ir+Tr°w°, Phys. Lett. B312 (1993) 247; 3. W. Adam, (A. Budziak, W. Duliński, A. Florek, B. Florek, K. Gałuszka, J. Michałowski, K. Pakoński, G. Polok, M. Stodulski, Z. Stopa, M. Turala) et al., Performance of the Forward RICH Detector System at DELPHI, IEEE Trans. Nucl. Sci. 40 No 4 (1993) 583-588; 4. J. Bartke, Wspomnienie o Profesorze Marianie Mięsowiczu (1907-1992), Postępy Fizyki 44 (1993) 515-521; 5. P. Białas, J.G. Korner, M. Kramer, K. Zalewski, Joint Angular Distribution in Exclusive Weak Decays of Heavy Mesons and Baryons, Z. Phys. C57 (1993) 115; 6. P. Białas, J.G. Korner, K. Zalewski, Complete Angular Analysis of the Decay Cascade B_>D**(->D*(->D7r)+7r) + W(->h/), Z. Phys. C59 (1993) 117; 7. Big Bubble Chamber Neutrino Collab., A.E. Arsratyan, (W. Burkot, T. Coghen) et al., Diffractive Production of Charmed Strange Mesons by Neutrinos and Antineutrinos, Z. Phys. C58 (1993) 55-60; 8. Big Bubble Chamber Neutrino Collab., V.A. Korotkov, (T. Coghen) et al., Bose-Einstein Correlations in Neutrino and Antineutrino Interactions with Nucleons, MPI-PhE/93-11 (1993); Z. Phys. C60 (1993) 37-51; 9. N. Bingefors, (P. Briickman, P. Jałocha, P. Kapusta, M. Turala, A. Zalewska) et al., The DELPHI Microvertex Detector, CERN-PPE/92-173 (1992); Nucl. Instr. and Meth. A328 (1993) 447-471; 10. R. Brenner, (A. Czermak, S. Gadomski, M. Turala) et al., Measurements of the Spatial Resolution of Double-Sided Double-Metal AC-Coupled Silicon Microstrip, Nucl. Instr. and Meth. A326 (1993) 189-197; 11. R. Brenner, (A. Czermak, S. Gadomski, P. Jałocha, M. Turala) et al., Results from Double-Sided Silicon Microstrip Detector with Field Plate Separation, Nucl. Instr. and Meth. A326 (1993) 198-203; 12. Z. Burda, K. Zalewski, R. Peschanski, B. Wosiek, Finite Size Scaling Analysis of Intermittency Moments in the Two-dimensional Ising Model, Phys. Lett. B314 (1993) 74; 13. W. Czyż, J. Turnau, Quark in a Magnetic Vacuum, Acta Phys. Pol. B24 (1993) 1501; 14. R. Decker, (Z. Was) et al., Tau Decays Into Three Pseudoscalar Mesons, Preprint TTP-92-25; Z. Phys. C58 (1993) 445-452; 15. D.B. DeLaney, (S. Jadach) et al., Multiple Photon Effects in Fermion-(anti)-Fermion Scattering at SSC Energies, Univ. of Tennessee preprint UTHEP-92-0101, Phys. Rev. Lett. D47 (1993) 853; 16. DELPHI Collab., P. Abreu, (P. Jałocha, K. Korcyl, W. Krupiński, T. Lesiak, B. Muryn, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., A Measurement of B Meson Production and Lifetime Using Dl~ Events in Z° Decays, CERN-PPE/92-174 (1992); Z. Phys. C57 (1993) 181;

200 17. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, G. Polok, M. Witek, A. Zalewska) et al., Measurement of Inclusive Production of Light Meson Resonances in Hadronic Decays of the Z°, CERN-PPE/92-183; Phys. Lett. B298 (1993) 236; 18. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, G. Polok, M. Witek, A. Zalewska) et al., A Search for Lepton Flavour Violation in Z° Decays, CERN-PPE/92-190 (1992); Phys. Lett. B298 (1993) 247; 19. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Determination of a, for b Quarks at the Z° Resonance, Phys. Lett. B307 (1993) 221; 20. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, G. Polok, M. Witek, A. Zalewska) et al., A Measurement of the Tau Lifetime, CERN-PPE/93-12; Phys. Lett. B302 (1993) 356; 21. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Measurement of the Triple-Gluon Vertex from 4-Jet Events at LEP, CERN-PPE/93-29; Z. Phys. C59 (1993) 357; 22. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., Measurement of Aj, Production and Lifetime in Z° Hadronic Decays, CERN-PPE/93-32; Phys. Lett. B311 (1993) 379; 23. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., Determination of a, Next-to-Leading-Log Approximation of QCD, CERN-PPE/93-43; Z. Phys. C59 (1993) 21; 24. DELPHI Collab., P. Abreu, (A. Budziak, P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska et al., Limits on the Production of Scalar Leptocpiarks from Z° Decays at LEP, CERN preprint CERN-PPE/93-161; Phys. Lett. B316 (1993) 620; 25. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., A Study of B° - B° Mixing Using Semileptonic Decays of B Hadrons produced from Z°, Phys. Lett. B301 (1993) 145; 26. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Determination of a, from the Scaling Violation in the Fragmentation Functions in e+e~ Anihilation, Phys. Lett. B311 (1993) 408; 27. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., A Measurement of D Meson Production in Z° Hadronic Decays, Z. Phys. C59 (1993) 533; 28. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Search for Z° Decays to two Leptons and a Charged Particle-Antiparticle Pair, Nuci. Phys. B403 (1993) 3; 29. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., A Measurement of the Mean Lifetimes of Charged and Neutral B-Hadrons, Phys. Lett. B312 (1993) 253; 30. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik, P. Stopa) et al., An Investigation of Bose Einstein Correlations in Muon-Nucleon, Phys. Lett. B308 (1993) 418; 31. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik, P. Stopa) et al., Perturbative QCD Effects Observed in 490 GeV Deep-Inelastic Muon Scattering, FERMILAB-PUB-93-169-E; accepted to Phys. Rev. D;

201 32. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik, P. Stopa) et al., Q2 Dependence of the Average Sqared Transverse Energy of Jets in Deep-Inelastic Muon Scattering with Comparison to QCD Predictions, FERMILAB preprint FNAL-PUB-93-171-E; submitted to Phys. Rev. Lett. ; 33. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik, P. Stopa) et al., Measurement of the Ratio a(N)/

202 49. M. Jeżabek, T. Teubner, Momentum Distributions in tt Production and Decay near Treshold (II): Momentum Dependent Width, Z. Phys. C59 (1993) 669; 50. KLM Collab., A. Dąbrowska, (R. Hołyński, A. Jurak, A. Olszewski, M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek, K. Woźniak) et al., Particle Production in Interactions of 200 GeV/nucleon Oxygen and Sulfur Nuclei in Nuclear Emulsion, INP Report 1595/PH (1992); Phys. Rev. D47 (1993) 1751; 51. KLM Collab., A. Dąbrowska, (R. Hołyński, A. Olszewski, M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek, K. Woźniak, K. Zalewski) et al., Evidence for a Nuclear Phase Transition in Target Nuclei after Relativistic Nuclear Interactions, INP Report 1617/PH; Z. Phys. C59 (1993) 399; 52. KLM Collab., K. Sengupta, (A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski, M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek, K. Woźniak) et al., Multifractal Analysis of Nucleus-Nucleus Interactions, Phys. Rev. D48 (1993) 3174; 53. M.W. Krasny, E.M. Levin, M.G. Ryskin, Semilocal Evolution of Singlet Structure Function for GLAP and GLR Equation, Z. Phys. C57 (1993) 273; 54. LEP Collab.: ALEPH, DELPHI, L3, OPAL, Measurement of the Mass of the Z Boson and the Energy Calibration of LEP, Phys. Lett. B307 (1993) 187; 55. NA22 Collab., LV. Ajinenko, (K. Olkiewicz) et al., Two Particle Azimuthal and Rapidity Correlations in Intervals of Momentum in 7r+p Interactions at 250 GeV/c, Z. Phys. C58 (1993) 357; 56. NA22 Collab., N. Agababyan, (K. Olkiewicz) et al., Pomeron-Pomeron Cross Section from Inclusive Production of a Central in Quasielastic p and K p Scattering at 250 GeV/c, Nijmegen preprint HEN-360; Z. Phys. C60 (1993) 229; 57. NA22 Collab., N. Agababyan, (K. Olkiewicz) et al., Factorial Moments, Cumulants and Correlation Integrals in x+p and K+p Interactions at 250 GeV/c, Z. Phys. C59 (1993) 405; 58. NA22 Collab., N. Agababyan, (K. Olkiewicz) et al., Influence of Multiplicity and Kinematical Cuts on Bose-Einstein Correlations in 7r+p Interactions at 250 GeV/c, Z. Phys. C59 (1993) 195; 59. NA35 Collab., J. Bachler, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek) et al., Multiplicity Distributions in Small Phase-Space Domains in Central Nucleus-Nucleus Collisions, Raport MPI-PhE/92-21 (1992); Z. Phys. C57 (1993) 541-550; 60. NA35 Collab., J. Bachler, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al., Production of Charged Kaons in Proton-Nucleus and Nucleus-Nucleus Collisions at 200 GeV/nucleon, Raport MPI-PhE/92-21 (1992); Z. Phys. C58 (1993) 367-375; 61. NA35 Collab., D. Rohrich, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al., Hadron Production in S+Ag, S+Au Collisions at 200 GeV/nucleon, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys A ; 62. NA35 Collab., M. Gaździcki, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek) et al., New Data on Strangeness Enhancement in Central Nucleus-Nucleus Collision at 200 GeV, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ; 63. NA35 Collab., J.T. Mitchell, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek) et al., Charged Hadron Distribution in 200 GeV/n S+Au Collisions: A Look at Stopping, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl Phys. A ;

203 64. NA35 Collab., G. Roland, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek) et al., Systematic Study of the Target-Rapidity- and Transverse Momentum Dependence of the 2II~ Correlation Function in 200 GeV/nucleon S+A Collisions, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ; 65. NA35 Collab., B. Wosiek, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al., A Study of Correlation Integrals in Proton-Nucleus and Nucleus-Nucleus Collisions, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ; 66. J. Pluta, (P. Stefański, H. Dąbrowski) et al., Possible Observation of Medium Effects Using a Pion Correlation Technique, Nucl. Phys. A562 (1993) 365-388; 67. RD11 Collab., J. Badier, (P. Malecki, Z. Natkaniec, A. Sobala) et al., Evaluating Parallel Architectures for Two Real-Time Applications with 100 kHz Repetition Rate, IEEE Trans. Nucl. Sci. 40 No 1 (1993) ; 68. RD20 Collab., N. Bingefors, (S. Gadomski, P. Jalocha) et al., A Novel Technique for Fast Pulse-Shaping Using a Slow Amplifier at LHC, Nucl. Instr. and Meth. A326 (1993) 112-119; 69. K. Rybicki, R. Rylko, Spin Alignment of Z>*+(2010) Produced in 230 GeV/c II-Cu Interactions, Acta Phys. Pol. B24 (1993) 1049; 70. M. Sadzikowski, K. Zalewski, Isgur-Wise Functions from the MIT Bag Model, Z. Phys. C59 (1993) 677; 71. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski, B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Observation of Two-Jet Production in Deep Inelastic Scattering at HERA, Phys. Lett. B306 (1993) 158-172; 72. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski, B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Search for Leptoquarks with the ZEUS Detector, Phys. Lett. B306 (1993) 173-186; 73. ZEUS Collab., M. Derrick, (W. Burkot, A. Eskreys, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Initial Study of Deep Inelastic Scattering with ZEUS at HERA, Phys. Lett. B303 (1993) 183-197; 74. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski, B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Search for Excited Electrons Using the ZEUS Detector, DESY 93-075, June 1993; Phys. Lett. B316 (1993) 207; 75. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski, B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Hadronic Energy Distributions in Deep-Inelastic Scattering Electron-Proton Scattering, DESY 93-068, May 1993; Z. Phys. C59 (1993) 237; 76. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski, B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Observation of Events with a Large Rapidity Gap in Deep Inelastic Scattering at HERA, Phys. Lett. B315 (1993) 481; 77. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Measurements of the Proton Structure

Function F2 in ep Scattering at HERA, Phys. Lett. B316 (1993) 412; 78. S. Jadach, Z. Was, R. Decker and J.H. Ktihn, "The tau decay library TAUOLA: Version 2.4", Comput. Phys. Commun. 76 (1993) 361; 79. R. Decker, E. Mirkes, R. Sauer and Z. Was, "Tau decays into three pseudoscalar mesons", Z. Phys. C58 (1993) 445; 80. S. Jadach, B.F.L. Ward and S.A. Yost, " Exact results on e+e~ -* e+e~27 at SLC / LEP energies" Phys. Rev. D47 (1993) 2682;

204 81. S. Jadach, M. Skrzypek and B.F.L. Ward, "Analytical results for low angle Bhabha scattering with pair production", Phys. Rev. D47 (1993) 3733; 82. M. Jeżabek and C. Junger, Energy of W distribution in top quark decays, Acta Phys. Polonica B (1993) in print, preprint TTP 93-20, Karlsruhe 1993.

II. Contributions to Conferences:

1. F. Arqueros, S. Martinez, M. Różańska, 7/proton Discrimination in Cosmic Rays (1013 - 1015 eV) Using EAS Information from Electrons and Air Cerenkov Light, Proc. of the 23rd ICRC, Calgary 4 (1993) 738; 2. S. Gadomski, P. Erola, N. Ellis, Reconstruction of B% -> T+T" Decays in the ATLAS Experiment at LHC, B-Physics Workshop, Snowmass, May (1993) ; 3. I. Holi, ( M. Różańska) et al., A Matrix of Wide Angle Air Cerenkov Counters as an Alternative Air Cerenkov Teleskopes, Proc. "Towards a Major Atmospheric Cerenkov Detector for TeV Astro/particle Physics", eds. P. Fleury, G. Vacanti (1993) 287; 4. JACEE Collab., H. Wilczyński, (R. Hołyński, A. Jurak, B. Wilczyńska, W. Wolter, B. Wosiek) et al., Multiple Photon Emission in Decays of Particles Produced in Cosmic Ray Interactions, Proc. 23rd ICRC, Calgary 4 (1993) 29; 5. JACEE Collab., K. Asakimori, (R. Hołyński, A. Jurak, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek) et al., Tickling the Knee with JACEE, Proc. 23rd ICRC, Calgary 4 (1993) 708; 6. JACEE Collab., K. Asakimori, (R. Hołyński, A. Jurak, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek) et al., Cosmic Ray Composition and Spectra: (I) Protons, Proc. 23rd Int. Cosmic Ray Conf., Calgary 2 (1993) 21; 7. JACEE Collab., K. Asakimori, (R. Hołyński, A. Jurak, B. Wilczyńska, H. Wilczyński,

W. Wolter, B. Wosiek) et al.f Cosmic Ray Composition and Spectra: (II) Helium and Z>2, Proc. 23rd Int. Cosmic Ray Conf., Calgary 2 (1993) 25; 8. M. Jeżabek, J.H. Kuhn, T. Teubner, Radiative Corrections to the Top Quark Width, Proc: Workshop on Physics and Experiments at Linear e+e~ Colliders, Waikoloa, Hawaii, April 1993, Karlsruhe Univ. preprint TTP 93-21 (1993) ; 9. M. Jeżabek, J.H. Kuhn, T. Teubner, Production and Decay of tt Pairs in the Treshold Region, Proc. of II Workshop on e+e~ Collisions at 500 GeV, Munich, Annecy, Hamburg (1993); 10. M. Jeżabek, J.H. Kuhn, T. Teubner, Comment on the Average Momentum of Top Quarks in the Treshold Region, Proc. of II Workshop on e+e~ Collisions at 500 GeV, Munich, Annecy, Hamburg (1993); 11. A. Karle, (M. Różańska) et al., First Running Experience with the Novel Wide Angle Air Cerenkov Matrix Detektor AIROBICC, Proc. of the 23rd ICRC, Calgary 4 (1993) 666; 12. KLM Collab., R. Hołyński, (A. Dąbrowska, A. Olszewski, M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek, K. Woiniak) et al., Comparison of Particle Production in Nucleus-Nucleus Collisions with Prediction of the Venus Monte Carlo Model, Proc. 23rd ICRC, Calgary 4 (1993) 9; 13. KLM Collab., C.J. Waddington, (A. Dąbrowska, R. Hołyński, A. Jurak, M. Szarska, B. Wilczyńska, W. Wolter) et al., Fragmentation of High Energy UH Nuclei, Proc. 23rd Int. Cosmic Ray Conf., Calgary 2 (1993) 203; 14. KLM Collab., W. Wolter, (A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski, M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, B. Wosiek, K. Woźniak, K. Zalewski) et al., Evidence for a Critical Temperature in Excited Nuclei Due to High Energy Nuclear Interactions, Proc. 23rd Int. Cosmic Ray Conf., Calgary 4 (1993) 5;

205 15. F. Krennrich, (M. Różańska) et al., Observation of VHE 7-Emission from the Crab Nebula with the Prototype of the HEGRA Air Cerenkov Telescope Array, Proc. of 23rd ICRC, Calgary 1 (1993) 251; 16. M. Merck, (M. Różańska) et al., Search for the UHE 7 Sources with the HEGRA EAS Scintillator Array, Proc. of the 23rd ICRC, Calgary 1 (1993) 361; 17. M. Merck, (M. Różańska) et al., Search for the UHE 7's from the Direction of the Crab Nebula and Mrk 421 with the HEGRA Scintillator Array, Proc. of the 23rd ICRC, Calgary 1 (1993) 290; 18. NA35 Collab., D. Rohrich, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al., Hadron Production in S+Ag, S+Au Collisions at 200 GeV/nucleon, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys A ; 19. NA35 Collab., M. Gaździcki, (J. Bartke, E. Gladysz, M. Kowalski, P. Stefański, B. Wosiek) et al., New Data on Strangeness Enhancement in Central Nucleus-Nucleus Collision at 200 GeV, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ; 20. NA35 Collab., J.T. Mitchell, (J. Bartke, E. Gladysz, M. Kowalski, P. Stefański, B. Wosiek) et al., Charged Hadron Distribution in 200 GeV/n S+Au Collisions: A Look at Stopping, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl Phys. A ; 21. NA35 Collab., G. Roland, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek) et al., Systematic Study of the Target-Rapidity- and Transverse Momentum Dependence of the 211- Correlation Function in 200 GeV/nucleon S+A Collisions, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ; 22. NA35 Collab., B. Wosiek, (J. Bartke, E. Gladysz, M. Kowalski, P. Stefański) et al., A Study of Correlation Integrals in Proton-Nucleus and Nucleus-Nucleus Collisions, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ; 23. K. Rybicki, High Energy Physics in Poland, Proc. of European School of Particle Physics, Zakopane, September 12-25 (1993) ; 24. A. Trzupek, Y. Lu, J. Poirier, The Energy Scale of Extensive Air Showers, Proc. of 23rd ICRC, Calgary 4 (1993) 359; 25. A. Trzupek, Y. Lu, J. Poirier, Is there a Moon Shadow in Single Muon Data, Proc. of 23rd ICRC, Calgary 4 (1993) 422; 26. A. Zalewska, B-Hadrons at LEP, Proc. of the XV Int. Warsaw Meeting on Elementary Particle Physics "Quest for Links to New Physics", Kazimierz 1992, (World Scientific) (1993) 105; 27. S. Jadach, B.F.L. Ward and Z. Was, "KORALZ: Physics Monte Carlo for high statistics LEP I: toward the ultimate version" Talk on International Europhysics Conference on High Energy Physics, Marseille, France, 22-28 July 1993; 28. K. Zalewski, "Heavy flavors (theory)", Plenary talk International Europhysics Conference on High Energy Physics, Marseille, France, 22-28 July 1993;

206 III. Reports:

1. W. Adam, (A. Budziak, W. Duliński, A. Florek, B. Florek, K. Gałuszka, J. Michałowski, K. Pakoński, G. Polok, M. Stodulski, Z. Stopa, M. Turała) et al., The Forward Ring Imaging Cherenkov Detector of DELPHI, CERN preprint CERN-PPE/93-154 (1993); 2. ALICE Collab., N. Antoniou, (J. Bartke, E. Gładysz-Dziaduś, M. Kowalski, P. Stefariski) et al., Letter of Intent for a Large Ion Collider Experiment, CERN/LHCC/93-16, March 1 (1993); 3. ALICE Collab., N. Antoniou, (J. Bartke, E. Gładysz-Dziaduś, M. Kowalski, P. Stefański) et al., Answers to LHCC Questions, CERN/LHCC/93-59 November 10, 1993; ALICE Internal Note /GEN/93-33 (1993); 4. J. Bartke, E. Gładysz-Dziaduś, M. Kowalski, P. Stefański, A.D. Panagiotou, Interesting Physics Beyond Midrapidity, ALICE Internal Note PHY/93-12, January 19 (1993); 5. J. Blocki, Mechanical Properties of Superconducting Wires Treated as Unidirectional Composits, CERN, MT Report, February (1993); 6. J. Blocki, Moderator and Support Structure with Rail System for the ATLAS Experiment, NIKHEF, Technical Report, December (1993); 7. J. Blocki, J. Godlewski, K. Pakoński, Gas Cooling for Silicon Strip Detectors, CERN Report RD20-TN26 (1993); 8. J. Blocki, M. Stodulski, ANSYS Study of the Effects of Friction in the CERN LHC "One in One" Dipole Magnet Model, Technical Note, CERN/MT-ESH/93-02 (Part 1, Part 2) (1993); 9. J. Carter, Z. Hajduk, K. Korcyl, J. Strong, A Second Level Calorimeter Trigger Algorithm, ATLAS Internal Note, January 12 (1993); 10. J.C. Chollet, D. Froidevaux, S. Gadomski, L. Serin, Update on Latest Particle Level Simulations for H -> ZZ* -> 4/, ATLAS note PHYS-No-019 (1993); 11. A. Czarnecki, M. Jeżabek et al., QCD Corrections to Decays of Polarised Charm and Bottom Quarks, Preprint MZ-TH/93-35; HEP-PH 93-12249; TTP 93-32 (1993); 12. R. Decker, (Z. Was) et al., Tau Decays Into Three Pseudoscalar Mesons, Preprint TTP-92-25; Z. Phys. C58 (1993) 445-452; 13. D.B. DeLaney, S. Jadach et al., Renormalization Group Improved Exponentation of Soft Gluons in QCD, Preprint UTHEP-93-0401 (1993); 14. DELPHI Collab., P. Abreu, (A. Budziak, Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., Production of A and A A Correlations in the Hadronic Decays of the Z°, CERN preprint CERN-PPE/93-171 (1993); 15. DELPHI Collab., P. Abreu, (A. Budziak, Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak, H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., Production Rate and Decay Lifetime Measurements of B° Mesons at LEP Using D, and Mesons, CERN preprint CERN-PPE/93-176 (1993); 16. S. Gadomski, Studies of Pattern Recognition in SiTV, ATLAS note INDET-No-025 (1993); 17. HI Collab., B.Andrieu, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, K. Rybicki, J. Turnau) et al., Results from Pion Calibration Runs for the HI Liquid Argon Calorimeter and Comparison with Simulations, DESY Report 93-047 (1993); 18. HI Collab., I. Abt, (E. Banaś, J. Godlewski, L. Gorlich, L. Hajduk, M.W. Krasny, M. Lender, J. Martyniak, S. Mikocki, G. Nowak, J. Olszowska, K. Rybicki, J. Turnau) et al., The HI Detector at Hera, DESY Report DESY-93-103 (1993);

207 19. HI Collab., B. Andrieu, (E. Banaś, J. Godlewski, L. Gorlich, L. Hajduk, M.W. Krasny, M. Lender, J. Martyniak, S. Mikocki, G. Nowak, K. Rybicki, J. Turnau) et al., The HI Liquid Argon Calorimeter System, DESY Report DESY-93-078 (1993); 20. HI Collab., I. Abt, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki, G. Nowak, K. Rybicki, J. Turnau) et al., A Measurement of Multi-Jet Rates in Deep Inelastic Scattering at HERA, DESY Report DESY-93-137 (1993); 21. HI Collab., I. Abt, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki, G. Nowak, K. Rybicki, J. Turnau) et al., Measurement of the Proton Structure Function F2 (x, Q2) in the Low x Region at HERA, DESY Report DESY-93-117 (1993); 22. S. Jadach, B.F.L. Ward, Role of A(LR) in High Precision Z Physics, Preprint UTHEP-93-0101 (1993); 23. S. Jadach, M. Skrzypek, B.F.L. Ward, Soft Pairs Real and Virtual Infrared Functions in QED, Preprint UTHEP-93-0301 (1993); 24. S. Jadach, Z. Was, B.F.L. Ward, The Monte Carlo Program KORALZ, Version 4.0, for the Lepton or Quark Pair Production at LEP/SLC Energies, CERN Report CERN-TH/7075/93 (1993); 25. KLM Collab., M.L. Cherry, (A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski, M. Szarska, B. Wilczyńska, W. Wolter) et al., Interactions of 10.6 GeV/nucleon Gold Nuclei in Nuclear Emulsion, INP Report 1637/PH (1993); 26. PHOBOS Collab., D. Barton, (A. Budzanowski, T. Coghen, R. Hołyński, J. Kotula, K. Pakoński, M. Stodulski, A. Trzupek, H. Wilczyński, B. Wosiek, K. Woźniak, K. Zalewski) et al., PHOBOS Conceptual Design Report, PHOBOS Report, July (1993); 27. RD-11 Collab., Z. Hajduk, W. Iwański, K. Korcyl, MODSIM II Simulations of Architectures for LHC Triggering Systems, Nota Wewnętrzna, Kraków, czerwiec (1993); 28. RD-11 Collab., Z. Natkaniec et al., HIMAX - HLPPI to MaxVideo Interface, EAST Note, CERN 93-04 (1993); 29. RD-11 Collab., K. Cetnar, (Z. Hajduk, W. Iwański, K. Korcyl, P. Malecki, A. Sobala) et al., Status Report - Embedded Architectures for second level Triggering, EAST Note, CERN 93-08 (1993); 30. RD-11 Collab., Z. Hajduk, (K. Korcyl, W. Iwański) et al., The FEAST Project, EAST Note, CERN 93-11 (1993); 31. RD-6 Collab., K. Cetnar, (J. Chwastowski, S. Jagielski, P. Malecki, Z. Natkaniec) et al., Integrated Transition Radiation and Tracking Detector for LHC, RD-6 Status Report, Cem November 9 (1993); 32. RD20 Collab., A. Holmes-Siedle, (A. Moszczyński, M. Turała) et al., Radiation Tolerance of Single-Sided Silicon Microstrips, CERN preprint CERN-PPE/93-137 (1993); 33. RD20 Collab., (J. Blocki, A. Czermak, S. Gadomski, J. Godlewski, P. Jalocha, J. Kapłon, K. Pakoński, A. Moszczyński, M. Turała) et al., RD20 Status Report to the DRDC. Development of High Resolution Silicon Strip Detectors for Experiments at High Luminocity at LHC, CERN Report CERN/DRDC 93-30 (1993); 34. S. Narison and K. Zalewski, "The Ratio of decay constants f(B) / f(D)", preprint CERN TH 7058/93; 35. E. Barberio and Z. Was, "PHOTOS- A universal Monte Carlo for QED radiative corrections: version 2.0", CERN-TH.7033, October 1993; 36. A.H. Hoang, M. Jeżabek , J.H. Kuhnand T. Teubner, Hadron radiation in leptonic Z decays, preprint TTP 93-34, Karlsruhe, Dec.1993.

