LXII MEETING ON NUCLEAR SPECTROSCOPY AND NUCLEAR STRUCTURE
LXII INTERNATIONAL CONFERENCE NUCLEUS 2012
FUNDAMENTAL PROBLEMS OF NUCLEAR PHYSICS, ATOMIC POWER ENGINEERING AND NUCLEAR TECHNOLOGIES
DEDICATED TO THE MEMORY OF D.V. SKOBELTSYN
BOOK OF ABSTRACTS
June 25-30, 2012 Voronezh Russia
SAINT-PETERSBURG 2012 RUSSIAN ACADEMY OF SCIENCES JOINT INSTITUTE FOR NUCLEAR RESEARCH VORONEZH STATE UNIVERSITY SAINT-PETERSBURG STATE UNIVERSITY
LXII INTERNATIONAL CONFERENCE «NUCLEUS 2012»
FUNDAMENTAL PROBLEMS OF NUCLEAR PHYSICS, ATOMIC POWER ENGINEERING AND NUCLEAR TECHNOLOGIES
DEDICATED TO THE MEMORY OF D.V. SKOBELTSYN
BOOK OF ABSTRACTS June 25 – 30, 2012 Voronezh Russia
Saint-Petersburg 2012
LXII INTERNATIONAL CONFERENCE «NUCLEUS 2012». FUNDAMENTAL PROBLEMS OF NUCLEAR PHYSICS, ATOMIC POWER AND NUCLEAR TECHNOLOGIES (LXII MEETING ON NUCLEAR SPECTROSCOPY AND NUCLEAR STRUCTURE). BOOK OF ABSTRACS. Editor A.K. Vlasnikov.
The scientific program of the conference covers almost all problems in nuclear physics and its applications such as: neutron-rich nuclei, nuclei far from stability valley, giant resonances, many-phonon and many-quasiparticle states in nuclei, high-spin and super-deformed states in nuclei, synthesis of super-heavy elements, reactions with radioactive nuclear beams, heavy ions, nucleons and elementary particles, fusion and fission of nuclei, many-body problem in nuclear physics, microscopic description of collective and single-particle states in nuclei, theory of few-particles systems, non-linear nuclear dynamics, meson and quark degrees of freedom in nuclei, mesoatoms, hypernuclei and other nuclear exotic systems, double beta-decay and neutrino mass problem, interaction of nucleus with electrons of atomic shell, verification of theories of elementary particles interaction and conservation laws, physics of nucleus and particles in application to astrophysical objects, theory of direct and statistical nuclear reactions, theory of multiple scattering, theory of reactions with clusters and heavy ions, theory of relativistic nuclear collisions, theory of polarization phenomenon in nuclear reactions, theories of proton, two-protons and cluster radioactivity and fission of nuclei, instruments and methods of nuclear-physical experiment, analysis of measurements, accelerators, radio-ecology, application of nuclear-physical experimental methods to astrophysics, medicine and other fields of research, fundamental problems of nuclear power and nuclear technologies, experience and problems of qualitative training of Russian and foreign specialists in field of nuclear physics, atomic power engineering and nuclear technologies.
IBSN 978-5-98340-283-6
ORGANIZING COMMITTEE
S. Kadmensky chairman Voronezh State University K. Gridnev co-chairman St.Petersburg State University N. Zelenskaya co-chairman Moscow State University V. Popov co-chairman Voronezh State University A. Vlasnikov co-chairman St.Petersburg State University V. Vakhtel vice-chairman Voronezh State University L. Titova scientific secretary Voronezh State University
CONTENTS
N.S. Zelenskaya. Dmitry Vladimirovich Skobeltsyn (on the 120-th anniversary of his birth). 5
Conference Program 6
Plenary and Semiplenary Sessions 28
Section 1. Experimental Investigations of Atomic Nucleus Properties 66
Section 2. Experimental Investigations of Nuclear Reactions Mechanisms 86
Section 3. Theory of Atomic Nucleus and Fundamental Interactions 137
Section 4. Nuclear Reactions Theory 179
Section 5. Technique and Methods of Experiment and Applications of Nuclear-Physical Methods 213
Section 6. Fundamental Problems of Nuclear Power and Nuclear Technologies 258
Section 7. Experience and Problems of Qualitative Training of Russian and Foreign Specialists in Field of Nuclear Physics, Atomic Power Engineering and Nuclear Technologies 258
Author Index 270
DMITRY VLADIMIROVICH SKOBELTSYN (on the 120-th anniversary of his birth) N.S. Zelenskaya Academician Dmitry Vladimirovich Skobeltsyn is an outstanding physicist of the twentieth century, the patriarch of Russian nuclear physics, the creator of a large school on nuclear physics, elementary particles, cosmic rays and the largest organizer of science.
D.V. Skobeltsyn name is associated with many important milestones in the history of physics. D.V. Skobeltsyn developed a new method for studying the interaction of gamma rays with matter, which is based on the use of Wilson chamber. He carried out the first reliable test for the existence of the momentum of photon. He obtained the first rigorous result in the quantum electrody-namics, namely confirmation of the theory of the Klein– Nishina–Tamm. Investigating Compton effect with Wilson chamber in a magnetic field, D.V Skobeltsyn discovered particles with energies much higher than the energy of the gamma-ray from the radiation source. He interpreted these particles as a cosmic radiation. D.V. Skobeltsyn elucidated the nature of cosmic rays, by showing that cosmic rays consist mainly of high energy charged particles. In addition he found that the cosmic-ray particles with high energies appear as genetically jointed groups. In fact, it was the first observation of multiple avalanche processes. In the present the scientific works of D.V. Skobeltsyn are considered as fundamental in modern high energy physics and the make up of its gold fund. In 1952, D.V. Skobeltsyn organized the first All-Union Conference on Nuclear Spectroscopy, held in the conference hall of the Presidium of the USSR Academy of Sciences. On the third meeting it was established a permanent organizing committee (the first Chairman – B.S. Dzhelepov). These meetings have the status of International conferences and held annually till now. In the 1946–1960 years D.V. Skobeltsyn became a director of the Institute of Nuclear Physics Moscow State University created by him. Since 1993 the Institute bears his name. In the 1951–1973 years D.V. Skobeltsyn was the director of the Lebedev Institute (FIAN). He was one of the organizers and active members of the Pugwash movement of scientists for peace. D.V. Skobeltsyn was awarded the title Hero of Socialist Labor, Laureate of Lenin and State prizes, and awarded many orders and medals, including Gold Medal of the S.I. Vavilov, the medal of the World Peace Council, the D.I. Mendeleev premium of Academy of Sciences of USSR, etc.
5 CONFERENCE PROGRAM June 25, Monday, 10:00 Plenary session I
Page N.S. Zelenskaya. Dmitry Vladimirovich Skobeltsyn (on the 120-th anniversary of his birth). - 30 min. 5
Yu.Ts. Oganessian. Synthesis of new elements – present and future. - 30 min. —
Yu.E. Penionzhkevich. Super-neutron-rich nuclei of light elements. Results and perspectives. - 30 min. 28
G.M. Gurevich. Measurement of spin polarisabilities of the nucleon. - 30 min. 29
V.A. Karnaukhov. Properties of hot nuclei produced in collisions of light relativistic ions with heavy target. – 30 min. 30
V.I. Kukulin. Short-range components of nuclear forces: experiment vs. mythology. - 30 min. 31
A.I. Vdovin. Inelastic neutrino-nucleus scattering in hot and dense stellar environment. - 30 min. 32
June 25, Monday, 15:30 Section II Experimental Investigations of Nuclear Reactions Mechanisms
N.I. Vogel. Laser-induced nuclear reactions and target radioactivity with modest laser pulse energy of ~ 200 mJ. – 15 min. 86 Page V.V. Varlamov. Partial photoneutron reaction cross sections on 115In and neutron multiplicity sorting. – 15 min. 87
6 Joint talk: The cross-sections of (γ, n) reactions for 120Te and 122Te isotopes in the E1-giant resonance energy region. 88 Investigation of isomeric yields ratios in (γ, n) reactions on 127Te nucleus for the 10-20 MeV energies. 89 Reporter D.M. Symochko – 15 min.
Joint talk: Threshold dependence of the nucleon–emission yields in reactions induced by photons. 90 Peculiar behavior of the yields for different reactions induced by photons. 91 Reactions with isomers as a probe of the level density at intermediate spins and energies. 92 Reporter S.A. Karamian – 15 min.
D.A. Gorelov. Experimental study of fission products yield distributions with JYFLTRAP. – 15 min. 93
V.А. Zheltonozhsky. Isomeric ratios in 233U and 241Am photofission fragments. – 15 min. 94
A.A. Kuznetsov. Mass distribution of 238U photofission products. – 15 min. 95
Yu.N. Koblik. Energy characteristics of fissionable nucleus in scission point for different fission modes. – 15 min. 96
G.V. Sinev. Correlation femtoscopy of kaons in the SELEX experiment. – 15 min. 97
A.V. Voinov. Level density problem in nuclear reaction codes. Calculations versus experiment. – 15 min. 98
June 25, Monday, 15:30 Section III Theory of Atomic Nucleus and Fundamental Interactions
V.A. Kulikov. Light nuclei with JISP-type NN interaction and with other modern strong interaction models. – 15 min. 137
7 O.A. Rubtsova. New treatment of the few-body breakup. – 15 min. 138 Page N.N. Arsenyev. Description of properties of quadrupole states in 94Mo with Skyrme interaction. – 15 min. 139
Joint talk: Investigation of super deformation manifestations in nuclei with extreme neutron excess. 140 The peninsula of neutron stability of nuclei in the neighborhood of neutron magic number N = 126. 141 Reporter K.A. Gridnev – 15 min.
Y. Martinez Palenzuela. Calculation of nuclear ground states properties within the statistical learning framework. – 15 min. 142
A.P. Severyukhin. Effects of tensor interaction on Gamow-Teller states in 118,120Sn. – 15 min. 143
Iu.A. Skorodumina. Spin and orbital nuclear currents’ interference in the electroexcitation of 1f2p-shell nuclei. – 15 min. 144
A.I. Chugunov. Simple analytic model for astrophysical S-factors. – 15 min. 145
Joint talk: Boson mapping of the Fermion Dynamical Model of nuclei. 146 Fermion microscopic basis of the Interacting Boson Model. 147 Reporter K. Baktybayev – 15 min.
June 25, Monday, 15:30 Section IV Nuclear Reactions Theory
M.N. Platonova. Manifestation of quark degrees of freedom in backward pd scattering. - 15 min. 179 Page T.L. Belyaeva. (d, p) Reactions as a probe for neutron halo in excited states of nuclei. - 15 min. 180
8 L.I. Galanina. The analysis of (t, p) reactions on 7,9Li isotopes. – 15 min. 181
Yu.L. Ratis. Nuclear reactions at the Δ-isobar excitation region. – 15 min. 182
E.T. Ibraeva. Rescattering effects in proton elastic scattering from 15N nucleus. -15 min. 183
G.K. Nie. Ratio of the neutron asymptotical normalization coefficient to the proton’s one for mirror nuclei 11B and 11C from analysis of direct reactions. -15 min. 184
A.E. Ivanov. Hadron production in hadron-nucleus interactions at high energies. -15 min. 185
June 26, Tuesday, 9:00 Plenary session II
А.А. Ogloblin. “Ghost” of alpha-particle condensate in nuclei. – 30 min. 33 Page A.A. Pasternak. New experimental results of atomic nuclei chirality studies. Nuclei of А ≈ 120 and А ≈ 190. – 30 min. 34
W. Furman. New ADS scheme with deep subcritical multiplying core for energy production and transmutation of radioactive wastes. First experimental results and perspectives. – 30 min. 35
S.G. Kadmensky. Mechanisms of the formation of the P-odd, P-even and T-odd asymmetries in the angular distributions of products of binary and ternary nuclear fission by cold polarized neutrons. – 30 min. 36
V.Z. Goldberg. Unusual states in light nuclei. – 30 min. 37
A.M. Shirokov. No-core full configuration approach: ab initio theory of light nuclei. - 30 min. 38
9 M.H. Urin. Problems of experimental and theoretical studies of the Gamow-Teller resonance in antimony isotopes. – 30 min. 39
V.B. Brudanin. GEMMA and DANSS – experiments with the reactor antineutrino. - 30 min. 40
June 26, Tuesday, 15:30 Section I Experimental Investigations of Atomic Nucleus Properties
B.G. Novatsky. Search for nuclear stable multineutrons and their identification in the channels of the multiple neutrons capture. – 15 min. 66 Page L.Yu. Korotkova. Study of highly excited states of the 8Li isotope. – 15 min. 67
S.I. Sidorchuk. Correlation studies of 10He low-energy spectrum. – 15 min. 68
K.P. Marinova. N and Z dependence of nuclear charge radii and correlation with other spectroscopic observables. – 15 min. 69
Yu.A. Baurov. The results of permanent experimental investigations of 60Co -decay rate change during 2010–2011. – 15 min. 70
Joint talk: Study of the decay 157Er → 157Ho. 71 Study of the decay 156Ho → 156Dy. 72 Experimental and theoretical studies of the structure of the nonrotational states in nuclei 155,157,159,161,163,165Но. 73 Reporter V.I. Stegailov – 15 min.