208 SCIENTIFIC DEGREES: M.Sc. degrees Maciej Przybycień Artur Wolak

Ph.D. degrees Piotr Białas (supervisor: K. Zalewski) Wiesław Płaczek (supervisor: S. Jadach) Wojciech Burkot (supervisor: T. Coghen) Andrzej Olszewski (supervisor: W. Wolter)

LECTURES AND COURSES: The HEPD staff participates in the education process of physics at the Jagellonian University in Kraków. The following staff members participated in this activity in 1993: • "Selected topics of the experimental techniques of high energy physics" undergraduate course led by P. Malecki and M. Turała • "Experimental high energy physics" undergraduate course led by K. Rybicki • "Experimental high energy physics" undergraduate course led by J. Bartke • Students' seminar on experimental high energy physics led by J. Figiel, J. Turnau, B. Wosiek and B. Pawlik

SEMINARS:

Joint seminars with the Theoretical Physics Department of the Jagellonian University (the list for the autumn period is not complete)

08.01.1993 W. Busza (MIT): " The PHOBOS project at RHIC " 15.01.1993 J. Szwed (Univ.): " Spin effects in deep inelastic scattering " 22.01.1993 M. Różańska (INP): " Point-like galactic sources of photons (the HEGRA experiment)" 19.02.1993 W. Wolter (INP): " Evidence for a critical temperature in high energy heavy ion collisions " 26.02.1993 A. Dyrek (Univ.): " New experiment on electron scattering on nuclei (the ELFE project) " 05.03.1993 A. Sitarz (Univ.): " Non- comutative geometry " 12.03.1993 M. Nowak (Univ.): " The Berry phase "

19.03.1993 T. Lesiak (INP): " The Ab production in LEP experiments " 26.03.1993 W. Florkowski (INP): " Screening masses of mesons " 16.04.1993 E. Leader (London): " The EMC effect "

209 23.04.1993 G. Wonnser (LAL, Orsay): " Recent physics results from DELPHI using its particle identification " 30.04.1993 A. Białas (Univ.): " Meaning of intennittency " 14.05.1993 K. Fiałkowski (Univ.): " Power growth of cumulants in 3-d bins " 21.05.1993 R.J. Peterson (Colorado): " Interactions of mesons with nuclei " 28 05 1993 "*' r^urnau (INP): " First physics results from the HI experiment at " ' HERA " 08.10.1993 R. Hołyński (INP ): " Interactions of 10 A GeV gold ions with emulsion nuclei " 19.11.1993 J- Bartke (INP): " New results on Bose-Einstein correlations in collisions of relativistic heavy ions "

Internal seminars

06.01.1993 A. Sobala: " New computer technology - hardware and software " 13.01.1993 A. Budziak: " Hadron identification in the DELPHI experiment (detectors FRICH and BRICH) " 20.01.1993 G. Wilk (Institute for Nuclear Studies, Warsaw): " Coherence and chaos in the interacting gluon model for hadronic and nuclear collisions " 24.02.1993 K. Korcyl: " Microprocessors in high energy physics - application to the DELPHI experiment " 10.03.1993 M. Krawczyk (Warsaw University): " Investigating the photon structure with the HERA collider " 17.03.1993 A.. Filipkowski (Institute for Nuclear Studies, Warsaw): " What can we still learn from hypernuclei ? " 24.03.1993 M. Kowalski: " Project of the heavy ion experiment "ALICE" at the LHC machine " 31.03.1993 K. Golec-Biernat: " Small x physics with HERA - expectations" - part 1

07.04.1993 K Golec-Biernat: " Small x physics with HERA - expectations" - part 2 14.04.1993 E. Kryś (University of Łódź): " Investigation of the gamma- ray bunches from point-like cosmic sources " 21.04.1993 S. Ratti (Univ. Pavia): " Photoproduction of charm at Fermilab " 12.05.1993 B- Badelek ( Warsaw University): " New information on structure functions at small x measured by the NMC Collaboration in CERN " 19.05.1993 H. Pałka: " Searches for the Higgs particles in LEP experiments " 07 06 1993 D- TreiUe (DELPHI - CERN): " Physics for the future e+e" accelerators" 16.09.1993 Ch. Fabjan (CERN): " LHC physics with ATLAS" 29.09.1993 Y. Arnoud (CEN Saclay): " All you wanted to know about B, but were afraid to ask " 06.10.1993 A. Górski: " Formfactor of the nucleon from the chiral soliton model of Nambu-Jona and Lasinio " 13.10.1993 H. Bialkowska (Institute for Nuclear Studies, Warsaw): " The conference QUARK MATTER '93 in Borlange, 20-24 June 1993"

210 20.10.1993 H. Pałka : " The EPS Conference on High Energy Physics in Marseille, 22-28 July 1993 " 27.10.1993 B. Pietrzyk (LAPP Annecy): " Does LEP test the standard model ? " 03.11.1993 M. Różańska: " The TRISTAN II project at KEK " 10.11.1993 Z. Hajduk: " Computer as a necessary aid for an engineer " 17.11.1993 L. Leśniak: " Interaction of the J/* mesons with atomic nuclei at high energies " 24.11.1993 F. Kapusta (LPNHE Paris): " The photon structure function " 01.12.1993 A.D. Martin (Durham,UK & ESTP): " Deep inelastic scattering " - part 1 08.12.1993 A.D. Martin (Durham,UK & LNP): " Deep inelastic scattering " - part 2 15.12.1993 A.D. Martin (Durham,UK & LNP): " Deep inelastic scattering " - part 3 22.12.1993 S. Jadach: " QED corrections to the precise measurements of luminosity at LEP" SHORT TERM VISITORS TO THE DEPARTMENT: Dr G. Wonnser - LAL, Francja Dr D. Treille - CERN Dr 0. Ullaland - CERN Dr E. Dahl-Jensen - Niels Bohr Inst., Kopenhaga Dr F. Kapusta - Univ. Paris VI-VII Dr A. Elliot-Peisert - CERN Prof. A. Wagner - DESY Prof. G. Fliige - RWTH Aachen - CERN Dr C. Fabjan - CERN Dr P. Faugeras - CERN Dr P. Rohmig - CERN Prof. R. Sosnowski - INP Warszawa Prof. J.A. Zakrzewski - LEP Warszawa Dr G. Feofilow - Inst. of Physics, St.Petersburg Dr 0. Godisov, Meson Scientific Association, St.Petersburg Dr H. Kristiansen - SI Oslo Dr K. Ratz - CERN Prof. S. Rati - Univ. Pavia Dr Y. Arnound - CEN Saclay Prof. A. Martin - Univ. Durham Dr B. Pietrzyk - LAPP Annecy Dr G. Wilk - LNP Warszawa Dr M. Krawczyk - LEP Łódź Dr B. Badelek - IEP U W Dr H. Białkowska - INP Warszawa Prof. W. Busza - Massachusetts Institute of Technology Dr B. Wyslouch - Massachusetts Institute of Technology (2 times) Dr J. Ryan - Massachusetts Institute of Technology

211 Department of Environmental and Radiation Transport Physics PL9601095

DEPARTMENT OF ENVIRONMENTAL AND RADIATION TRANSPORT PHYSICS

Head of Department: Prof. J. Łoskiewicz Secretary: E. Lipka telephone: (48) (12) 37-02-22 ext.: 345 e-mail: [email protected]

PERSONNEL: Research staff: Jerzy Łoskiewicz, Professor - Head of the Department Jan A. Czubek, Professor Andrzej Zuber, Professor Jan Lasa, Professor Piotr Małoszewski, Assoc.Professor Urszula Woźnicka, Assoc.Professor Krzysztof Drozdowicz, Ph.D. Jan M. Zazula, Ph.D. Ireneusz Śliwka, Ph.D. Joanna Bogacz, M.Sc. Teresa Cywicka-Jakiel, M.Sc. Bogdan Drozdowicz, M.Sc. Dominik Dworak, M.Sc. Joanna Dąbrowska, M.Sc. Barbara Gabańska, M.Sc. Andrzej Igielski, M.Sc. Ewa Krynicka, M.Sc. Jadwiga Mazur, M.Sc. Eugeniusz Mnich, M.Sc, E.Eng. Janusz Swakoń, M.Sc. - postgraduate student Grzegorz Tracz, M.Sc. Jarosław Płaszczyca, M.Sc. Technical staff: Jacek Burda, Eng. Jerzy Dysiek Władysław Kowalik Ryszard Haber Antoni Rościszewski Janina Wanic Tadeusz Z dziarski Administration: Ewa Lipka

213 GRANTS: Grants from the State Committee for Scientific Research: 1. Prof. A. Zuber grant No 0 9602 030 04, "Investigations of noble gases in some mineral waters of southern Poland" 2. Prof. J. Lasa grant No 6-040591-01, "Measurements of atmospheric trace gases - greenhouse effect" 3. Prof. J.A. Czubek grants No 6-631891-02 and 9-060691-01, "Physics of radiation transport in nuclear well logging" 4. Prof. J. Łoskiewicz grant No 2-026091-01, "Determination of the influence of the humidity and ash content changes on neutron measurement of coal calorific value" 5. Assoc.Prof. U. Woźnicka grant No 2-019991-01, "Thermal neutron diffusion in small heterogenous media" 6. Dr. K. Drozdowicz grant No 2 P302 074 05, "Implementation of a new model of the synthetic neutron-scattering function for calculation of the diffusion parameters in finite hydrogenous media" 7. A. Igielski, grant No 2 P302 021 05, "System for an effective measurement of the decay constant of non-stationary neutron fields".

Grants from the International Atomic Energy Agency, Vienna (Austria):

1. Prof. A. Zuber Coordinated Research Programme on "Mathematical Models for Quantitative Evaluation of Isotope Data in Hydrology", (completed in June 1993). 2. Prof. J. Łoskiewicz Coordinated Research Programme on "Nuclear Techniques in Exploration and Exploita- tion of Coal: On Line and Bulk Analysis and Evaluation of Potential Environmental Pollutants in Coal and Coke".

OVERVIEW: The research activity in the Department is carried out by the three Laboratories: 1. Laboratory of Environmental Physics (head: Professor Andrzej Zuber) 2. Laboratory of Neutron Transport Physics (head: Assoc.Prof. Urszula Woźnicka) 3. Laboratory of Radiation Transport Physics and Modelling (head: Professor Jerzy Łoskiewicz) The Department employs: 4 professors, 2 associated professors (docent), 3 doctors , 11 research physicists, 2 electronic engineers and 7 technicians of different specialities. The De- partment is engaged in theoretical and experimental research in the following areas:

214 1. The physics of tracer transport in porous (geological) media. 2. The physics of molecular phenomena in chromatographic detectors. 3. The physics of nuclear radiation transport in solids. 4. The physics of neutron interactions with nuclei (low energy region). 5. The physics of nuclear well loggings. Basic research is carried out in order to apply the results to the following problems: 1. Development of a theory of solute transport in porous and fractured media for the improvement of the interpretation of artificial and environmental tracer data. Studies related to determining the origin of formation waters from environmental isotope and radioisotope data. Both directions of studies are related to the management and protection of ground water reser- voirs, mineral and thermal waters used for therapeutical purposes (in close cooperation with the Faculty of Nuclear Physics and Techniques of the Academy of Mining and Metallurgy in Kraków and the Institute fur Hydrologie, GSF, Neuherberg, Germany). 2. Environmental physics problems using gas chromatographic methods: measurements of freons in the atmosphere, extraction of methane from the atmosphere for mass spectrography of carbon isotope ratio, methods of CO, CH4 and CO2 measurements in the atmosphere, the physics of the electron capture detectors in gas chromatography, measurements of trace concentration of other gases in the atmosphere in connection with the greenhouse effect (in close cooperation with the Faculty of Nuclear Physics and Techniques of the Academy of Mining and Metallurgy in Kraków). 3. Research into the physics of neutron transport in solids. The evaluation of neutron material cross sections needed in the calculations of radiation fields in matter (in collaboration with the Centro Atomico Bariloche, Argentina and with the Dept. of Reactor Physics of Chalmers University of Technology, Gothenborg, Sweden). 4. Development of theoretical and experimental determines of the neutron and radioactive parameters of geological formations and the technological parameters of some raw materials (mainly coals and coke). The methodology of the measurement of the decay constant of the thermal neutron fields in bounded heterogenous media using the pulsed neutron generator. 5. Establishing the calibration procedures for neutron well logging methods (in collaboration with the Laboratory of Geophysics of the Academy of Mining and Metallurgy in Kraków). 6. Consulting in: radon and its decay products determination in air; application of geostatistics in mining. The results of basic research are published in open literature, whereas the results of applied research carried out on the requirements of industry or other research institutes are included in the internal reports.

Prof. J. Łoskiewicz

215 PL9601096 PL9601097 PL9601098 REPORTS ON RESEARCH: ;f\. Theory of a semi-empirical way of neutron tool calibration; further development Jan A. Czubek

The true and apparent neutron parameters have been calculated for basic sedimentary rocks represented by SiO2, CaCO3 , CaMg(CO3)2 of variable porosity saturated with fresh water and brines. The apparent parameters have been calculated for geometry requirements corresponding to the dual detector Western Atlas No 2435 tool situated inside boreholes of variable diameter. Using the semi-empirical approach the whole set of interpretation correction charts have been established for this tool for the following conditions: variable borehole diameter, variable borehole and formation fluid salinity, variable tool stand-off inside the borehole, variable lithology, variable rock matrix absorption cross section. The agreement of interpretation charts obtained by the semi-empirical method with those published by the Western Atlas was very good. In a few cases the inadequacy of some of the Western Atlas results have been found. The true neutron parameters have been calculated for the calibration pits at Zielona Góra. Then the apparent neutron parameters have been calculated for the DSN-102 tool (Polish design) and for the tool, dead times 20 and 40 /is, the semi-empirical porosity calibration curves have been calculated. For the 40 fis dead time a full set of interpretation charts have been designed. Paper prepared: "Neutron tool calibration by scaling procedure" (submitted to Nucl. Geophys).

,, f Critical review of methods used in Poland for the radon and f its decay products determination Jan A. Czubek

At the beginning of 1993 several laboratories involved in the monitoring of radiation hazards in the atmosphere (underground mines, buildings, dwellings, etc.) reported serious discrepancies observed between the assay results obtained by different labs at the same spots. The review was performed on the demand of the President of the Polish Atomic Authority. It contains a short review of techniques used by different laboratories and very detailed analysis of all available experimental data. Several possible origins of observed discrepancies have been found and the lack of proper data treatment has been shown. Several recommendations to the Polish Atomic Authority have been made in order to improve the reliability of assays. Paper prepared: "Critical review of the routine measurements of radon and its decay products performed in the mine conditions in Poland" (submitted to the Progress in Nuclear Technique, in Polish).

r? The use of a hydrogen signal in correcting the carbon concentration from 12C(n,n'7)12C reaction in coal T. Cywicka-Jakiel, J. Loskiewicz and G. Tracz

The idea to use the 2.22 MeV proton-neutron capture 7-ray as the correcting signal for carbon content measurements has been shown in our earlier papers [1,2]. The range of change of the 4.43 MeV carbon 7-ray intensity from 12C(n,n'7)12C reaction with changing water content of coal was investigated for different coal samples. The decrease in carbon 7-ray intensity is significant and results in l-f3 % per one percent of additional water. We do think that the use of 2.22 MeV hydrogen 7-ray correcting signal will

216 PL9601099 PL9601100 PL9601101 make the use of the inelastic neutron scattering gauges more precise in the measurement of the calorific value of coal and its carbon content using inexpensive Nal(Tl) scintillation detectors. References:

1. T. Cywicka-Jakiel, J. Łoskiewicz and G. Tracz, Nuci. Geophys. (1993) 7, 529-537. 2. T. Cywicka-Jakiel, J. Łoskiewicz and G. Tracz, The Journal of Coal Quality (in press).

Development of natural radioactivity measurements / / ^ J. Bogacz, T. Cywicka-Jakiel, J. Łoskiewicz, J. Mazur, J. Swakoń and G. Tracz

In 1993 the Laboratory of Physics of Radiation Transport and Modelling obtained from the State Committee of Nuclear Security and Radiological Protection the ability to certificate the value of concentration of natural radionuclides in building and waste materials. The natural radioactivity measurements are carried out for samples from different industrial places. The new computer programme KONGAM for gamma-ray spectra analysing was prepared and tested.

f Numerical calculations of doses at high energy accelerators ) jfJ D. Dworak and J.M. Zazula

A new field of activity was opened with radiation transport numerical calculations of doses at high energy accelerators. We have taken part in calculations performed for the future LHC accelerator and ATLAS detector at CERN Geneva. More substantial collaboration was developed with the DESY Radiation Protection Group (Dr Klaus Tesch), which resulted in the modified version of the FLUKA code, calculations of neutron transport in labyrinths, estimations of the neutron dose equivalent attenuation coefficient for concrete shielding at high energy proton accelerators (HERA ring). 13 common reports and papers were published during 1989-1993. We have now entered into official collaboration between our groups.

Methodology of measurement of the thermal neutron time jff decay constant on pulsed neutron generator K. Drozdowicz, B. Gabańska, A. Igielski, E. Krynicka and U. Woźnicka

A pulsed beam of fast neutrons produced by a pulsed neutron generator is the source of the decaying thermal neutron flux which can be observed in a medium of interest. Knowledge of the decay constant of the thermal neutron flux in a bounded medium gives information on the thermal neutron transport and diffusion parameters of the medium. The high values of the decay constant (which correspond to the thermal neutron life time in the range of 20 /xs to 50 /xs) have been of interest in the present research. These values characterize the decay of the thermal neutron fields in small volumes of the investigated materials having a high absorption cross section and/or characterized by a high heterogenity. Theories which describe the behavior of the time dependent thermal neutron field in bounded media can be verified by a measurement of the fundamental mode of the time decay constant in the medium of interest. The values of the decay constants should be measured with an accuracy better than 0.5 per cent and the measurement time should be reduced to a minimum. This requires a proper experimental system with precisely defined parameters. The method of measurement of the thermal neutron time decay constant has been directed to the measuring and recording system which consists of a thermal neutron 3He detector, pulse forming and amplifying electronics, and the multichannel time analyzer Canberra 35 + [2]. The

217 PL9601102 main item of the system is a fast multiscaler (MCS 7880) and the accuracy of the measurement is strongly influenced by its performance and possibilities. The methodology of the measurement has to be adjusted to the equipment used. An experimental verification of a dead time of the instrumentation system has to be done and a count-loss correction has to be introduced to the data collected by the time analyzer. Optimum parameters for the measurement and for the determination of the decay constant have to be adjusted to the instrumentation system being used. The operation system of the registration part of the Can- berra 35+ analyzer and the multiscaler have forced us to develop an unconventional procedure of the die-away curve collection and of the determination of the decay constant. The procedure is presented in [2] including a detailed statistical description and results of test measurements. An application of a fitting procedure to experimental data which can be represented by a sum of decaying exponentials is presented in [1]. The method can be used for a general case when any number of the exponentials with a constant component is taken into account. Attention is paid to the problem of separation of the fundamental mode decay constant in the presence of higher modes and background. For this purpose a computer program has been written that within a set of experimental data performs a "fit" to one and two exponentials with a constant term. The "fit" interval can be moved along the time axis and in this way the found estimators of the decay constants can be observed as a function of the initial delay time. This offers a possibility to separate the fundamental term with high precision. A detailed discussion of statistical errors is given, utilizing the variance method. The methodology can be applied to instrumentation systems developed for a thermal neutron time decay constant measurement different from the particular one used in the INP. References: [1] K. Drozdowicz, B. Gabańska and E. Krynicka, INP Report No 1635/PM (1993), Institute of Nuclear Physics, Kraków. [2] K. Drozdowicz, B. Gabańska, A. Igielski, E. Krynicka and U. Woźnicka, INP Report No 1651/AP (1993), Institute of Nuclear Physics, Krakow.

Statistical analysis of the calibration method of the thermal neutron absorption cross section determination E. Krynicka

A calibration method for the determination of the thermal neutron macroscopic mass absorption cross section S^f for rock samples has been derived. The cross section is determined on the basis of only one measurement of the time decay constant A of thermal neutrons in a particular cylindrical system where the investigated sample is surrounded by a moderator of fixed size H^g- A big advantage of the method is that the calibration lines t>S(A) | H.tg (the relationship between the absorption rate t>£ of the sample and the measured decay constant A) have been obtained using real rock samples [1,2]. The total number of the investigated samples is 85. Individual calibration lines for different sizes K^g of the moderator have been obtained using / (equal from 20 to 60) independent experimental points {A,, t;St} | H2g- A computer simulation method has been utilized for an estimation of the standard deviation £ ) of the absorption rate vE of the measured composed sample [3]. The standard deviation 0-(t;£ ) is influenced by both the standard deviation

218 Then, a simple calculation is performed to achieve the corresponding macroscopic mass absorption cross section S*f of the investigated rock matrix itself and its standard deviation

References: [1] E. Krynicka, INP Report No 1541/AP(1991), Institute of Nuclear Physics, Kraków. [2] E. Krynicka, Nucl.Geophys. (1994) — in print. [3] E. Krynicka, INP Report No 1627/AP(1993), Institute of Nuclear Physics, Kraków.

LIST OF PUBLICATIONS: I. Articles:

1. T. Cywicka-Jakiel, J. Łoskiewicz and G. Tracz, "The use of hydrogen signal in correcting the carbon concentrations from 12C(n,n*7)12C reaction in coal", Nucl. Geophys. 7 (1993) 529. 2. J.A. Czubek, "Neutron parameters of brines", Nucl. Geophys. 7 (1993) 1-34. 3. J.A. Czubek, "Neutron tool calibration by scaling procedure", (submitted to Nucl. Geophys.). 4. J.A. Czubek, "Critical rewiev of the routine measurements of radon and its decay products performed in the mine atmosphere in Poland", (submitted to the Progress in Nuclear Technique, in Polish). 5. P. Małoszewski and A. Zuber, "Principles and practice of calibration and validation of mathematical models for the interpretation of environmental tracer data in aquifers", Adv. Water Resour. 16 (1993) 173-190. 6. P. Małoszewski and A. Zuber, "Tracer experiments in fractured rocks: matrix diffusion and the validity of models", Water Resour. Res. 29 (1993) 2723-2735. 7. A. Fasso, A. Ferrari, J. Ranft, P. Sala, G.R. Stevenson and J.M. Zazula, "Comparison of FLUKA simulations with measurements of fluence and dose in calorimeter structures", CERN/TIS-RP/93-2/PP, Geneve, Dec.1992, accepted for publ. in Nucl. Instr. Meth. 8. J. Łasa, B. Drozdowicz and I. Śliwka, "Physical model of the electron capture detector", Chromatographia, (in press). 9. H. Dinter, D. Dworak and K. Tesch, "Attenuation of the neutron dose equivalent in labyrinths through an accelerator shield", DESY Report D3-74, and Nucl. Instr. Meth. A333 (1993) 507. 10. J. Lasa, I. Śliwka, B. Drozdowicz and J. Rosiek, "Measurements of trace atmospheric gases active in greenhouse effect", Environment of Poland and Global Change, PAN Krakow (in Polish, in press). 11. J. Lasa, "Influence of trace gases on the climate of Earth", Problemy Ekologiczne Krakowa, No 16. Edited by AGH for Polski Klub Ekologiczny, Kraków 1993 (in Polish). 12. A. Zuber, "Calculation of hydraulic conductivity from grain-size distribution curve", Współczesne Problemy Hydrogeologii, Oficyna Wyd. Sudety, Wrocław 1993, pp. 415-419 (in Polish). 13. J. Motyka and A. Zuber, "Parameters of fissures and the hydraulic conductivity of rocks", as above, pp. 421-425 (in Polish). 14. A. Zuber, K. Osenbrueck, S.M. Weise, J. Grab czak and W. Ciężkowski, "Noble gases and their isotope ratio in thermal waters of Lądek Zdrój and Cieplice Śląskie", as above, pp. 151-156 (in Polish).

219 15. I. Pluta, A. Zuber, J. Grabczak, R. Śląski and M. Bebek, "Origin of brines in the southern part of the Upper Silesian Coal Basin (GZW) as determined in the Morcinek coal mine", as above, pp. 95-100 (in Polish). 16. S. Geyer, J. Grabczak, I. Śliwka and A. Zuber, "Application of C-14 in DOC and chlorine compounds to age identification of inflows to the Wieliczka salt mine", as above, pp. 353-357 (in Polish).

II. Contributions to Conferences:

1. A. Fasso, A. Ferrari, J. Ranft, P. Sala, G.R. Stevenson and J.M. Zazula, "FLUKA 92", presented at the Workshop on Simulation of Accelerator Radiation Environments, Santa Fe, USA, Jan. 1993. 2. P. Aarnio, A. Fasso, A. Ferrari, J-H. Mohring, J. Ranft, P. Sala, G.R. Stevenson and J.M. Zazula, "Electron-photon transport: always as good as we think? Experience with FLUKA", presented at the Int. Conference on Monte Carlo Simulation in High Energy and Nuclear Physics, Tallahassee, USA, Feb. 1993. 3. P. Aarnio, A. Fasso, A. Ferrari, J-H. Mohring, J. Ranft, P. Sala, G.R. Stevenson and J.M. Zazula, "FLUKA: hadronic benchmarks and applications", presented at the Int. Conference on Monte Carlo Simulation in High Energy and Nuclear Physics, Tallahassee, USA, Febr. 1993. 4. J. Lasa, "The Earth ozon layer", presented at the Commission of Health Protection, Polish Academy of Science (PAN), 17 June 1993, Kraków. 5. A. Korus and J. Lasa, "Estimation of the applicability of the photo-ionization detector (PID) to analyse stable gases " (poster), VI National Chromatography Seminar "Science - industry; modern analytical methods", Lublin, 15-17 Sept. 1993. 6. B. Drozdowicz and J. Lasa, "Measurements of CO, methane and carbon dioxide in troposphere" (poster), as above. 7. I. Śliwka, B. Drozdowicz, J. Lasa and J. Rosiek, "A method of measurements of chlorine compounds in the air with enrichment" (poster), as above. 8. T. Cywicka-Jakiel, J. Loskiewicz and G. Tracz, "The hydrogen signal use in correcting the neutron measurements of the calorific value of coal", presented at The 1993 Int. Symposium of Int. Atomic Energy Agency "On-line Analysis of Coal", Vienna, Oct. 1993. 9. T. Cywicka-Jakiel, "Ecological aspect of the determination of coal calorific value using the inelastic neutron scattering method", presented at the International Workshop, "Ecological aspects of underground mining of usable mineral deposits", Szczyrk, Poland, 23-25 Nov. 1993. 10. J. Lasa, "Applications of gas chromatography in investigations of environmental pollution", invited talk for the 2-nd Conference on "Geochemical, hydrochemical and biochemical changes in the environment in the areas of anthropogenic pression", Krakow, 9-10 Dec. 1993.

III. Reports:

1. E. Krynicka, "Determination of the thermal neutron absorption cross section for rock samples by a single measurement of the time decay constant", INP Report No 1627/AP, Kraków 1993. 2. K. Drozdowicz, B. Gabańska and E. Krynicka, "Fitting the decaying experimental curve by a sum of exponentials", INP Report No 1635/PM, Krakow 1993.

220 3. K. Drozdowicz, B. Gabańska, A. Igielski, E. Krynicka and U. Woźnicka, "Methodology of measurement of thermal neutron time decay constant in Canberra 35+MCA system", INP Report No 1651/AP, Kraków 1993. 4. G.R. Stevenson and J.M. Zazula, "Estimates of dose in the LHC Tunnel due to beam-gas scattering", CERN/TIS-RP/TM/93-6, Geneve Dec. 1992. 5. J.A. Czubek, T. Kuc and P. Olko, "Report of the Committee for verification of methods used in Poland to the radon and its decay products determinations", (in Polish), June 1993, pp. 173. 6. J.A. Czubek, "Calculation of general neutron parameter for porosity, lithology and salinity determination", report to the Polish Scientific Committee for the grant No 9 9047 91 02-P02, Nov. 1993, pp. 66 (in Polish). 7. J.A. Czubek, "Check of semi-empirical method of calibration for the tools DSN-102 and PKNN-3", report to the Polish Scientific Committee for the grant No 9 9211 93C, Nov. 1993, pp. 10 + programs: NEWCROSS, SLOWN22A, NEROTH22, REPRNT22 and LMBIRN22 (in Polish). 8. J.A. Czubek, "Catalogue of neutron parameters for Zielona Góra calibration blocks", report to the Polish Scientific Committee for the grant No 6 6318 91 02, Dec. 1993, pp. 17 (in Polish). 9. J. Łasa, I. Śliwka, B. Drozdowicz and J. Piotrowski, "Methodology of applications of electron negative tracers in investigations of gastightness of industrial vessels and exchange of air in buildings", INP Report No 1636/AP, Krakow 1993.

PARTICIPATION IN CONFERENCES AND WORKSHOPS: J. Dąbrowska, "Seminar on advanced Monte Carlo computer programs for radiation transport", 27-29 April 1993, Centre d'Etudies Saclay, France.

LECTURES AND COURSES: K. Drozdowicz: Lecture: "Research activities at the Institute of Nuclear Physics in Kraków. Applications of nuclear radiation interactions in matter", Centro Atomico Bariloche, CNEA, Argentina, March 1993. K. Drozdowicz: Lecture: "Thermal neutron macroscopic absorption cross section measurement and related neutron diffusion problems", Centro Atomico Bariloche, CNEA Argentina, March 1993. K. Drozdowicz: "Physics of a measurement of the thermal neutron absorption cross section of rock materials", a course for students of Universidad Nacional de Cuyo, Instituto Balseiro, Bariloche, Argentina, March 1993. K. Drozdowicz: Lecture: "Experiment for water-flow measurement by the pulsed-neutron activation", Chalmers University of Technology, Dept. of Reactor Physics, Goeteborg, Sweden, Oct. 1993. /. Lasa: Lectures and practicals on "Chromatographic analytical methods" for Ph.D. students of the Faculty of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, Kraków.

221 U. Woźnicka, A. Igielski and B. Gabańska: "14 MeV pulsed neutron generator - geophysical application", a course for students of the Faculty of Geology, Geophysics and Environmental Protection, Academy of Mining and Metallurgy, June 1993. A. Zvber: "Tracer methods in hydrology", 12-hours course for students of the Faculty of Geology, Geophysics and Environmental Protection, Academy of Mining and Metallurgy, Kraków. INTERNAL SEMINARS:

1. J. Łoskiewicz, "Estimation of the Ea value from K,TJ,Th concentrations and rock lithology data", 2 Feb. 1993. 2. T. Cywicka-Jakiel, "News on a determination of the calorific value of coal using neutron inelastic scattering method", 3 March 1993. 3. D. Dworak, "Calculation of gamma doses outside shields of the high energy proton accelerators", 6 April 1993. 4. J. Swakoń, "Analysis of complex gamma-ray spectra using the method of the standard gamma-ray spectra", 18 May 1993. 5. J. Dąbrowska, "A new method to asses Monte Carlo convergence", 1 June 1993. 6. J. Łoskiewicz, "Use of the hydrogen signal for a correction of results of measurements of the neutron inelastic scattering on carbon in coal", 5 Oct. 1993. 7. J.A. Czubek, "Radon measurements in Poland", 16 Nov. 1993. 8. K. Drozdowicz, "Water-flow measurement by the neutron activation", 23 Nov. 1993. 9. G. Tracz, "Analysis of the coal composition using a pair spectrometer", 21 Dec. 1993.

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Dr S.M. Weise - Institute for Hydrology, Neuherberg, Germany. 2. Dr K. Osenbrueck - University of Heidelberg, Germany. 3. Mr Wang Zhiming - Deputy Director of Res. Dept., China National Nuclear Industry Corporation, Beijing, China. 4. Dr Hu Shaokang - China National Nuclear Industry Corporation, Beijing, China.

222 Department of

and Environmental Biology PL9601103

DEPARTMENT OF RADIATION AND ENVIRONMENTAL BIOLOGY

Head of Department: Assoc. Prof. Antonina Cebuhka-Wasilewska Secretary: Ewa Bartel telephone: (48) (12) 37-02-22 ext.: 322 e-mail: [email protected]

PERSONNEL:

Research Staff Antonina CEBULSKA-WASILEWSKA Assoc.Prof., Janusz GAJEWSKI M.Sc, Jerzy HUCZKOWSKI Ph.D., Małgorzata KAJTA M.Sc., Beata KSIAŻKIEWICZ M.Sc., Bogusława KRZYKWA M.Sc., Małgorzata LITWINISZYN M.Sc., Barbara ŁAZARSKA Ph.D., Barbara PAŁKA Ph.D., Igor PAWŁYK M.Sc.

Technical Staff Jolanta ADAMCZYK, Ewa BARTEL, Barbara JANISZEWSKA M.Sc., Eng., Tomasz JANISZEWSKI, Ewa KASPER M.Sc., Stanisław KRASNOWOLSKI M.Sc, Krystyna KULCZYKOWSKA M.Sc, Eng., Monika MOSZCZYŃSKA M.Sc, Eng., Bożena POŁCZYŃSKA, Janusz SMAGAŁA Eng., Anna WIERZEWSKA M.Sc, Joanna WILTOWSKA.

GRANTS:

1. Assoc. Prof. A. Cebulska-Wasilewska Environmental Studies: a) PECO 10964 CIPDCT 925100 (Joint Research CEC Project) b) PECO 6943 East/West CEC grant No - ERB 3510 PL920811

223 Radiobiology: a) PECO 2992 CIPDCT 925008 (Joint Research CEC Project) b) PECO 2981 East/West CEC grant No - ERP 3510 PL922981 c) BMH-CT 92-0859 PL1012, PL93-1013 (Joint Research Project) 2. Dr B. Łazarska Joint grant No 550079102 (the State Committee for Scientific Research) with the Academy of Agriculture, Kraków, Poland.