V.А. Zheltonozhsky. Penetration effects in the E1 and E2 hindered transitions in the Sn nuclei. - 15 min. 74
E.A. Bychkova. Competition of decay channels of 90Zr GDR and its isospin splitting. - 15 min. 75
10 Joint talk: Alpha-stability of superheavy nuclei. 76 Beta-stability of superheavy nuclei. 77 Nuclear shells and the structure of the energy surface of heavy elements. 78 Reporter N.N. Kolesnikov – 15 min.
M.V. Shumeiko. Algorithms of search for rare decays in the experiments on the synthesis of superheavy nuclei. – 15 min. 79
June 26, Tuesday, 15:30 Section II Experimental Investigations of Nuclear Reactions Mechanisms
L.Z. Dzhilavyan. The 238U photofission in the giant resonance region. – 15 min. 99 Page А.M. Savrasov. Isomeric cross-sections ratios for 120m,gSb in (p, n)-reaction for nearthreshold region. – 15 min. 100
T.K. Zholdybayev. Double-differential and integral cross-section of (p, xp) reaction on 58Ni nucleus at Ep=29.9 MeV. – 15 min. 101
S.P. Avdeyev. From sequential processes to multifragmentation in proton reactions with gold. – 15 min. 102
V.I. Kryshkin. Production of hadrons at large transverse momentum in 50 GeV p-nucleus collisions. – 15 min. 103
I.P. Bondarenko. Experimental investigation of 19F(n, α)16N reaction excitation function in 4-7.35 MeV energy region. – 15 min. 104
T.A. Ivanova. New experimental data for 10B(n, αt)4He reaction. – 15 min. 105
V.A. Khryachkov. Investigation of fast neutron interaction with chromium nuclei. – 15 min. 106
11 N.S. Zelenskaya. The orientation parameters of 24Mg(2+) from correlation experiments in 24Mg(d, d)24Mg reaction. – 15 min. 107
V.M. Lebedev. 24 Investigation of d-scattering on Mg at Ed = 15.3 MeV. – 15 min. 108
O.O. Beliuskina. Energy and angular distributions of deuterons from the reaction D + D p + n + d. – 15 min. 109
S.B. Sakuta. Coupled channels effects in the d, 3He and α-particles scattering on 6Li nuclei. – 15 min. 110
June 26, Tuesday, 15:30 Section III Theory of Atomic Nucleus and Fundamental Interactions
M.L. Gorelik. On distribution of the isoscalar monopole strength in medium-heavy spherical nuclei. – 15 min. 148 Page G.K. Nie. Radii of last proton position in symmetrical nuclei. – 15 min. 149
A.D. Efimov. Microscopical calculations of E2 effective charges for IBM. – 15 min. 150
Joint talk: The analysis of the mixed transitions in 160Dy. 151 Properties octupole states in 160Dy. 153 Reporter P.N. Usmanov – 15 min.
A.N. Kuzmina. Role of quasiparticle structure in alpha decays of the heaviest nuclei. - 15 min. 154
P.M. Krassovitskiy. Quantum transparency of barriers in resonance tunneling of coupled pair of particles or ions. – 15 min. 155
A.V. Glushkov. Muon--nuclear spectroscopy: discharge of metastable nuclei during – capture. – 15 min. 156
12 F.F. Karpeshin. Resonance excitation of the nuclear isomer via resonance conversion in the ions of Th-229. – 15 min. 157
Yu.I. Sorokin. Heisenberg transformation and Born approximation in problem shaking of atomic electrons under beta decay. – 15 min. 158
A.A. Kurteva. Beta-decay 229U 229Pa. – 15 min. 159
K.N. Gusev. The search for neutrinoless double beta decay with the GERDA experiment. – 15 min. 160
June 27, Wednesday, 9:00 Semiplenary session I
V.G. Nedorezov. Polarization experiments with back scattered gamma beams. – 30 min. 41 Page V.E. Bunakov. On the enhancement of the fundamental symmetry breaking effects. - 30 min. 42
S.G. Kadmensky. Т-odd correlations and Т-invariance in nuclear reactions and fission. - 30 min. 43
V.V. Samarin. Application of two-center states at the description of nucleon transfers processes by a coupled channel method. – 30 min. 44
B.A. Zon. Relative magnitude of cross sections for elastic and inelastic scattering of a fast particle on a many-particle target. – 30 min. 45
V.M. Vakhtel. Analytical capabilities of nuclear-physical techniques. – 30 min. 46
A.S. Kornev. Quasi-classical formula for alpha decay rate in electromagnetic field. - 30 min. 47
13 June 27, Wednesday, 9:00 Semiplenary session II
V. Bystritskii. FRC on the road to controlled thermonuclear fusion. Problems and promise. – 30 min. 48 Page Joint talk: Neutron halo rotation in 11Be and 9Be. 49 Does the Hoyle state in 12С rotate? 50 Measuring the radii of nuclear excited states with radioactive beams. 51 Reporter А.S. Demyanova – 30 min.
V.V. Tokarevsky. Nuclear transmutations: state-of-the-art, challenges and perspectives. - 30 min. 52
S.P. Kamerdzhiev. Self-consistent approaches in microscopic nuclear theory. Static moments of odd-odd nuclei. – 30 min. 53
A.A. Smolnikov. New generation of experiments searching for neutrinoless double beta decay. – 30 min. 54
A.G. Kadmenskii. Problems of forecasting radiating firmness and parametrical reliability of element completing base for space vehicle equipment. – 30 min. 55
M.Yu. Barabanov. Perspectives of the study of charmonium and exotics in experiments using antiproton beam with momentum ranging from 1 to 15 GeV/c. – 30 min. 56
Joint talk: Analysis of the pion-nucleus elastic scattering using the microscopic optical potential. 57 A modeling of the pion-nucleus microscopic optical potential at energies of 33-resonance and in-medium effect on the pion-nucleon amplitude of scattering. 58 Reporter V.K. Lukyanov – 30 min.
14 June 27, Wednesday, 15:30 Section III Theory of Atomic Nucleus and Fundamental Interactions
Joint talk: Page Role of endothermic beta decays in abundance forming processes of 113In and 115Sn nuclei. 161 Thermal beta decay and problem of p-nuclei 113In and 115Sn. 162 Reporter I.A. Hussain – 15 min.
M.Ya. Safin. On P- and T-symmetries violation in polarized neutrino-proton elastic scattering. – 15 min. 163
O.Yu. Khetselius. Weak interaction and parity nonconservation effect in heavy finite Fermi-systems: relativistic nuclear many-body theory. – 15 min. 164
Yu.I. Romanov. The description of the weak leptonic processes on the basis of the currents with the complex coupling constants. – 15 min. 165
A.K. Vlasnikov. Extension of equations-of-motion method to the multilevel systems with pairing. – 15 min. 166
Joint talk: Properties of rotational band states with Kπ≤2+ in 170,172,174Yb isotopes. 167 + 160 Influence of 1 states on the gR-factors of ground-state band in Dy and 170,174Yb isotopes. 168 Reporter A.A. Okhunov – 15 min.
V.M. Kartashov. Non-stationary processes in radioactive oxides with dynamic polarization as possible exhibiting of discrete symmetry violations. – 15 min. 169
June 27, Wednesday, 15:30 Section IV Nuclear Reactions Theory
B.A. Tulupov. On the direct and semidirect radiative capture of neutrons by medium-heavy nuclei. – 15 min. 186
15 R.A. Kuzyakin. Isotopic trends of capture cross section and mean-square angular momentum of captured system. – 15 min. 187
Joint talk: Page Р-odd asymmetries for products of spontaneous fission of oriented nuclei. 188 T-odd asymmetries for the reaction of ternary spontaneous fission of oriented nuclei. 189 Reporter L.V. Titova – 15 min.
L.V. Titova. The P-odd asymmetries for the reactions of binary fission of oriented target-nuclei by cold polarized neutrons. – 15 min. 190
N.E. Aktaev. Influence of the potential barrier height on the rate of the thermal decay of the metastable state. – 15 min. 191
V.A. Rachkov. Effect of neutron transfer in fusion reactions with weakly bound nuclei at sub-burrier energy. – 15 min. 192
June 27, Wednesday, 15:30 Section V Technique and Methods of Experiment and Applications of Nuclear-Physical Methods
Joint talk: Page Enhancement of dose field during radiative exposure of heterogeneous biological substance with nanoparticles. 213 Transformation of hard X-rays irradiation into characteristic irradiation in biological substance with heavy nanoparticles. 214 Reporter M.A. Dolgopolov – 15 min.
Joint talk: Acoustic pressure temperature dependence of heavy charged particle radiation moving in condensed medium. 215 Possible mechanism of absorbed radiation dose adjustment at proton radiation therapy. 216 Reporter P.V. Lukin – 15 min.
A.V. Belousov. Influence of photonuclear reactions products on biological efficiency of photon at the thin layers irradiation. – 15 min. 217
16 G.A. Kulabdullaev. Determination of kerma in biological tissue irradiated by neutron beam of WWR-SM reactor. – 15 min. 218
A.V. Lubashevskiy. Investigations and development of the suppression methods of the background in the LArGe low-background test facility for the GERDA experiment. – 15 min. 219
E.A. Yakushev. Radon in LSM underground laboratory. – 15 min. 220
T.V. Chuvilskaya. Nuclear reactions on Si and Al induced by cosmic protons and -particles. - 15 min. 221
V.R. Gitlin. Radiation-technological processes based on low-energy radiation in production of products with structure “metal-oxide-semiconductor. - 15 min. 222
E.N. Voronina. Mathematical simulation of radiation impact on nanostructures. – 15 min. 223
K.A. Stopani. Simulation of a radiation shielding for the manned Mars mission. – 15 min. 224
Joint talk: Photoactivation influence on catalytic characteristics of ZnO nanoparticles during conversion of methanol. 225 Photonuclear method of Cu-67 manufacture for nuclear medicine. 226 Reporter N.P. Dikiy – 15 min.