OVERVIEW:

This year, our research programme was particularly exciting as the new group structures were established and newly denned projects were appearing in the Department of Radiation and Environmental Biology: 1. Laboratory of Radiation and Environmental Cytogenetics, 2. Laboratory of Radiation and Environmental Mutagenesis, 3. Neutron Therapy and Preclinical Studies Group. This year we reorganized our laboratory for cytogenetics studies while continuing our basic research into the genotoxic effects of ionizing and nonionizing radiation, chemicals mutagenic in the environment and their interaction with radiation. In two types of eucariotic cells we continued the studies begun last year on the relationship between the amount of energy deposited and the various types of damage that result from the exposure to fast neutrons and X-rays. We extended our studies to look at the effects of low radiation doses in human blood lymphocytes and we are now looking at possible increased levels of mutation in TSH system resulting from low radiation doses of X-rays and 5.6 MeV neutrons. Finally, we started the new radiobiology projects concerning comparisons between relative biological effectiveness of high LET radiation, particularly neutrons from HFR JRC in Petten and fast neutrons from U-120 in Cracow in the induction of various genetic end-points. Our proposals won grants to join the ongoing CEC project CLLNCT aimed at the application of fission neutrons for cancer therapy. In co-operation with the Radiobiology Group from the National Radiological Protection Board, Chilton, UK and the Radiobiology Group from ECNICE in Petten, using our two best assays ( TSH and CA in lymphocytes), we made our first attempt to compare experimentally the effectiveness of fission neutrons and fast neutrons in the induction of gene and lethal mutations in Iradescantia and chromosome aberrations in human blood lymphocytes. The studies of cytogenetic damage induced by fast neutrons are almost finished, while fission neutrons are still under study. Our environmental studies were also going exceedingly well. With an application of gene mutations in Tradescantia assay (TSH) we continued studies into the genotoxic effects of organic chemicals related to pesticides. We were looking for the results of both types of treatment: individual and combined with radiation. In the field applications of TSH assay for in situ studies of genotoxicity of ambient air pollution, we repeated monitoring at site of the primary school No 12 in Cracow. At this site a new shield against traffic noise and pollution had just been constructed, and our data showed a great improvement in air quality. Our studies in situ with the TSH as a bio-indicator also demonstrated that a high genotoxic effect was to be observed at the tested sites along the main traffic routes in Cracow. In some places the average mutagenic effect observed was higher than that observed in the vicinity of the petroleum plant in Płock. Due to our long term studies into the genotoxic effects of benzene related compounds, two European Community grants (training + research) were given to join the ongoing project in the field of environmental studies aimed at finding the cause or early markers and indicators of the process involved in cancer and genetic damage induction. These grants will allow us to

224 PL9601104 broaden further our research field, and to develop Unking programs between the Department of Radiation Genetics and Chemical Mutagenesis at the Faculty of Medicine at Leiden University, the Department of Genetic BIBRA, Carshalton and our Department. The studies on cytogenetic damage in blood lymphocytes of persons occupationally exposed to benzene related compounds have already been started, following parallel studies at BIBRA into the checking of the presence of oncoproteins. The third line of research in our Department is more linked to the possible improvement that might be achieved in clinical cancer therapy. A. Cebulska-Wasilewska was successful with a grant application to Gray Laboratory, Mount Vernon Hospital for participation in ESTRO Advanced Radiobiology Course for Radiotherapists in late April 1993, which was followed by a 2-day workshop devoted to techniques commonly used at Gray Laboratory. These included cell culture, animal studies and molecular biology. Our own preclinical studies on early and late health tissue response performed on C3H mice have been going on intensively this year. They concerned various dose fractionation systems, and aimed at replacing the classical fractionation system with a new shorter one that would give good clinical results. It should also be noted, that besides our research goals we continued our duties connected with therapy treatment (one week per month cycle), performing irradiation of patients of the Oncological Centre in Cracow using the fast neutron beam from 9Be + d reaction at our U-120 cyclotron.

, \

Assoc. Prof. Antonina Cebulska-Wasilewska

REPORTS ON RESEARCH:

Comparison between ambient air genotoxicity in urban areas with genotixicity of known mutagens A. Cebulska-Wasilewska

The aim of the studies begun in 1991 was to compare the genotoxicity of ambient air in two urban areas affected by benzene and petrol associated compounds. Various sites have been tested in the Cracow area and in the vicinity of a petroleum plant in central Poland. Iradescantia clone 4430 plants grown according to the conditions described elsewhere [1,2], were exposed on sites potentially in danger of chemical pollution. In somatic cells of Tradescantia gene, lethal mutations rates as well as disturbance of cell cycle were measured, beginning on the 11th day of exposure, the biological effect of exposure being expressed as the number of mutations per 100 hairs. Studies performed in Cracow resulted in the highest value of mutation frequency, which was observed in the year 1991, at the site situated about 30 meters from the heavy traffic road- crossing near primary school No 12. The biological effect observed in plants exposed at that place was significantly higher than at the site which was not affected by traffic pollution from the crossroads (Table 1). In 1992 biological monitoring with TSH assay was performed in Cracow at the sites situated along traffic routes. Differences between the levels of mutation observed at those sites ranged from 0.25 to 0.33 mutations per 100 hairs. Chemical monitoring data reported for the time of plants exposition showed that the levels of pollutant contents in the air were much below permissible levels. In spite of that fact, the biological effects measured at sites

225 affected by traffic pollution were significantly higher than those observed at the site situated at the Institute. In 1993 biological monitoring was repeated when a screen shielding primary school No 12 had been constructed. A significant decrease in the biological effects induced in plants exposed at site of the school was observed (Fig.l). There was no significant difference between the effects measured at the same sites as were tested in 1991. Biological monitoring with TSH-assay confirmed that the screen protection from traffic pollution works effectively. Biological monitoring in the city of Płock area revealed the average mutation rate detected was comparable or lower than that observed in Cracow. There was also a variation between the levels of mutation observed at various sites tested. Mutation frequencies appeared to be weakly dependent on the distance from the Petroleum Work (MZPiR) center (Fig.2). The correlations between mutation frequencies induced and chemical concentrations in the air were stronger than between mutations and the distance from the petroleum plant. It means that traffic in the city center significantly contributes to both pollution and the final biological effect. It can also play an important role in physiological cellular processes [5]. The average mutation rate detected in the Płock area in 1993 achieved the lowest value, 0.24 mutations per 100 hairs, since the studies began in 1991. Many mutagens and carcinogens including radiation, the well known mutagen like EMS and such carcinogenic agents, classified as self pollution, like cigarette smoke and filter residue, were also tested by the bio-assay based on gene mutations in somatic cells of Tradescantia (Table 2)[3-5]. The last columns in Table 1 present X-ray doses which would induce quantitatively the same effects in TSH as the biological effects observed after the exposures under study. Gy- equivalents calculated for biological effects in TSH caused by in situ exposures greatly extend the permissible annual effective dose. The data presented above allow us to conclude that the mutagenic effects of chemical pollutants present every day in the ambient air of the urban areas of Cracow and Płock, particularly at the places affected by benzene or traffic associated pollution, are comparable to the biological effect which was caused by the fallout from the serious nuclear accident in Chernobyl [6] or with known strong mutagens and carcinogens.

Mutation frequently detected BIOLOGICAL MONITORING •t Public School No IS PŁOCK 1993 I - 1991 av. mirt. rat* 0.40

[~|- 1993 au. mut raU 0.25

I ri I rl 0.20 to 11 13 14 15 IB 17 IB 19 20 3 5 B 10 13 15 IB 20 23 25 28 30 33 12 13 Days14 of15 exposure Distance from Petroleum. Plant 1 1cm 1 Fig.l. Mutation values induced in TSH at Fig.2. Relationship between mutation ra- public school No 12 before and after the tes induced in plants exposed and distance shield construction. from the work center.

226 TABLE 1. MEAN VALUE OP MUTATION FREQUENCIES DETECTED in situ BY TSH ASSAY IN DIFFERENT PERIODS AND PLACES AND in vitro AFTER MUTAGENIC TREATMENT 1 Site NOH PF+SE STF Gy-equiv. [Gy] || Krakow: (IFJ) May 1991 22615 0.20 +0.010 0.37 0.002 (1)** 47473 0.40 +0.025 0.29 0.05 (2) 30316 0.28 +0.026 0.31 0.02 (3) 140027 0.35 0.36 0.036 (IFJ) May 1992 142650 0.19 +0.009 0.15 * (1) 138152 0.33 +0.016 1.38 0.03 (2) 46056 0.25 +0.010 0.15 0.013 (3) 700830 0.29 1.00 0.022 (IFJ) May 1993 164693 0.24 +0.025 0.55 0.016 (1)** 141758 0.26 +0.023 0.93 0.016 (2) 105960 0.22 +0.010 0.84 0.007 (3) 541210 0.24 0.89 0.011 Płock: (Z) June 1991 - - - - (1) 98550 0.33 +0.023 0.20 0.024 (2) 105400 0.25 +0.016 0.12 0.013 (3) 768150 0.30 0.15 0.024

(Z) September 1991 117679 0.36 +0.007 0.78 0.038 (1) 15670 0.41 +0.023 3.29 0.049 (2) 43144 0.29 +0.016 1.34 0.022 (3) 631118 0.32 1.60 0.029 (Z) September 1992 13325 0.39 +0.025 0.60 0.044 (1) 30416 0.37 +0.023 1.95 0.040 (2) 36080 0.27 +0.023 0.51 0.018 (3) 190192 0.33 0.94 0.029 (Z) June 1993 27952 0.28 +0.015 1.93 0.020 (1) 136380 0.25 +0.013 0.82 0.013 (2) 120090 0.21 +0.015 0.52 0.004 (3) 1113808 0.23 0.90 0.009 cigarette smoke 6h [7] 0.08 + 0.004 - 0.018 filter deposit 10 fA [7] 0.19 + 0.010 - 0.042 EMS 20 //I (0.045%) [2] 0.60 + 0.003 - 0.133 NOH - number of analyzed hairs, PP - gene, STF - lethal mutation frequency, (*) - level taken as a control value, (**) - public school No 12. Mutation's rates detected in the city: (1) - the highest, (2) - the lowest, (3) - an average References: 1. Underbrink A.G., Schairer L.A., Spparrow A.H., (1973) in: Chemical mutagens: Principles and Methods for their detection. Ed. A. Hollaender Plenum Press, New York-London, Vol.3, 171-207. 2. Cebulska-Wasilewska A., IFJ Raport, No 1335/B (1986). 3. Cebulska-Wasilewska A., Nukleonika, Vol.33, No 4-6 (1988) 91-105. 4. Cebulska-Wasilewska A., Kuternozińska, Applied Biology 1993 (in press). 5. Cebulska-Wasilewska A., Pawłowski J., Raport IFJ, No 1587/B (1992). 6. Cebulska-Wasilewska A., (1992), Mut. Res. (in press).

227 PL9601105 Induction of chromosomal aberrations in human lymphocytes by X-rays and fast neutrons A. Cebulska-Wasilewska, A. Wierzewska E. Kasper and B. Krzykwa

The most developed and efficient way in which irradiation caused damage can be checked is the lymphocyte model system based on the in vitro culture of human lymphocytes delivered by the basal blood vessels. After irradiation culturing is terminated at the first mitosis, some chromosomal aberrations become visible in the cytogenetics samples slides. The method based on the screening aberrations known as the ring and dicentric chromosomes has been accepted all over the world as the basic for the measurement of the absorbed dose [1]. This paper presents some results of studies investigating the ability of different amount of energy and different types of radiation to induce chromosomal aberrations. The efficiency of neutrons as well as X-rays to induce such abnormalities (rings and dicentrics) in human lymphocytes was assessed. A comparison between these efficiencies was used to establish the relative biological efficiency (RBE) for 5.6 MeV average energy neutrons. Blood samples were irradiated with neutron doses of 0.07 - 2.5 Gy produced by the U- 120 cyclotron. X-radiation ranged from 0.1 to 5.0 Gy and was generated by a source with the following parameters: 250kV, llOR/min, 0.5mm Cu filter. Blood samples collected from middle- aged volunteer donors, was placed into sterile and hemiparesis glass tubes and then irradiated at room temperature. Lymphocytes were cultured in new, sterile reseals poured with media containing Eagle medium with antibiotics (80%) and fatal calf serum (20%). Cell divisions were stimulated for 46 hr (previously 52 hr) with the LF-7. After that time colcemid was added into the media and 2 hr later culturing was stopped. The collected samples were then stained with Giemsa solution and analyzed for the presence of chromosomal aberrations. It was assumed that the measure of biological effect would be the number of ring and dicentric chromosomes per cell and the number of cells with chromosomal aberrations. Depending on the dose 200 to 700 metaphases were analyzed. For several doses of X-rays and neutrons, the yield has been measured. Fig. 1 demonstrates the results as regards the influence of irradiation on the number of chromosomal aberrations induced in human lymphocytes by different doses of fast neutrons and X-rays. Fig. 2 oversteps curves which show the number of aberrations per cell depending on the neutrons dose. Comparison between the X-ray and neutrons dose response curves shows that neutron doses, which induce the same arbitrarily chosen level of chromosome aberration, are much more efficient than X-rays. Relative biological effectiveness depends on dose and in a range of investigated doses the RBE changes from 3.7 at low doses to 2.7 for high doses region. The data in Fig. 1 shows the number of aberrations induced depending on the X-ray doses in a linar-quadratic function. Generaly, the number of rings as well as dicentric chromosomes depends on the dose of irradiation and should be described by the following function [2]: Y = C + aD + f3D2 where: Y - yield of chromosome aberrations a - the linear coefficient (3 - the dose-squared coefficient D - dose of irradiation. For fast neutrons quadratic relation is rather bad and this dependence should be linear. The best fit for our data results in the following equations: for X-rays, Y = C + 0, 05148Z? + 3,66910-2£2 for neutrons: a) Y = 0,508-D and

228 PL9601106 b)Y = 1,25-D. Equation "a" describes the best fit for the data achieved in different dosimetry and culture conditions [3], with a slightly longer time of culturing (52h), equation "b" emerged from the data obtained in a new conditions of culture [1]. The comparison between alpha parameters derived from the best fit for neutrons and X-rays dose response curves results in two RBE values for 5.6 MeV neutrons [(a)-9.9 and (b)-24.3]. It seems that the first value was a little lower than the value expected from Lloyds estimation [2], on the base of which, RBE should be in the range of 14 for 14.7 MeV neutrons and 59 for 0.7 MeV neutrons. The RBE value 24.3 resulting from the recent data obtained after modification in the method and new dosimetry gives a much better estimation, however the studies of the reason for the observed difference should be continued.

»0.M

•OOJO

O.Ó0 i.4» IM *M' Hi" iM i'io Vii' Neutron dose 1 Gy 1 Dose ( Gy ) Fig.l. Dose respouse relationship for the in- Fig.2. The influence of experimental condi- duction of dicentrics and rings aberrations by tions on efficiency of detection of dicentrics X-rays and fast neutrons. and rings.

Acknowledgment This work is partly supported by CEC contract number PECO 2992 CIPDCT 925008 References:

1. Biological Dosimetry: Chromosomal Aberration Analysis for Dose Assessment, IAEA, Technical Reports No.260, Vienna, 1986. 2. D.C. Lloyd, Biological dosimetry by cytogenetic methods, RIS Dosimetria Biologica, 1990 Madrid. 3. A. Cebulska-Wasilewska, A. Wierzewska, E. Kasper, B. Krzykwa, H. Phiciennik, J. Occup. Med. (in press).

An evaluation of genotoxic activity of pesticides and its interaction with X rays using TSH assay M. Litwiniszyn, B. Pałka and A. Cebulska-Wasilewska

Extensive use of pesticides in modern agriculture has led to a dramatic increase in the number of synthetic chemical compounds to which man is exposed directly or indirectly. Pesticides are of potential hazard not only to farmers but also to the general public, because pesticide residues are present in food [1], groundwater and soil [2], Pesticides are highly reactive and toxic compounds and their harmful impact upon the environment and public health has to be evaluated. In assessing genotoxic effects of pesticides different short-term bio-assays can be employed, based on: mutation induction, chromosomal aberrations or micronuclei induction in different

229 systems [3]. In our studies we applied a TSH (Tradescantia Stamen Hair) assay [4] to evaluate the genotoxic activity of seven pesticides, i.e. Benomyl, Carbofuran, 2,4-D, Heptachlor, Methoxychlor, Parathion-methyl and Propachlor.1 All tested compounds are produced by well-known chemical companies (Bayer AG, du Pont de Nemours & Co., Ciba-Geigy AG), and are widely used in agriculture. All these compounds have benzene rings. Concentrations of pesticides employed for TSH assay were within the range of those used in agriculture. To test possible interaction with any other agent in the environment a combined treatment using small doses of X-rays was applied. All tested pesticides were screened for mutagenicity and lethality in TSH assay using Tradescantia clone 4430, and the data are presented in Table 1. Our findings shown in Table 1 revealed that only one of the pesticides tested, i.e. 2,4-D, was positive for mutagenicity in TSH assay. 2,4-D is an active compound of "Aminopielik" (a pesticide widely used in Poland), which was found to be mutagenic in our earlier studies [5]. The majority of the screened chemicals (five of seven) showed positive response for lethality. Synergistic effect of radiation and pesticides was not observed in our studies. These data are only preliminary ones and the use of higher concentrations of the tested agents is recommended in further studies. With the wide use of pesticides in modern agriculture, prudence requires the use of different systems in assessing the mutagenic properties of these agents. For example, some pesticides require plant or animal activation to be genotoxic [6]. Furthermore, some chemicals may interact with small doses of radiation present in the environment and an enhancement of the effect can be observed. So, the use of TSH assay which is very sensitive to both: chemicals and radiation seems to be appropriate and such studies should be continued.

TABLE 1. DATA OF GENOTOXIC ACTIVITY OF PESTICIDES IN TSH ASSAY Pesticide Treatment Mutagenicity Lethality Synergistic common name effect Benomyl 10/d-0.004% — 20/xl-0.004% nt Carbofuran 10/il-0.004% 20/d-0.004% : : nt 10^1-0.004% + 2,4-D 20/d-0.004% + + 10/xl + lGy 10/xl-0.004% + Heptachlor 20^1-0.004% - + 10/d + lGy 10/d-0.004% + Methoxychlor 20^1-0.004% - + 10/d + lGy Parathion- 10/d-0.004% + methyl 20/d-0.004% - + 10/xl + lGy 10/d-0.004% Propachlor 20/d-0.004% - + 10/d + lGy

"-" - negative response, "+" - positive response, nt - not tested

'Chemically pure pesticides were kindly provided by Prof. J.M. Gentile from Department of Biology, Hope College, Holland, MI 49423, U.S.A.

230 n . PL9601107 References: 1. Pesticide residues in food - 1991: Evaluations, Part II - Toxicology, Report of the FAO /WHO Joint Meeting on Pesticide Residues, Geneva, 16-25 Sept., (1991). 2. N.W.H. Houx, W.J. Aben: Report - DLO Staring Centre, Wageningen, No. 60, (1992). 3. I.S. Grover, A.K. Dhingra, N. Adhikari, S.S. Ladhar: Nucleus, 31, 69-77, (1988). 4. A. Cebulska-Wasilewska: Raport No. 1434/B, IFJ Kraków, (1990). 5. A. Cebulska-Wasilewska: Raport No. 1511/B, IFJ Kraków, (1990). 6. M.J. Plewa, E.D. Wagner, G.J. Gentile, J.M. Gentile: Mutat. Res., 136, 233-245, (1984).

Biological effects of electromagnetic fields estimated by TSH assay A. Cebulska-Wasilewska, I. Pawłyk, S. Szmigielski1, G. Sokolska1 and R. Kubacki2

department of Biological Effects of Electromagnetic Fields, Military Institute of Health and Epidemiology, 00-950 Warszawa, ul. Szaferów 128 2Department of Microwaves, Military Institute of Health and Epidemiology, 00-950 Warszawa, ul. Szaferów 128

Much technology used nowadays is based on or is in itself a source of various types of magnetic, electromagnetic and sound fields which may disturb the biological process [1]. Studies on the influence of microwave radiation and symmetric stripe field on living organisms were based on a biological test (TSH-assay) in which the bio-indicator Iradescaniia, clone 4430 was used. Gene mutations are visible as change of cell color from blue to pink, while lethal mutations - as a decrease of the cell number in a hair to below 16 cells. The pink gene mutations occur as a change of color of a single cell or group of cells situated next to one another. The relationship between the number of single pink cells and the number of all pink cells informs the observer of the possible cell cycle perturbations. Frequency of mutations expressed as the number of mutations per 100 hairs has been accepted as the measure of mutagenic effectiveness of a checked factor or group of factors [2]. Exposures were carried out in the Military Medical Academy in Warsaw, where it was possible to generate different types of fields with the desired power. During the experiment the grouped inflorescens were exposed for 1 or 2 hr to microwave field or to stripe line field in an anti-echoed chamber. The generated fields had the following parameters: - microwave field: frequency f=2850 [MHz] - stripe line field: frequency f=332 [MHz]. For each field two different powers were generated. The characteristics of the exposures are presented in Table 1. In the exposures in anti-echo chamber two controls were introduced. In the first of them, control plants were placed in the chamber where only a small effect of the field was expected (code 2). This checking point was included to detect the potential mutagenic impact of synthetic resin in the chamber induced by specially prepared glystyrene. The second control (code 9) plants were situated near the chamber which generated the microwave field. In this case plants were exposed to sounds of high intensity; some of these sounds were also of high frequency which was typical for the interior of the chamber. During the investigations devoted to the stripe line field plants were exposed for different periods of time to the field in the central part of the chamber, where the most uniform field was

231 expected. The control plants were kept in the same room as the chamber (code 6). During the experiment some fluctuations in temperature occurred. On the 11th day, after the plants have been under the influence of the field, the measurement of frequency of mutations started. Table 2 presents the average biological effects observed. These effects of exposures were set in order of density of the fields. The first column (I) shows both the densities of the field and its codes. The second column (II) shows the numbor of analyzed hairs for each code. The third (III) column presents the average frequency of pink mutations in stamens of hair cells in the exposed flowers. Column IV in Table 2 demonstrates the frequency of single pink mutations and column V in the same table - frequency of mutations of hairs with less than 16 cells. Column VI shows the value of the cell cycle index, which was counted as the ratio of the number of single pink mutations to the number of all pink mutations. Columns VHI-X present values of t Student function in comparison with proper codes. Our data revealed that the plants of codes 1 and 4, which were exposed to the field of the lowest density and for the shortest period of time are the only ones in which differences in gene mutation frequency from control values are of statistical importance (with level of confidence of 5%). The remaining groups of plants differ one from another as well as from the control group statistically insignificantly, and no correlation between mutation rate and the type of exposure was found. There is a visible variation in the cell cycle factor, however alterations of cell cycle factor are also observed in the plants controlling exposure conditions. It should be taken into account that it is known that temperature affects the mutation level in TSH, so, it is possible that variation in temperature can be a strong factor affecting the results of exposure. Therefore, our data demonstrate that the investigations of those fields did not result in clearly visible effects which could explain our previous findings with 250 kHz electromagnetic field [3]. Considering the previous data, where the influence of electromagnetic field was established, a new experiment should be carried out using field parameters similar to those from the previous studies and with an intensity similar to 353 V/m, and in conditions with better temperature control.

TABLE 1. CHARACTERISTICS OF EXPOSURE. Code Field Power Time Temp.[°C] 1 stripe line 20F/ro 1 hrs 28.5-32.0 2 a - 2 hrs 35-30 3 microwave 100W/m2 1 hrs no data 4 microwave 20W/m2 1 hrs 28-35 5 stripe line 80 V/m 2 hrs 32-27 6 c - 3 hrs 28.5-21.0 7 microwave 100W/m2 2 hrs 35-30 8 stripe line 80 V/m 1 hrs no data 9 b - 3 hrs 28-21 10 d - - - a - control plant in microwave chamber; b - control plant near microwave chamber; c - control plant near stripe line field; d - control of the trip.

232 PL9601108

TABLE 2. AVERAGE BIOLOGICAL EFFECTS CAUSED BY EXPOSING TO THE MICROWAVE AND STRIPE LINE FIELDS. I n in IV V VI vn vni IX X 1 Code NOH PF +SE SPF STF CC Codes t FD Signif.% 1 MICRO WAVE FIELD [W/m2] 4 19188 0.30 + 0.090 0.088 0.50 0.35 4:10 2.663 8 97.13 3 15322 0.19 + 0.083 0.079 0.44 0.41 4:11 2.686 8 97.23 7 17621 0.24 + 0.141 0.092 0.51 0.41 2 17822 0.26 + 0.088 0.103 0,51 0.40 9 22489 0.31 + 0.095 0.743 0.76 0.24 10 37027 0.17 + 0.066 0.068 0.71 0.45 STRIPE LINE FIELD[V/m] 1 14475 0.30 + 0.107 0.114 1.07 0.38 1:10 2.309 8 95.03 8 14403 0.24 + 0.099 0.076 0.70 0.29 1:11 2.329 8 95.18 5 19116 0.19 + 0.072 0.072 0.64 0.40 6 16230 0.22 + 0.090 0.062 0.71 0.31 10 37027 0.17 + 0.066 0.068 0.71 0.45

NOH - number of hairs; PF, SPF, STF - pink, single pink, lethal mutation frequency; CC - cell cycle factor; FD - degrees of freedom. References:

1. Indulski A.J., "Environmental Health Criteria" PZWL, Warsaw (1987) in Polish. 2. Cebulska-Wasilewska A., Raport IFJ 1434/B (1990) in Polish. 3. Cebulska-Wasilewska A., Raport IFJ 1587/B (1992) in Polish.

Acute Reaction of Mouse Skin to Fractionated X -ray Irradiation Performed with the Use of Various Schedules J. Huczkowski, B. Janiszewska, T. Janiszewski, S. Krasnowolski, K. Kulczykowska, B. Lazarska, J. Skołyszewski1, V. Svoboda2, K. Trott 3 and B. Wilczyńska1

ICentre of Oncology Maria Skłodowska-Curie Memorial Institute, Kraków 2St. Mary Hospital, Portsmouth, England 3Department of Radiobiology, University of London, London, England.

The results shown in this paper are the continuation of our previous investigation (Annual Report 1992) of the reaction of normal tissues to a fractionated irradiation. The mouse skin system was used to compare the results of various fractionated schedules. The reactions in groups of 4 C3H mice, each exposed to a given 250 kV X-rays dose, were scored on an arbitrary scale (1) and the average daily reaction was plotted against time. To compare the total doses needed to produce a given biological response dose response curves were used. The preliminary results of the first part of out investigation showed that there was no difference in the acute skin reaction between groups of mice irradiated with 20 fractions, twice a day with 3 and 6 hours interfraction intervals. The short half-time for the sublethal damage repair (T 1/2 ) could be the principal cause of this observation. To get more information about the recovery kinetic a new experiment was performed. Mice were irradiated over 2 weeks, twice a day with 0.5, 1, 3 and 6 hour intervals between fractions. The results are showed in the Fig.l. The data obtained allowed us to calculate T 1/2 at the 3 different levels of skin damage. According to the first order of kinetics we assumed the exponential repair curve. The values of Tl/2 are: 1.27, 1.2 and 1.16 hours for a level of skin damage of 1.3, 1.65 and 2 respectively. These values agree with the repair

233 half-time (1.3 h) found for skin by Henkelman et al (2). Howevei Tl/2 does not explain the absence of difference in skin reaction in mice irradiated with 3 and 6 hours interfraction intervals. If Tl/2 is 1.2 h and the full recovery dose is about 14 Gy there is 2.5 Gy still available for the repair when the time interval between fractions increases from 3 to 6 hours. Nevertheless such a 2.5 Gy "gap" between series with 3 and 6 hours interfraction intervals was not observed in all our experiments. Even more, the results obtained showed, that there is a slight, nonsignificant tendency to a more pronounced skin reaction after irradiation with split doses with a 6 hours time interval between fraction. The data about the kinetics of the split-dose recovery showed that the longer intervals between fractions might produce a decrease in the survival, which could be attributed to the progression of survivors to more sensitive phases of the cell cycle. If the increase in the time interval between fractions from 3 to 6 h is sufficient to start the cell cycle progression this mechanism could be a possible explanation of the effect observed. The second part of our present work presents estimation of the a/f3 value, which is a sensitive, quantitative index, convenient for predicting the radiation response of different normal and malignant tissues. The a/0 value was calculated using the data of 3 series of experiment and the Linear-Quadratic Model as a reciprocal of the total doses plotted against the dose per fraction in the two different regimens of fractionation. This gave a straight line and the a/0 ratio was read off as a negative dose per fraction intercept, i.e. 9.5 Gy ( Fig.2 ). This value is comparable with the a/0 values for the mouse skin 8.6 - 12.5 Gy found in the literature [1,3]. The investigation of the response of late reacting tissues ( lung, kidney ) is in progress.

0.2 -

0.15-

0.05-

it as •5 -101234567 d (Gy) Tllll II! [ (Gy)

Fig.l Dose -response curves for mouse skin reaction. Fig.2. Estimation of the a/0 ratio. References:

1. Douglas B.G. and Fowler J.F., Radiation Research, (1976), 401 2. Henkelman R.M. et al., Radiation Research, (1980), 276 3. Joiner M.C. et al., International Journal of Radiation Biology, (1986), 565.

LIST OF PUBLICATIONS: I. Articles:

1. A. Cebulska-Wasilewska, Correlation between physico-chemical monitoring and pollution genoticity detected by bio-indicators, (in polish), Proc. of Geochemical, Hydrochemical and Biochemical Changes of Natural Environment Cracow, 10-15, 1993; 2. J. Gajewski, E.B. Ramsay, L.E. Reinstein, Refinement of Monte Carlo Calculations for BNCT at the Brookhaven Medical Reactor, Progress in Neutron Capture Therapy for Cancer eds R.F. Barth, A.H. Solovay (Plenum Press, New York) (1993) 1; 3. L.E. Reinstein (J. Gajewski) et al., SBNCT-PLAN: A 3-Dimensional Treatment Planning System for Boron Neutron Capture Therapy, Progress in Neutron Capture Therapy for Cancer eds R.F. Barth, A.H. Solovay (Plenum Press, New York) (1993) 10;

234 4. A. Cebulska-Wasilewska, W. Flakiewicz, In situ studies of biological effects of electromagnetic field, J. Occup. Med. (in press); 5. A. Cebulska-Wasilewska, H. Pruciennik, Estimation of the mutagenic effectiveness of some pesticides, J. Occup. Med. (in press); 6. A. Cebulska-Wasilewska, Effectiveness of TSH assay for in situ biological monitoring of ambient air pollutants mixtures (in press); 7. A. Cebulska-Wasilewska, H. Pruciennik, A. Wierzewska, E. Kasper, B. Krzykwa, Comparison between genotoxic effects of pesticides with genotoxicity of known mutagens and radiation (in press).

II. Contributions to Conferences:

1. A. Cebulska-Wasilewska, Comparison between ambient air genotoxicity in two urban areas in Poland, Proc. of 23rd Annual Meeting of the European Environmental Mutagen Society, Barcelona, September 1993; 2. A. Wierzewska, E. Kasper, B. Krzykwa, A. Cebulska-Wasilewska, Chromosome aberrations in human blood lymphocytes in studies of fast neutrons biological effectiveness (in polish), Proc. VIII Annual Conference of Cytogenetics, Wroclaw, September 1993.

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. A. Cebulska-Wasilewska: VIII Annual Conference of Cytogenetics, Wrocław, September 1993, Seminar "Young People and Ecology", Cracow, October 1993, 23rd Annual Meeting of the European Environmental Mutagen Society, Barcelona, September 1993, Geochemical, Hydrochemical and Biochemical Changes of Natural Environment. Cracow, December 1993, 2. J. Huczkowski: XVIII Proton Therapy Group Meeting, Orsay April 1993, 3. E. Kasper: VIII Annual Conference of Cytogenetics, Wroclaw, September 1993, 4. B. Krzykwa: VIII Annual Conference of Cytogenetics, Wrocław, September 1993, 5. A. Wierzewska: VIII Annual Conference of Cytogenetics, Wroclaw, September 1993.

LECTURES AND COURSES:

1. A. Cebulska-Wasilewska: "Radiobiology, environmental mutagenesis, comparative environmental genotoxic risk analysis", Lecturing in a course for undergraduate students of Medical Physics and Dosimetry, at the Physics and Technology Department at AGH, Kraków, Winter semester 1993, 2. A. Cebulska-Wasilewska, Participation in Fourth Advanced Radiobiology Course, ESTRO April 1993. Mount Vernon Hospital, Northwood, Cancer Research Center, Gray Laboratory, 3. B. Księżkiewicz, Participation in a Course of Health Risk Estimation, Łódź, April 1993.

235 INTERNAL SEMINARS:

1. J. Huczkowski, February 1993 "Early and late effects in mice as a model system foi fractionation studies". 2. A. Cebulska-Wasilewska, Match 1993 " Tradescantia assay (TSH) as a bio-indicator in environmental studies". 3. I. Pawłyk, April 1993 "Biological methods in wastes control". 4. B. Łazarska, April 1993 "Measurements and methods of absorbed dose estimation in neutron cancer therapy". 5. A. Wierzewska, May 1993 "Chromosome aberration and sister chromatid exchange: application in radiobiology and environmental studies". 6. B. Krzykwa, May 1993 "Development of cytogenetic methods for environmental studies". 7. B. Ksiażkiewicz, May 1993 "Epidemiological methods in health risk analysis". 8. B. Pałka, June 1993 "Biochemical methods in studies of environmental hazards". 9. H. Płuciennik, June 1993 "Biological effects of incorporated radionuclides". 10. M. Plewa (USA), October 1993 " Characterization of stable high molecular weight mutagenic products of plant-activated aromatic amine promutagens". 11. J. Gajewski, November 1993 " Refinement of Monte Carlo Calculations for BNCT at the Brookhaven Medical Reactor".

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Prof. R.M. CORTES - University UTAD, Vila Real, July 1993. 2. Drs P. CHAUVEL and N. BRASS ART - Department of Medical Application Center, Antoine - Luacassagne Nicaea, France, August 1993. 3. Prof .dr M. PLEWA - Eksperimental Botany Institute, Praga, October 1993. 4. Dr E. WAGNER - University of Ilinois, Urbana-Champain, USA, October 1993. 5. E. RADETSKI (from Prof, dr J.F. FERARA) - Institut Ecology, Metz, France, October 1993.

236 Department of Nuclear Radiosp ectroscopy PL9601109

DEPARTMENT OF NUCLEAR RADIOSPECTROSCOPY

Head of Department: Prof. Jacek W. Hennel Secretary: M. Zych telephone: (48) (12) 37-02-22 ext.: 253 e-mail: [email protected]

PERSONNEL: Magnetic Resonance Laboratory Research Staff: Artur Birczyński, Ph.D. Jerzy Blicharski, Professor Jacek W. Hennel, Professor, Head of Department and Laboratory Zdzisław T. Lalowicz, Ph.D. Zbigniew Olejniczak, Ph.D. Stanisław Sagnowski, Ph.D. Robert Serafin, M.Sc. Administration: Secretary: Magdalena Zych Magnetic Resonance Imaging Laboratory Research Staff: Franciszek Hennel, Ph.D. Andrzej Jasiński, Assoc. Professor, Head of Laboratory Jacek Kibiński, Ph.D. Stanisław Kwieciński, M.Sc. Artur Krzyżak, M.Sc. Tomasz Skórka, M.Sc. Zenon Sułek, Ph.D. Krzysztof Szybiński, M.Sc.Eng. Bogusław Tomanek, M.Sc. Piotr Kulinowski, Technician Laboratory of Solid State Physics and Computer Simulations Research Staff: Krzysztof Parliński, Professor, Head of Laboratory, Małgorzata Sternik, Ph.D.

GRANTS:

1. Dr Z. T. Lalovncz grant No 2 033649 91 01, (the State Committee for Scientific Research), Studies of quantum and classical reorientation of ND% ions by means of NMR spectroscopy.

237 2. Assoc. Prof. A. Jasiński, grant No 2 2442 91 02, (The State Committee for Scientific Research), Nuclear Magnetic Resonance Microscopy. 3. Prof. K. Parliński and Dr M. Sternik, grant No 2 2377 92 01, (The State Committee for Scientific Research), The mechanisms of structural phase transitions.

OVERVIEW: Research at the Department of Nuclear Radiospectroscopy of the H. Niewodniczański In- stitute of Nuclear Physics is concerned with various problems of nuclear magnetic resonance (NMR) and their application in different areas of science with molecular dynamics in the first place. The Department is equipped with a 1.5T, 6cm gap electromagnet, 6.4T superconducting magnet, a XP4-100 Bruker spectrometer, a laboratory developed 25.5MHz microimaging system and a laboratory developed Zero-Field NMR spectrometer of unique design allowing work at helium temperatures. The Department closely cooperates with the NMR group of Prof. J.S. Blicharski at the Department of Physics of the Jagellonian University in Cracow. The current research program covers three areas: magnetic resonance, magnetic resonance imaging and solid state physics by computer simulations. MAGNETIC RESONANCE LABORATORY. There are in principle two mechanisms of molecular reorientations in solids: tunnelling through the potential barriers and random jumps between distinct reorientations. The former is responsible for orientational delocalisation at liquid helium temperatures, causing so-called tunnelling splitting of the ground torsional energy level and therefore strongly influencing the NMR spectrum. Random jumps are possible at higher temperatures since the molecule needs a sufficient amount of energy to overcome the potential barrier. This type of motion can be treated classically. This also influences the NMR spectrum but in a manner quite different from that of tunnelling. In particular the deuteron NMR spectra exhibit the explicit evidence of the type of motion, moreover measurements of the tunnelling frequency and the reorientation rate are possible. Both supply data on height and symmetry of the potential. Cases of multiaxial reorientation at low symmetry potentials are particulary challenging. Ammonium tetrachloroplatinate can be given as an example of complex mobility. Combined analysis of proton and deuteron spectra of powder and single crystal samples, proton and deuteron relaxation, guided us among several feasible motional models. It was also shown that the use of partially deuterated + compounds containing NH3D ions may supply evidence of a substructure at the bottom of a potential well due to the observation of limited jumps and tunnelling. In order to find whether some of the classical jump motion is present even at helium temperature, T\ was measured at low magnetic field using the laboratory developed Zero-Field NMR spectrometer. Another problem studied in 1993 by deuteron NMR in solids was the behaviour of hydrogens of crystallisation water in crystalline oxalic acide (COOD)22D2O. It was found that there is exchange of hydrogen nuclei between the water molecules and carboxylic groups. Work on writing the book "Fundamentals of Nuclear Magnetic Resonance" by J.W. Hennel of this Laboratory and J. Klinowski from Cambridge University has been completed, and it was published by Longman Publ. Company in England early in 1993. "Fundamentals of Nuclear Magnetic Resonance" explains simply and precisely the physical and mathematical foundations of nuclear magnetic recsonance (NMR). The fundamental concepts are comprehensively presented to enable the reader to achieve a full understanding of the phenomenon, the reasons for and the significance of the various spectral effects and to enable him or her to read original research papers. The mathematical basis of the subject is fully explored and explained. There

238 are nine chapters covering different aspects of NMR. The initial chapter includes a condensed account of quantum mechanics at a level suitable for readers unfamiliar with the subject, the background to which is necessary to understand NMR fully. The remaining chapters discuss the areas of magnetic properties of the nucleus: nuclear paramagnetism, motion of magnetiza- tion, continuous wave NMR, pulsed NMR, NMR of liquids, the dipolar interaction and nuclear magnetic relaxation. The five appendices are a valuable addition, with information on complex numbers, scalar and vector products, calculation of traces, Dirac's delta function and sinusoidal operators. Undergraduate and postgraduate students, chemists, physicists, earth scientists, mineralogists, anyone seriously interested in NMR will find this text easily accessible, and a dependable reference source. MAGNETIC RESONANCE IMAGING LABORATORY. Work on MR microscopy supported by a grant from the Polish State Committee for Scientific Research involved the construction of a MR microscope based on a 6.3T superconducting magnet. This work was brought to its final stage. Other work concerned the design of a local actively shielded coil for the human head. Per- formance of this coil was optimized using a purpose written software for direct Biot-Savart field calculation. A surface gradient coil for the human chest was also developed. In collaboration with the Institute for Biodiagnostics of the NRC of Canada in Winnipeg MR functional images of the brain active visual centers were recorded. LABORATORY OF SOLID STATE PHYSICS AND COMPUTER SIMULATIONS. In the Laboratory of Solid State Physics and Computer Simulations the work has been concentrated around two topics: The tweed microstructure, experimentally observed in the high Tc superconducting material YBa2Cu3O7_i, has been extensively studied on the model of molecular-dynamics simulation. The model has been supplemented by a term of external field which could be coupled to the oxygen concentration. This allows one to establish the temperature-oxygen concentration phase diagram with the tetragonal-orthorhombic phase boundary. Analytical mean field theory derived for this model, agrees with the MD findings. Special attention has been devoted to the oxygen distribution in the tweed microstructure. It has been shown that oxygen vacancies gather mainly within the domain walls arising as a result of the elastic tetragonal-orthorhombic phase transition. Also, the microstructure changes with the oxygen concentration. The ground state of our hexagonal model contains one-dimensional lq and two-dimensional 3q modulations. This model has been extensively simulated by the MD method in order to elucidate the phase transition mechanisms between different types of modulated phases. The folowing phase transition mechanisms have been found: (i) Stripple mechanism occurs in the phase transition from commensurate to incommensurate one-dimensional phase. The stripple structure is uniquely defined by the domain structure of the commensurate phase, (ii) For the first time it has been shown by simulation that the column phase 3q exists. The phase transition from column 3q phase to a stripe lq phase relies on column merging, (iii) The phase transition from column phase 3q, characterized by one wave vector, to another column phase with a different wave vector is driven by the nucleation of the dislocation loop defined by the discommensuration lattice. Correlations between stripple appearence on the vast system (176000 particles) has confirmed the serial mechanism of nucleation. / ¥ f

Prof. J.W. Hennel

239 REPORTS ON RESEARCH: PL9601110 Single-Shot Fourier Velocity Imaging F. Hennel, Z. Sułek and A. Jasiński

This paper describes a two-dimensional Fourier velocity experiment based on the concept of echo-planar imaging (EPI), in which a flow profile can be determined in a subsecond time. The measured signal s is a function of six dimensions of reciprocal space (k,q) and is connected to the spin density p by the following formula

s(kq) — I p(rv)exp[-i(k • r + q • v)]d?rd3v where r is the position in space, v - velocity and

*(*) = 7 /* G(t')dt', q(t) = 7 f t'G{t')dt' Jo Jo G is the (switched on and off) gradient of the magnetic field. The demanded quantity proportional to the amount of spins in the position r having velocity v is P(T\). It can be obtained by Fourier transformation of the measured function s(kq) or s(ka!qz) if we confine the problem to two dimensions. To sample the signal s over the two-dimensional reciprocal space (k^qj) a special pulse and gradient sequence has been developed. A repeated pair of gradient pulses of duration T amplitude g, separated by a time T causes the following changes: kx —• -kx and q^ —• -q2+ 7 Gz r T. In result the (kj-qj) space is sampled along a trajectory shown in Fig.l.

Fourier transformation of the 2D data in kx and qz gives a projection of the spin density on the xvz plane as shown in Fig.2. A full account of this paper is to be found in the Journal of Magnetic Resonance, Series A102, 95-97 (1993).

Fig.l Trajectory in the reciprocal space cor- Fig.2 Image obtained by the reported EPI- responding to the reperted sequence. like Fourier velocity imaging method showing velocity distribution of water flowing through a tube. Horizontal axis: dimension across the

tube x, vertical axis: velocity vz, brightness: density of spins.

240 PL9601111 PL9601112

NMR and NQR Spin-Lattice Relaxation in Partially

Deuterated (NH4)2SnCl6 C. Dimitropoulos* and Z.T. Lalowicz * Institut de Physique Experimentale, Ecole Polytechnique Federale de Lausanne, Ch-1015 Lausanne, Switzerland

The chlorine-NQR and the deuteron NMR relaxation have been investigated in large "cross- relaxation" maximum of relaxation rate observed in both natural and partially deuterated compound at about 55K. The35 C1 NQR relaxation rate shows two smaller maxima at 20K and 30 K in the deuterated salt only. These maxima are shifted to a higher temperature for 37C1 isotope. The peak at 30K has a corresponding tunneling channel in the 2D-NMR relaxation rate. Deuteron spin-lattice relaxation rates, measured at 13.86 MHz and 52.37 MHz, besides the level-crossing maxima, show also classical maxima related to molecular motions against a barrier about 15 % of the full potential. All these effects are explained by jumps in a substructure at the bottom of the potential. The nonabridged version of this work has been accepted for publication in Phys. Rev. B.

Fig.l The possible orientations of the ion in the crystal lattice. The ion (represented by the tetrahedron) is shown in a mean position, but according to the con- M clusion of this work there are three possible, slightly different, orientations so that a N deuteron on the apex may occupy any of the D three sites marked by the black dots. Bet- ween these positions jumps and tunneling take place.

Local and Nonlocal Hydrogen Dynamics in a-Oxalic Acid ibo Dihydrate. A ID and 2D Single Crystal Deuteron NMR Study A. Birczyński, Z. Sułek, A. Muller * and U. Haeberlen * * Max-Planck-Institut fur Med. Forschung, AG Molekulkristalle, Heidelberg, Germany

The aim of this work is to investigate the hydrogen dynamics in crystals of a-oxalic acid dihydrate by 2H-NMR line shape analysis and2 H 2D-exchange spectroscopy. We identify and characterize three types of hydrogen motions: (1) flips of water molecules, (2) exchange of a carboxylic deuteron with the deuterons of the nearest, hydrogen bonded water molecule, and (3) exchange of a carboxylic deuteron with the deuterons of a distant, non-hydrogen bonded water molecule. In addition, we observe hydrogen diffusion over macroscopic distances. The work was done at the Max-Planck-Institut, Heidelberg. It has been published in Zeitschrift fur Physikalische Chemie, 178,133 (1992).

241 PL9601113

-r so-

Fig.l Two dimensional spectrum of a single crystal of deuterized oxalic acid (C00D)2 2D2O. The appearance of the offdiagonal peaks labelled CW and C'W demonstrates the existence of an exchange process between carbolic and water deuterons.

Computer Simulation of the Tweed Microstructure in YBa2Cu3O7_* K. Parlinski and M. Sternik

The tweed microstructure in the stoichiometric crystal of YBa2Cu2O7 has been already studied by computer simulation [1,2]. A two-dimensional model of 99 X 99 unit cells represents a layer of this crystal with an oxygen deficit and shows the ferroelastic tetragonal-orthorhombic phase transition. Recently, we applied this model to the case of non-stoichiometric oxygen concentration [3]. The simulation allows us to determine the temperature-oxygen concentration phase diagram. Below the transition temperature the strain fluctuations form a grid of needle- shaped areas, the density of which increases with the increasing degree of non-stoichiometry. On quenching, the tweed texture orders through the intermediate stripe phase, to a single orthorhombic area. Changes of the microstructure of the system while increasing the annealing time are shown for three oxygen concentrations in Fig.l. Oxygen vacancies, appearing due to non-stoichiometric oxygen concentration, gather along the domain walls, and hence slow down the kinetics of the annealing process. References: 1. K. Parlinski, V. Heine and E.H. Salje, J.Phys: Condensed Matter 5, 497 (1993) 2. K. ParMski, E.K. Salje and V. Heine, Ada Metali. A41, 839 (1993) 3. K. Parlinski and M. Sternik, J.Phys: Condensed Matter (to be published)

242 Fig.l. Maps of the strain order parameter obtained during annealing at temperature

Ta=0.63Tc after quenching from temperature T-1.24TC, for three values of off- stoichiometry parameters (a-d) 8 = 0.0, (e-h) 8 = 0.24, (i-j) 8 = 0.40. Maps (aei), (bfj), (cgk) and (dhl) correspond to annealing time t = 0.3, 0.9, 3.0 and 20.0 r0, respectively. The maps show 99 x 99 unit cells. The bright and dark shading corresponds to two different orthorhombic areas.

LIST OF PUBLICATIONS: Books:

1. J.W. Hennel and J. Klinowski, Fundamentals of Nuclear Magnetic Resonance, Longman Scientific and Technical, Harlow, England (1993)

I. Articles:

1. Y. Wu, Z-Y. Peng, Z. Olejniczak, B.Q. Sun and A. Pines, Effects of double rotation on homonuclear spin systems, J. Mag. Res., A102, 29 (1993) 2. F. Hennel, Z. Sułek and A. Jasiński, Single shot Fourier velocity imaging, J. Magn. Resonance, A102, 95 (1993) 3. G. Bacić, K.J. Liu, J.A. O'Hara, R.D. Harris, K. Szybiński, F. Goda and H.M. Swartz, Oxygen tension in a murine tumor: a combined EPR and MRI study, Magn. Reson. Med., 30, 568 (1993) 4. A. Birczyński, Z. Sułek, A. Muller and U. Haeberlen, Local and nonlocal hydrogen dynamics in a-oxalic acid dihydrate. A ID and 2D single crystal deuteron NMR study, Zeitschrift fur Physikalische Chemie, 178, 133 (1993) 5. C. Dimitropoulos and Z.T. Lalowicz, Deuterium NMR and chlorine NQR relaxation in

partially deuterated (NH4)2SnCl6, Phys. Rev. B (in print)

243 6. K. Parliński, Effect of hysteresis on the phase transition between high-order commensurate phases, Ferroelectrics, 141, 7 (1993) 7. K. Parliński, Phase diagram of the square-lattice model with lq and 2q incommensurate modulations, Phys. Rev., B48, 3016 (1993)

8. K. Parliński, E.K.H. Salje and V. Heine, Annealing of tweed microstrucure in high Tc superconductors studied by a computer simulation, Acta Metali. Mater., 41, 839 (1993) 9. K. Parliński and G. Chapuis, Mechanisms of phase transitions in a hexagonal model with lq and 3q incommensurate phases, Phys. Rev. B47, 13983 (1993) 10. K. Parliński, V. Heine and E.H.H. Salje, Origin of tweed texture in the simulation of a cuprate superconductor, J.Phys.: Condens. Matter, 5, 497 (1993)

11. K. Parliński and M. Sternik, Computer simulation of tweed microstructure in high Tc superconductors, Journal of Physics: Condensed Matter (in print) 12. K. Parliński and G. Chapuis, Phase transitions mechanisms between hexagonal commensurate and incommensurate structures, Phys. Rev. B (in print)

II. Contributions to Conferences:

1. K. Parliński, Two dimensional modulated phases in tetragonal and hexagonal models, The 3-rd Meeting on Disorder in Molecular Solids, Gachy, France (1993) (Invited talk) 2. K. Parliński, Discommensuration Patterns and Phase Transition Mechanisms in Hexagonal Incommensurate System, RAMIS (1993) (Invited talk) 3. K. Parliński and M. Sternik, Microstructure of YBa2Cu3O7_$ studied by molecular dynamics technique, RAMIS (1993) 4. K. Parliński and M. Sternik, Computer-simulation of the tweed-microstructure in YBaCuO, IV Workshop on Hightemperature Superconductors, Poznań, Poland (1993) 5. K. Parliński, Two-dimensional modulated phases in tetragonal and hexagonal models, Proceedings of "The 3-rd Meeting on Disorder in Molecular Solids", Gachy, June 14-17, 1993 6. K. Parliński, Models with multi-q IC phases, European Research Conference on Dynamical Properties of Solids, Lunteren, Netherland (1993) 7. C. Dimitropoulos and Z.T. Lalowicz, Deuterium NMR and chlorine NQR relaxation in

partially deuterated (NH4)2SnCl6, Conference on Quantum Molecular Tunnelling in Solids, Windsor, England, July 1993 8. Z.T. Lalowicz, E.E. Ylinen, M. Punkkinen and A.M. Vuorimaki, Ammonium ion tunnelling and reorientation study in ammonium tetrachloroplatinate by proton and deuteron NMR, Conference: as above 9. J.W. Hennel, Zero-Field NMR (Invited talk), Jagellonian University Spring School on NMR, Zakopane, Poland, May 1993 10. Z.T. Lalowicz, Tunnelling Rotation and Classical Jumps of Ammonium Ions at Low Temperatures, Conference RAMIS-93, 29-30.04.1993, Poznań, Poland l 11. Z.T. Lalowicz, Z. Olejniczak, R. Serafin, Low Field K NMR Ti Relaxation in NH4C1O4 at 4.2K, Conference: see above 12. Z. Olejniczak, A. Llor, Multipolar Analysis in Zero-Field NMR, Conference: see above 13. Z.T. Lalowicz, Z. Olejniczak, R. Serafin, Low field proton NMR spin-lattice relaxation in NH4CIO4 at low temperatures, AMPERE Summer Institute on Advanced Techniques in Experimental Magnetic Resonance, Portotoz, Slovenia, 12-18.09.1993 14. Z. Olejniczak, A. Llor, Multipolar Analysis of Zero-Field NMR, Conference: see above

244 15. B. Tomanek, A. Jasiński, E. Staszków, Magnetic Resonance Imaging of Carbon Imolants in the Rabbit Achilles Tendon in vivo, Proceedings of the Society of Magnetic Resonance in Medicine, XII Annual Scientific Meeting, New York, USA (1993), p. 885 16. P. Rapley, A. Jasiński, P. Kozlowski and J.K. Saunders, A Design for Semi-cylindrical Surface Gradient Coils, Proceedings of the Society of Magnetic Resonance on Medicine, XII Annual Scientific Meeting, New York, USA (1993), p. 315 17. M. Szayna, P. Kozlowski, J.K. Saunders, A. Jasiński, XH and 31P Spectroscopic Imaging Study of 9L Brain Tumor, 2nd International Conference in Magnetic Resonance Microscopy, Heidelberg 1993, p. 50 (invited lecture) 18. Z. Sułek, A. Jasiński, B. Tomanek, F. Hennel, J. Kibiński, T. Skórka, A. Krzyżak, P. Kulinowski and J. Muszyńska, MR Microscopy Study of Honey Bee in vivo, 2nd International Conference on Magnetic Resonance Microscopy Heidelberg 1993, p. 54 19. M. Rydzy, T. Jakubowski, F. Hennel, A. Jasiński, Z. Sułek, B. Tomanek, MARIS - Software Pachage for Spectroscopy and Imaging, Conference: see above, p. 83 20. Z. Sułek, A. Jasiński, B. Tomanek, J. Kibiński, T. Skórka, S. Kwieciński, Modular System for MR Microimaging, Conference: see above, p. 84 21. M. Szayna, P. Kozlowski, A. Jasiński and J.K. Saunders, *H, 31P Spectroscopic Imaging Study of Tumor Implanted in Rat Brain, Conference RAMIS-93, Poznań, Poland, 29-30 April 1993

SCIENTIFIC DEGREES:

1. Małgorzata Szayna - Ph.D. degree Localized magnetic resonance spectroscopy. Study of the tumor implanted in the rat brain, Supervisor: Assoc. Professor Andrzej Jasiński.

LECTURES AND COURSES:

1. J.W. Hennel "Introduction to the theory of NMR", a set of lectures given at the A. Mickiewicz University in Poznań, 5-10th July, 1993. 2. J. W. Hennel "A short course of the theory of NMR ", Set of 6 lectures given in the H. Niewodniczański Institute of Nuclear Physics, Krakow, October 1993. 3. Z. Olejniczak "Multiple-Quantum NMR spectroscopy ", A set of lectures given at the Jagellonian University Spring School on NMR, Zakopane, May, 1993. 4. K. Parliński

"Molecular-dynamic simulation of phase transitions in hexagonal model and in high Tc superconductor", University of Antwerp, Belgium. 5. K. Parliński "Computer simulation of incommensurate phase transitions in hexagonal model". Institut fur Festkroperforschung, KFA, Julich, Germany. 6. K. Parliński "MD simulation of phase transitions between phases in hexagonal model", Laboratoire de Physique des Solides, Orsay, France.

245 7. K. Parliński

"Simulation of phase transitions in hexagonal model and high Tc superconductors", Max-Planck-Institut fur Medizinische Forschung, Heidelberg, Germany. 8. K. Parliński "Phase transitions between incommensurate phases", Laboratoire ^Instrumentation Nucleaire, Sacley, France. 9. K. ParUński

"MD simulation of elastic phase transition in high Tc superconductor YBaCuO", Institut de Cristallographie, Universite de Lausanne, Switzerland. 10. K. Parliński "Simulation of phase transitions between incommensurate phases in hexagonal model", Institute of Physics, Academy of Sciences of the Czech Republic, Prague. 11. Z. Olejniczak "NMR spectroscopy in solids", Set of two lectures at the Institute of Catalysis and Physical Chemistry of Surfaces, March, Kraków.

ORGANIZED CONFERENCES: 26th National Seminar on NMR and its Applications Krakow, 1st and 2nd December 1993 (130 participants). The Department organize these conferences each year in the first days of December. INTERNAL SEMINARS:

1. R. Serafin

"Low field measurements of Ti for NH4C1O4 at 4.2K" 2. Z. Olejniczak "SIN-NMR" 3. A. Birczyński "Chemical exchange in hydrated oxalic acid investigated with 2D spectroscopy" 4. A. Birczyński "Tunnelling of CD3 group in potential of sixfold symmetry" 5. J.K. Saunders, Institute for Biodiagnostics, NRC, Ottawa, Canada "Magnetic resonance imaging and spectroscopy investigation of brain on animal models and human volountiers at NRC" 6. B. Sulikowski, Institute of Catalysis and Physical Chemistry of Surfaces, Krakow "Application of NMR in chemistry of zeolites" 7. M. Szayna 'łlH and 31P SI in brain cancer investigations" 8. R. Serafin "Low-field dipole-dipole driven NMR" 9. S. Clough, University of Nottingham, England "Magnetic manipulation of methyl group tunneling at low temperatures" 10. P. Kamiński "Tunnelling in fermion groups of Su(2) symmetry" 11. P. Focke, Max-Planck-Institute, Heidelberg, Germany "Tunnelling of CD3 groups in aspirin"

246 12. B. Tomanek "Annual SMRM meeting in New York - report" 13. A. Jasiński "Conference on microimaging in Heidelberg - report" 14. K. Szybiński "Quantitative analisis of MR images of knee joint" 15. F. Hennel "Interference effects in NMR tomography"

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Prof. S. Clough, University of Nottingham, Nottingham, UK 2. Dr J.K. Saunders, National Research Council of Canada, Winnipeg, Man 3. Dr W. Kuhn, Fraunhofer Institute for Biomedical Engineering (EBMT), St. Ingbert, Germany 4. Dr P. Kozlowski, National Research Council of Canada, Winnipeg, Man 5. P. Focke, Max-Planck-Institut fur Medizinische Forschung, Heidelberg, Germany 6. Prof. U. Haeberlen, Max-Planck-Institut fur Medizinische Forschung, Heidelberg, Germany 7. Eng. K. Bartusek, Institute of Scientific Instruments, Czech Republic 8. Eng. P. Gran, MVT Kooperativ-Zavod Tesla Elektronika, Czech Republik 9. Eng. B. Jilek, Institute of Scientific Instruments, Czech Republik 10. Dr P. Jonsen, Chemagnetics, 7, Claro Court Bussiness Centre, England 11. Dr M. Kiral'varga, Department of Physics, Technical University, Kosice, Slovakia 12. Dr J. Klinowski, Dept. of Chemistry, University of Cambridge, England 13. Dr L. Mucha, Department of Physics, Technical University, Kosice, Slovakia 14. Dr P. Tekely, Groupe de Nancy I, France 15. Dr M. Tureckowa, MTV Kooperativ-Zavod, TESLA Elektronika, Brno, Czech Republik 16. V. Zeman, STELAR CS, Spol. S.R.O., Brno, Czech. Republik

247 Department of Nuclear Physical Chemistry u PL9601114 DEPARTMENT OF NUCLEAR PHYSICAL CHEMISTRY

Head of Department: Prof.dr Jan Mikulski Deputy Head of Department: dr Barbara Petelenz telephone: (48) (12) 37-02-22 ext.: 390 to 399 e-mail: [email protected]

PERSONNEL Laboratory of Nuclear Physical Chemistry Research staff Jan Mikulski, Professor, Barbara Petelenz, Ph.D., Head of Laboratory Ewa Ochab, Ph.D., Deputy Head of Laboratory, General Inspector of the Occupational Health and Safety, Paweł Zagrodzki, Chem.E., M.Sc. Technical staff Paweł Grychowski, M.Sc. Ryszard Misiak, M.Sc. Mirosław Szałkowski, Chem.E., M.Sc. Bogdan Was, Chem.E., M.Sc. Laboratory of Chemistry and Radiochemistry Research staff Zdzisław Szeglowski, Assoc.Prof., Head of Laboratory Barbara Kubica, Ph.D., Deputy Head of Laboratory Technical staff Maria Tuteja-Krysa, M.Sc. Roman Fiałkowski Environmental Radioactivity Laboratory Research staff Mirosława Jasińska, M.Sc, Head of Laboratory Krzysztof Kozak, Nucl.E., M.Sc. Piotr Macharski, M.Sc. Jerzy Wojciech Mietelski, M.Sc.

249 GRANTS

The following grants have been received from the State Committee for Scientific Research (KBN):

1. Head: Professor Jan Mikulski. Research Grant no. 202599101 Neutron - deficient isotopes for medicine. Optimization of radiometrie and analytical methods. 2. Head: dr habil. Zdzisław Szeglowski; Research Grant no. 226129102 Studies on the chemical properties of transactinium elements (Z>104) in aqueous solutions in model systems with their homologues (Zr, Hf, Nb, Ta, W). 3. Two investment grants (INP symbols: A02 and A09) for the upgrading of the gamma spectrometric measurements, 1993.