June 27, Wednesday, 18:00 Poster Session Section I Experimental Investigations of Atomic Nucleus Properties
O.V. Bespalova. Evaluated occupation probabilities of single-particle orbits in medium range nuclei. 80 Page O.V. Bespalova. Proton shell evolution of nuclei with 20 Z 28 and 20 N 50 and dispersive optical model. 81
17 Yu.L. Khazov. Evaluation of nuclear structure and decay data for A=146 mass chain. 82
A.P. Lashko. The gamma-ray intensities from the 177mLu decay. 83
A.P. Lashko. Precise measurement of the gamma-ray energies from the 175Hf decay. 84
V.A. Morozov. Determination of the precise value of half life of 212Po. 85
Section II Experimental Investigations of Nuclear Reactions Mechanisms
S.M. Taova. Effect of electron screening in the main thermonuclear reactions. 126 Page V.V. Gauzshtein. Measurement of the tensor analysing power components of the negative pion photoproduction on deuterons. 127
E.A. Kuznetsova. Some experimental manifestations of new ternary cluster decay of heavy nuclei. 128
M.V. Mordovskoy. Diffuseness parameter for even-even nuclei with 58≤A≤250 and the coupled channel optical model. 129
S.R. Palvanov. Excitation of isomeric states in reactions (γ, n) and (n, 2n) on 113In and 198Hg nuclei. 130
S.R. Palvanov. Isomeric yield ratios and cross section ratios of the reaction (, 2n) on 89Y, 113In and 197Au nuclei. 131
O.A. Parlag. Mass distribution of the 241Am photofission fragments. 132
18 O.A. Parlag. Mass distribution structure of the 238U photofission. 133
O.A. Parlag. Prompt neutron multiplicity parameterization of actinide nuclei photofission. 134
A.A. Sidorov. Measurement of the differential cross sections of the negative pion photoproduction on deuteron at large proton momenta. 135
N.S. Rumyantseva. Muon capture in 12C. 136
Section III Theory of Atomic Nucleus and Fundamental Interactions
A.V. Glushkov. Resonance states of compound super-heavy nucleus and EPPP in heavy nucleus collisions. 170 Page O.Yu. Khetselius. Relativistic energy approach to cooperative electron--nuclear processes: NEET effect. 171
V.S. Kinchakov. The Brink model with tetrahedral alpha-clusters for the three-body forces. 172
A.M. Nurmukhamedov. About validity of use of Student’s t criterion for experimental proof of restoration of Wigner’s SU(4) spin–isospin symmetry in atomic nuclei. 173
A.M. Nurmukhamedov. Abnormal values of empiric function bA() of the mass formula of Wigner in the field of light nuclei. 174
Yu.V. Orlov. Nuclear vertex constants and asymptotic normalization coefficients for 8Be resonant states from the scattering effective-range function expansion. 175
I.N. Serga. Spectroscopy of the hadronic atoms and superheavy isotopes: energy shifts and widths and strong K-, -N interaction correction. 176
19 I. Tleulessova. The analysis of structure of 6He and 8He nuclei. 177
S.Yu. Torilov. Cluster states in the neutron excess nuclei. 178
Section IV Nuclear Reactions Theory
L.D. Blokhintsev. Effective range expansion and vertex constants for 6Li. 200 Page E.T. Ibraeva. Shell structure effects of nuclei in р15C and р15N scattering in diffraction theory. 201
R.S. Kabatayeva. Dynamic polarization of 6,7Li nuclei in α-particle elastic scattering. 202
R.S. Kabatayeva. Elastic scattering of neutrons on 7Li nucleus at low energies. 203
V.I. Kovalchuk. Calculation of scattering length for nuclear three-body problem using hyperspherical basis expansions. 204
V.I. Kudriashov. Energy dependence of (P–Ay) spin observables in ( p, p) scattering and knock-on exchange treatment. 205
V.I. Kudriashov. Exchange approximations in the calculations of the ( p, p) scattering using the DWBA 91 and LEA programs at energies near 100 MeV. 207
N.A. Maltsev. The influence of the elastic and inelastic cluster transfer on the elastic scattering of 16O+12C and 16O+16O. 208
S.N. Fadeev. Core exchange and 16O+12C elastic scattering. 209
20 V.V. Samarin. Few-nucleon transfers and weakly-dissipative processes in GRAZING-model of low-energy nuclear reactions. 210
K.V. Samarin. Time-dependent quantum description of few nucleons transfers at nuclear reactions 40Са + 96Zr, 40Са + 208Pb, 90Zr + 208Pb. 211
M.V. Fomina. MC estimation of DANSS sensitivity to the neutrino oscillations. 212
Section V Technique and Methods of Experiment and Applications of Nuclear-Physical Methods
M.V. Anokhin. The stand for test VLSI in the field, modelling radiating fields in space vehicles. 244 Page V.A. Andrianov. Self-recombination and 2Δ-phonon exchange in STJ X-ray detectors. 245
S.S. Belyshev. 18F production in the 19F(, n) reaction. 246
A.S. Kurilik. Measurement of the atomic number by means of electron accelerator. 247
N.V. Morozova. Time correlation of the PMT noise impulses. 248
E.P. Prokopev. Possible development of a problem of physics, chemistry and technology of antimatter for projects of spaceships. 249
A.V. Salamatin. TDPAC spectrometer for the study of hyperfine interactions in a condensed matter at low temperatures and high pressures. 250
V.A. Skvortsov. On the theory of nuclear forces, elementary particles and «unlimited» energy cumulation. 251
21 V.M. Vakhtel. Converters for Mössbauer resonance detectors. 252
F.F. Valiev. Collective optical bremsstrahlung generated narrow beam of gamma quanta. 253
S.N. Mustafaeva. X-ray sensitivity of iron-doped CdIn2S4 single crystals. 254
А.S. Tatarintsev. Radiation current transfer in metal-dielecrtic-semiconductor structures. 255
M.N. Levin. Edge effects in MOS-structures under the action of the low-energy radiation exposure. 256
V.A. Sergienko. Radioecological measurements in Leningrad region. 257
Section VI Fundamental Problems of Nuclear Power and Nuclear Technologies
A. Aleinikov. Maximal fuel depletion depth evaluation for PWR. 263 Page O.V. Bespalova. Non-destructive hydrogen analysis by nuclear proton method backscattering spectrometry. 264
E. Rubashkina. About the slow wave burning reactor. 265
S. Sementsov. Cermet fuel reactor core investigation. 266
V.A. Sergienko. Search for Fukushima fallout in Peterhof. 267
V.A. Sergienko. Anticoincidence spectrometer for control of fuel rods in nuclear reactor. 268
N. Skrinnik. The development of PWR reactors containment leaks detecting methods. 269
22 June 28, Thursday, 9:00 Section II Experimental Investigations of Nuclear Reactions Mechanisms
А.N. Danilov. Cluster states of 11В with abnormally large radii. – 15 min. 111 Page Yu.A. Gloukhov. Inelastic scattering with excitation of lower density Hoyle state. – 15 min. 112
B.V. Zhuravlev. Neutron emission mechanisms in 56Fe(, xn) reaction. – 15 min. 113
Joint talk: Cross sections for isotopes 43Sc and 46Sc in the 45Sc+3He reaction. 114 Study of fusion and nucleon transfer channels for the reaction 197Au +6He at 6He energies up to 20 MeV/A. 115 Reporter N.K. Skobelev – 15 min.
T.V. Chuvilskaya. Fusion and transfer nuclear reactions in the interaction of 6He with 197Au. - 15 min. 116
A.P. Krutenkova. Fragmentation of carbon ions at intermediate energies. – 15 min. 117
D.O. Kotov. Electromagnetic and hadronic signatures of quark-gluon plasma in heavy- ion collisions at 62.4 GeV in PHENIX experiment at RHIC. – 15 min. 118
V.A. Rebyakova. J/ψ-meson detection possibility in ultraperipheral Pb-Pb collisions at √S=2.76 TeV. – 15 min. 119
V.G. Riabov. Dielectron measurements in heavy ion collisions at 200 GeV in PHENIX experiment at RHIC. – 15 min. 120
B.A. Chernyshev. A-dependence of the yields of the deuterons emitted in stopped pion absorption. – 15 min. 121
23 V.N. Stibunov. Measurement of the exclusive reaction of the negative pion photoproduction on polarized deuterons in the region of the large values of the final proton momenta. – 15 min. 122
Joint talk: CLAS collaboration data base on photo- and electroproduction of mesons on nucleons and nuclei. 123 Contributions from exclusive meson electroproduction channels to the inclusive structure functions F1 and F2 from the CLAS physics database. Reporter V.V. Chesnokov – 15 min. 124
K.A. Stopani. Photonuclear reactions on palladium isotopes. – 15 min. 125
June 28, Thursday, 9:00 Section IV Nuclear Reactions Theory
V.E. Bunakov. Diffusion coefficients in heavy-ion reactions with deep inelastic nucleon transfer. – 15 min. 193 Page L.V. Titova. Yields and angular and energy distributions of the light particles in true quaternary fission. – 15 min. 194
S.S. Kadmensky. Transition fission states for heated nuclei. – 15 min. 195
A.T. D’yachenko. Calculation scheme of heavy-ion collisions within the framework of a modified hydrodynamic approach. – 15 min. 196
V.P. Zavarzina. The relations between the differential cross sections for diffractive processes of halo-nucleus core stripping and nucleon stripping. – 15 min. 197
Yu.S. Lutostansky. Calculation of transuranium elements yields under conditions of neutron pulse. – 15 min. 198
E.E. Lin. Cluster model of formation of subnuclear and subatomic objects. – 15 min. 199
24 June 28, Thursday, 9:00 Section V Technique and Methods of Experiment and Applications of Nuclear-Physical Methods
A.G. Kadmenskii. Non Bogolubov confusing of swift charged particles in a crystal. Antichanneling. – 15 min. 227
V.I. Grafutin, E.P. Prokopev. Research by method positron annihilation spectroscopy of condensed matter with its own radiation. – 15 min. 228
V.M. Lebedev. Studying of supra-atomic structure of the reactor irradiation aluminium alloys by small-angle neutron scattering technique. – 15 min. 229
A.A. Bezbakh. New OTPC detector at the ACCULINNA separator. – 15 min. 230
Joint talk: Page Detection of low-intensity gamma-neutron fluxes from static and dynamic multiplying systems by polystyrene-based scintillation detectors. 231 A neutrino detector at the BIGR pulsed reactor. 232 Reporter A.A. Sushko – 15 min.
Joint talk: High efficiency HPGe γ-spectrometer for the investigations of ββ decay to excited states. 233 Using of pixel detectors in investigations of EC/EC decay. 234 Reporter N.I. Rukhadze – 15 min.
S.V. Rozov. Development of low energy threshold HPGe detectors in JINR. – 15 min. 235
I.M. Sharapov. The neutron beam spectrometer based on scintillation detector with n-γ pulse shape discrimination. – 15 min. 236
S.V. Zuyev. The setup for studying quasifree nn scattering in energy range of 20-60 MeV. – 15 min. 237
A.V. Rusakov. Neutron detection using double-scattering method. – 15 min. 238
25 R.A. Sadykov. The neutron scattering installations complex for condensed matter research and nano-diagnostics based on the pulsed spallation neutron sources RADEX and IN-06 at INR RAS. – 15 min. 239
Joint talk: About generation of strongly directed coherent neutron radiation. 240 Physics of nuclear activation of metallic targets by laser radiation. 241 Reporter V.A. Skvortsov – 15 min.
V.I. Lyashuk. Powerful antineutrino source on the base of accelerator and lithium converter. – 15 min. 242
D.O. Spirin. The dual-energy method in X-ray CT. – 15 min. 243
June 28, Thursday, 9:00 Section VI Fundamental Problems of Nuclear Power and Nuclear Technologies Section VII Experience and Problems of Qualitative Training of Russian and Foreign Specialists in Field of Nuclear Physics, Atomic Power Engineering and Nuclear Technologies
V.M. Lebedev. Investigation of element composition of the dust on the Globus-M tokamak. – 15 min. 258 Page I.N. Izosimov. Decay schemes completeness and decay heat calculation problems. - 15 min. 259
V.V. Varlamov. Atomic nuclei ground and isomer states parameters database for science research and education. – 15 min. 260
E. Käbin. "Nuclear physics in Internet" - the experience of using Internet technologies in education. – 15 min. 261
V.V. Radchenko. The educational abilities of MSU Nuclear Physics Institute and Nuclear Physics Department of Physics Faculty. – 15 min. 262
26 June 29, Friday, 9:00 Plenary session III
A.P. Chernyaev. Accelerators in the world today. – 30 min. 59 Page P.I. Zarubin. Cluster structure of light radioactive nuclei in processes of relativistic fragmentation. – 30 min. 60
О. Povoroznyk. Study of excitation spectra by particle-decay spectroscopy. – 30 min. 61
Yu.L. Ratis. Neutrino catalysis of nuclear fusion in cold hydrogen. – 30 min. 62
Yu.M. Tchuvil’sky. Alpha-decay in the electronic surrounding. – 30 min. 63
E.S. Konobeevski. nd Breakup reaction as a tool for studying neutron-neutron interaction. - 30 min. 64
V.V. Varlamov. New data on partial photoneutron reactions (, n), (, 2n) and (, 3n). - 30 min. 65
27 PLENARY AND SEMIPLENARY SESSIONS
SUPER-NEUTRON-RICH NUCLEI OF LIGHT ELEMENTS. RESULTS AND PERSPECTIVES
Yu.E. Penionzhkevich Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
The interest in light neutron rich nuclei is connected with the possibility to discover their unusual properties – the nuclear exotics. In the region of the lightest nuclei (the isotopes of hydrogen, helium, lithium, beryllium) it became possible to identify the border between bound (nucleon stable) and unbound (nucleon unstable) nuclei, viz. the neutron dripline. The experiments aimed to study the properties of exotic nuclei with extreme values of N/Z (situated far away from the β-stability line), performed in different laboratories, made it possible to reveal a series of unexpected phenomena – the existence of the neutron and proton halo, new deformation regions, new types of decay, changes in the filling up of nuclear shells, weakening or even disappearing of the “traditional” shells, the appearance of new magic numbers, etc. Until recently the information on nuclear levels in light exotic nuclei was rather scarce. For instance, excited states in the particle stable 8Не, 11Li, 14Be, and particle unstable 10Не, 10Li, 16В nuclei the presence of excited states was revealed during the past few years. Experimental information will be presented on the levels and their quantum characteristics, which makes it possible to determine the filling of orbits and in this way to check the validity of theoretical models, the presence of collective excitations (e.g. the soft dipole mode), the decay mode, etc. Results will also be presented from studies of neutron-rich isotopes of О, F, Ne, Na, Mg. The properties of these nuclei (binding energy, deformation) strongly change further from the stability line and new effects manifest themselves, which lead to changing (lowering or increasing) the stability of nuclei close to the limit of stability. In these nuclei, close to the shells N=20 and N=28, two shapes were found to co-exist in the ground state – a spherical and a deformed one. This brings forth the necessity to re-consider the existing shell models when predictions are to be made for the limits of stability for light nuclei and the appearance of new magic numbers N=16, 26. Of great importance for these investigations is the possibility to use beams of radioactive nuclei. This will allow determination of the isospin dependence of the structure of many light exotic nuclei. The latest results of such studies are also presented in this talk.
28 MEASUREMENT OF SPIN POLARISABILITIES OF THE NUCLEON
G.M. Gurevich (for A2 collaboration) Institute for Nuclear Research RAS, Moscow, Russia E-mail: [email protected]
Although static electric and magnetic polarisabilities of the nucleon has been measured in different laboratories using unpolarised Compton scattering experiments, there exist no experimental data about vector (spin) polarisabilities which describe the response of the nucleon spin to the photon multipolarity. There are four unique spin polarisabilities for the nucleon, one for each initial and final state multipole combination of photons. The most model-independent way to measure the spin polarisabilities is in the double-polarised Compton scattering at photon energies near the π meson threshold using polarized photon beam and polarized target. Measurements of this type has never been performed earlier. To perform double polarization experiments A2 collaboration in Mainz Institute of Nuclear Physics uses circularly or linearly polarized beam of energy marked photons from MAMI C accelerator and the longitudinally/transversely polarized proton or deuteron target. The Crystal Ball/TAPS 4π detecting system surrounding the polarized target detects reaction products. Typically, butanol is used as a target material which contains carbon nuclei besides protons. Unfortunately, the coherent Compton scattering from 12C in the target is approximately 20 times larger than the cross section of interest. To eliminate this background we are going to detect recoil protons using an “active” (scintillating) polarized target. We have selected polystyrene film with a scintillator dopant as a material for “active” target. In the preliminary study a proton polarization about 70% and polarization relaxation time ~150 hours were reached at the target temperature ~30 mK in the magnetic field 0.4 T. To extract information on the proton spin polarisabilities, double-spin asymmetries Σ2x (circularly polarized photons, transversely polarized target) and Σ2z (circularly polarized photons, longitudinally polarized target) will be measured, as well as the single-spin asymmetry Σ3 (linearly polarized photons, unpolarised target).
29 PROPERTIES OF HOT NUCLEI PRODUCED IN COLLISIONS OF LIGHT RELATIVISTIC IONS WITH HEAVY TARGET
V.A. Karnaukhov and FASA collaboration* Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
The nuclear multifragmentation is the main decay mode of hot nuclei at the excitation energies higher than 3.5 MeV/nucleon. This is a multibody decay with emission of the intermediate mass fragments. The latter are heavier than alpha-particles, but lighter than fission fragments. The process takes place after expansion of hot nucleus (driven by the thermal pressure) into the “spinodal” region. The nuclear multifragmentation is considered as a liquid-fog phase with characteristic temperature (5-6) MeV. Here we report on the present status of the experimental determination of the critical temperature Tc for the nuclear liquid-gas phase transition. This parameter is very important for the nuclear equation of the state. It is found that Tc=(17±2) MeV. Temporal characteristics of the process are measured by the analysis of the correlation functions with respect to the relative angle or the relative velocity for pairs of fragments. It is revealed that the expansion of hot nucleus takes ~ 4·10-22 s which is followed by the fast disintegration. All the data are obtained by FASA collaboration using the relativistic deuteron beams of Dubna Nuclotron and gold target.
*) S.P. Avdeyev, A.S. Botvina, W. Karcz, V.V. Kirakosyan, P.A. Rukoyatkin, H. Oeschler, E. Norbeck, O.V. Strekalovski
30 SHORT-RANGE COMPONENTS OF NUCLEAR FORCES: EXPERIMENT vs. MYTHOLOGY
V.I. Kukulin, M.N. Platonova Skobel’tsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected]
The talk is dedicated to a critical analysis of a number of statements, which have been commonly accepted in the scientific and academic literature on the theory of nuclear forces but contradicted or put in doubt by the modern experiments and/or new theoretical approaches. It is actually about the basic paradigm of nuclear forces, which was first formulated by Yukawa in the mid 30ies of the last century and since then has remained essentially unchanged, despite the great progress made in recent times to clarify the different parts of the meson exchange. Unfortunately, the modern development of this important field of nuclear physics in the form of the effective field theory (EFT) has even worsened the situation, because, instead of clarifying all the details of the mechanism of short- range nuclear forces, it is postulated in the EFT approach that the short-range interaction can be parametrized by a set of relevant constants, whereas the peripheral part of the nuclear interaction is treated in the framework of the perturbation theory in the multiplicity of meson exchanges. Such an approach necessarily focuses on the description of low-energy processes with relatively small momentum transfers only, and does not allow in principle to understand the mechanics of short-range interactions. In the present talk, in contrast, the main attention is paid to the description of the mechanisms of short-range nuclear forces within the concept of dressed dibaryons, and to verification of this concept in numerous experiments at intermediate and high energies. In particular, we analyze the following processes, where the short-range components of the nuclear forces are dominant: (i) electro- and photodisintegration of the deuteron at energies Eγ ~ 450-800 MeV; (ii) p-d backward scattering at energies Ep ~ 1 GeV; (iii) the so-called ABC-puzzle, i.e. the production of the two-pion resonance in the reactions p + n → d + (π0π0), 3 0 0 p + d → He + (π π ) and others at energies Ep ≥ 800 MeV; (iv) the fragmentation of high-energy deuterons (Ed ~ 3-5 GeV) on hydrogen target; (v) "old" dibaryon resonances with large widths and large inelasticities, studied in detail in the p-p scattering at energies Ep ~ 1-2 GeV in the 80ies of the last century, etc. As has been shown by numerous studies, the results obtained in these experiments contradict to the traditional models of nuclear forces based on the Yukawa’s concept of meson exchange. In the present talk, the authors plan to discuss in detail these experiments and their modern interpretations.
31 INELASTIC NEUTRINO-NUCLEUS SCATTERING IN HOT AND DENSE STELLAR ENVIRONMENT
A.A. Dzhioev1,2, A.I. Vdovin1 1 Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Russia; 2 Department of Physics, Université Libre de Bruxelles, Brussels, Belgium E-mail: [email protected]
Neutrinos play a decisive role in core-collapse supernova explosions since they carry out most of the gravitational binding energy released. The transport of neutrinos through the hot and dense stellar environment is believed to ultimately be responsible for a successful explosion, although the details are not fully understood yet. The inelastic neutrino-nucleus scattering (INNS) contributes to the neutron opacities and thermalization during the collapse phase, the revival of the stalled shock wave in the delayed explosion mechanism, and to explosive nucleosynthesis [1]. We study a role of thermal effects in the INNS in the iron core during infall and shortly after bounce. Cross sections of inelastic neutrino-nucleus scattering off 54,56Fe nuclides were calculated at different temperatures of stellar environment. For the reaction part the formalism by Walecka-Donnelly [2] which describes in a unified way electromagnetic and weak semileptonic processes was applied. The nuclear structure input as well as the temperature effects were considered within the thermal quasiparticle random phase approximation in the context of Thermo- Field-Dynamics formalism [3]. For 54Fe the allowed and first-forbidden tran- sitions were considered whereas for 56Fe the excitation of a wide set of states of both natural and unnatural parities was taken into account and analyzed. In contrast to the large-scale shell-model studies [4] we do not assume the Brink hypothesis when treating the down-scattering component of the cross section. Despite these differences between the two approaches, our calculations revealed the same thermal effects as [4]. A temperature increase leads to a considerable enhance of the INNS cross section for neutrino energies lower than the energy of the GT0 resonance. This enhancement is mainly due to neutrino up-scattering at finite temperature. The finite temperature does not affect the asymmetry in the inelastic neutrino scattering: at any temperature neutrinos are scattered backward.
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32 “GHOST” OF ALPHA-PARTICLE CONDENSATE IN NUCLEI
А.А. Ogloblin1, Т.L. Belyaeva2, А.S. Demyanova1 1 NRC Kurchatov Institute, Moscow, Russia; 2 Universidad Autonoma del Estado de Mexico, Mexico E-mail: [email protected]
During last 10 – 15 years new theoretical approaches to studying cluster phenomena in nuclei were developed. They predict the appearance of unusual structures in the vicinity of the thresholds of complete dissociation of nuclei into alpha-particles. The most ambitious of these theories is a model of alpha- particle condensation [1] according to which one might expect the existence of nuclear structures resembling the gas of almost non-interacting alpha-particles. The radii of such states could be more than twice larger than the normal ones. The condensate model initiated a lot of works. The progress in the experimental researches was achieved in large extent due to developing the methods of measuring the radii of the excited states [2] and angular moment distributions of alphas [3]. A review of current situation including very recent investigations some of which are presented at this Conference is given. The existence of nuclear states with radii by 20 – 30% exceeding those of the normal ones is reliably established (e.g., the famous 0+, 7.65 MeV Hoyle state in 12C and its analogs in 11В and 13С). However, these values are in most cases lower than predicted by the condensate model. Such relatively moderate radii enhancement was predicted also by some other cluster theories. The predicted by condensate model “giant” states in 12C and 11B with extremely large sizes comparable with those of Uranium nuclei were not observed. On the other hand, the probability of alpha clusters to have the moment L = 0 in the Hoyle state occurred to be ~ 60% what is close to the theoretical value. Thus, some important features of alpha condensation in nuclei have been observed while some others did not exhibit themselves in full extent. By the analogy with some other phenomena one may speak only about observation of a “ghost” of alpha condensation. The obtained results are the challenge to modern theoretical conceptions about the structure of light nuclei. Critical for solving the problem new experiments are formulated. The possibility of search the condensate effects in heavier nuclei is discussed.