OVERVIEW: The Department consists of three laboratories working on various projects of pure and applied nuclear, analytical and physical chemistry. Laboratory of Physical Chemistry of Separation Processes The main interest of this research group is the production and separation of neutron-deficient isotopes for medical diagnosis (SPECT). Recently, the main interest was in mIn which is a promising tracer for cancer diagnosis. To increase the effectiveness of production of indium mIn, the reaction with deuterons on the enriched cadmium target was carried out instead of the previously used one with alpha particles on natural silver. The change of in the way of production required switching from thermal separation of the radioactivity to the extraction method. The separation processes were controlled by means of gamma spectrometry. Owing to the investment and research grants from KBN, the measurement equipment has been recently upgraded by purchasing two HPGe detectors from the detector laboratory of the Institute and two gamma spectrometry tracts from SILENA. Non-radioactive contaminats in the samples were detected by means of atomic absorption spectroscopy (AAS). The AAS laboratory is also involved in programs to determine of trace elements in evironmental and biological samples. The main cooperation in this respect has been with the Environmetal Radioactivity Laboratory of this Department, with the Medical School of the Jagellonian University and with the Institute of Nuclear Research in Reź (Czech Republic). Another project in the group is the preparation of thin layers using the Langmuir-Blodgett method. The method turned out excellent for the preparation of sources for alpha and electron spectroscopy. Finally, a project on the sulphide-sulphite method of flue gases desulphurization was also carried out in the Laboratory. Laboratory of Chemistry and Radio chemistry The studies of physicochemical properties of transactinide elements 104,105 and 106 in model systems with their homologues Hf, Ta (Pa) and W were continued in collaboration with the JINR in Dubna as well as the IPN Orsay, and were partially supported by the Polish State Committee for Scientific Research (Grant No. 226129102). In the scientific program investigations have been carried out on the following subjects:

250 PL9601115 1. Rapid methods of isolation of the short-lived (>5 sec) isotopes of Hf, Ta and W from the nuclear reaction products obtained in the targets bombarded by heavy ions from the U-400 Cyclotron of JINR Dubna. 2. Studies of Hf sorption on ion exchange resins from acetic acid media as well as from mixtures of acetic and nitric acid. 3. A method for deep decontamination of the 178m2Hf isomer from microquantities of Sc, Te, Co, Ni, Sb and Ag.

Environmental Radioactivity Laboratory As a part of the National Network for the Early Warning of Radioactive Contamination in the Air, the Laboratory conducts continuous monitoring of radioactive contamination of the atmosphere at ground level, using a field station ASS-500 situated at the premises of the Institute. Weekly reports are submitted to the National Atomic Agency (PAA) and to the Central Laboratory for Radiation Protection (CLOR). The Laboratory is also involved in the research programme on radioactive contamination in forests. During 1993 nearly 300 samples of mushrooms (34 species), plant (blueberry) and two layers of forest litter, collected in the autumn of 1991 from all over Poland, were analysed with the low-background HPGe gamma-spectrometer. This work was carried out as the continuation of investigations which were started in 1991. Altogether 800 samples were analysed. Besides the gamma-spectrometric measurements, in 1993, several alpha-spectrometric measurements of the activity of plutonium isotopes in forest litter samples were carried out. For this purpose a radiochemical procedure for plutonium determination was developed and tested. In collaboration with the Institute of Geography of the Jagellonian University, studies on local (vertical and spacial) variation of radiocaesium content in various kinds of soil were carried out for various landforms.

Prof. J. Mikulski

REPORTS ON RESEARCH: Langmuir-Blodgett Films Used for Mono-Molecular ^ Alpha-Spectroscopic Source Preparation B. Was

A modified Langmuir-Blogdett technique which had been developed previously1 for the preparation of mono-molecular sources for low-energy beta spectroscopy was applied to the preparation of 241Am source for alpha-spectroscopy. High efficiency of the americium ions sorption has been achieved. The obtained energetic resolution was limited by the alpha spectrometer but it seems to be better than 30 keV. A further investigation with other alpha-emitters will be performed next year. The improvement of the spectrometer resolution is planned, and the actual value for the FWHM will be determined. The method seems of great promise.

1B. Was, Nucl. lustrum. Meth. Phys. Research A332 (1993) 334-331.

251 PL9601116 PL9601117 Flour Characteristics by Means of Pattern Recognition Methods P. Zagrodzki 1|2, M. Schlegel-Zawadzka2, P. Malec3, E. Dutkiewicz1, M. Krośniak2 and A. Bichoński4

1H. Niewodniczański Institute of Nuclear Physics, Kraków; 3Department of Food Chemistry and Nutrition, Collegium Medicum, Jagellonian University, Kraków; 8Department of Phy- siology and Biochemistry of Plants, J. Zurzycki Institute of Molecular Biology Jagellonian University, Kraków; 4Institute of Cultivation and Acclimatization of Plants, Kraków.

Samples of twenty various brands of flour which originated from the fields of the Plant Experimental Stations in Smolice and Oleśnica Mała were examined for the content of selected toxic elements (Pb, Cd) and some macro- and microelements (Mg, Cu, Fe, Mn, Zn). The chemical composition of flour and its baking characteristics determined through the routine analysis were also included as parameters into the statistical analysis. Metal levels were measured independently by the atomic absorption spectrometry (AAS), and anodic/cathodic stripping voltammetry (ASV/CSV). The CEM Corporation's Microwave Digestion System MDS-2000 was used for the mineralization of samples prior to the analysis. The atomic absorption analyses of Cd, Cu, Fe, Mn, Pb were performed with the Perkin-Elmer 5100 PC atomic absorption spectrometer equipped with the 5100 ZL Zeeman Furnace Module. In Mg and Zn measurements the flame device of the Perkin-Elmer 5100 PC atomic absorption spectrometer was used. In the ASV/CSV methods (Cd, Cu, Mn, Pb) the UPE-3 electrochemical analyser (Radius Cooperative, Gdańsk, Poland) was used. Methods of advanced statistics were applied to achieve an exhaustive interpretation of the results. An attempt was made to recognize patterns and isolate clusters on the basis of the selection of relevant variables. The applicability of the asumptions of the linear discriminant technique for this case was tested.

Vi Forest Litter Accumulation of Cesium and Radiocesium in Selected Regions of Poland P. Zagrodzki12, J.W. Mietelski1, M. Krośniak2 and B. Petelenz1

1H. Niewodniczański Institute of Nuclear Physics, Kraków; 2Department of Food Chemistry and Nutrition, Collegium Medicum Jagellonian University, Kraków. The study was a continuation of investigations into the forest ecosystems samples collected in 1991 from woods all over Poland. In 20 samples (out of 345) of the two upper layers of the forest litter, which revealed the highest radioactivities (Cs-137, Cs-134), the stable cesium was assayed by the AAS preceded by microwave digestion. The samples originated from Upper Silesia and from North Eastern Poland. An attempt was made to find any significant correlation between the contents of stable and radioactive cesium in the litter samples. The results were compared with those obtained for mushrooms from the same sites. The influence of the stable cesium content on the radiocesium transfer factor Tf (from litter to mushroom) was studied and no simple correlation was found. More complex relations provided very high correlation coefficients but the validity of the proposed models needs further checking.

252 PL9601118 Determination of the half-life of 165Hf D. Schumann1, R. Dressier1, S. Fischer1, S. Taut1, R. Binder2, Z. Szeglowski3, B. Kubica3, L.I. Gusieva4, G.S. Tikhomirova4, V.P. Domanov5, O. Constantinescu5, G.V. Buklanov5, M. Constantinescu5, Dinh Thi Lien5, A. Jakushev5, Yu.Ts. Oganessian5, V. Brudanin5, A.F. Novgorodov6 and H. Bruchertseifer7

XFG Radiochemie, Institut für Analytische Chemie, Technische Universität Dresden, FRG; 2Kern- und Radiochemie Leipzig, FRG; 3H. Niewodniczański Institute of Nuclear Physics, Kraków, Poland; 4 Institute of Geochemistry and Analytical Chemistry RAN, Moscow, Russia; BLaboratory of Nuclear Reactions, JINR, Dubna, Russia; 6Laboratory of Nuclear Problems, JINR, Dubna, Russia; 7PSI Villigen, Switzerland.

Many neutron-deficient isotopes are produced in heavy ion reactions. The nuclear properties of these nuclei have been not well-known till now. For instance, the half life of 165Hf was determined by several authors, the values differing from 75 s to 108 s. We re-examineded this half Ufe using a multichannel analyzer system (ACCUSPEC-A) which was previously tested by determining the half-life of 81mKr . Experimental Short lived isotopes of hafnium were produced via the following heavy ion reaction:

147,149Sm + 20Ne _> 165Hf (95.9g Mey) at the U-400 cyclotron. The recoiled atoms were transported from the target chamber using a KCl/Ar gas jet (1 1/min). The equipment for the separation experiments has been described earlier. Columns (20X3mm) were filled with Dowex 50X8 or Dowex 1X8 (240 mesh) and preequilibrated for 12 hours. 0.2 M HF solution was used to adsorb hafnium completely on Dowex 1X8. Flow rates of 1-3 ml/min were used. The activity was collected on the anion column for three minutes, then the column was measured off-line 30 times for 15 s, using a high resolution HPGeX detection system. During the whole time the column was washed with 0.2 M HF. This experiment was repeated 40 times. Results and Discusión The gamma peak at 179.9 keV was used for the half-life calculation (Fig.l). We obtained a value of 78.6±1 s for the half-life of 165Hf. This result shows that the multichannel system used in this experiment is suitable for the determination of the half-life of short-lived isotopes and can probably be applied to investigations of short lived W isotopes (i64/165"W).

ICO 300 300 400 SOO

165 Figure 1: Calculation of Hf half-life, E7 =179.9 keV.

253 PL9601119 Physics of the Long-Lived High-Spin 165 Hf Isomer Ch. Briançon1, M. Aiche1, D. Ledu1, R. Meunier1, P. Quentin1, Ch. Vieu1, M. Hussonnois2, J.B. Kim2, D. Trubert2, F. Le Blanc2, M.D. Lunney2, Yu. Ts. Oganessian3, 0. Constantinescu3, S.A. Karamian3, Z. Szeglowski4 and R. Kulessa5

^SNSM-Orsay, IN2P3-CNRS, Orsay, Prance; 2Institut de Physique Nucléaire Orsay, France; 3Joint Institute for Nuclear Research, Dubna, Russia; 4H. Niewodniczański Institute of Nuclear Physics, Kraków, Poland; 5Jagellonian University, Kraków, Poland.

Nowadays a large interest is attached to the production of exotic beams and targets for 178 nuclear structure and reaction studies. The nucleus Hf, with its long-lived {T1/2 = 31 years) high-spin isomeric state V = 16+ at a relatively low-excitation energy (2.45 MeV), is indeed a unique probe to study nuclear phenomena in a new way. For a few years a Dubna-Orsay collaboration has been established to produce this isomer using the 176 Yb(a,2n) reaction and to obtain microweight quantities of it which are sufficient for target preparation. Up to now 1.3 X 1015 atoms of the isomer have been produced. Methods of irradiations with high-intensity beams, of high-purity chemistry, of isotopic separations with yields as high as 25% have been developed. Various targets have been prepared and adapted to different types of experiments. A wide research program is underway in the framework of the "Hafnium Collaboration" which now covers around 80 scientists from 16 Institutes. A series of experiments are being carried out or are in preparation. This report gives the results of the recent experiments of this collaboration.

On-Line Study of Neutron Deficient Hafnium Isotopes as Homologues of Element 104 D. Trubert1, M. Hussonnois1, J.F. Ledu1, L. Brillard1, V. Barci2, G. Ardisson2, Z. Szeglowski3, 0. Constantinescu4 and Y.T. Oganessian4

institute of Nuclear Physics, Orsay, France; laboratory of Radiochemistry, Nice, France; 3H. Niewodniczański Institute of Nuclear Physics, Kraków, Poland; 4Joint Institute for Nuclear Research, Dubna, Russia.

A rapid method of continuous production, separation and purification has been developed at the tandem accelerator of Orsay (FRANCE). This device, developed in Dubna for transactinide chemistry, was tested in producing different neutron-deficient hafnium isotopes. Most of the spectroscopic properties of the isotopes produced were unknown. We have developed a special device for the study of these isotopes. Throughout irradiations of mono-isotopic targets

I54,I55,156Q¿ ^y I6Q ions wjt]j appropriate energy, and with the help of the continuous purification through Chromatographie ion exchange, we are able to obtain practically pure X and 7 spectra of the selected isotope. Coincidence measurements have also been carried out and the analysis is now in progress. For example, for 168Hf, more than 100 new gamma transitions have been identified. Thus, spectroscopy of hafnium isomers from 164 to 169, with half-lives ranging from 76 seconds to 26 minutes has been investigated. We present here merely some of the preliminary results obtained.

254 PL9601122 PL9601121 High-Spin Nuclear Target of 178m2Hf: Creation and Nuclear Reaction Studies Yu. Ts. Oganesian1, S.A. Karamian1, Yu. P. Gangrsky1, B. Górski1, B.N. Markov1, Z. Szeglowski2, Ch. Briancon3, O. Constantinescu3, M. Hussonnois3, J. Pinard3, R. Kulessa4, H.J. Wollersheim4, G. Graw5, J. de Boer5, G. Huber6 and H.V. Muradian7 XFLNR, JINR Dubna, Russia; 2H. Niewodniczański Institute Nuclear Physics, Kraków, Poland; 3CSNSM, IPN, Orsay, France; 4GSI, Darmstadt, Germany; 6Miinchen University, Germany; 6Mainz University, Germany; 7Kurchatov Institute, Moscow, Russia. Investigations of the hafnium-178 isomers are a new scientific direction promising the development of a fundamental knowledge both in the field of the nuclear structure and of nuclear reactions. The completed experiments give grounds for hope of obtaining data on the electromagnetic moments, on the mean radius and the deformation of the 178Hf nucleus in the state 16+, on the wave function structure of this state, as well as to study the influence of the target high spin on the differential cross sections of nuclear reactions, to find and investigate neutron resonances with a high spin, to obtain direct information on the density of the levels in the earlier inaccessible region of the spin and of the excitation energy, to measure directly the parameters of a giant dipole resonance based on the high spin state and to clarify in detail the role of the structure hindrances in nuclear reactions.

Sorption Behaviour of Short-Lived W and Hf Isotopes on Ion Exchangers from HC1/HF Solutions in Fast On-Line Experiments D. Schumann1, R. Dressier1, S. Fischer1, St. Taut1, R. Binder2, Z. Szeglowski3, B. Kubica3, L.I. Gusieva4, G.S. Tikhomirova4, 0. Constantinescu5, G.I. Buklanov5, V.P. Domanov5, M. Constantinescu5, Dinh Thi Lien5, A. Jakushev5, Yu.Ts. Oganessian5, I. B. Brudanin6, A.F. Novgorodov 6 and H. Bruchertseifer7

*FG Radiochemie, Institut fur Analytische Chemie, Technische Universitat, FRG; 2Kern- und Radiochemie Leipzig, FRG;3 H. Niewodniczański Institute of Nuclear Physics, Kraków, Poland; institute of Geochemistry and Analytical Chemistry RAN, Moscow, Russia; laboratory of Nuclear Reactions, JINR Dubna, Russia; 8Laboratory of Nuclear Problems, JINR Dubna, Russia; 7PSI Villigen, Switzerland. Introduction The 4-6 subgroups of elements are suitable tracers to investigate the chemical properties of the heavy elements 104-106. The main problem in this field is the fast separation of these elements from all other nuclides produced in heavy ion reactions. Previous works showed that the separation of W from Hf and lanthanides in mixed solutions of HC1 and HF at low concentrations can be carried out using the ion exchange method. It was shown that W can be completely separated from Hf by adsorbing the latter on Dowex 50X8 using 0.05 M HC1 / 10"3M HF solution. First on-line experiments at the TRIGA reactor in Mainz showed that Mo can be completely separated from the lanthanides, Zr and Nb by using the degasser from the SISAK system and separation columns filled with cation exchanger. In the present work we tested these conditions in fast one-line separations using heavy ion reactions at the U-400 cyclotron (Laboratory of Nuclear Reactions JINR Dubna, Russia). Experimental Short lived isotopes of tungsten and hafnium were produced via the following heavy ion reactions:

255 i47,i49Sm + 2oNe __> Hf (95-98 MeV)

152,154,158Qd + 20Ne _^ W (96 MeV) at the U-400 cyclotron. The recoiled atoms were transported from the target chamber using a KCl/Ar gas jet (1 1/min). The equipment for the separation experiments has been described earlier. Columns (20 X 3 mm) were filled with Dowex 50X8 or Dowex 1X8 (240 mesh) and preequilibrated for 12 hours. All separation experiments were performed with the mixture of 0.05 M HC1 and 10 ~3M HF using flow rates of 1-3 ml/min. The measurements were performed using a high resolution HPGeX detector (ORTEC) and a HPGe-PT detector (ORTEC). Results and Discussion 1. Tungsten The main products of the nuclear reaction were mW (2.38 min), 170W (2.42 min), 169W (1.27 min) and 168W (53.2 s) produced in the 3n and 4n reaction channel, respectively. l74W (29 min.) and mW (34 min.) could not be detected due to their relatively long half-life. The results of the separation using the 0.05 M HC1 / 10"3M HF solution are shown in Fig.l. It can be seen that all four W isotopes are found on Dowex 1X8 (171W: 294,8 keV, 170W: 316.2 keV, 124.7 keV, 169W: 136.8 keV, 168W: 178.8 keV). These peaks cannot be found after the separations on Dowex 50X8. Some peaks from these W isotopes can be observed on the cation exchanger too, but they are overlapped with those of other nuclides for example: mW/168Hf - 183.7 keV. Therefore, the conclusion can be drawn that W can be completely separated in the described way, as had already been expected from previous studies.

100 150 200 250 300 350 400 450 500

2500- DOUEN 1X8

2000-

1300- f 9 1000- "' ' a ? 500-

100 150 200 250 300 350 400 450 500 trwrgy | k«V ]

Figure 1: 7-Spectra of the Dowex 50X8 and Dowex 1X8 columns: nuclear reaction: i52,i54,i58Gd + 20Ne -* W; solution: 0.05 M HC1 / 10"3 M HF.

256 PL9601123

200 2SO 300 anwgy (kav ]

Figure 2: 7-Spectra of the Dowex 50X8 and Dowex 1X8 columns: nuclear reaction: 147-149Sm + 20Ne -» Hf solution: 0.05 M HC1 / 10~3 M HF.

2. Hafnium As can be seen from Fig.2 the main reaction products 166Hf (1.25 min.) and 186Hf (6.77 min.) can be found on Dowex 50X8. Only small peaks of 165Hf (179.9 keV) and 166Hf (228.0 keV) are observed on the anion exchange column. The calculation shows that 99% of Hf is adsorbed on the cation exchanger while Lu is completely adsorbed on this column. Summary The results show that in the described system of cation and anion exchange columns with 0.05 M HC1 / 10~3M HF solution tungsten can be separated from nearly all other elements produced in heavy ion reactions, mainly from lanthanides and hafnium. Consequently, the developed system should be applicable for fast on-line separations of the element 106.

Ion Exchange Behaviour of Zirconium and Hafnium as Homologues of 104 Element in Phosphoric Acid Solutions Z. Szeglowski1, L.I. Guseva2, Din Thi Lien3, V.P. Domanov3, O. Constantinescu3, G.S. Tikhomirova2 and M. Hussonnois4

XH. Niewodniczański Institute of Nuclear Physics, Krakow, Poland; institute of Geoche- mistry and Analitycal Chemistry RAN, Moscow, Russia; 3Laboratory of Nucleai Reactions, JINR, Dubna, Russia; 4IPN, Orsay, France. The distribution coefficient of Zr, Hf, Sr and some actinide and lanthanide elements between ion exchange resins and phosphoric acid solutions were determined. The optimum conditions for the concentration and separation of Zr(Hf) from the trivalent actinides in H3PO4 - ion exchange resins systems have been found. The high decontamination factor (>106) of hafnium from europium was obtained using the Dowex 50 resin in 0.5 M H3PO4 solution. In the conditions imitating the isolation of element 104

257 PL9601124 PL9601125 a model experiment was performed on the short lived hafnium isotopes isolated from a natural gadolinium target bombarded with the18 0 ions on the U-400 cyclotron at JINR.

Aerosols Radioactivity Measurements in the Ground Level Air in the Institute of Nuclear Physics - Kraków K. Kozak, M. Jasińska, P. Macharski and W. Kwiatek

An air sampling station ASS-500 (located in the Institute of Nuclear Physics) is used for the constant monitoring of radioactive contamination in the atmospheric air. The station is a free standing, all-weather instrument for the continuous collection of air aerosols. The high air-flow rate of 400-500 m3/h through a polypropylene filter (Petrianov type FPP 15-1.5) allows for representative sample taking. The efficiency of this filter for aerosols of diameters between 0.3 and 1.25 /mi, at linear air velocities through the filter varying from 0.25 to 4 m/s with a pressure drop through the filter from 500 - 9300 Pa, is between 95 and 99%. Collection of aerosols from air volume of 30000 to 60000 m3 enables accurate spectrometric measurements (HPGe detector, low-background gamma spectrometer, SILENA) of natural and human-made radionuclides in a wide range of their concentration, starting from 0.5 /iBq/m3. The Aerosol Sampling Station ASS-500 is equipped with an on-line radioactivity control system i.e. G-M counters and a URL type ratemeter. As a result of aerosols radioactivity measurements in the ground level air, weekly reports providing data for 7Be, 40K,137 Cs, 226Ra and228 Ra are issued. Any anomalies of any human- made radionuclides are also presented. These weekly reports are sent to the Central Laboratory for Radiological Protection and to the National Atomic Agency. In 1993 our Station became a part of the National Network for the Early Warning of Radioactive Contamination in Air. During 1993 we have detected no emergency situations. Computer software (AFASS) for automatatic calculation of the activity level in air (for normal and emergency situation), including a library of isotopes was elaborated. This program evaluates the sample activity, specific air activity, Low Limit Detection, Minimum Detecable Level, and produces a complete filter analysis protocol. By the end of 1993, more than 30 additional samples of air niters from the network station of PIOS were analyzed using low-background gamma spectroscopy. The samples were collected in winter 1992 and spring 1993 in different places in Krakow. Collaboration with PIOS will be used in the case of a nuclear emergency situation. Additionally, concentrations of selected heavy metals in 22 samples of the air filters from ASS-500 were analysed by means of the PIXE method in the INP PIXE Laboratory.

Distribution of Radioactive Contaminaton in Poland J.W. Mietelski, P. Macharski, M. Jasińska and R. Broda

An investigation of radioactive contamination in forest litter of A0 and Al layers from all over Poland was used to obtain an inventory of geographical distribution of the contamination with several artificial radioisotopes. Among them, 137Cs and134 Cs as well as 106Ru, 125Sb and144 Ce were analysed. The method of sampling and measuring has been described in separate papers [1,2]. The distribution of 137Cs and 134Cs (Fig.l and 2, respectively) obtained now confirmed basically the results of investigation on the upper 10 cm of soil [3], presented by the Warsaw group previously, with the highest contamination activity observed in the region of Silesia. The complete maps showing the distribution of other radioisotopes are given for the first time. The distribution of 125Sb (Fig.3) and 106Ru (Fig.4) isotopes shows a similar pattern to that of 137Cs, although in some samples from Eastern Poland 106Ru relative to cesium abundance is much higher. Quite different is the distribution obtained for 144Ce (Fig.5) which was found almost

258 solely in the North-East corner of Poland. The distribution of europium isotopes (184Eu and 15BEu) shows the same pattern, with initial activities smaller by the factor of 1000. They are likely to be accompanied by the actinide isotopes of Chernobyl origin [2]. The traces of 60Co are present mainly in the North-East regions of Poland (Fig.6). It is important to note that all maps are based on the measurements of samples originating from 125 sites distributed semi-randomly all over Poland, so they could be regarded only as a rough estimate of radioactive contamination distribution in Poland. References 1. J.W. Mietelski, M. Jasińska, B. Kubica, K. Kozak, P. Macharski - Proceedings of the Third International Conference on Nuclear and Radiochemistry, Sept. 7-11, 1992, Vienna (to be published in J. Radioanal. Nucl. Chem.) 2. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Proceedings of the Conference "Nuclear and Analytical Methods in the Life Sciences", Prague, September 13-17, 1993 (to be published in Biol. Trace Elem. Res.) 3. M. Biernacka, J. Henschke, J. Jagielak, A. Korczyński - Proceedings of the Interna- tional Symposium on Post-Chernobyl Environmental Radioactivity Studies in East Eu- ropean Countries, Kazimierz, September 17-19, 1990, UMCS Press, Lublin, (1991) pp. 26-33.

259 Maps of radioactive contamination with selected radionuclides in forest litter ( AO and Al layers) from Poland in autumn 1991. All activities are decay corrected for September 1st, 1991.

260 PL9601126 Plutonium from Chernobyl in Poland J.W. Mietelski and B. Was

239 240 According to the UNSCEAR Report [1], the deposition of . pu from global fallout in Poland should be about 58 Bq/m2, and that for 238Pu about 2.3 Bq/m2. There were no measurements of Pu in pre-Chemobyl Poland. The values estimated from Pu activities in Baltic 2 239 240 Sea sediments are from 30 to 98 Bq/m for . pu [2]. Plutonium from the Chernobyl fallout appears in Poland mainly in a large diameter aerosole form -"Hot Particles" (HP) [3]. Such large aerosols are not too dangerous from the dosimetric point of view, as they are not respirable. The activity of Chernobyl plutonium in the so called continous fraction of the contaminated air over Warsaw [4] in April-May 1986 was equal to 5.7xlO~"6 of the 137Cs activity, and activities of both radionuclides were well correlated. Thus, the expected maximum activity of Pu deposited from the Chernobyl cloud in Poland, in other a HP form was smaller than 1 Bq/m2. Large-scale gamma-spectrometry measurements of forest litter from all over Poland [5] established the presence of 144Ce, 165Eu and 154Eu in some samples from the North-East and East of the country. The cerium and europium activity seems to be distributed evenly throughout each sample, so they did not originate from typical HP. As the decay corrected activity ratio of Chernobyl Pu to cerium 144Ce is known to be practically constant, the expected level of Chernobyl Pu was 10 Bq/m2. The measurements of the initial batch of 20 samples confirmed this expectation. The radiochemical procedure developed at the IAEA Laboratories, Seibersdorf [6] has been applied in our work. Sources for alpha-spectrometry have been prepared using the NdF3 co-precipitation method. The 238pu^239,24Opu actjvity ratio in some samples reaches 0.60, which is a hallmark of Chernobyl plutonium. The project is still in progress, but our preliminary results indicate clearly that Chernobyl Pu is present in the environment of Poland not only in the large HP form. Acknowledgment Dr Rolph Zeisler, Head of the Chemistry Unit of the IAEA Laboratories Seibersdorf, is warmly acknowledged for the long-term loan of the Canberra 7401 Alpha-Spectrometer. We would also like to express many thanks to Dr Jerrome J. La Rosa, of the IAEA Laboratories Seibersdorf, for his great support, help and the stimulation he gave our work.

References: 1. UNSCEAR Report to the General Assembly with Annexes, (1982), New York p. 238; 2. B. Skwarzec, R. Bojanowski - J. Environmental Radioactivity 15 (1992) 249-263; 3. R. Broda, B. Kubica, Z. Szeglowski, K. Zuber - Radiochimica Ada 48 (1989) 89-96; 4. A. Pietruszewski, R. Bojanowski - Proceedings of the International Symposium on Post- Chernobyl Environmental Radioactivity Studies in East European Countries, Kazimierz nad Wisła, 17-19 September 1990, pp. 118-126, Lublin, UMCS Press 1991; 5. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Proceedings of the Conference "Nuclear Analytical Methods in the Life Sciences", Prague, 13-17 September 1993 (to be published in Biological Trace Elements Research); 6. J.J. La Rosa, E.L. Cooper, A. Ghods - Esphahani, V. Jansta, M. Makarewicz, N. Vajada - /. Environ. Radioactivity 17 (1992) 183-209.

261 PL9601127 A M U Local Variations in Distribution of Radio caesium in Soils of the Carpathian Foothills W. Chełmicki1, J. Swicchowicz1, J.W. Mietelski, M. Jasińska, K. Kozak and P. Macharski 1 Jagellonian University, Institute of Geography, 31-044 Kraków, Poland The research on natural factors of radioactive caesium distribution in soils of the Carpathian Foothills was a part of the project entitled "Circulation and Transformation of Antropogenic Contaminants in Geoecosystems of the Edge Zone of the Carpathian Foothills" carried out at the Jagellonian University, Institute of Geography Research Field Station in Łazy (Grant: PB 0389/P2/93/04). While the study done in 1992 was focused on caesium distribution along the forested slope profile [1], the idea behind the measurements made in 1993 was to determine the spatial distribution of caesium in the valley bottom sediments of the elementary drainage basin (A), as well as along the downslope profile of the active landslide (B). In the first case (A) the soil samples for 137Cs and 134Cs measurements were collected at 3 sites from 50 cm deep soil profiles, with depth increments of 5 cm. In the second case (B) the samples were taken from 4 sites situated at various parts of the active landslide, and 1 site situated above the upper crest of this landform. The activities for caesium isotopes, as well as those for natural radionuclides were determined with low-background gamma-spectrometers. The obtained inventories for the caesium isotopes in whole profiles for each site of case (A) or (B), are presented in Fig.l. In both cases the results are being elaborated and should lead to a better understanding of the role of different landforms and soil properties (infiltration capacity, grain-size distribution, acidity and humus content) in the redistribution of radioactive contaminants in the geoecosystems of the Carpathian Foothills. Up to date results show, that slope processes (overland flow and soil-wash) along with soil properties are important factors in radioactive caesium redistribution. The 137Cs content on slopes is much lower than in valley bottom deposits. Thus the valley bottoms can be recognized as areas of accumulation of radioactive contaminants.

mlddte bottom Above

Elementary Drainage Baain Edg« Active Landslide 8itea Figure 1: Inventories of 137Cs and 134Cs in soils profiles from various landforms. Activities are decay corrected for the 1 May 1986, the Chernobyl fallout date, to reveal global-fallout component (137Cs to 134Cs activity ratio in Chernobyl fallout was equal 2±0.2). Cases A and B as in text.

References 1. W. Chełmicki, J.W. Mietelski, P. Macharski, J. Święchowicz - Report INP no. 1615/D (1993).