1. A.Tohsaki et al. // Phys. Rev. Lett. 2001. V.87. 192501. 2. A.N.Danilov et al. // Phys.Rev. C. 2009. V.80. 054603. 3. T.L.Belyaeva et al. // Phys. Rev. C. 2010. V.82. 054618.
33 NEW EXPERIMENTAL RESULTS OF ATOMIC NUCLEI CHIRALITY STUDIES. NUCLEI OF А ≈ 120 AND А ≈ 190
A.A. Pasternak1,2,3, D.B. Gin1 1 A.F. Ioffe Physical-Technical Institute, St.Petersburg, Russia; 2 Heavy Ion Laboratory, Warsaw University, Poland; 3 iThemba LABS, Somerset West, South Africa E-mail: [email protected]
Lifetimes (τ) of high spin states in 194Tl have been studied by DSAM in the 181Ta(18O, 5n) reaction using 91 MeV 18O beam at iThemba LABS in the framework of a project devoted to the investigations of chiral bands in the A ≈ 190 region [1]. The 124Cs nucleus was produced in the 114Cd(14N, 4n) reaction using 73 MeV 14N beam at Heavy Ion Laboratory of the University of Warsaw. Fig. 1 illustrates B(M1) and B(E2) spin dependenses in partner bands of 124Cs and 194Tl, which have been extracted from preliminary analyses of lifetimes measured by DSAM. Partner bands in 124Cs belong to configuration and typical fingerprint of chirality – straggling of B(M1) values has been expected. Similar to 126,128Cs [2, 3] B(E2) values are not show explicit straggling. Another unexpected situation was in partner bands of 194Tl belonged to the configuration when even B(M1) straggling is optional. In this case strong B(E2) straggling has been observed.
124Cs 194 Tl
Fig. 1. B(M1) and B(E2) spin dependenses in partner bands of 124Cs and 194Tl.
This work was partly supported by funds “Program for Basic Research RAS Elementary particle physics, fundamental nuclear physics and nuclear technology” and NRF-RFBF grant № 11-02-93963-ЮАР_а.
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34 NEW ADS SCHEME WITH DEEP SUBCRITICAL MULTIPLYING CORE FOR ENERGY PRODUCTION AND TRANSMUTATION OF RADIOACTIVE WASTES. FIRST EXPERIMENTAL RESULTS AND PERSPECTIVES
W. Furman1, J. Adam1, M. Artyushenko2, A. Baldin1, A. Berlev1, V. Chilap3, B. Dubinkin3, A. Chinenov3, B. Fonarev3, M. Galanin3, N. Gundorin1, B. Gus’kov1, M. Kadykov1, A. Khilmanovich4, S. Kislitsin5, V. Kolesnikov3, Yu. Kopatch1, S. Korneev6, E. Kostyuhov1, M. Kucheryavii1, A. Makan’kin1, B. Marcynkevich4, I. Mar’in1, A. Potapenko6, A. Rogov1, A. Safronova6, V. Schegolev1, A. Solnyshkin1, S. Solodchenkova3, V. Sotnikov2, V. Stegailov1, O. Svoboda7, V. Tsupko-Sitnikov1, S. Tyutyunnikov1, A. Vishnevsky1, N. Vladimirova1, V. Voronko2, V. Wagner7, W. Westmeier8, S. Zhdanov5, I. Zhuk6 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 NSC Kharkov Institute of Physics and Technology, Kharkov, Ukraine; 3 CPTP “Atomenergomash”, Moscow, Russia; 4 Stepanov Institute of Physics, Minsk, Belarus; 5 Institute of Nuclear Physics NNC RK, Almaty, Kazakhstan; 6 Joint Institute for Power and Nuclear Research - Sosny near Minsk, Belarus; 7 Nuclear Physics Institute, Rez near Praha, Czech Republic; 8 Gesellschaft for Kernspektrometrie, Ebsdorfergrund-Mölln, Germany E-mail: [email protected]
Recently new ADS scheme was proposed [1] aimed at energy production and transmutation of radioactive wastes. Main physical idea of this approach is to use deep subcritical and quasi infinite (with negligible neutron leakage) multiplying target of natural (depleted) uranium or thorium combined with ~ 10 GeV proton or deuteron incident beam. In accordance with semi- phenomenological estimations such ADS provides large enough beam energy gain and extremely hard neutron spectrum inside of subcritical core that can ensure effective burning of core material as well as spent reactor fuel added to the initial core. To preserve hard neutron spectrum it is necessary to use helium gas cooling of the fist circuit and core material as target for incident beam. During 2009-2012 the experiments with massive (315 kg and 500 kg) natural uranium targets irradiated by deuteron beam from JINR NUCLOTRON with energy from 1 up to 6 GeV have been carried out [2, 3]. Preliminary data on the energy spectra of prompt neutrons within the targets and the time spectra of delayed neutrons after fission of the target nuclei were obtained. Beside that there were measured spatial distributions of fission rates and 239Pu production. Obtained results confirm a validity of basic ideas of proposed ADS scheme and provide solid grounds for planning of future experiments with quasi- infinite (22 tons) target of depleted uranium available for the “Energy and Transmutation RAW” collaboration at JINR.
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35 MECHANISMS OF THE FORMATION OF THE P-ODD, P-EVEN AND T-ODD ASYMMETRIES IN THE ANGULAR DISTRIBUTIONS OF PRODUCTS OF BINARY AND TERNARY NUCLEAR FISSION BY COLD POLARIZED NEUTRONS
S.G. Kadmensky, D.E. Lubashevsky Voronezh State University, Russia E-mail: [email protected]
The basic mechanisms of the asymmetries formation in angular distributions of products of nuclear binary and ternary fission by cold polarized neutrons with polarization vector pn and wave vector kn are realized for the cases of P-odd
()pkn, LF (a) and P-even ()kkn, LF (b) and (pn,,[] kk n LF ) (c) asymmetries for light fission fragments with asymptotic wave vector k LF and T-odd asymmetries pk,,0 k (d) for analogous fission fragment having the ( n LF LF ) 0 wave vector k LF in the moment of the flight from fissile nucleus, and pk,, k (e) for prescission third particles with asymptotic wave vector ( n LF 3 )
k3 in the true ternary fission. It is shown that the asymmetries (a) – (c) are defined by the interference of fission amplitudes for s- and p-neutron resonances of the fissile compound nucleus and asymmetries (d) – (e) – by the analogous interference for s-neutron resonances with taking into account the influence of collective rotation of the polarized fissile nucleus onto the amplitudes of the angular distributions of fission fragments and prescission third particles. It is demonstrated that the combinations of the asymmetries (a) – (c) with the angular distributions of the prescission and evaporation third particles kk, W33()()LF give the possibility to receive the P-odd ()pkn, 3 and P-even ()kkn, 3 and p,, kk asymmetries for angular distributions of named above third ()nn3 particles in the true and delayed ternary fission. It is shown that the combination 0 of the asymmetry (d) with the additions ∆W33()kkLF , to the evaporation third particle’s angular distributions caused by the wriggling-vibrations of fissile nucleus near it’s scission point give the possibility to receive T-odd asymmetry of type (e) in the angular distributions of evaporation third particles for the delayed ternary fission. The work is supported by RFBR № 12-02-00218-а.
36 UNUSUAL STATES IN LIGHT NUCLEI
V.Z. Goldberg Cyclotron Institute, Texas A&M University, College Station, TX USA; RRC “Kurchatov Institute”, Moscow, Russia E-mail: [email protected]
Light nuclei are the interesting objects. The properties of light nuclei can change drastically with adding or removal a single nucleon. Only in the region of light nuclei, species beyond both borders of nuclear stability are known, and the nuclei with the highest N/Z ratio are investigated. Additionally ab initio calculations could be made for nuclei in this region. These calculations provide for reliable criterion for selection of the most interesting findings. Recent developments in the experimental technique and analysis [1-5] revealed a group of the unusual levels in light nuclei; some of them were in the nuclei beyond the stability borders. The single particle or the cluster structure of the levels in question is a conventional issue of the “old” models; only the extreme pure character of the structure seems unusual. However, the understanding of the structure observed at the neutron rich border of stability should overstep the limits of the present knowledge. I’ll consider the most interesting observations using mainly Refs. [1-5]. I’ll consider perspectives for future experiments.
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37 NO-CORE FULL CONFIGURATION APPROACH: AB INITIO THEORY OF LIGHT NUCLEI
A.M. Shirokov1,2,3, J.P. Vary2, P. Maris2, A.I. Mazur3, V.A. Kulikov1 1 Skobeltsyn Institute of Nuclear Physics, Moscow State University, Russia; 2 Department of Physics and Astronomy, Iowa State University, Ames IA, USA; 3 Pacific National University, Khabarovsk, Russia E-mail: [email protected]
One of the mainstreams of modern nuclear theory is an ab initio description of nuclei, i. e. model-free calculations of many-nucleon systems using supercomputers. Recently we have suggested an ab initio no-core full configuration (NCFC) approach [1] based on the extrapolation of no-core shell model (NCSM) results to the case of infinite model space. The NCFC approach makes it possible to improve essentially and evaluate the accuracy of ab initio theoretical predictions for light nuclei. The NCFC extrapolations are performed for NCSM results obtained with `bare’ nucleon-nucleon forces, not with effective NN interactions obtained from intrinsic NN force by means of a Lee–Suzuki–Okamoto or another effective interaction renormalization. High-quality NCFC predictions can be obtained with a NN interaction providing a fast convergence of NCSM calculations; it is also desirable to avoid the use of three-nucleon and higher-order interactions to use larger NCSM basis spaces in calculations. Therefore we use in the NCFC approach relistic NN interactions of the JISP type [2, 3] known to provide an adequate description of observables in light nuclei. We present a review of recent results obtained with the NCFC approach and of progress in development of the JISP-type NN interactions.
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38 PROBLEMS OF EXPERIMENTAL AND THEORETICAL STUDIES OF THE GAMOW-TELLER RESONANCE IN ANTIMONY ISOTOPES
S.Yu. Igashov, I.V. Safonov, M.H. Urin National Research Nuclear University, Moscow, Russia E-mail: [email protected]
Systematical experimental studies of the Gamow-Teller resonance (GTR) in antimony isotopes [1, 2] by means of the charge-exchange 112-124Sn(3He, t)-reactions have initially been motivated by prediction of the GTR configurational splitting for antimony isotopes near A=118 [3]. In these experiments the GTR has been found as a wide structureless bamp with the anomalously large total width ( 6 MeV for A=118). Being theoretically found within a simplified version of the "charge-exchange" continuum-QRPA (pn-cQRPA), the structure effect of the GTR splitting is due to filling the single- particle level with the largest angular momentum in the neutron open shell in a given parent nucleus (1h11/2 for tin isotopes) [3]. Early the alternative and not repeated up to now method of the experimental GTR study has been realized in Ref. [4]. The method consisted in studying the excitation function of the resonance 117Sn(p, n)-reaction with observation of the GTR, as a resonance in the compound nucleus 118Sb. Two relatively narrow bumps with relatively small total width (about 1 MeV) in the mentioned excitation function have been assigned in Ref. [4] to GTRs in 118Sb. In the present work within the modern version of the (pn)-cQRPA [5] we confirm the existence of the GTR configurational splitting in antimony isotopes near A=118. On this base we explain: (i) found in Ref. [2] the anomalously large total width of the GTR in 118Sb; (ii) found in Ref. [4] the energies of two GTRs in 118Sb under the supposition that one GTR is built on the simple –1 118 two-quasiparticle (d3/2, s1/2 ) state of the parent nucleus Sn; (iii) qualitatively (within the simplified version of the pn-cQRPA) the GTR elastic proton width also deduced from the data of Ref. [4]. The open problems with understanding the experimental data of Ref. [4] are: (i) explanation on the relatively small total width of the observed GTRs; (ii) quantitative description of the GTR elastic proton width. Therefore, continuation of the experimental (in the spirit of Ref. [4]) and theoretical (in the spirit of Refs. [5, 6]) studies of the GTR(s) in antimony isotopes seems to be necessary. This work is partially supported by the Russian Foundation for Basic Research (grant no. 12-02-01303-a).
1. J.Janecke et al. // Phys. Rev. C. 1993. V.48. P.2828. 2. K.Pham et al. // Phys. Rev. C. 1995. V.51. P.526. 3. V.G.Guba, M.A.Nikolaev, M.G.Urin // Phys. Lett. B. 1989. V.218. P.283. 4. B.Ya.Guzhovskii, B.M.Dzyuba, V.N.Protopopov // JETP Lett. 1984. V.40. P.1322. 5. S.Yu.Igashov, V.A.Rodin, M.H.Urin, A.Faessler// Phys. Rev. C. 2011. V.83. 044301. 6. I.V.Safonov, M.G.Urin // Phys. At. Nucl. 2012. V.75 (to be published).
39 GEMMA AND DANSS – EXPERIMENTS WITH THE REACTOR ANTINEUTRINO
V.B. Brudanin, V.G. Egorov Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
Standard industrial reactor WWER1000 generally exploited by Russian nuclear power industry produces huge number of electron antineutrinos with a broad energy spectrum up to ~9 MeV. In our GEMMA and DANSS experiments performed in collaboration with ITEP (Moscow) we use the unique possibilities of the Kalinin NPP providing the antineutrino flux of 5×1013 1/cm2/s at ~10 m distance from the core. The report describes the status and perspectives of the projects. The GEMMA spectrometer includes a Germanium detector measuring the recoil spectra after the ν-e scattering. The last portion of experimental data measured with the GEMMA-1 spectrometer has been analyzed and a new upper –11 NMM limit derived: μν< 2.9×10 μB at 90 % CL. Nowadays, the spectrometer is being upgraded to GEMMA-2, the renewal is done in several ways: new HPGe detector of higher mass, new “U-type” cryostat of lower background, new measurement site under the reactor #3 with the higher neutrino flux, new detector cooling system, etc. The DANSS is the 1 m3 detector of the reactor antineutrinos. It consists of 2500 independent cells – 4×1×100 cm3 bars made of polystyrene-based scintillator covered with thin Gd-containing and light-reflecting layer. We estimate the Inversed Beta-Decay registration efficiency as 73 %, and expect that, being placed at 11 m distance from the 3 GWth reactor, the spectrometer would detect about 10000 IBD-events per day. It is shown that, being equipped with a special lifting gear, the DANSS will be able to detect short-range neutrino oscillations to the 4th sterile type.
40 POLARIZATION EXPERIMENTS WITH BACK SCATTERED GAMMA BEAMS
V.G. Nedorezov Institute for Nuclear Research RAS, Moscow, Russia E-mail: [email protected]
A review on experimental study of photonuclear reactions using Compton back scattered gamma beams at intermediate energies (from pion photo- production threshold up to some GeV) is given. Main attention is paid to the beam asymmetry results obtained for meson photo-production on protons and neutrons by the GRAAL (Grenoble Accelerateur Anneau Laser) collaboration at ESRF (European Synchrotron Radiation Facility) [1]. This review summarizes the 20 years beam activity of the GRAAL collaboration on this subject. Last review on this subject was published about 10 years ago, for this period new fundamental results on spin structure of nucleons, photonuclear excitation mechanisms have been obtained. It was shown that in addition to principal polarization experimental program based on the high photon polarization degree, new results on different applications have been appeared. For example, total photoabsorption and partial meson photoproduction cross sections were measured with high accuracy indicating new features for the proton and neutron processes. New method to study interaction of unstable mesons with nuclear media (tagged mesons) was proposed. Recent GRAAL results on the light speed anisotropy relatively to the relict dipole radiation are also discussed. It is shown that new possibilities are based on the Compton back scattering technique providing hard spectrum of photons, high polarization degree, low backgrounds.
1. V.G.Nedorezov // Submitted to Phys.of Elementary Particles and Nuclei. 2012.
41 ON THE ENHANCEMENT OF THE FUNDAMENTAL SYMMETRY BREAKING EFFECTS
V.E. Bunakov1,2 1 St. Petersburg State University, Russia; 2 Petersburg Nuclear Physics Institute, Gatchina, Russia E-mail: [email protected]
It is assumed that the largest magnitude of the symmetry-breaking effect allows to measure it with the largest accuracy (i.e. with the smallest relative error). This assumption is shown to be often misleading. Consider as an example P-violating effects in γ-transitions between the compound-nucleus states measured by the ratio A RF≈=sb α (1) Asc of the symmetry-breaking transition amplitude to the symmetry-conserving one. F is the ratio of weak-to-strong interaction constants, while α stands for possible enhancement factors (see e.g. [1]). In experiment we measure this effect as the ratio of the normally distributed numbers of numerators n to denominators d. Taking their absolute errors to be σ and neglecting the correlation between them, one obtains for the relative error of the effect σ σσ22 R = + (2) R nd22 Consider now the dynamical enhancement of the effect which increases its numerator by several orders of magnitude. We see that this decreases the relative error and indeed leads to the enhanced accuracy of the effect’s measurement. Now consider the structural enhancement of the effect coming from the structural hindrance of the parity-conserving denominator dA= sc . We see that this hindrance increases the value (1) of the effect. However it also increases the relative error (2) and thus leads to the poorer accuracy of the effect’s measurement. We also consider more complicated cases of P-violation in polarized neutron transmission [2], when the artificial enhancement is obtained by inserting only a small part of Asc into (1). Even more odious suggestions are considered [3] of enhancements in measuring CP-violation effects around the point where the
Asc amplitude passes zero while changing its sign. The work was supported by RFBI grant 11-02-00006.
1. I.S.Shapiro // Sov. Phys. Uspekhi. 1968. V.95. P.647. 2. V.E.Bunakov // Phys. of Particles and Nuclei. 1995. V.26. P.285. 3. V.E.Bunakov, I.S.Novikov // Phys. Lett. B. V.429. P.7.
42 Т-ODD CORRELATIONS AND Т-INVARIANCE IN NUCLEAR REACTIONS AND FISSION
S.G. Kadmensky1, V.Е. Bunakov2, L.V. Titova1 1 Voronezh State University, Russia; 2 Saint-Petersburg Institute of Nuclear Physics, Gatchina, Russia E-mail: [email protected]
In differential cross-sections of nuclear reactions σ fi can appear T-odd correla- tions of type Afi = =AA(p f,σ f ;, pσ ii)(=−−−−− pf , σ f ; p i , σ i) , where p,σ and −−p, σ – moments and spins of particles for direct and time-reversed initial (fi- nal) state of nuclear system with wave functions i ( f ) and ii=τ ( f ), where τ – time reversal operator [1], accordingly. Since the cross-section σ fi is 2 defined as σ~fi fTi , where fTi is the matrix element of T-matrix, the correlations Afi can appear only because of the interference of matrix element of two different representations of T-matrix Tk with k,=12 when ** A~ fTi fT i+ fTi fT i . Then if operators T and T are fi 12 1 2 1 2
T-invariant: f Tkk i= iT f , the analyzed Т-odd correlations satisfy the condi- tion: AA(p f,σ f ;, pσ ii)(+= pσp ii ,; f , σ f) 0 (*). It means that the non-zero value of the defined by left part of the formula (*) quantity is the evidence of the T-invariance violation for analyzed nuclear reactions. Т-odd correlations which are observed in cross-sections of elastic scattering of polarized neutrons with neutron polarization vector σn and initial (final) mo- ments p (p' ) on spinless nuclei such as ,,' and reactions of binary n n ()σn pp nn and ternary fission of nuclei by polarized cold neutrons with moments of the fly- ing light fragment and third particle pLF and p3 such as (σn,,[] pp n LF ),
()σnn,,[] pp3 and (σn,,[] pp3 LF ) , satisfy the condition (*) and don’t give any in- formation about Т-noninvariant interactions. The condition (*) is not realized for the Т-odd correlations in probabilities of nuclear α-, β- and γ-decays, since these correlations include [2] only the initial nucleus spin being integral of motion and all particles of final state fly out at the same time moments. Therefore in these probabilities T-odd correlations can appear as for T-invariant so as for T-noninvariant interactions [2]. The work is supported by RFBR № 12-02-00218-а.
1. M.L.Goldberger, K.M.Watson. Collision theory. N.-Y.: Wiley, 1967. 919 р. 2. R.J.Blin-Stoyle. Fundamental Interactions and the Nucleus. Amsterdam: N-Holland Pub. Comp., 1973. 359 p.
43 APPLICATION OF TWO-CENTER STATES AT THE DESCRIPTION OF NUCLEON TRANSFERS PROCESSES BY A COUPLED CHANNEL METHOD
V.V. Samarin Joint Institute for Nuclear Research, Dubna, Moscow region, Russia E-mail: [email protected]
The method of perturbed stationary states, founded on decomposing of a full wave function of a system of two nuclei and nucleon by a system of two-center nucleon functions Φα ()Rr, , is applied for the description of nucleons transfers at low-energy nuclear reactions. The system of multichannel equations for wave functions of nuclei relative movement Fα with kinetic energy matrix is solved numerically by method similar to a coupled channels method for collective excitations of nuclei [1]. The two-center nucleon energy levels εα ()R
(Fig. 1 a) - additions to nucleus-nucleus potential vR12 () in a channel α , and wave functions Φα ()Rr, (Fig. 1 b) are calculated by a method offered in [2].
a b Fig. 1. a) Some two-center neutron levels of energy in a system 18O+58Ni as to a function of internuclear distance R for moment projection on internuclear axis Ω=32 (solid lines),
Ω=32 (dashed lines), Ω=52 (dotted lines), RB corresponds to top of a Coulomb barrier. b) Probability density level lines in cylindrical coordinates for two-center neutron wave 18 functions with Ω=32, conforming to a occupied state 1d5/2 of O and a free state 1g9/2 of 58 Ni, at RR= B .
This work was supported in part by the Russian Foundation for Basic Research (RFBR) and Deutsche Forschungsgemeinschaft (DFG) through Grant No 11-02-91349-ННИО_а.
1. V.Samarin. V.Zagrebaev // Phys. Atom. Nucl. 2004. V.72. P.1462. 2. V.V.Samarin // Phys. Atom. Nucl. 2010. V.73. P.1416.
44 RELATIVE MAGNITUDE OF CROSS SECTIONS FOR ELASTIC AND INELASTIC SCATTERING OF A FAST PARTICLE ON A MANY-PARTICLE TARGET
B.A. Zon Voronezh State University, Russia E-mail: [email protected]
Data produced by experimental and theoretical means by different groups for fast particles scattering on a many-body target such as an atom or small molecule are examined. Through this analysis we found that the scattering of a fast incoming electron on such a many-body target is increasingly dominated by elastic processes with an increasing amount of particles for target with similar electron configuration. This tendency is a consequence of quantum mechanical interference of the amplitudes for the elastic scattering and appears as a trend of ratio between elastic and total cross sections going to unity with growth of the target. Furthermore, we discuss why this tendency breaks down for large molecules and condensed matter.