262 LIST OF PUBLICATIONS: I. Articles

1. B. Was, A. KovaKk, A.F. Novgorodov, J. Rak - A new Technique for the Preparation of Small-Size Radioactive Samples Based on the Langmuir-Blodgett Method - Nucl. Instr. Meth. Phys. Research A332 (1993) 334-341; 2. Z. Szeglowski, L. Gusiewa, et al. - Studies of the ion-exchange properties of zirconium and hafnium as homologues of the element 104 in phosphoric acid solutions - Radiokhimiya 35 (1993) 59-65; (in Russian); 3. D. Trubert, M. Hussonnois, Z. Szeglowski et al. - On Line Study of Neutron Deficient Hafnium Isotopes as Homologues of Element 104 - Radiochim. Acta (1993), in press; 4. Z. Szeglowski, Dinh Thi Lien, M. Hussonnois, O. Constantinescu, B. Kubica, S.A. Karamian - Hafnium Decontamination from Microquantities of Some Elements of Groups I, II and HI - submitted to J. Radioanal. Nucl. Chem., Letters (1993), in press; 5. Z. Szeglowski, Dinh Thi Lien - Ion-exchange isolation of short-lived isotopes of Hf, Ta and W, as homologues of trans-actinide elements in the solutions of H2C22O4 and H2C22O4 - HC1 (in Russian) - Radiokhimiya, in press; 6. D. Trubert, M. Hussonnois, J. Ledu, L. Brillard, V. Barci, G. Ardisson, Z. Szeglowski, 0. Constantinescu, V.P. Domanov, Yu. Ts. Oganessian - On-Line Study of Neutron Deficient Hafnium Isotopes as Homologues of 104 Element - submitted in 1993 to Radiochim. Acta; 90 7. J.W. Mietelski, J. La Rosa, A. Ghods - Results of Sr, 239+240pU) 238pu and 24iAm Measurenients in Some Samples of Mushrooms and Forest Soil from Poland - J. Radioanal. Nucl. Chem., Articles 170 (1993);

II. Contributions to Conferences:

1. Z. Zachwieją, J. Chłopicka, M. Schlegel-Zawadzka, P. Zagrodzki, J. Wypchlo, M. Krośniak - Evaluation of Zinc Content in Childrens Hair - Proceedings of the 4th International Congress on Trace Elements in Medicine and Biology. Trace Elements and Free Radicals in Oxidative Diseases, Chamonix, 5-9 April 1993; 2. M. Krośniak, P. Zagrodzki - Mineralization of biological samples in the microwave oven and muffle furnace: comparison of methods - Proceedings of the 2nd Poznań Analytical Seminar: Modern Methods of Sample Preparation and Determination of Trace Elements, Poznań, 27-28 April 1993, (in Polish); 3. Z. Zachwieją, M. Schlegel-Zawadzka, J. Wypchlo, J. Chłopicka, M. Krośniak, P. Zagrodzki - The comparison of the copper content in the hair of children living in several towns in Southern Poland - Proceedings of the 8th International Symposium on Trace Elements in Man and Animals, TEMA-8, Dresden, 16-21 May 1993; 4. P. Zagrodzki, J.W. Mietelski, M. Krośniak, B. Petelenz - Forest littter accumulation of caesium and radioceasium in selected regions of Poland and its influence on litter-to-mushroom transfer factor - Proceedings of the Conference "Nuclear Analytical Methods in Life Sciences", Prague, 13-17 September 1993; 5. Z. Zachwieją, M. Krośniak, P. Zagrodzki, M. Folta, M. Schlegel-Zawadzka - Microwave technique in the minotoring of metal contamination in the environment - Proceedings of the 6th Conference "Analytics for Geology and for Environment Protection", Krasnobrod, Poland, 11-15 October 1993, (in Polish)-

263 6. Z. Zachwieją, P. Zagrodzki, M. Krośniak, J. Chłopicka, M. Folta, J.J. Pietrzyk, A. Nowak, Z. Mitkowska, A. Glińska, W. Wrzosek, T. Strzelecki, P. Dobosz - Heavy metals content (Pb, Cd, Ni) in maternal scalp and pubic hair from selected cities in southern Poland - Proceedings of the First Global and European Conference - Environment and Public Health. Antwerpen, 25-30 November 1993; 7. Z. Szeglowski, H. Bruchertseifer, V.B. Brudanin, G.V. Buklanov, 0. Constantinescu, Dinh Thi Lien, V.P. Domanov, L.I. Guseva, M. Hussonnois, G.S. Tikhomirova, I. Zvara, Yu. Ts. Oganessian - Possibilities of Chemical Isolation of Element 106 from Aqueous Solutions According to The Model Experiments with Short Lived Tungsten Isotopes - Proceedings of the 2nd Workshop "Chemie Schwerster Elemente", Solothurn, Switzerland, May 1993, submitted to J.Radioanal. Nucl. Chem., Letters; 8. Yu. Ts. Oganessian, S.A. Karamian, Yu. P. Gangrsky, B.N. Markov, Z. Szeglowski - High-Spin Nuclear Target of Hf: Creation and Nuclear Reaction Studies - Proceedings of the International Conference "Nuclear Physics of Our Times", Florida, USA; Proceedings of the International School-Seminar "Heavy Ion Physics", Dubna, Russia, 10-15 May 1993; Report JINR Dubna E15-93-96 (1993); submitted to J. Radioanal. Nucl. Chem., Letters; 9. Z. Szeglowski, M. Hussonnois, Yu. Ts. Oganessian et al. - Physics with the Long-Lived High-Spin 178m2Hf Isomer - Proceedings of the Eighth International Symposium on "Capture Gamma-Ray Spectroscopy", Fribourg, 20-24 September 1993; 10. K. Skarżyńska, E. Zawisza, M. Jasińska, M. Waligórski - Investigation of Radioactivity of Coal Mining Wastes Przezchlebie Stockpile - Proceedings of the Ą-th International Symposium on the Reclamation, Treatment and Utilization of Coal Mining Wastes, Kraków, 6-10 September 1993; 11. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Radioactive Contamination of Forests in Poland - Proceedings of the Nuclear and Analytical Methods in the Life Sciences, Prague, September 13-17 1993 (submitted to Biological Trace Elements Research); 12. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Distribution of Radioactive Contamination in Poland - International Symposium on Remediation and Restoration of Radioactive-contaminated Sites in Europe, 11-15.10.1993 Antwerpen (a poster, without further publication); 13. K. Kozak - AFASS program: a proposal for standardization of the procedures, processing and presentation of data from the gamma-spectrometric measurements of the ASS-500 stations filters - Seminar on the monitoring of the radioactive contamination in air in Poland, CLOR (Central Laboratory of Radiation Protection), Warsaw, 9-10 December 1993.

III. Reports:

1. Z. Mazgaj - "WIDMO" - a program for the automatic interactive analysis of gamma emission spectra - Report INP no. 1628/C (1993), (in Polish); 2. M. Szalkowski, J. Kulawik, J. Mikulski - Wasteless method of SO2 removal from the combustion products of sulphur-containing solid fuels - Report INP no. 1629/C (1993); 3. R. Misiak, A. F. Novgorodov, A. Kolaczkowski, J. Mikulski - A simple method of thermal separation of gallium, indium and thallium isotopes from thick targets - 4. P. Zagrodzki, E.M. Dutkiewicz, P. Malec, M. Krośniak, W. Knap, A. Bichoński - Instrumental methods for analysis of some elements in flour - Report INP no. 1648/CA (1993);

264 5. W. Chełmicki, J.W. Mietelski, P. Macharski, J. Świfchowicz - Natural Factors of 137-Cs Redistribution in Soil (Case Study from the Carpathian Foothills), Report INPNo 1615/D (1993).

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. M. Jasińska, contribution to the 4-th International Symposium on the Reclamation, Treatment and Utilization of Coal Mining Wastes, Kraków, 6-10 September 1993; 2. J.W. Mietelski - participation in the Conference "Nuclear and Analytical Methods in the Life Sciences", Prague, 13-17 September 1993; 3. P. Zagrodzki - participation in the Conference "Nuclear and Analytical Methods in the Life Sciences", Prague, 13-17 September 1993; 4. J.W. Mietelski - participation in the International Symposium on Remediation and Restoration of Radioactive-contaminated Sites in Europe, 11-15 October 1993 Antwerp en; 5. K. Kozak and B. Kubica - as observers on the conference "Radium and radon as sources of the radiological risk", National Atomic Agency (PAA), Warsaw, 25-26 February 1993; 6. K. Kozak - participation in the Seminar on the monitoring of the radioactive contamination in air in Poland, CLOR (Central Laboratory of Radiation Protection), Warsaw, 9-10 December 1993; 7. K. Kozak - followed the practical course "Off-Site Emergency Response to Nuclear Accidents", Belgian Nuclear Research Center, Mol, 21-25 June 1993.

LECTURES AND COURSES:

1. J.W. Mietelski - Radioactive contamination in the environment - a popular lecture for the secondary school teachers and students, 12 May 1993, Institute of Physics of the Jagellonian University, 1 hour; 2. B. Petelenz - Applications of nuclear chemistry in medicine - a popular lecture for the secondary school teachers and students, Institute of Physics of the Jagellonian University, 24 November 1993, 1 hour; 3. J.W. Mietelski - Natural and artificial radioactivty in the environment - lecture for the students of the Graduate School of the Environment Protection Agricultural Academy in Kraków, 27 October 1993, 2 hours; 4. Environmetal Radioactivity Laboratory, two lectures on the radiological situation in the Kraków region and in Poland, invited by the Consumers Federation in Kraków, 8 February 1993; 5. Environmetal Radioactivity Laboratory, co-organization (with the Museum of Natural Science) of the "Mycological Exhibition" and presentation of the materials about the radioactive contaminations in mushrooms in Poland, Kraków, 1-5 October 1993; 6. Environmetal Radioactivity Laboratory, popular presentations in the "Krater" TV station and radio interviews; 7. Environmetal Radioactivity Laboratory, a cycle of popular articles about the radioactivity in the environment in the "Forest Echoes" journal.

265 INTERNAL SEMINARS:

1. R. Misiak - Simple method of the high-temperature separation of Ga-67 from the massive germanium target; 2. P. Zagrodzki - Report from the 4th International Congress on Trace Elements in Medicine and Biology, Chamonix, 5-9 April 1993; 3. K. Kozak - OfF-site emergency response to nuclear accidents, report from the training; 4. J.W. Mietelski and P. Zagrodzki - Nuclear analytical methods in life sciences, Praque, 13-17 September 1993, report from the conference; 5. M. Vilgis (KfK, Karlsruhe) - New glass dosimetry in KfK Karlsruhe - jointly with the Radiation Protection Laboratory; 6. V.P. Domanov (JINR, Dubna) - The formation of volatile compounds by radioisotopes of

platinum metals with O2, H20, S and Se; 7. K. Kozak and J.W. Mietelski - International Symposium on Remediation and Restoration of Radioactive-Contaminated Sites in Europe, Antwerpen, 11-15 October 1993, a report; 8. P. Zagrodzki - Enviroment and Public Health, Antwerpen, 25-30 October 1993, Report from the conference; 9. J.W. Mietelski - Isotopes of plutonium in the forest litter in Poland.

SHORT TERM VISITORS TO THE DEPARTMENT:

1. participants of the Conference "Geochemical, Hydrochemical and Biochemical Changes of the Environment in the Antropopression Areas" and the aldermen from the Environment Protection Commission of the Kraków Municipal Council, 11 March 1993, in the Environmental Radioactivity Laboratory; 2. dr Miloś Beran, Head of the Central Analytical Laboratory of the Nuclear Research Institute in Reź, Czech Republic, 21-23 April 1993; 3. dr Jerrome J. La Rosa, Head of the IAEA Radiochemical Laboratory in Seibersdorf, Austria, in the Environmental Radioactivity Laboratory; 4. dr H. Vera-Ruiz (IAEA, Vienna) - 12-13 August 1993, in the Laboratory of Physical Chemistry of Separation Processes; 5. dr V.P. Domanov (Flerov Laboratory of Nuclear Reactions JINR, Dubna, Russia), October 1993, in the Laboratory of Chemistry and Radiochemistry; 6. high school and university students (28 groups, 600 people altogether during the school year), in the Environmental Radioactivity Laboratory; 7. physics teachers participating in Methodical Conferences (200 people), in the Environmental Radioactivity Laboratory; 8. participants of the Physicists Congress (60 people), September 1993, in the Environmental Radioactivity Laboratory.

OTHER: International agreement An agreement between the Institute of Nuclear Research in Reź (Czech Republic) and the Institute of Nuclear Physics has been signed. The subject of the agreement is the preparation and standardization of the reference material for determinations of radioactive cesium and of selected heavy metals in mushroom samples. Preparation of 500 certified samples is expected to be the result of the cooperation.

266 Health Physics Laboratory HEALTH PHYSICS LABORATORY

Head of Laboratory: Assoc. Prof. Michał P.R. Wałigórski Deputy Head: Dr Paweł Olko Secretary: Irena Lipeńska telephone: (48) (12) 37-02-22 ext.: 411, 415 e-mail: [email protected] PERSONNEL: Research Staff:

1. Paweł BILSKI, M. Sc. (Technical Physics) - Assistant, Radiation Safety Inspector 2. Maciej BUDZANOWSKI, E. Eng. (Nucl. Eng.) - Assistant, Radiation Safety Inspector 3. Tadeusz NIEWIADOMSKI, Ph. D. Assoc. Prof. (Physics) - Consultant 4. Małgorzata NOWINA-KONOPKA, M. Sc. (Physics) - Assistant 5. Paweł OLKO, Ph. D. (Physics), E. Eng. (Nucl. Eng) - Adjoint, Deputy-Head of Labora- tory 6. Maryla OLSZEWSKA-WASIOŁEK, Ph. D., E. Eng. (Nucl.Eng) - on leave of absence to New Mexico Institute of Mining and Technology, Socorro, NM, USA) 7. Michał WAŁIGÓRSKI, Ph. D., Assoc. Prof. (Physics) - Head of Laboratory 8. Piotr WASIOŁEK, Ph. D. (Physics) - on leave of absence to New Mexico Institute of Mining and Technology, Socorro, NM, USA

Technical Staff:

1. Józef DYBEŁ - Technician 2. Jerzy IBKOWSKI - Technician, Radiation Safety Officer 3. Irena LIPEŃSKA - Laboratory Assistant, Secretary 4. Bronisław MOTYKA - Technician, Radiation Protection Officer 5. Elżbieta RYBA, E. Eng. - Chief Specialist, Chief Radiation Safety Officer, INP 6. Marta W0ŹNIAK, M. Sc. (Chemistry) - Chemist

GRANTS:

1. M.P.R. Wałigórski, grant No 607359101, (The State Committee for Scientific Research), "Analysis of microdeposition of energy for determination of radiation hazard, including that from radon" 2. M.P.R. Wałigórski, grant No 224309203, (The State Committee for Scientific Research), "Modelling of interaction of nuclear radiation in nanometre volumes" 3. T. Niewiadomski, grant No 607379101, (The State Committee for Scientific Research), "Investigation of the concentration of radon in dwellings over southern Poland"

267 Dl QROI INTERNATIONAL COLLABORATION PROGRAMMES: 1. Polish-German Collaboration: Quantitative Assessment of Radiation Hazard, with Prof. Muller-Gartner/Dr. Th. Schmitz, Institute of Medicine, KFA Julich 2. Polish-German Collaboration: Neutron Dosimetry with TL Detectors, with Dr. Piesch, HSD, KfK Karlsruhe

OVERVIEW: The activities of the Health Physics Laboratory at the Institute of Nuclear Physics in Kraków are principally research in the general area of radiation physics, and radiation protection of the employees of the Institute of Nuclear Physics. Theoretical research concerns radiation detectors, radiation protection (modelling of radiation effects in biological and physical systems) and studies of concepts in radiation protection. Experimental research concerns solid state dosimetry, mainly thermoluminescence (TL) dosimetry (present thrust: development of thin TL detectors for beta-ray and mixed neutron field dosimetry, development of ultra-sensitive LiF;Mg,Cu,P phosphors) and environmental radiation measurements (radon in dwellings, low-level natural radiation). The Laboratory provides expert advice on radiation protection regulations at national and international levels. Routine work of the Health Physics Laboratory involves design and maintenance of an in-house developed TL-based personnel dosimetry system for over 200 radiation workers at the INP, monitoring and supervision of radiation safety on INP premises, and advising other INP laboratories on all matters pertaining to radiation safety. Over the years, under the leadership of Prof. Tadeusz Niewiadomski, considerable expertise in TL dosimetry has been gained at the Laboratory: TL detectors, based on LiF (Mg,Ti- doped, equivalent to HAR- SHAW TLD-100, TLD-600 and TLD-700, and Mg,Cu,P- doped, equivalent to ultra-sensitive "Chinese" phosphors) are produced, as well as TLD readers, gamma-irradiators and annealing ovens. The Laboratory is able to accept not only commercial orders for production of large quantities of TL detectors and of TL laboratory equipment, but also to produce on request non-typical TL detectors according to specification, and to train and advise in the applications of TL dosimetry. 1993 was a busy but perhaps less spectacular year for the Laboratory than 1992, when we participated in two important international conferences in our field in the United States: the 10th Solid State Dosimetry Conference at Washington DC, and the 11th Symposium on Microdosimetry at Gatlinburg, Tennessee, and several other meetings in Europe. Some of our papers presented at these meetings, reviewed in the 1992 edition of the INP Yearly Report, have by now appeared in print (see List of Publications). This year we took part in several meetings in Poland and in Europe. In the beginning of 1993 our group was invited to the national meeting Radium and Radon as Sources of Radiological Hazard (Warsaw, February 25-26) organized by the President of the Polish National Atomic Energy Agency (NAEA). We have been active in formulating the scientific outline of the future Polish National Radon Programme Dr Paweł Olko had been selected as a member of a national committee (headed by Prof. Jan Czubek) to report to the Presi- dent of the NAEA on the state-of- art of measurements of radon and daughter concentrations in Polish mines. Measurements of radon and radon daughter concentrations in dwellings of Southern Poland were continued by Prof. Niewiadomski under a grant from the Polish State Committee for Scientific Research. We are also preparing a general report on the properties of radon in dwellings and on ways to measure and reduce its concentration, intended for the local administration and for the Regional Sanitary Inspection Office in Kraków, in view of radon concentration limits to be introduced in Poland in 1995. In our TLD research, we have succeeded in developing a technology of producing thin-layer TL (so-called sandwich) detectors for measuring the skin dose of low-penetrating radiation (beta-

268 PL9601129 and X-rays) and for dosimetry in mixed neutron- gamma fields, to comply with recent recom- mendation of the ICRU. This work is carried out in close collaboration with the Radiation Safety Department of KfK Karlsruhe, under a Polish-German scientific collaboration programme, and is partly sponsored by another grant from the Polish State Committee for Scientific Research. We have also, in collaboration with KfK Karlsruhe, investigated the calibration and the TL background signal of ultra-sensitive LiF;Mg,Cu,P detectors developed in our laboratory, for environmental measurements. A set of these and other detectors was exposed for about 18 months at a depth of 600 m underground (Asse salt-mine, Germany) and at the surface of the Bagersee lake in the Karlsruhe area. We found that calibration coefficients applied to evaluate cosmic-ray doses, typically obtained using Cs-137 sources, may have to be re-evaluated to account for the anomalous response of LiF:Mg,Cu,P to low-energy photons. The book Thermoluminescent materials, edited by D.R. Vij in which Prof. Niewiadomski contributed the chapter Lithium Fluoride, has been published by PTR New Jersey in 1993. The third edition of a comprehensive book Natural Medicine (in Polish) in which Prof. Niewiadomski contributed a chapter on ionizing radiation, will appear early in 1994. Our work on applying phenomenological models (microdosimetry and track structure) to interpret radiation effects in physical and biological detectors has been continued under yet another grant from the Polish State Committee for Scientific Research, and under a Polish- German collaboration agreement with the Institute of Medicine of the KFA Julich. We have submitted for publication a model evaluation of the risk factor for radon exposure. Within our routine personnel monitoring service, we have upgraded our automatic reader with a computer interface and are presently developing the software to transfer readout data to a personnel dosimetry data base. Since the beginning of 1993 Dr Waligórski has, apart from leading the Health Physics Laboratory, taken on the duties of Head of the Medical Physics Department of the Kraków Division of the Maria Skłodowska-Curie Centre of Oncology. This will bring some of the research activities of the Health Physics Laboratory closer to physics in radiotherapy. In particular, we envisage work on applying TL and alaninę dosimetry to clinical measurements in vivo and on continuing and further developing medical applications of the INP accelerators.

Assoc. Prof. Michał P.R. Waligórski REPORTS ON RESEARCH: A. Environmental Radiation Protection: Investigation of radioactivity of coal mining wastes-the Przezchlebie Stockpile K. Skarżyńska1, E. Zawisza1, M. Jasińska and M. Waligórski 1 University of Agriculture, Kraków, Poland (presented at the 4th International Symposium on the Reclamation, Treatment and Utiliza- tion of Coal Mining Wastes, Kraków, Poland 6-10 September 1993) A complex investigation of background gamma-ray dose rate and radioactivity of wastes in the Przezchlebie stockpile near Gliwice has been performed. The gamma- ray dose rate was measured 1 m above the minestone dumping ground and above the ash lagoon using ultra-sensitive LiF:Mg,Cu,P thermoluminescent detectors produced at the INP. The activity of radioactive elements in the wastes taken from the dumping ground, from the transport vehicles, from the ash

269 PL9601130 PL9601131 lagoon, as well as in surface samples of infiltrating water from the lagoon, was measured by gamma-ray spectrometry. The gamma-ray dose rates above ground correlated with the gamma- activity of the natural elements of uranium and thorium series in the waste materials. The stockpile was found not to be radioactively hazardous to the environment, suitable for reculti- vation and for use in other economic activities. The described measurement technique in which field exposures of TL detectors can be completed within two weeks rather than after 3 months, is readily applicable to large-area waste stockpiles.

A Regional Survey of Indoor Radon Concentration in South-Eastern Poland T. Niewiadomski (submitted to Nukleonika)

The Central Laboratory for Radiological Protection and the Institute of Nuclear Physics began in 1991 a country-wide study of radon concentration in dwellings in which CR-39 track- etch detectors located in diffusion cups were used. South-Eastern Poland (a geo-morphologically diversified area constituting 17% of Poland's territory) was assigned to the INP and two surveys were performed between November 1991 and November 1993. A total of 350 cups were randomly placed on the territory of 10 voivodships and about 300 cups were returned to the laboratory for chemical etching of plastics and optical track density counting. A computer data base was set up to store and process the results. Using the calibration factor of 4.2 tracks*cm~2 per (kBq*h*m~3) it was found that the radon concentration over the investigated area exhibits an approximately log-normal distribution with an arithmetic mean of 70 Bq m~3 in the first and 80 Bq m~3 in the second measurement series (which was longer by a few autumn-winter months). In about 3% of housing stock which were monitored (i.e. 60 000 households with about 250 000 inhabitants) the radon concentration exceeded 200 Bq m~3. If these results are extrapolated to the population, the mean annual effective dose due to radon inhalation is equal to 1.5 mSv while the above-mentioned 3% of population receive from this source doses higher than 5 mSv per year. Houses with higher radon concentration indoors have been found mainly in the southern, mountainous part of the area surveyed by the INP. Analysis of two measurement series allows one to assess the sources of uncertainty in these measurements, which originate both in the laboratory and in the field. (This research is partly supported by grant No 607379101 from the State Committee for Scientific Research).

Long - Term Measurements of Gamma Background Radiation Using TŁ and Phosphate-Glass Detectors B. Burghkardt1, M. Budzanowski2, P.Olko2, W. Pessara3 and K. Gmuer4

1 Karlsruhe Nuclear Research Centre, Germany, 2Institute of Nuclear Physics, Kraków, 3PTB Braunschweig, Germany, 4Paul Scherer Institut, Villigen, Switzerland

(work in progress)

The cosmic component of background gamma radiation, the intrinsic background or "self- dose" and the fading of TL (TLD-600, TLD-700, and TLD-200, all from HARSHAW, and MCP-N, i.e. LiF:Mg,Cu,P, produced at the INP Krakow) and Phosphate-Glass (SC-1) detectors (Toshiba) were measured over a period of c. 1.5 y (557 days) in the Asse salt-mine (Braunschweig, Germany) at a depth of c. 775 m, on a buoy placed on the surface of an artificial lake (Baggersee,

270 Karlsruhe, Germany), at the top of Jungfraujoch (3576 m ) in the Alp mountains and in a steel castle at the KfK laboratory. The "self-dose" for TL detectors in Asse salt mine was 0.07 fiGy/y for TLD600/700, 29 fiGy/y for TLD200, 7.3 /*Gy/y for MCP-N and 9.4 juGy/y for SC- 1. The average values of cosmic-ray gamma background dose rate estimated from readings of TL and glass detectors were (250±2) //Gy/y, (140±1.7) /xGy/y, (1040±7) fiGy/y at the lake surface, laboratory and Jungfraujoch peak, respectively. Based on measurements in the Asse mine (constant temperature of 33 C, relative humidity below 25%) the fading of all types of detectors did not exceed 5%/y.

B. Developmeijit of new TL materials and model analyses of the response of TL detectors:

6LiF Sandwich-Type Detectors For Low-Dose Individual Monitoring in Mixed Neutron-Photon Fields P. Olko1, M. Budzanowski1, P. Bilski1, B.Burgkhardt2, and E. Piesch2

1 Institute of Nuclear Physics, Kraków, 2Kernforschungszentrum Karlsruhe, Germany (presented at the International Workshop on Individual Monitorun of Ionizing Radiation; the Impact of Recent ICRP and ICRU Publications, Villigen, Switzerland, May 5-7 1993) ICRP publication 60 recommends the reduction of the annual dose limit for occupational exposure from 50 mSv to 20 mSv and to double the quality factor for medium energy neutrons. If occupational doses are evaluated every month (which is obligatory e.g. in Germany and in Poland), the individual neutron dosimeter will have to measure neutron doses in the range of 100 /xSv. No commercially available, automatic individual dosimetry monitoring system exists which fulfils this requirement. We studied some of the parameters which influence evaluation the neutron dose from readings of TL dosimeters in order to decrease the variance of the measured neutron signal. In mixed neutron-photon fields, clear separation of the neutron component from the total reading depends also on the uncertainty of the gamma dose measurements. While the thermal albedo neutrons are absorbed mostly at the surface of the 6LiF detector, the reduction of the detector thickness results in decresing its photon sensitivity keeping neutron sensitivity almost constant. In concequence, uncertainty of gamma dose contributes with lower weight to the variance of the evaluated neutron signal. First tests of an optimised 200 /xm sandwich detector and 0.9 mm thick standart LiF chips were made at low neutron and photon dose ranges using different readers, in order to find out the uncertainty versus dose for different neutron/photon combinations. We demonstrate conditions under which the new sandwich-type detectors may improve albedo neutron dosimetry.

271 PL9601133 PL9601134 Thermoluminescent Efficiency of LiF:Me,Cu,P (MCP-N) Detectors to Photons, Beta-Electrons, Alpha Particles and Thermal Neutrons P. Bilski1, P. Olko1, B. Burgkhardt2, E. Piesch2 and M.P.R. Waligórski1'3

1Institute of Nuclear Physics, Kraków, 2Nuclear Research Centre Karlsruhe, Ger- many, 3 Centre of Oncology, Kraków

(submitted to Radiation Protection Dosimetry)

The thermoluminescent efficiency, 77, of LiF:Mg,Cu,P (MCP-N detectors, commercially produced at the INP, Kraków, Poland), relative to 662 keV Cs-137 gamma rays, has been measured for (i) 1250 keV Co-60 gamma-rays, (ii) filtered X- ray beams of average energies in the range 15 - 300 kVp , (iii) Pm-147 beta-electrons, (iv) thermal neutrons and (v) stopping alpha-particles of initial energies in the range 0.5 - 5 MeV. A rapid decrease of TL efficiency with decreasing mean photon energy from 77=1.04 ± 0.02 for Co-60, 77=0.93 ± 0.02 for 300 kVp X-rays to 77=0.59 ± 0.016 for 15 kVp X-rays was observed. The measured value of relative efficiency for Pm-147 beta-electrons was 77=0.90 ± 0.02. The relative efficiency for alpha particles decreased from T7=O.O6 ± 0.004 to 77=0.03 ± 0.007 for particles of initial energies of 5 MeV and 1 MeV, respectively. The measured response of MCP-N detectors after doses of thermal neutrons was equal to 0.72 1010 Gy n^cm2, which corresponds to 77 =0.104 ± 0.012. The efficiency for 2.73 MeV3H tritons was found to be 77 = 0.155 ± 0.02. The rapid decrease of sensitivity of LiF:Mg,Cu,P with increasing ionization density is a microdosimetric effect, resulting from the saturation of the TL signal from high energy deposits. An empirical relationship between the mean lineal energy, yp, and 77 has been found which can be used to predict the TL efficiency of MCP detectors for photons and electrons. However, TL efficiency 77 is not a unique function of yp, so this relationship cannot be used to predict the value of 77 over the whole range of ionization densities (LET) of heavy charged particles stopping in the detector. (This research is partly supported by grant No 224309203 from The State Committee for Scientific Research, and by the Polish-German cooperation programme).

C. Theoretical Radiobiology, Microdosimetry and Radiation Protection:

On Model-Based Assessment of Risk from Radon Daughters- the Microdosimetric Approach P. Olko1 and M.P.R. Waligórski12

1Institute of Nuclear Physics, Krakow, 2Centre of Oncology, Kraków

(Nukleonika, in print)

Inhalation of radon daughters is considered to be the major source of radiation exposure to man. The quantitative estimate of risk of radon-induced lung cancer is presently based on two complementary methods. In the first method risk coefficients are derived directly from epidemiological studies on radon-exposed uranium miners. In the second, dosimetric approach, a lung model is used to estimate doses to the bronchial epithelium. To express the dose from the radon daughter a-particles absorbed in the epithelium in terms of dose equivalent a quality

272 PL9601136 PL9601135 factor, Q, is applied the value of which is recommended by international bodies (ICRP). The presently used value of Q appears to be of limited relevance for evaluating the risk of lung cancer. We analyze the results of radiobiological experiments in order to derive a more realistic value of Q for radon exposure, basing our investigations on the microdosimetric analysis of measurements of oncogenic transformation per surviving C3H10T1/2 cells after doses of protons, deuterons, helium-3. We argue that the probability relevant to radiation protection is that of cell transformation per exposed cell, therefore probability of cell transformation must be considered in conjunction with that of cell survival. The RBE for cell transformation following irradiation of these cells by alpha particles should therefore decrease because some of the cells are killed and cannot undergo consecutive transformation. This conditional probability of cell transformation leads to a decrease of the value of Q for alpha particles, especially at the stopping end of the particle track. We therefore suggest that the value of Q applied presently in the dosimetric approach may be overestimated. (This research is partly supported by grant No 607359101 from The State Committee for Scientific Research).

Microdosimetry of Tritium K. Morstin1, M. Kopeć1, P. Olko, T. Schmitz2 and L.E. Feinendegen2

1 Institute of Physics and Nuclear Techniques, The Mining Academy, Kraków, Poland 2 Institute of Medicine, Research Centre Julich, Julich, Germany. Microdosimetric aspects of tritium radiotoxicity are discussed. The level of coincidence of tritium locations and of radiation-sensitive sites doses not appear to be decisive for relative effectiveness of tritium exposures. The actual target structure and dimensions seem to be of more importance. Particularly efficient germ cell destruction by chronic exposures to tritiated water is unlikely to be explainable on the basis of classical principles of microdosimetry. The phenomenological approach of investigating biological response functions may be a useful alternative for the interpretation of unexpected experimental results, especially when combined with bidimensional microdosimetry. The latter allows for clustering of nanometer sites within a target of cellular dimensions.