45 ANALYTICAL CAPABILITIES OF NUCLEAR-PHYSICAL TECHNIQUES
A.P. Kobzev1, V.M. Vakhtel2, V.A. Rabotkin2 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Voronezh State University, Russia E-mail: [email protected], [email protected] Nuclear-physical analytical techniques are widely used to study the deep profiles of elements in the solution of various technical, scientific and experimental problems. Rutherford backscattering technique has become especially popular because it provides the ability to measure deep profiles of almost all elements, from carbon and up to the heaviest. However, in practice it is often necessary to measure deep profiles of hydrogen and deuterium, which in principle is not available for Rutherford backscattering techniques. In this case the method of recoil nuclei can be used. Together, these two techniques allow us to study the deep profile of any element. The paper presents research results of deep profiles of elements in the near-surface layers of the samples used in practice. It is shown that the deep resolution of RBS technique is about 50 nm at a beam of helium ions with energies up to 3 MeV, and its sensitivity allows detection of certain admixture of Bi in the near-surface layer in the amount of 8.5 x 1014 at./sm2. The content of Bi in the surface layer of the sample was less than the number of atoms contained in the monolayer (∼9.24х1014 at./sm2). For light elements such sensitivity can not be achieved because the Rutherford scattering cross section is proportional to the square of the charge of the scattering nucleus. In addition, the spectrum of helium ions scattered at light elements, is usually superimposed on the spectra of helium ions scattered at the heavier elements, making it difficult to estimate helium ions yield scattered at light elements. With regard to the sensitivity of RBS technique to atoms of oxygen, it can be significantly improved by increasing the beam energy of analyzing helium ions to the energies > 3.045 MeV, when a resonance in the elastic cross section occurs and at the peak it is 17 times greater than the Rutherford one. The oxygen atoms are present in the surface layers of many samples used in practice. One example of the use of this resonance to study the deep profile of oxygen in the near-surface layer is given in this investigation. When using a beam of helium ions with the energy of 2 MeV, the depth of analysis is about 3 microns. In cases where this depth is insufficient, the proton beam is usually used to study samples. At the protons’ energy up to 2 MeV the depth of analysis increases to 20 microns, but the depth resolution, of course, is reduced. We propose a study of elements’ deep profiles at a beam of helium ions as well as protons. Examples of such studies are given and it is also shown that in this case not only expands the depth of analysis, but also increases the sensitivity to light elements. The cross section for proton scattering at all light elements up to silicon is of non-Rutherford character, as a result, it is even possible to analyze the deep profile of such a light element as lithium. An example of this kind of research of deep profiles of elements at the beams of protons and helium ions is given in this study.
46 QUASI-CLASSICAL FORMULA FOR ALPHA DECAY RATE IN ELECTROMAGNETIC FIELD
I.V. Kopytin, A.S. Kornev Voronezh State University, Russia E-mail: [email protected]
A quasi-classical correction to the α-decay rate in an alternating electromagnetic field is obtained. The formula for decay rate is derived by the analogy with the Gamow theory [1]. This problem is solved in parabolic coordinates. A quasi-static approximation is used. We have 2 4 10 2 ∆−WFαα() 1 39π (Z 2) e mF = 12F ; 1, ; 25 −1 (1) WEαG 22 8 α for the ratio between the α-decay rate in an alternating linearly polarized optical electromagnetic field Wα(F) (F is an electric field strength amplitude) and rate in the Gamow theory WαG. In Eq. (1) ΔWα(F) = Wα(F) – WαG, Z is the charge number of a parental nucleus, mα and Eα are the mass and the energy of the α- particle respectively, 1F2 is the generalized hypergeometric function, a z aa(+ 1) z2 12F(;,;) abcz =++ 1 + bc1! b ( b++ 1) c ( c 1) 2! The equation (1) does not take into account the distortion of the α-particle trajectory in a sub-barrier region. At present the achievable electromagnetic wave intensity does not exceed 1021…1022 W·sm–2. In this case the ratio (1) is close to a zero. It becomes 25 –2 appreciable only if the electromagnetic wave intensity is higher than 10 W·sm . 162 For example, the rate of Sm isotope α-decay (Eα = 1.87 MeV) increases by (0.026…0.26)% if the intensity is in the (1025…1026) W·sm–2 range. For heavier 238 nuclei this factor is smaller. For U isotope (Eα = 4.27 MeV) the α-decay rate increases by (0.002…0.021)% for the same intensities. In the last case for the limiting value of the 1028 W·sm–2 intensity the rate increases only by 2.1%. At present even the (1025…1026) W·sm–2 intensities are unachievable [2]. Such ultra-strong electromagnetic fields can be probably created by a free electron laser radiation (European XFEL [3], e.g.).
1. G.A.Gamow // Physics–Usp. 1993. V.36(4). P.267. 2. G.A.Mourou, T.Tajima, S.V.Bulanov // Rev. Mod. Phys. 2006. V.78. P.309. 3. http://www.xfel.eu.
47 FRC ON THE ROAD TO CONTROLLED THERMONUCLEAR FUSION. PROBLEMS AND PROMISE
M. Binderbauer, H. Guo, D. Barns, S. Putvinski, N. Rostoker, M. Tuszewski, M. Anderson, V. Bystritskii, E. Garate, F. Giamanco1, E. Ruskov, A. VanDrie Tri Alpha Energy, Inc., Rancho Santa Margarita, California, USA; 1 Department of Physics, University of Piza, Italy E-mail [email protected]
This report presents a brief review of the basic physics, including status, main problems and potential of the FRC (compact plasma with a Field Reversed Configuration) for the controlled thermonuclear fusion (CTF). It addresses important characteristics and pertinent unique properties of FRC, which differ it from tokamak plasma configuration, such as: absence of B-flux links with embodiment hardware, simple symmetric B-field topology, high energy density of the plasma, robust behavior during its translation and evident engineering feasibility. During the last two decades FRC became an object of the worldwide research [1, 2]. The report describes scalings of its characteristics and their interdependence, deals with formation, stability, and transport issues, including pertinent problems and promise of bringing FRC to breakeven level parameters. Brief description of planned and future breakeven level experiments [3] is given, based on several suggested schemes and scenarios for using FRC for fusion reactors [3, 4].
TOROIDAL CURRENT COIL CURRENT
0.5 <
external current coil
1. M.Tuszewski // Nuclear Fusion. 1988. V.28. P.2033. 2. L.Steinhauer // Phys. of Plasma. 2011. V.18. P.070501. 3. M.Binderbauer, H.Guo, M.Tuszewski, et al. // Phys. Rev. Lett. 2010. V.105. 045003. 4. J.Slough, G.Votroubek, K.Phil // Nuclear Fusion. 2011. V.51. P.053008.
48 NEUTRON HALO ROTATION IN 11Be AND 9Be
A.S. Demyanova1, T.L. Belyaeva2, S.A. Goncharov3, A.A. Ogloblin1 1 NRC Kurchatov Institute, Moscow, Russia; 2 Universidad Autonoma del Estado de Mexico, Mexico; 3 Skobeltzin Institute of Moscow State University, Russia E-mail: [email protected]
11Be ½+ ground state is considered to be a standard of a one-neutron halo. Its RMS radius is
The obtained result demonstrates that the Rdif, fm Rdif, fm conception of neutron halo is
5.77±0.15 much wider than it was thought before. Halos can
5.72±0.17 exist in excited states > 6.3 including those located in continuum. They do not 5.60±0.07 6.38±0.14 belong exclusively to the drip-line nuclei. Evidently, new structures can appear, and one of them is rotating 2 2J/ћ 2.50 2.59 halo.
11 9 1. V.Lapoux // Phys. Lett. Fig. 1. Rotational states of Ве and Ве et al. B. 2008. V.658. P.198 ; having abnormally large sizes. The values of N.Fukuda // Phys. Rev. diffraction radii are given at the levels et al. C. 2004. V.70. 054606. positions. The lowest line denotes the inertia 2. A.A.Ogloblin // Phys. moments. et al. Rev. C. 2011. V.84. 054601. 3. R.J.Peterson et al. // Nucl.
Phys. A. 1982. V.377. P.41. 4. A.S.Demyanova et al., to be published.
49 DOES THE HOYLE STATE IN 12С ROTATE?
A.S. Demyanova1, А.А. Ogloblin1, T.L. Belyaeva2, N. Burtebaev3, S.А. Goncharov4, Yu.B. Gurov5, А.N. Danilov1, S.V. Dmitriev1, Yu.G. Sobolev6, W. Trzaska7, G.P. Tyurin7, P. Heikkinen7, S.V. Khlebnikov8, R. Julin7 1 NRC Kurchatov Inst., Moscow, Russia; 2 Universidad Autonoma del Estado de Mexico, Mexico; 3 Nuclear Phys. Ins. Almati, Kazakhstan; 4 Skobeltzin Inst., Moscow, Russia; 5 MEPhI, Moscow, Russia; 6 Nuclear Phys. Ins., Rez, Czech Republic; 7 JYFL, Jyvaskyla, Finland; 8 Khlopin Radium Inst, St.-Peterburg, Russia E-mail: [email protected]
12 + The structure of the C state 0 2, Е* = 7.65 MeV (the Hoyle state) attracts attention for many years and still remains to be some kind of mystery. The renewed interest to the Hoyle state is connected with conjecture that it represents a prototype of a dilute alpha-particle condensed state. Very recently two new + + excited states: 2 2 (9.84 MeV) [1] and, possibly, 4 2 (13.3 MeV) [2] were claimed to be discovered. If so, these states may form a new rotational band based on the Hoyle state (Fig. 1) and consequently have similar structure. In this paper we 1) applied the modified diffraction model (MDM) [3] for determining the radius of the 9.84 MeV state from the scattering cross-sections obtained in [1] and 2) measured the inelastic 12C + α cross-sections leading to the 12C levels with the excitation energies in the vicinity of 14 MeV at E(α) = 65 MeV. The RMS radius of 9.84 MeV state occurred to be
50 MEASURING THE RADII OF NUCLEAR EXCITED STATES WITH RADIOACTIVE BEAMS
А.А. Ogloblin1, Т.L. Belyaeva2, А.S. Demyanova1, S.А. Goncharov3 1 NRC Kurchatov Institute, Moscow, Russia; 2 Universidad Autonoma del Estado de Mexico, Mexico; 3 Skobeltzin Institute of Moscow State University, Russia E-mail: [email protected]
Development of methods of measuring the radii of unstable nuclear states opens new perspectives in studying exotic nuclei with the radioactive beams. Two such methods are discussed in this paper. The first one [1] is based on measuring the scattering cross-section in the diffraction region of the angles. The RMS radius
, fm coefficients (ANC). The latter can , fm dif dif 5.6 R R 10 Be, El 11 de obtained from the cross-sections Be, El Be, QE 5.4 of the (d, p) stripping reactions 5.2 instead of usual spectroscopic 5.0 0 100 200 300 400 500 factors. Both methods were Ecm, MeV compared [3] in the case of
measuring the halo radius of the excited state ½+, 3.09 MeV of 13C Fig. 1. Diffraction radii of some nuclear states and gave identical results.
obtained from elastic, quasielastic and Both diffraction and ANC methods inelastic 12C + RN scattering. Diffraction radii obtained from 12C + 12C elastic scattering are are complimentary. Their use in the shown for comparison. inverse kinematics measurements
with the radioactive beams requires some new experimental developments connected with necessity of detecting low energy protons. Possible applications are discussed.
1. A.N.Danilov et al. // Phys. Rev. C. 2009. V.80. 054603. 2. Z.H.Liu et al. // Phys. Rev. C. 2001. V.64. 034312. 3. A.A.Ogloblin et al. // Phys. Rev. C. 2011. V.84. 054601.