D. Studies of Concepts in Radiation Protection:

Will it be possible to Implement the Limitation of Radon Concentration in Polish Dwellings from January 1995 Onwards? T. Niewiadomski

(Nulcieoniia, in print)

The requirement in the current national regulation that the equivalent radon concentration in houses constructed in Poland after January 1st 1995 must not exceed 100 Bq/m3 appears presently to be impossible to implement from that date onwards. The extensive range of operations required to realize this implementation is outlined. Despite the present difficulties and elays in this matter, it would be inhuman not to undertake every effort to decrease the numner of lung cancers due to exposure to radon in Poland. A national programme for reducing radon exposure in Poland which would resemble those realized in other countries should therefore begin as soon as possible.

273 PL9601137 What Should the National Programme of Reducing the Incidence of Lung Cancer due to Radon Inhalation Contain? T. Niewiadomski1 and M. Waligórski1'2

1Institute of Nuclear Physics, Krakow, 2Centre of Oncology, Kraków

(INP Report No. 1619/D and Postępy Techniki Jądrowej, in print - in Polish) Radon and its daughters, prevalent in the atmosphere in dwellings, are one of the known causes of lung cancer. This is one of the few environmental factors which can be controlled, i.e. the radon and daughter concentration decreased, in order to decrease the incidence of lung cancer in the population. For these reasons several countries have undertaken complex measures in the areas of research and preventive measures, on a national scale. We present an outline of such a programme and of research and administrative activities which should be undertaken in Poland in the next few years. Our aim is to demonstrate that instead of a number of uncoordinated and fragmentary efforts now under way in Poland, a complex, comprehensive and well-designed national programme of reducing the incidence of lung cancer due to inhalation of radon and its daughters should be proposed and implemented as soon as possible. LIST OF PUBLICATIONS: I. Books:

1. T. Niewiadomski, Lithium Fluoride, in: Thermoluminescent Materials, D.R. Vij, Ed., PTR, New Jersey, 1993, pp. 142-180

II. Articles:

1. P. Olko, P. Bilski, E. Ryba and T. Niewiadomski, Microdosimetric Interpretation of the Anomalous Photon Energy Response of Ultra-Sensitive LiF:Mg,Cu,P TL Detectors, Radiat. Prot. Dosimetry 47, 31-36 (1993) 2. M.P.R. Waligórski, P. Olko, P. Bilski, M. Budzanowski and T. Niewiadomski, Dosimetric Characteristics of LiF:Mg,Cu,P Phosphors - A Track Structure Interpretation, Radiat. Prot. Dosimetry 47, 53-58 (1993) 3. M. Budzanowski, P. Bilski, P. Olko, T. Niewiadomski, B. Burghardt and E. Piesch, New TL Detectors for Personal Neutron Dosimetry, Radiat. Prot. Dosimetry 47, 419- 423 (1993) 4. K. Morstin, P. Olko and L. E. Feinendegen, Micro dosimetry of Tritium, Health Phys. 65, 648-656 (1993) « 5. T. Niewiadomski, Will it be Possible to Implement the Limitation of Radon Concentration in Polish Dwellings from January 1st 1995 Onwards? (Nukleonika, in print) 6. M. Nowina-Konopka, On the Interpretation of Results of a National Survey of Indoor Radon Concentration (Nukleonika, in print) 7. P. Olko, P. Bilski and V.M. Michalik, Microdosimetric Analysis of the Response of LiF Thermoluminescent Detectors for Radiations of Different Qualities (Radiat. Prot. Dosimetry, in print) 8. M.P.R. Waligórski, Track Structure Analysis of Two Mouse Lymphoma L5178Y Cell Strains of Different Radiation Sensitivity (Radiat. Prot. Dosimetry, in print)

274 9. K. Morstin and P. Olko, Calculation of Neutron Energy Deposition in Nanometric Sites (Radiat. Prot. Dosimetry, in print) 10. R. Kat z and M.P.R. Waligórski, On the Linear Extrapolation to Low Doses (Radiat. Prot. Dosimetry, in print) 11. P. Olko, M. Budzanowski, P. Bilski, B. Burghardt and E. Piesch, 6-LiF Sandwich- type Detectors for Low-Dose Individual Monitoring in Mixed Neutron-Photon Fields (Radiat. Prot. Dosimetry, in print) 12. P. Olko and M. Waligórski, On Model-Based Assessment of Risk from Radon Daughters - The Microdosimetric Approach (Nukleonika, in print) 13. P. Bilski, P. Olko, B. Burghardt, E. Piesch and M.P.R. Waligórski, Thermoluminescent Efficiency of LiF:Mg,Cu,P (MCP-N) Detectors to Photons, Beta- Electrons, Alpha-Particles and Thermal Neutrons (submitted to Radiat. Prot. Dosimetry)

III. Contributions to Conferences:

1. B. Skarżyńska, E. Zawisza, M. Jasińska and M.P.R. Waligórski, Investigation of Radioactivity of Coal Mining Wastes - the Przezchlebie Stockpile, Proc. of the 4th International Symposium on the Reclamation, Treatment and Utilization of Coal Mining Wastes, Kraków, 6-10 Sept. 1993 2. P. Olko and M.P.R. Waligórski, Radiobiological Assessment of the Quality Factor of Radon Alpha Particles, Proc. of the 25th Annual Meeting of the European Society for Radiation Biology, Stokhohn, 10-14 June 1993 (abstract) 3. B. Rozwadowska, J. Lesiak, E. Byrski and M. Waligórski, Quality Assurance Programme for the SELECTRON LDR/MDR, Programme and Abstracts of the Second Biennial Meeting on Physics in Clinical Radiotherapy, Prague, Czech Republic, 28-30 May 1993, p. 46 (abstract) 4. B. Burghardt, M. Budzanowski, P. Olko, W. Pessara and K. Gmur, Langzertexperiment zur Ermittlung des Egennulleffekts und des Kosmischen Anschprechvermoegeus von Feskoerperdosimetem - in press, 110 Physikalisch Technische Bundesanstalt Seminar, Braunschweig, 30 Nov. - 1 Dec. 1993, Ortosisleistungmessungen Ionisierender Strahlung inn Bereich (1993)

IV. Reports:

1. T. Niewiadomski and M. Waligórski, Co powinien zawierać ogólnopolski projekt obniżenia zachorowalności na nowotwory phic w wyniku wdychania radonu? (What should the national programme of reducing the incidence of radon-induced lung cancer contain?), INP Report No. 1619/D, Kraków 1993, and to be published in Postępy Techniki Jądrowej (in Polish)

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. M.P.R. Waligórski, (Member of the International Scientific Advisory Board of the 11th International Conference on Solid State Dosimetry, Budapest 1995) (Member of the Subcommittee on Radiation Protection of the National Board for Atomic Energy)

275 (Member of the Subcommittee on Medical Applications of Ionizing Radiation of the National Board for Atomic Energy) (Member of the INP Scientific Council) (President of the Kraków Division of the Polish Medical Physics Society) National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26 February 1993; keynote adress: "Radon - Physics, Environment, Society" Annual Brachytherapy Meeting GEC-ESTRO, Venice (Italy), 12-14 May 1993 International Symposium on Measurement Assurance in Dosimetry, Vienna, 24-27 May 1993 Second Biennial Meeting on Physics in Clinical Radiotherapy, Prague, 28-30 May 1993; presentation: B. Rozwadowska, J. Lesiak, E. Byrski, M. Waligorski - Quality Assurance Programme for the SELECTRON LDR/MDR Meeting of the Scientific Advisory Committee of the 11th International Conference on Solid State Dosimetry, Budapest, Hungary, 11-13 July 1993 The Second International Summer School "Physics in Radiotherapy", Centre of Oncology Warsaw (Ursynów) 26 August - 3 September 1993 4th International Symposium on the Reclamation, Treatment and Utilization of Coal Mining Wastes, Kraków, 6-10 September 1993, presentation:: B. Skarżyńska, E. Zawisza, M. Jasińska, M. Waligorski - Investigation of Radioactivity of Coal Mining Wastes - The Przezchlebie Stockpile 3rd Central European Nucletron Brachytherapy Working Conference, Zakopane, Poland, 6-8 October 1993 International Workshop on Proton Therapy, Bonn, Germany, 15-17 November 1993 2. P. Olko, (Member of EURADOS WG 10 Group) (Member of the NAEA President's Committe for Assessment of the State-of-Art of Radon Measurement in Mines in Poland) National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26 February 1993; presentation: "Controversies on the Value of Risk actors for Exposure to Radon and Progeny, Based on Radiobiological Models" 25th Annual Meeting of the European Society for Radiation Biology, Stokholm, Sweden, 10-14 June 1993; presentation (poster sesssion): P. Olko, M. Waligrski - Radiobiological Assesment of the Quality Factor of Radon Alpha Particles Working Meeting of EURADOS WG 10, Kraków, 5-6 November 1993: Host and organizer International Workshop on Proton Therapy, Bonn, Germany, 15-17 November 1993 3. T. Niewiadomski, National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26 February 1993; presentation:"Will it be Possible to Implement the Limitation of Radon Concentration in Polish Dwellings from January 1st 1995 Onwards?" 4. M. Budzanowski, International Workshop on Individual Monitorun of Ionizing Radiation; the Impact of Recent ICRP and ICRU Publications, Villigen, Switzerland, 5-7 May 1993; presentation: P. Olko, M. Budzanowski, P. Bilski, B. Burghardt and E. Piesch, "6-LiF Sandwich-type Detectors for Low-Dose Individual Monitoring in Mixed Neutron-Photon Fields" 5. P. Bilski, International Workshop on Individual Monitorun of Ionizing Radiation; the Impact of Recent ICRP and ICRU Publications, Villigen, Switzerland, 5-7 May 1993; presentation: P. Olko, M. Budzanowski, P. Bilski, B. Burghardt and E. Piesch, "6-LiF Sandwich-type Detectors for Low-Dose Individual Monitoring in Mixed Neutron-Photon Fields"

276 6. M. Nowina-Konopka, National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26 February 1993; presentation: "On the Interpretation of Results of a National Survey of Indoor Radon Concentration"

SCIENTIFIC DEGREES: M. Sc. Theses:

1. B. Mysliwa-Kurdziel (Medical Physics, Jagiellonian University) Optimization of a Method of Measuring Radon Concentration in Dwellings (advisor: Prof. M. Waligórski) 2. T. Ho diak (Technical Physics, Academy of Mining fe Metallurgy) Investigation of Selected Dosimetric Properties of the Ultra-Sensitive LiF:Mg,Cu,P TL Detector on the Conditions of its Thermal Treatment (advisor: Prof. M. Waligórski)

LECTURES AND COURSES:

1. M. Waligórski, lecture: Track Structure Modelling of the Response of Solid State Detectors, at the International School on ESR Dosimetry, Marciana Marina, Italy, 2-11 June 1993 2. M. Waligórski, invited lecture: Radiation-Induced Effects and Track Structure, at the International Training Course on Problems of Radiation Safety and Radiobiology, Dubna, Russia, 28 July - 7 August 1993

INTERNAL SEMINARS:

1. Dr. L. Kalmykov (Institute of Medical Radiology, Kharkov, Ukraine) "Dosimetric problems in the Chernobyl Area", 12.01.1993 2. Prof. T. Niewiadomski, "Comparison of basic dosmetric units wi ICRP-26 and ICRP- 60", 28.04.1993 3. Dr. M. Vilgis (KfK Karlsruhe) "Modern Glass Dosimetry in KfK", 5.10.1993 4. EURADOS (European Dosmietry Group) "WG 10 Working Meeting", 4-7.11.1993

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Prof. N. Pilipenko, Institute of Medical Radiology, Kharkov, Ukraine 2. Dr L. Kalmykov, Institute of Medical Radiology, Kharkov, Ukraine 3. Dr. Hlawacz-Martinez, University of Caracas, Venezuela 4. Dr. M. Vilgis, KfK Karlsruhe, Germany 5. Dr. P. Segur, University of Tulouse, France 6. Dr. P. Colautti, Lab. Nazionale di Legnaro, Italy 7. Dr. P. Pihet, IPSN, Fontenay-aux-Roses, France 8. Dr. A. Waker, Chalk River Laboratory, Canada 9. Dr. Th. Schmitz, KfA Julich, Germany

277 Cyclotron Laboratory

Cyclic Accelerator R & D Laboratory

Electronics Laboratory

Computing and Networks

Division of Mechanical Constructions

Energy Efficiency Center PL9601138

CYCLOTRON LABORATORY

Head of Division: Edmund Bakewicz, M.Sc.E.E. telephone: (48) (12) 37-02-22 ext.: 365 e-mail: [email protected] PERSONNEL:

Head of Division: Edmund Bakewicz, M.Sc.E.E.

U-120 Cyclotron Section:

Head of the Section: Bronisław Wojniak, M.Sc. Józef Cora Tadeusz Francuz Mieczysław Kubica Maria Mirek Stanisław Papierz Zbigniew Pazdalski Bogusław Sałach Bogdan Sułek Jacek Sulikowski, M.Sc. Marek Talach, M.Sc.E.E. Ryszard Tarczoń Lucyna Włodek

AIC-144 Cyclotron Section:

Head of the Section: Henryk Doruch, M.Sc.E.E. Krzysztof Daniel, M.Sc.E.E. Leszek Dzieża Jerzy Korecki, M.Sc.E.E. Janusz Łagisz Tadeusz Norys Wojciech Pyzioł Marek Ruszel Jerzy Starzewski, M.Sc.E.E. Ryszard Taraszkiewicz, Ph.D.

279 Acceleration techniques have been development in our Institute from the very beginning of its existence. The first cyclotron we had was a "small" cyclotron C-48, built in Cracow. In 1992 the "small" C-48 was decomissioned. At the same time we had finished building the AIC-144 cyclotron. In June 1993, the Division of Cyclotron was created in our Institute. It consists of two sections: U-120 Cyclotron Section and AIC-144 Cyclotron Section. 1. U-120 Cyclotron Section The U-120 cyclotron has been exploited in our Institute since 1958. Its parameters are as follows:

Magnet pole diameter: 120 cm Magnetic field: 13-15 kGs Number of dees: 2 (a = 180°) R-F system: 8-16 MHz/120 kW Dee voltage: 150 kV Extraction radius: 52,5cm Ion sources: PIG, internal Extraction system: electrostatical, XJj - 60 kV (+magnetic channel) Particles Energy Intensity deuterons 12-14 MeV 60 /iA H2-ions 12-14 MeV 40 /iA 3H-ions 29-32 MeV 3 /xA alpha 24-28 MeV 20 /zA Emittance: e, = 50 mm-mrad ez = 35 mm-mrad

The equipment of U-120 consists of five beam transport lines with many facilities and apparatus' for nuclear research. We have a stand for radionuclides production, the radiobiological research and neutron theraphy. The radionuclide Ga-67, In-Ill, J-123, Tl-199 have been produced on the U-120 cyclotron for many years. This year we finished the experiments on the obtaining of In-111 by deuteron bombarding of Cd-110 targets. Ten sessions of the theraphy with fast neutron beem from U-120 (one week per month cycle) were run in 1993. Theraphy was run for the patients of the Oncological Centre in Cracow. For the first time we have accelerated alpha-particles up to 30 MeV (before we were able to reach only 28 MeV). According to the plan of modernization we have manufactured a new power supply for the main magnet coils. It is a high stability arrangement with a range of direct current up to 600 A. We have constructed and manufactured a head of the press for preparing the tablet targets for radio chemical needs and a distance control stand for the production of neutron-deficient radioizotopes.

280 2. AIC-144 Cyclotron Section Our new AIC-144 isochronous cyclotron has the following parameters:

Magnet pole diameter: 144 cm Magnetic structure: 4 sectors with the spirals angle of 54° Magnetic field: 8.5 - 18 kGs Fields' variation: B4/< B > = 0.2 Frequency of the betatron oscillators: Qz = 0.42; Qz = 0 - 106 Number of concentric coils: 20 Number of azimutal coils: 8 Number of dees: 1 (a = 180°) Radiofrequency generator: 8-26 MHz/150 kW Dee voltage: 50 kv Extraction radius: 62 cm Ion source: internal, PIG type Acceleration coeff: K = 60 Range of energy: Protons: 10 - 60 MeV Deuterons: 15 - 30 MeV a-particles: 30 - 60 MeV Emittance: ex — 25 mm-mrad, ez = 20 mm-mrad.

The AIC-144 cyclotron has been built and tested in a vault without radiation shields. We are planning to instal it in a proper operation vault. The simplest and the cheapest way of achieving this is to finish using the U-120 cyclotron and to install the AIC-144 in its place. Now, the cyclotron for future exploitation. In 1993 we succesfully ran many tests in the following parameter areas:

1) B = 14.2 kGs and f = 10.8 MHz 2) B = 16.1 kGs and f = 12.2 MHz 3) B = 17.2 kGs and f = 13.0 MHz 4) B = 18.0 kGs and f = 13.5 MHz In July the test on the maximum intensity of the internal beam was carried out. We obtained a beam current of over 200 /xA (for deuterons, with B = 14.2 kGs and f = 10.8 MHz). The experiments on acceleration of the molecular hydrogen have failed to show good results, probably because the vacuum was not good enough. For improving the vacuum, we have installed a new set up for vacuum controlling inside the acceleration chamber. We have also worked out a new system to improve the residual gas pumping, especially from the deflector area. As a result of many tests we have optimized the parameters of ion's source and reduced the gas losses. Changing the trimmers' capacity and improving the resonance circuit gives better stability and more precise controlling of the RF-generator.

LECTURES AND COURSES:

1. E. Bakewicz, M.Sc.E.E., "Development of the Cyclotrons in Institute of Nuclear Physics in Cracow"; a lecture given at the Institute of Nuclear Physics KFA Julich, Germany.

281 SHORT TERM VISITORS TO THE DEPARTMENT:

1. DT E. Vera Ruiz, Industrial Application and Chemistry Section of the International Atomic Energy Agency, Vienna, Austria, August 1993 2. Prof, dr A.T. Rutchik Ukr. Academy of Sciences, Kiev, October 1993 3. DT M.F. Shabashov Joint Institute for Nuclear Research, Dubna, November 1993.

282 PL9601139 CYCLIC ACCELERATOR R & D LABORATORY

Head of the Research Group: Assoc.Prof. Jerzy Schwabe Secretary: Halina Szymańska telephone: (48) (12) 37-02-22 ext.: 381, 371 e-mail: [email protected] PERSONNEL: Research Staff: Jerzy Schwabe Andrzej Balmas Helena Godunowa Maria Potempa Administration: Halina Szymańska

Since the time that the AIC-144E has been in operation in IFJ, our group has been engaged in investigating and developing the physics and techniques of cyclic accelerators as an independent laboratory. During building the AIC-144E our staff gained considerable experience as regards to the isochronous cyclotrons. The investigations concerning the improvement of the operation parameters of cyclotrons that are at present operating in the world are one of the main subjects of our interest. The AIC-144S is the basic tool for some experimental investigations devoted to the aforementioned topic. The theoretical explorations of the acceleration processes are based on computer codes developed in our laboratory. Here are some of the topics that we are able to design with high accuracy and quality: • dynamic of charged particle acceleration in three dimensional structures of HxE fields • basic parameters of conventional isochronous cyclotrons as well as sector ring isochronous cyclotron with separated magnets • HF - Resonator cavity and RF - Generator for isochronous cyclotrons • magnetic field spatial structure • effects of the resonance excitation in the accelerated beam on the isochronous cyclotrons • compact cyclotron for therapeutical purposes and for the production of neutron deficient radioisotopes. We invite also other research groups which are interested by the topics to collaboration on them.

283 IHI REPORTS ON RESEARCH ™ "L9601 140

Investigating and Developing the Physics and Technique of the Cyclic Accelerators J. Schwabe, M. Potempa, A. Balmas, H. Godunowa l.The AIC-144S Operation Investigations (01.01.93-05.06.93) To get the optimum parameters of AIC-144S was the main topic of experimental work on the AIC-144E carried out by our group this year. Here we present it in headlines: a. Increasing the accelerated beam energy (Z/A = 0.5) for deuterons and for \He. b. The extraction of the accelerated beam by using the modified magnetic extraction system. The extraction coefficient has been increased to about 3-5%. c. Designing and testing the water cooled probe aimed at the irradiation of the isotope targets on the internal beam. d. Designing and applying the beam energy measurement method. e. Putting into operation at 60 kW power (pulse mode) the R.F. Generator (MBC). The MBC has operated on AIC-144S in pulse mode with duty factor of 27%. 2. The AIC-144S Theoretical Investigations (15.09.93-31.12.93) The following topics were investigated: a. The high efficient extraction problems on isochronous cyclotrons. The AIC-144E has been utilized as an experimental investigation model [1]. b. The most economical operation conditions for the proton beam acceleration up to 60 MeV. Theoretical investigations and the design of its applicatios on AIC-144S were worked out [2]. c. Dynamics of the H~ acceleration process on GC-80 Isochronous Cyclotron (designed in Gatchina, Russia) were simulated by using the AMIC-II computer code [3]. d. The conditions of the mirror axial inflection of the H~ ions accelerated on GC-80 was estimated and optimized with the aid of AMIC-IH computer code [4]. Short Outline of Selected Topics

la. Increasing the accelerated beam energy on AIC-144S Since the MBC is not at present put into operation at full power the excitation power on the wanted frequency is unachievable. Therefore the investigations were carried out in the deuteron acceleration operation mode on the AIC-144S (Z/A — 0.5). The beam energy increase was achieved in two steps: E=22MeV (d) E=24MeV (d) The AIC-144S operation parameters and its energy dependencies are given in Fig.l. The precession and the deformation of the orbits were observed within the radius range 54-57 cm during the acceleration process. These phenomena have taken place in the region of extraction radius where there are the isochronous operation conditions and the AIC-144S has been operating in the higher beam energy mode. The valley correction coils were used to compensate in large part these effects.

284 The phenomenon analysis made by using the AMIC-II code [3] has shown that there are two reasons which could cause these effects: either the first subharmonic is appearing in the magnetic field structure (see Fig.2), or there is the beam excitation effect during the time of the beam passage along the coupling resonance zone; 2Qz + Qr = 0; AR=53-57cm (see Fig.3). In order to solve the problem further investigations have to be carried out. lb. The accelerated particle extraction from AIC-144S The passive magnetic expander was used in the AIC-144S extraction system. It has been set in the place where the electrostatic expander had been located before. The magnetic field perturbation of the expander has increased the extraction coefficient t] up to 12-15%. The computer simulation of the extraction process has shown its influence on the orbit distribution, the results are shown in Fig. 4a, 4b, where the shift of the orbit maximum separation point from A to A! is marked. The analysis of this simulation has indicated that there is a possibility to control the beam input in the non-linear excitation space ( Qr — N/q, for N = q = 4) and thus to optimize the extraction process in the required direction. 2b. The most economical operation conditions for the acceleration of proton beam up to 60 MeV The AIC-144S cyclotron has been designed for operation in the wide range of proton beam energies (K = 20 - 55MeV) and with a variety of accelerated particles and ions in the range of Z/A = 1 - 0.285. The wide range of possibilities results in the uneconomical conditions of the resonator cavity operation. It is proposed to apply the AIC-144E for proton therapy. In this case it will be operated in its highest energy mode and it follows that the economical operation rate has become the important parameter. Therefore the conversion of the acceleration system that enables one to limit, the excitation power to 42-45 kW at frequency of 26.1 MHz has been designed. This convertion allows one to reduce R.F. power consumption by about 100 kW against the primary design. The lower band of the frequency range on cavity will be only slightly limited by this conversion. If need be it will be possible to return quickly to the primary construction of the cavity.

ACCELERATION OF ALPHA PARTICLES AIC-144 8 :ENERQY , Bis . Frequenoy Bls(KO») TK(MEV) 20

10 100 200 300 400 600 I mag (A) "Series 1 -•- 8erteB 2 - -Series 3 TKCMEV) FOtMttt)

Figure 1: AIC-144S operation parameters

285 DYNAMICS OT ACCBISgAIION (24.5 SfeV (D) : AIC-144 S >A.-a. i13.1 783 mewa. OKILMTSQNS • Cen>

ACC.PtMSE (rad)

00 100 120

Figure 2: First subharmonic influence on orbit distribution

9. SIS R=5-ł.7M DR—B.SJS RNB 4K-144 8 t OMITS* PE8CSSSI0K ON R>fi4-fiB Of 1 t-csawatoHicB w HM. rta*

rcst.rnu

=2 ZOB=I EPS=0.156 NR=fi

Figure 3: Coupling resonance excitation of the accelerated beam at radius 54 cm

AIC-1** S KKnUCTKM SISTOt | 4B TKKS.

>9 B -14.36 SB.M.:, FOB-10. 91 10

1 1

;

2 •u <<^^^^B^^%S

:I EP3=0.123 NR= 1 1

Figure 4a: Extraction of the beam by electrostatic expander field

286 AlC-m S DETRACTION SYSTEM i 4C VSRS.

MCKIIC no* rwwuMTjm •• MC.E

MT.I

=1 EPSse NR=I2

Figure 4b: Extraction of the beam by magnetic expander field

References: [1] J. Schwabe, "AIC-144 Isochronous Cyclotron Conversion Aimed at Using it Right Away for Medical Purpose" (to be published) [2] J. Schwabe, "The High Efficiency Extraction Problems on Isochronous Cyclotron" (to be published) [3] Mathematical Analogue of the Isochronous Cyclotron -Ilcomputer code, developed by J. Schwabe [4] Mathematical Analogue of the Isochronous Cyclotron -HI computer code, developed by J. Schwabe LECTURES AND COURSES: /. Schwabe Lectures given in KINPh Gatchina near St. Petersburg, Russia, November 1993: 1. "AIC-144S Status: Extraction and Dynamics of the Accelerated Beam" 2. "Some Design Problems of the Beam Dynamics on Isochronous Cyclotron GC-80, Gatchina" 3. "Exploration of the Axial Extraction of the Beam Accelerated on GC-80" 4. "The Possibility of the AIC-144S Conversion Aimed at Obtaining the Proton Acceleration up to 60 MeV". Lecture given in JINR Dubna, Russia, December 1993. INTERNAL SEMINARS:

J. Schwabe, "The Orbit Symmetrization of the Accelerated Beam on AIC-144S". J. Schwabe, "Increasing the Accelerated Beam Energy on AIC-144S: problems and realization". J. Schwabe, "Beam Extraction from Isochronous Cyclotrons: The High Efficient Extraction Methods". SHORT TERM VISITORS:

V.A. Eliseev and E.M. Ivanov - KINPh, Gatchina, near St. Petersburg, Russia. H.C.J. Fliderbaum and M. Grynberg - Providers Export International Inc. USA

287 PL9601141 ELECTRONICS LABORATORY

Head of Laboratory: M. Kajetanowicz, M.Sc.E.E., Deputy Head of Laboratory: F. Kościelniak, M.Sc.E.E. Secretary: Jolanta Pluta, telephone: (48) (12) 37-02-22 ext.: 432 e-mail: [email protected]

PERSONNEL: Design Section: Head of the Section: Adam Czermak, M.Sc.E.E. Engineers : Elżbieta Banaś Barbara Dulny1 Wiesław Iwański Jan Kapłon Piotr Kapusta2 Krzysztof Korcyl Jolanta Olszowska Wacław Ostrowicz Technicians: Adam Adamski Jacek Garwoliński Tomasz Gdański Bogdan Sowicki

Maintenance Section: Head of the Section: Franciszek Kościelniak, M.Sc.E.E. Engineers: Ryszard Lerch Maria Wasik Technicians: Wacław Kozub Edward Kochan Bogdan Lipka Artur Włodarczyk Administration: Kazimiera Drożyńska Jolanta Pluta

The main activities of the Electronics Division are: • design and test of electronic equipment for experiments in physics, • development of software for trigger and data acquisition systems, • maintenance of Institute electronic equipment. Division designers take part, together with physicists, in big, international collaborations set up for the preparation of experiments in physics. Our main partners are CERN in Geneve and DESY in Hamburg. In CERN we participate in the DELPHI experiment on LEP accelerator and in the future ATLAS experiment on the new LHC accelerator. We take part in four research and development programs for LHC experiments: RD6, RD11, RD16 and RD20.

xon leave of absence to Max Planck Institute, Munich, 3on leave of absence to CERN, Geneve.

288 • DELPHI: the work concerned the development of Inner Detector software. The main area of our activity was the optimalization and maintenance of the on line data acquisition system as well as local third level triggering system, • ATLAS: - RD6: VME test system composed of four VME modules has been designed and manufactured. It is aimed for tests of the front-end electronics for the Transition Radiation Tracker (TRT), one of the future ATLAS detectors. In the second half of the year the system was extensively used for tests in CERN, - RD11: Modelling of local and global architectures for second level triggering at the ATLAS experiments using MODSIM II language. Study on algorithms for the local second level trigger system for the calorimeter in the ATLAS experiment, - RD16: Modelling of the architecture of the ATLAS calorimeter readout board, •— RD20: tests of the ATLAS silicon tracker front-end electronics comprising amplifier/shaper, analog delay buffer and analog pulse shape processor. Participation in design of a chip comprising whole front-end readout electronics for the ATLAS silicon tracker. Study on readout architecture for the silicon tracker in the ATLAS experiment. Design of a hybrid board for readout electronics for the silicon strip detector. In DESY our engineers were involved in preparing the Hi experiment. Software providing a fast link between the VME 0S9 station and monitoring micro VAX computer was developed. It was used in the data acquisition system for Liquid Argon Calorimeter LAR. Our designers also took part in the development of calibration software for Liquid Argon Calorimeter LAR and for the local LAR level one triggering system. The control part of the monitoring software for the HI second level trigger system is under development in cooperation with LAL Orsay, France. An 8 bit pipeline Analog to Digital Converter developed in cooperation with CNR in Stras- bourg has been tested. A new, improved ADC chip has been designed. The design was formulated using in AMS 1.2 /xm CMOS technology. An upgraded multiparameter data acquisition system for experiments in nuclear spectroscopy has been developed and succesfully tested. Two university students have begun their thesis in the the Electronics Division. One thesis is in VLSI intergrated circuit design and another in data acquistion with digital signal processor. Two university students had their summer placement at the Electronics Division.

M. Kajetanowicz

289 REPORTS ON RESEARCH: PL9601142 " J Low offset, low power comparator for silicon strip detector readout M. Kajetanowicz and J. Kapłon

Abstract: A comparator chip required for use in silicon strip detector read-out was designed and manufactured using 1.5 firn bulk CMOS DM DP Mietec technology. This paper presents a short description of the comparator and the results of tests carried out on four chips. Introduction: In currently designed experiments on LHC, and especially in silicon trackers, data compression in front end electronics is indispensable. This is a result of the very big channel number and the low occupancy of detector. Besides an analog signal from the strip digital information is also necessary to know if a given strip was hit. Thus, a comparator in each channel is necessary. The comparator design was done within the scope of the RD20 research and development programme at CERN. Technical specification: Comparator parameters are defined by the gain and signal to noise ratio in the read-out chain. Assuming a signal to noise ratio 15 and gain 60 mV/MIP the offset variation of 5 mV is satisfactory. Because of the great number of detector channels a very small amount of power should be dissipated in one channel. A trade-off between speed and power is necessary. The following parameters were assumed in this comparator:

• dissipated power less than 0.4 mW, • offset spread less than 4 mV, • response delay 100 ns. Principle of operation: The comparator circuit is composed of two stages. A differential amplifier in a transconductance amplifier configuration is the first stage and a D-type flip-flop is the second one. Because of a high transconductance of the input transistors the comparator offset depends only on their threshold voltage mismatch. Aspect ratio of the input transistors is optimized according to this parameter. The high slew rate of the comparator is guaranteed by the strong positive feedback of the second stage. Refresh signal - COMPARE - is provided to cancel the hysteresis of the comparator. The high level of this signal resets a flip-flop, i.e. an output voltage goes to a Vss level. The comparator schematics shown in Fig.l. The output voltage level is established as a result of opening the switches. When i\ is greater than i2 the output goes to VDD level and in the opposite case goes to Vss level. The output slew rate is defined by equation (1).

9mf

where:

• gmf - D flip/flop transconductance

• gm - differential pair transconductance

290 o-2r

tnp o-

COMPARE

Fig.l Schematic view of the comparator. Tests: The comparator chip was tested in conditions similar to those required for an operation of the ATLAS silicon tracker read-out chip. Test set-up: The chip supply voltage is ± 2 V, the input voltage has a step of 0.1 mV. The COMPARE signal has a frequency of 250 kHz. A counter is on the output of the comparator. An integrated Gaussian curve was recorded by counting the output pulses when the input voltage was changed from -5mV to +5mV. The bending point on that curve is the offset of the comparator. The comparator noise is extracted after differentiating the experimental plot which results in a Gaussian curve. Results: Four chips, 24 channels each, were tested. The following results were recorded: • integrated Gaussian plots, • offset distribution depending on channel, • histogram of offset distribution. The maximum offset spread among comparators from different chips is less than 4 mV and in one chip is less than 3 mV. The standard deviation

1. P.E. Allen, D.R. Holberg, "CMOS Analog Circuit Design", Holt, Rinehart and Winston, inc., 1987 2. V. Valencic, "Low-Power and Fast CMOS A/D Converters", Front End Electronics Wor- king Group CERN/ECP Jan 29, 1992 3. R. Brenner et al., "Performance of a LHC FRONT-END running at 67 MHz", CERN- PPE/93-139 July 5, 1993

291 PL9601143 Development of VLSI electronics for readout of X-ray silicon strip detectors A. Czermak and J. Kapłon

This work has been supported by the Commisssion of EC, grant nr 941 and performed in LEPSI-Strasbourg as a joint project with INP-Cracow. Two VLSI fully custom designed integrated circuits of 1.2 fim. CMOS technology have been designed and placed for production at AMS-Austria. The first prototype chip contains four channels of low noise preamplifiers, after which stretch- ers and discriminators follow. In a foreseen imaging application of such front-end electronics with low energy X-ray Si detectors, it is necessary that the chip provides also a trigger, in order to tell the external readout system to record the hit when the photon is fully absorbed within the silicon detector. This circuit has been simulated with the HSPICE signal simulator, before and after layout processes. The noise performance of the charge preamplifier has been optimized so as to guaran- tee the measurements of X-ray energies starting from 3.5 keV with a resolution (FWHM) of less than 1.0 keV. These features of the chip should facilitate the investigation of biological objects using low energy X-ray sources. The second prototype chip contains logic for a spars-scan-readout of 64 channels. The chip has been designed to reduce and compress data from Silicon Strip Detectors. Together with an eight-bit pipeline ADC, which has been already designed and tested successfully, and with some FIFO buffor, which is under consideration for construction in the near future, the logic should be placed into a single chip. Having such a complete circuit fast data readout from Si strip detectors should be demonstrated. This should considerably facilitate some real-time imaging applications of X-ray detectors as well as having some influence on the proposed architecture of the readout system for Si tracker detectors for future experiments on the LHC. The simplified block diagram of the whole spars-scan-readout circuits is presented in Fig.l.

CONTROL UNIT V CONTROL SIGHALS

PRIORITY ADORESS APSP ENCODER 128 > 12B ADDRESS

(DATA W ANALOG \ ADC MEMORY APSP ANALOG SELECTOR / 8bit

Fig.l Block diagram of spars-scan-redout circuits.

292 PL9601144 Modelling of architecture of the ŁHC calorimeter readout

board f W. Iwański

The FERMI [1] is a digital multichannel front-end module intended for acquisition of calorimeter data in ATLAS detector at Large Hadron Collider. It is designed as a microsystem consisting of on-chip shapers, amplifiers, ADC and memories to serve autonomously up to 9 input channels. However, the communication of the FERMI chip with the rest of a system strongly depends on the external environment. A dedicated controller is needed in order to provide chips with pointers to internal memory, to receive requests or to initiate data transfers to triggers and data acquisition systems. FERMI chips are grouped on boards (FERMI boards) together with electronics, which or- ganise data transfers. Two types of data transfers are assumed : • filtered value, • full time frame data. In the first case only one word represents data stored for one bunch crossover signal (BCO), in the second one the set of ADC samples reflects the data concerning particular BCO. The conceptual view of the FERMI board is presented in Fig.l. There are 36 FERMI chips on board in the current implementation. They are read out in a chain, pointers and strobe signals are asserted by the Readout sequencer. After being read, the data are compared with the programmed threshold. The data which survived the comparator veto are stored together with an associated identifier in Data or Tag Buffers, respectively. When reading full time frame data, the zero suppress option is disabled. After scanning all chips, the next sequence for the new event can be started. Simultanously, the data which have already been read out are fetched by the Sending controller, which builds the message and then sends it off the board over a serial link. Behavioural models of the board components were coded in VHDL language [2]. Different cofigurations of the board are tested in ongoing simulations. High radiation in a real experiment makes this design very demanding. The board should be simple to be fault tolerant and concurrently to have enough functionality. The following concepts are considered: • dividing of the board into local and global parts, where only the local part will be mounted on the detector and communicate with the global one via serial link, • multiplexing of output messages coming from different boards belonging to the same energy tower into one fast optical link. The goal of this work is to build and simulate a full VHDL model, containing internal description of the FERMI chip and functional description of the external environment. This work is carried out in collaboration with Stockholm University as a part of the EAST [3] and FERMI collaboration activities. References: 1. The FERMI collaboration: "A Digital Front-end and Readout Microsystem for Calorimetry at LHC", CERN/DRDC/90-74, December 1990. 2. Mentor Graphics Corporation - VHDL 1076 System Reference Manual. 3. Embedded Architectures for Second-level Triggering (EAST), Status Raport CERN/DRDC/92-11, March 1993.

293 36 x FERMI chips

to (O

Fig The architecture of the readout channel in the FERMI controller PL9601145 COMPUTING AND NETWORKS A. Cyz, E. Górnicki, St. Jagielski*, A. Kotarba, W. Krupiński, B. Madeyski, P. Malecki, K. Oliwa, A. Sobala, and W. Wajda

The computer network and computing services are managed and maintained by two groups sharing the work and responsibilities: Computing Group at the Institute's main site and the Group of Numerical Computing of the High Energy Physics Laboratory at Kawiory. 1993 was a year in which our two clusters of DEC servers and workstations continued smooth running of the DEC VMS operating system. Network services were supported by TGV Multinet, upgraded and updated to the version 3.2 rev. B. It was, very likely, the last year of the dominance of the VMS machines. The number of UNIX computers increased considerably and some more have been ordered. Among them the Silicon Graphics Challenge L server, which will be installed in the first half of 1994. Two VAXservers 3400 have been upgraded to improve the network services. The 8 Mbyte memory module and 8 channel multiplexer card have been added to each one as well as "intel- ligent" SCSI interface. The local area network (LAN) continued to grow. The number of users exceeded 200, connected via terminal servers or Ethernet adapters. More Ethernet lines have been installed, increasing the total length of lines by about 3 km. New Ethernet repeaters (DEMPR) and terminal servers improved the LAN infrastructure. Basic software tools like CERN program library and TeX were maintained and continuously updated. Some new application programs have been installed and tested. In particular: NEWS, a system which organize an exchange of information inside the Institute and WWW, a world wide communication tool. Our software experts spent considerable part of their time as consultants to users. Our groups provided all necessary information and expertise in preparations for ordering new equipment by various divisions or projects. Behind the scenes, several important activities have been completed such us e.g., taking over the nameservicing for our domain (.ifj.edu.pl), introduction and improvement of the dynamic routing on our CISCO gateway, extension of mail services to the TCP/IP, connection to the national IP network NASK (hardware and software), optimization of the system tuning, new measures for the system safety, implementation of a limited (but safe) procedure to intervene in some system actions by advanced users etc. The hardware problems were fortunately rather rare. The most troublesome were caused by the instability of the Fideltronik's UPSes. Almost all devices have been replaced by the corrected model and, recently, a considerable improvement has been observed. Particularly annoying were occasional breakdowns caused by bad contacts on the Ethernet and/or by the wrong use of the Ethernet cable of which the grounding of the coaxial cable outer conductor was a too frequent mistake. (An Ethernet cable is required to be earthed at one point only, so, the care must be taken to cover all barrel connectors with the non-conducting sleeve in case it comes into contact with neighbouring metal objects). There were some hardware losses: two Exabyte drives, system disk at one of VAXservers and TK70 cassette tape drive, also for 3400 server. And some local triumphs as well: a serious crush of the gateway CISCO have been bravely repaired by our staff within few hours, saving us a lot of money and pain.

295 Coming year activities will be dominated by the further transitions to the UNIX system and, hopefully, by consequences of the development of the Metropolitan Area Network, in particular by its fiber optic link between Bronowice and Kawiory.

Faculty of Nuclear Physics and Techniques, Academy of Mining and Metallurgy

296 DIVISION OF MECHANICAL CONSTRUCTION

Head of Division: Włodzimierz Janczur, M.Sc.M.E. Deputy Head of Division: Leszek Zródłowski, M.Sc.M.E. telephone: (48) (12) 37-02-22 ext.: 450 e-mail: [email protected]

PERSONNEL: Design Section Head of Section: Leszek Zródłowski Engineers: Zbigniew Cioch Bogusława Hożewska Jerzy Kotuła Józef Ligocki Andrzej Ryś Krzysztof Wiśniewski Technicians: Władysława Materkowska Construction Section Head of Section: Włodzimierz Janczur Engineers: Adam Sokołowski Tadeusz Śmiałowski Technicians: Jarosław Adamek Zdzisław Błaszczak Mirosław Dubiel Jerzy Grzybek Jerzy Kantorski Krzysztof Kerc Władysław Kowalski Jan Kromka Jan Majka Józef Michniak Krzysztof Mistela Julian Mizioł Wacław Nędza Mirosław Papież Stanisław Pelc Piotr Piotrowski Kazimierz Pukała Ryszard Pyzioł Maciej Rachwalik Józef Rogowski Roman Romanów Adam Rzepa Andrzej Seweryn Maciej Sowiński Władysław Szwaja Henryk Świerk Zbigniew Toch Zygfryd Trulka Jerzy Wcisło Piotr Wójtowicz Ryszard Zając Zbigniew Zasadzki Tadeusz Zdziarski Bogusław Zięba Jan Zwoliński

297 The Department of Mechanical Construction has been established two years ago joining the Design Group and Central Mechanical Workshop. The activity of the department includes the following items: • complex designs of devices and equipment for experiments in physics and their mechanical construction and assembly, • maintenance and upgrade of existing installations and equipment in our Institute, • the participation of our engineers and technicians in design works, assembly of an equipment and maintenance for the experiments in foreign laboratories. In 1993 our design group has been equipped with microcomputers PC-486 and PC-386 type and graphic software AutoCAD, with its last version - release 12 that allows to make the drawings and mechanical documentation corresponding to the world standards required by such scientific centers like CERN, NIKHEF, MIT. Our mechanical workshop can offer the wide range of machining and treatment methods with satisfactory tolerances and surface quality. The possibilities of our mechanical workshop include:

• turning - cylindrical elements of a length up to 2000 mm and a diameter up to 400 mm, and also disc type elements of a diameter up to 600 mm and a length not exceeding 300 mm, • milling - elements of a length up to 1000 mm and gear wheels of a diameter up to 300 mm, • grinding - flat surfaces of dimensions up to 300 mm x 1000 mm and cylindrical elements of a diameter up to 200 mm amd a length up to 800 mm, • drilling - holes of a diameter up to 50 mm, • welding - electrical and gas welding in argon, vacuum tight welding, • soft and hard soldering, • mechanical works including precision engineering, • plastics treatment - machining, modelling, lamination of various shapes, polishing; technology of forming plexiglas and scintillators is under a development, • painting - paint spraying with possibility of using furnace fired drier of internal dimensions 800 mm x 800 mm x 800 mm.

In 1993 the Department of Mechanical Construction designed and manufactered the equipment for the following laboratories: 1. Institut fur Kernphysik, Julich, FRG, 2. Institut fur Mittelenergie Physik, Zurich, Switzerland, 3. Joint Institute of Nuclear Research, Dubna, Russia, 4. Jagellonian University, Cracow, 5. Academy of Mining and Metallurgy, Cracow,

W. Janczur

298 REPORTS ON ACTIVITY: PL9601146 The detectors for Institut fiir Kernphysik, Julich

In the frame of the cooperation with Institute of Physics of Jagellonian University and according to their requirements and foredesigns two sets of detectors for the experiment on COSY storage ring in the Institut fur Kernphysik have been designed and built in our department. Transmission Polarimeter. The polarimeter (Fig. 1) will be installed at the inlet of COSY-storage ring to test the proton beam and define its parameters. The collimated proton beam will collide with a target inside the polarimeter vacuum chamber and scattered products of the collision will be read-out by the scintillators after the crossing the windows covered with the thin (0.01 mm) stainless steel foil. The main part of the transmission polarimeter is the vacuum chamber made of amagnetic stainless steel (AISI 316L type) with 8 windows arranged in two perpendicular planes (horizontal and vertical) enabling the read-out of particles scattered in a front and a rear hemisphere at angles from 25 to 75 degrees. The scintillating detectors together with their photomultipliers move over each window along the circumference of a radius of 375 mm. They are fastened to the carriages driven independently by using remote controlled DC motors and moving angularly in the range from 25 to 75 degrees. The angular position of the particular scintillating detectors is denned with the accuracy ± 10'. The polarimeter is supported on the base-frame which enables its positioning and a precise adjustment to ensure the proper alignment with the existing elements of COSY-storage ring. The target mechanism of the polarimeter ensures the vacuum tight transfer and positioning of the replaceable frame with 5 different targets. The target mechanism is driven by the remotely controlled DC motor.

Target mechanism

SctntiUatng detectors

Fig. 1 Transmission Polarimeter.

299 PL9601148 PL9601147 Transit Time Detector Set. The detector set consists of the vertical frame of the drift chamber and the frame fixing the stationary scintillating detectors and the movable scintilllating detectors sets. The stationary detectors set is equipped with 17 x 4 scintillators which cover the active window of the drift chamber (1680 mm x 433 mm). These detectors are provided for precise measurements of charged particles trajectories and particularly two protons produced in the coincidence. The movable detectors set is a unit of 16 scintillators covering 2 sets (8 scintillators) of the stationary detectors. Scintillating detector AMADEUS is a separate part of the experiment used directly for the measurements of the particle transit time. The detector has been manufactured in our workshop according to the drawings provided by Institut fur Kernphysik. This set of detectors will be used in COSY-11 experiment at COSY-storage ring.

The equipment for Institut fur Mittelenergie Physik, Zurich. Movable Targets Stand. The stand consists of the flat frame equipped with the toothed bar in its lower part and the guiding unit which enables the frame movement relatively to the beam axis. Replaceable targets are fixed to the frame and can move together with it. The distance between the target centers is 1200 mm. The frame is driven by using DC flywheel motor and the transmission mechanism including the gear box, the transmission shaft and the secondary gear box which is meshed with the toothed bar of the target frame. The movement of the frame is controlled by the computer control system which ensures the target positioning accuracy of 0.1 mm. The target frame moves periodically, every 0.5 s. While the first target crosses the beam, the other one is inside the read-out part of the detector. Then the targets exchange their positions. Magnetic Field Correction Coils. The coil set consists of six self-supporting coils which form regular cube - 1000 mm x 1000 mm x 1000 mm. The coils are supported on the base-frame and their vertical position can be adjusted by using adjusting screws. Each of the coils can be operated independently what enables to achieve the required direction of the magnetic field. The coil set is used to correct the magnetic field on the movable targets stand. The detector for Joint Institute of Nuclear Research, Dubna. The detector is a kind of geometrical connection of two detecting systems: FOBOS - the system of gaseous detectors arranged in spherical geometry already existing and installed at U400M accelerator and new detector -ARGUS including scintillating detectors also spaced in 4TT geometry. Our part of detector plays a role of an intermidiate part connecting these two detecting systems and simultaneously a support structure for the central part of ARGUS detector. The detector (Fig. 2) has been designed and manufactured in close cooperation with Hahn-Meitner Institute in Berlin and Forschungszentrum Rossendorf. ARGUS scintillating detector is equipped with 92 photomultipliers spaced on the supporting rings covering the part of hemisphere of an angle - 50 degrees. The detector is fixed to the flange in the rear part of the FOBOS body. The whole unit of ARGUS is spatially adjustable. The design solution had to fulfil the following requirements: • to ensure the insertion of about 200 cables (HV supply to and signal cables from photomultipliers), • effective cooling system for supporting elements of ARGUS detector, • to find the procedure of assembling and design a device enabling an assembly and fixing ARGUS detector to the existing body of FOBOS detector and their relative alignment. The designed and manufactered detector should fulfil all above mentioned requirements.

300 Shielding

Fig. 2 ARGUS - FOBOS Intermediate Detector.

Apart from the detectors and installations describesd above some other interesting designs have been made in the last year:

• Vacuum tight test chamber for testing the gaseous detectors with radioactive sources manufactered for Institute of Physics of Jagellonian University. • Smelting furnace for monocrystal production and grinding machine for monocrystals machining - both made for Laboratory of the Structure of Nucleus of our Insitute. • Design and construction works for the isochronic cyclotron AIC 144 S and for the Van de Graaff accelerator.

Engineers and technicians of our department participated in research works for ATLAS experiment at future accelerator LHC at CERN, PHOBOS experiment on RHIC accelerator at Brookhaven National Laboratory and also in assembly and maintanance for ZEUS and HI experiments at HERA accelerator at DESY in Hamburg, in the frame of the activity of the Department of High Energy Physics.

301 ENERGY EFFICIENCY CENTER

Head of Center: Assoc.Prof. Edward Obryk Secretary: Anna Śpiewak telephone: (48) (12) 37-02-22 ext.: 280 e-mail: [email protected]

OVERVIEW: The Agreement on Cooperation between the Institute of Nuclear Physics and the Institutt for Energiteknikk, Kjeller (Norway) has initiated in the Institute new activities in the field of energy efficiency at Institute. In accordance with this Agreement the Energy Efficiency Center (EEC) has been established at the Institute of Nuclear Physics. The Center scope covers a wide range of activities related to all aspects of energy efficiency. Special emphasis is paid to the improvement of efficiency in the utilization of the final energy carriers. The main activities have been carried on within the framework of the Programme Proposal for Energy Efficiency Scheme, sponsored by the Government of Norway. This Programme includes the following activities: • Show-room, • Courses, Training of Staff, • Housing Projects, • Energy Efficiency Studies. The Center has also assisted the Institutt of Energiteknikk in carrying out the Industrial Efficiency Programme in Poland.

GENERAL ACTIVITIES: The EEC has established relations with the local and central authorities in the field of energy efficiency. Also roTnTnnnir.ftt.ioTi with producers and dealers of equipment and systems for improvement of of energy consumption has been established. Staff members of the EEC took part in many meetings, seminars, exhibitions etc. The EEC organized the Polish-Norwegian Seminar on Energy Efficiency as an Essential Factor in Solutions of Energy and Environmental Problems.

SHOW-ROOM: It was an ambitious and difficult task to establish, in a relatively short time, a modern Show-room appropriate for Polish conditions and needs. Due to the coherent efforts of the Norwegian specialists and the EEC staff the Show-room has been successfully organized, arranged and equipped. It was formally opened on June 8, 1993 with participation of officials from both, Norwegian and Polish side. The Show-room serves as a place for meetings of professionals in the field of energy efficiency, for courses and conferences and also lectures about energy and energy efficiency in everyday life for high school students. In the 1994 several courses related to energy efficiency in industry, public and apartment buildings and also lectures about energy efficiency in everyday life for students and general public in our Show-room are planned.

302 The Show-room will be equipped with more software and hardware, including an upgrading of the EDAS (Energy Data Acquisition System) installed at the Show-room. COURSES AND STAFF TRAINING: Three courses for the staff of the EEC have been organized and carried out: • Basic Energy Efficiency, • Measurements and Control, • Boilers, Steam and Condensate. The courses were very well prepared, lecturers were carefully selected and lectures very well presented. These courses gave a sound background for the staff for their activities in the field of energy efficiency, especially energy studies. The courses should be considerd very successful ones. On the basis of the above, materials for several future courses heve been prepared. During the 1994 about 3-5 such courses are planned.

HOUSING PROJECT: Monitoring of the parameters related to the heat supply of three centrally heated apartment buildings, with about 160 flats, will be done during the 1993/1994 heating season. Monitoring is carried out on a daily basis. The obtained informations will be important not only for the monitored but for other buildings as well. The operation of these new control units are satisfactory. It should improve comfort and at the same time save about 10 % of energy and cut substantially energy bills. This project shall be considered highly successful and its continuation should demonstrate the proper way for improvement of energy efficiency in apartment buildings in Poland.

ENERGY EFFICIENCY STUDIES: Energy efficiency studies for two dairy plants and one hospital are carried on under the guidance of Norwegian consultants. These studies will be completed at the beginning of 1994. It seems that the staff of the EEC has sufficient knowledge and experience to carry out such activities on their own. One obvious disadvantage of the EEC in these activities is its lack of portable measuring equipment and data logger for energy breakdown (plants in Poland are very poorly equipped with measuring equipment). The most welcomed assistance from the Norwegian side will be the supply of these necessary measuring equipment. In 1994 energy efficiency studies will be in 50 % supported by the Norwegian side and in 50 % of the cost will be covered by the companies involved. This should provide a smooth entrance for the EEC on the auditing market in Poland.

INDUSTRIAL PROJECT: General Remarks: In 8 plants in the Katowice and Kraków regions, data monitoring of energy and water consumption has been carried out. The quality of data were generally good. All data were processed using the 3-R Program (Norwegian software). This processing gives a clear picture of the energy situation. In many plants there is no sufficient measuring equipment to identify the full picture of energy flow in a plant. The installation of several water meters for condensate return will allow not only the establishment of heat distribution between processes, space heating and warm water but will also help to find the incorrect switching on the valves causing of high power peak on steam supply. There has been a lot of advises to the plants management relating to energy efficiency measures. A reasonable fraction of which has been considered and followed. In each of

303 plant participating in this project there has been made some improvement in energy and water management. In several cases it has led to significant savings. Probably far more important is fact that management has become aware of the problem and the opportunity for energy efficiency. This will produce a lasting influence on energy management and energy efficiency. The plants involved, as most of the plants in Poland, are in a difficult financial situation, having no clear perspective. Due to this fact managements are afraid to take credit for investment even if the payback period is reasonably short. On top of that it is clear that energy efficiency related investment has no high priority. One rather sad fact is, that in Poland there is no institution supporting activities related to energy efficiency in industry (it is assumed that the free market will solve everything).

Assoc.Prof. E. Obry

SHORT TERM VISITORS TO THE CENTER FROM NORWAY: William Christensen, Arne Palm, Per Finden, Tore Pettersen, Ola Fladmark, Einar Rensaa, Thor Gulbrandsen, Harald Rikheim, Harald Gundersen, Ingar Skallerud, Kjell Moe, Ole Veiby

304 INP AUTHOR INDEX:

Adamczak A., 13 Figiel J., 176 Adamski A., 142 Florek A., 142, 150, 198 Andiuszków J., 170 Fłorek B., 142, 150, 198 Bajorek A., 104 Florkowski W., 116, 117 Balmas A., 284 Fornal B., 36, 40, 42, 43 Bałanda M., 104 Freindl L., 14, 20, 22 Bartke J 180 Gabańska B., 217 Bednarczyk P., 38, 40, 42 Gadomski S., 161, 162, 163 Białas A., 189 Gałuszka K., 142, 198 Bilski P., 271, 272 Gdański T., 142, 146 Biiczyński A., 241 Glebowa L., 76 Blocki J., 142, 146, 161, 163, 198 Gładysz-Dziaduś E., 180 Bochnacki P., 118 Godlewski J., 142, 146, 161, 163, 189, 198 Bogacz J., 217 Godunowa H., 284 Borzemski P., 170, 171 Golec-Biernat K., 117, 118 Bożek A., 159 Górnicki E., 295 Bożek P., 113 Grębosz J., 36, 63 Broda R., 36, 38, 40, 42, 43, 258 Gruszecki M., 18, 19 Broniowski W 115 Gruszecki P., 142 Brückman P., 142, 146 Hajduk Z., 142, 148, 159, 161, 166, 168 Budzanowski A., ...7, 13, 14, 20, 21, 22, 23, 189 Hennel F., 240 Budzanowski M., 270, 271 Hołyński R., 185, 186, 189, 193 Budziak A., 142, 150 Horzela A., 118, 119 Cebulska-Wasilewska A., 228, 229, 231 Hrynkiewicz A., 56, 57, 69 Cerkaski M., 115 Huczkowski J., 233 Cetnar K., 166 Idzik M., 165 Chwastowski J., 161, 170, 171 Igielski A., 217 Coghen T., 189 IwańskiW., 63, 161, 168, 293 Cywicka-Jakiel T., 216, 217 Jagielski S., 166, 295 Cyz A., 295 Jakubowski Z., 171 Czerski P., 116 Jałocha P., 142, 146 Czermak A., 161, 165, 292 Janik J.A., 103 Czubek J.A., 216 Janiszewska B., 233 Czyż W., 117, 189 Janiszewski T., 233 Daniluk W., 170 Jasiński A., 240 Dąbrowska A., 185, 186 Jasińska M., 258, 262 Dąbrowski B., 170 Jurak A., 185, 186 Dąbrowski W., 165 Jurkiewicz P., 166, 170 Despet M., 142, 198 Kajetanowicz M., 63, 161, 165, 290 Drozdowicz K., 217 Kamiński P., 8, 114 Drożdż S., 2, 5, 7, 114 Kamiński R., 119 Drwifga M., 83, 86 Kantor W., 23 Dryzek E., 66 Kapłon J., 161, 165, 290, 292 Dryzek J., 66 Kapuścik E., 118, 119 Dutkiewicz E.M 76, 252 Karcz W., 14, 16 Dworak D., 217 Kasper E., 228 Dwuraźny A., 171 Kempczyński J., 118 Eskreys A., 170, 171, 176 Kisielewski B., 166

305 Kliczewski S., 14, 18, 19, 20, 22 Okzowska J 161, 166 Kmieć R., 67 Ostrowicz W., 161, 166 Kopeć M., 273 Pacyna A. W 103 Korcyl K., 63, 142, 161, 168 Pakoński K., 189, 198 Kotarba A., 166, 170, 295 Palarczyk H., 189 Kotuła J., 189, 198 Pałka B., 229 Kowalski M., 180, 182 Pałka H., 142, 146, 159 Kozak K., 258, 262 Parliński K., 242 Kozik E., 13 Pawłat T., 36, 40, 42 Kraczka J., 69, 70 Pawłyk I., 231 Krasnowolski S., 233 Pawlik B., 176 Krasny W., 118 Piotrzkowski K. 170, 171 Królas W., 36, 40, 42, 48, 51 Płoszajczak M., 8, 113, 114 Krupiński W., 142, 295 Polok G., 142, 150 Krynicka E., 217, 218 Potempa M., 284 Krzykwa B., 228 Przybycień M., 170 Kubka B., 253, 255 Rajchel B., 83, 86 Kucewicz W., 142, 146 Różańska M 158 Kulczykowska K., 233 Rybicki K., 142, 159 160 Kutschera M., 120 Ryłko R., 160 Kwiatkowska J., 78 Schwabe J., 284 Kwiatek W.M. 72, 73, 76, 258 Sellmann A., 86 Kwieciński J., 118, 120, 121, 122 Siwek A., 23 Lach M., 38, 46 Siudak R., 21 Lalowicz Z.T., 241 Skwirczyńska I., 14 Lekki J., 73, 80, 82 Sóbala A., 161, 295 Lemler M., 189, 198 Sosnowski W., 142 Lesiak T., 142, 143 Sowa M., 76 Leśniak L., 119, 122 Srokowski T., 7 Lipińska E., 83, 86 Stachuia Z., 80, 82 Litwiniszyn M., 229 Stefański P., 180 Łachut J., 86 Sternik M., 242 Łazarska B., 233 Stodulski M., 142, 189. 198 Łoskiewicz J., 216, 217 Stopa P., 176 Macharski P., 258, 262 Stopa Z., 142, 198 Madeja M., 14, 18, 19 Strączek A., 142, 198 Madeyski B., 295 Strçk M., 142, 198 Maj A 48, 50, 51, 52, 53, 54 Styczeń J., 38, 45, 46, 48 Makowska-Rzeszutko M., 21 Sułek Z., 240, 241 Malecki P., 161, 166, 176, 189, 295 Swakoń J., 217 Maniawski F., 78 Szarska M., 185, 186 Marczewska E., 72, 76 Szczurek A., 10, 11 Marszałek M., 57, 62 Szeglowski Z., 253, 254, 255, 257 Mazur J., 217 Szmider J., 14, 18, 19 Męczyński W., 38, 46, 63 Tracz G 216, 217 Michałowski J., 142, 146, 150, 198 Trzupek A. 186, 189 Mietelski J.W 258, 261, 262 Turała M., 142, 161, 163, 165 Moszczyński A.S., 161, 165 Wajda W., 295 Muryn B., 142, 145, 146 Waligóiski M. 272, 274 Natkaniec Z., 161, 166 Was B., 261 Niewiadomski T., 270, 273, 274 Wierba M., 83, 86 Nizioł B., 171 Wierba W., 170 Okołowicz J., 7 Wierzewska A., 228 Oliwa K., 170, 295 Wilczyńska B., 186, 189, 193, 233 Ołkiewicz K., 176 Wilczyński H., 186, 193 Olko P., 270, 271, 272, 273 Witek M., 142, 148, 159 Olszewski A., 186, 189 Witek W., 103

306 Wodniecka B 56, 57 Wodniecki P., 56, 57, 59, 60 Wolak A., 161, 163 Wolski R., 14 Wolter W., 186, 193 Wosiek B. 180, 185, 186, 189 Woźnicka U., 217 Woźniak K., 185, 186, 189 Wrzesiński J., 65 Zachara M., 170, 171 Zagrodzki P., 252 Zalewska A., 142, 146 Zalewski K., 189 Zawiejski L., 170, 171 Zazula J.M 217 Ziębliński M., 63 Zuber K 45 Żenczykowski P., 123

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