51 NUCLEAR TRANSMUTATIONS: STATE-OF-THE-ART, CHALLENGES AND PERSPECTIVES
V.V. Tokarevsky Institute for Chernobyl Problems of the Chernobyl Union of Ukraine, Kiev, Ukraine E-mail: [email protected]
The transformation of a chemical element to another one induced by nuclear reactions is generally called a nuclear transmutation (NT). The most known NT is production of dozens chemical elements in fission reactions or generation of new transuranium elements (TUE) in capture reactions induced by neutrons on the isotopes of U and Pu. As a rule, all chemical elements produced by fission reactions are out of use. Only the released kinetic energy of fission products is utilized. As for generated TUE some of them, especially 239Pu, are extracted from the irradiated materials for further use. Other examples of in-use NT-technologies are nuclear doping of semiconductors and production of radiopharmaceuticals for nuclear medicine. The main challenge that permanently accompanies the practical use of NT is the requirement to follow the radiation safety of personnel and consumers of NT products as well. Indeed, radioactive waste (RW), formed by hundreds of radioactive isotopes following nuclear energy generation, present the most risk for people and environment Long-term storage of RW in the specially engineered facilities or RW disposal within a stable geological formation is technically feasible but a general public perceives it with distrust. The application of NT-technology for transmutation of radioactive chemical elements is the most needed and tempting area of the applied nuclear physics. Conceptually everything looks very simple: one needs to transmute long-lived radionuclide into short-lived radionuclide or stable nuclide. To realize this concept appropriate nuclear reaction must be selected. After that, type and energy of the incident particle as well as irradiation exposure have to be optimized. The optimization procedure must take into account the real composition of the transmuted material since new additional radionuclides will be produced during irradiation. The ultimate goal – destruction of all radionuclides through NT – is feasible theoretically, but will require essential energy consumption. So, the economic feasibility of NT-technology has a crucial value. If energy consumption of NT-technology will exceed the energy generation due to nuclear fission or fusion, than it becomes insurmountable barrier in the path of the nuclear energy use. The optimization criterion is a compromise between implementation cost of NT-technology and the storage (disposal) cost of the residuals. The desired compromise, as it is seen nowadays, may be achieved by the use of NT-technology to reduce an activity of TUE containing in RW, or to decrease a volume of long-lived RW. It will make it possible to avoid storage (disposal) of long-lived RW during historical span of time estimated by hundreds thousand of years - the most formidable obstacle to exploiting the full potential of nuclear energy.
52 SELF-CONSISTENT APPROACHES IN MICROSCOPIC NUCLEAR THEORY. STATIC MOMENTS OF ODD-ODD NUCLEI
S.P. Kamerdzhiev1,2, O.I. Achakovskiy2, D.A. Voitenkov1 1 Institute for Physics and Power Engineering, Obninsk, Russia; 2 Institute for Nuclear Power Engineering National Research Nuclear University MEPhI, Obninsk, Russia E-mail: [email protected]
Two modern self-consistent approaches in the microscopic nuclear theory are discussed. They differ from each other in the initial formulation of many-body problem description. The initial step of the first one is to solve the Hartree-Fock-Bogolyubov equations while for the second approach the initial quantity is the Energy Density Functional (EDF). Each approach uses its own small set of parameters, i.e. the Skyrme or EDF, respectively. In principle these parameters are universal for all nuclei. They are used to calculate the self-consistent mean field and effective forces and then to obtain characteristics of both ground and excited states. For these reasons, both approaches have a great predictive power which is necessary for description of unstable nuclei. Also, we demonstrate the latest results of the calculations performed within these approaches. With the use of the Skyrme forces SLy4 and the self-consistent version of the Extended Theory of Finite Fermi Systems, the characteristics of pygmy and giant E1 resonances have been calculated in 15 stable and unstable Sn isotopes from A= 100 to A= 176 [1]. A parametric formula for the mean energy of E1 excitations within the (0 – 30) MeV interval, which takes into account pygmy dipole resonance, has been found. The comparison with the widely used phenomenological generalized Lorentzian approach for unstable 132Sn and 150Sn shows considerable differences both for the strength function and the radiative neutron capture cross section. The EDF approach used in calculations under consideration is the self- consistent TFFS [2] based on the EDF by Fayans et al. [3], with the known parameters. The latest results of calculations of static moments of odd [4] and odd-odd stable and unstable spherical nuclei are discussed. A good agreement with available experimental data has been obtained.
1. A.Avdeenkov, S.Goriely, S.Kamerdzhiev, S.Krewald // Phys. Rev. C. 2011. V.83. 064316. 2. V.A.Khodel, E.E.Saperstein // Phys. Rep. 1982. V.92. P.183. 3. S.A.Fayans, S.V.Tolokonnikov, E.L.Trykov, D.Zawisch. // Nucl. Phys. A. 2000. V.676. P.49. 4. S.V.Tolokonnikov, S.Kamerdzhiev, D.Voitenkov, S.Krewald, E.E.Saperstei // Phys. Rev. C. 2011. V.84. 064324.
53 NEW GENERATION OF EXPERIMENTS SEARCHING FOR NEUTRINOLESS DOUBLE BETA DECAY
A.A. Smolnikov1,2 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Max-Plank-Institut fur Kernphysik, Heidelberg, Germany E-mail: [email protected]
The search for neutrinoless double beta decay is one of the central research topics in fundamental physics. In fact, the observation of neutrinoless double beta decay would not only establish the Majorana nature of the neutrino but also provide a measurement of its effective mass
54 PROBLEMS OF FORECASTING RADIATING FIRMNESS AND PARAMETRICAL RELIABILITY OF ELEMENT COMPLETING BASE FOR SPACE VEHICLE EQUIPMENT A.G. Kadmenskii FGUP Central Research Institute of mashine building, Korolev, Moscow region E-mail: [email protected]
It is known, that influence of an ionising radiation (IR) space at long flight essentially changes physical and chemical characteristics of materials and space vehicle (SV) elements, in particular, completing onboard equipment (OE). It leads to the phenomena of radiating degradation and loss of working capacity of responsible blocks OE, essentially limiting term of active existence SV in an orbit. The developed methodology of forecasting of radiating firmness and parametrical reliability of the major class of element completing base – CMOS VLSIC is based on regular change of characteristics of microtransistors at influence of space IR at accumulation of a parasitic charge in dielectric materials of schemes and radiation defects in the crystal semiconductor. This process can be described by means of adaptive physical and mathematical models (PMM), the enclosed electric pressure considering an influence at irradiation and temperature, and also at correct calculation by a method of Monte-Carlo (taking into account multiple scattering, energy losses and their struggling, nuclear reactions, etc.) the absorbed energy of IR (dose) in individual volume of an element. In this connection the methodology includes as examples following components as necessary elements. Programs of simulation of transport of charged particles of space in transistor and computing design procedures of a dose analysis in channels of ionization and separately nuclear scattering taking into account properties of a primary cosmic rays (in particular, angular omnidirectionality), and also kernels of return and fragmentation products at course of nuclear reactions. Programs of mathematical modeling excited by radiation of electrocarrying over in dielectric layers of MOS structure taking into account contributions of charges of deep traps and superficial states, slow processes of their tunnel discharge and conversion (so-called effects providing the account small space IR intensity) and a computing design procedure of radiating shifts of parameters and characteristics n - and p - channel МОS transistors. Programs of experimental express inspection underthreshold characteristics in a mode of weak inversion for transistors of CMOS VLSIC test structures in the conditions of influence of radiation from a X-ray (UV-) source and thermal heating. Programs of identification of analytical PMM adaptive parameters, and also the important predicting parameters of transistors on the spent express tests. Techniques of grading of parties CMOS VLSIC in the form of chips on plates before framing after identification of special parameters defined by technology; and so on.
55 PERSPECTIVES OF THE STUDY OF CHARMONIUM AND EXOTICS IN EXPERIMENTS USING ANTIPROTON BEAM WITH MOMENTUM RANGING FROM 1 TO 15 GeV/c
M.Yu. Barabanov, A.S. Vodopyanov Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
The study of strong interactions and hadronic matter in the process of antiproton-proton annihilation seems to be a perspective nowadays. The research of charmonium, charmed hybrids spectra and their main characteristics (mass, width and branch ratios) in experiments using antiproton beam with momentum ranging from 1 to 15 GeV/c, are promising to understand the dynamics of quark interactions at small distances. Charmonium spectroscopy is a good testing tool for the theories of strong interactions: QCD in perturbative and non-perturbative regimes, LQCD and QCD inspired phenomenological potential models. 1 1 3 3 Nowadays the scalar P1, D2 and vector PJ, DJ, - charmonium states and 1 3 higher laying scalar S0 and vector S1 – charmonium states are poorly investigated. The domain over DD - threshold equal to 3.73 GeV/c2 is badly studied. According to the contemporary quark models namely in this domain, the existence of charmed hybrids with exotic (JPC = 0+–, 1–+, 2+–) as with non- exotic (JPC=0–+, 1+–,2–+, 1++, 1– –) quantum numbers is expected [1]. The elaborate analysis of spectrum of charmonium and charmed hybrids was carried out, and the attempts to interpret a great quantity of experimental data over DD - pair were considered. Using the combined approach based on the quarkonium potential model and model of confinement on the three-dimensional sphere embedded into four-dimensional Euclidian space, ten new radial excited states of charmonium in the mass region over DD -threshold are expected to exist. But much more data on different decay modes are needed for deeper analysis. These data can be derived directly from PANDA experiment with its high quality antiproton beam. The advantage of antiproton beam consists in intensive production of particle-antiparticle pairs which is observed in antiproton-proton annihilation. This fact allows one to carry out spectroscopic research with good statistics and high accuracy. Especial attention is given to the new states with the hidden charm discovered recently [2]. The experimental data from different collaborations were carefully studied. Most of these states were observed over DD - threshold in one definite channel. New particles were produced from B-meson decays and in electron-positron or two-photon collisions. Their interpretation is far from been obvious nowadays. Some of these states can be interpreted as higher laying radial excited states of charmonium. This treatment seems to be perspective and needs to be carefully verified in PANDA experiment at FAIR.
1. PANDA Collaboration // Physics Performance Report. 2009. P.63. 2. N.Brambilla et al. // European Physical Journal. C. 2011. V.71:1534. P.1.
56 ANALYSIS OF THE PION-NUCLEUS ELASTIC SCATTERING USING THE MICROSCOPIC OPTICAL POTENTIAL
V.K. Lukyanov1, E.V. Zemlyanaya1, K.V. Lukyanov1, Ali El Lithi2, Ibrahim Abdulmagead2, B. Slowinski3 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Cairo University, Giza, Cairo, Egypt; 3 NCNR, Otwock-Swierk, Poland E-mail: [email protected]
The pion-nucleus microscopic optical potential [1], defined by the pion-nucleon amplitude of scattering and by the density distribution function of a target nucleus, was applied for numerical solving the relativistic wave equation [2]. So, the elastic scattering differential cross sections were calculated and fitted to the experimental data of scattering of pions from the 28Si, 58Ni, and 58Pb nuclei at Tlab = 291 MeV [3]. One can stress that doing so the relativistic and distortions effects in initial and final channels were accounted for automatically. As the result of such an analysis the best fit set of in-medium parameters of the pion-nucleon amplitude was established and compared with the corresponding parameters of the amplitude of scattering of pions on free nucleons.
1. В.К.Лукьянов, Е.В.Земляная, К.В.Лукьянов // ЯФ. 2006. Т.69. No.2. С.262; V.K.Lukyanov, E.V.Zemlyanaya, K.V.Lukyanov // JINR Preprint P4-2004-115, Dubna, 2004; Phys. At. Nucl. 2006. V.69. No.2. P.240. 2. В.К.Лукьянов, Е.В.Земляная, К.В.Лукьянов, К.М.Ханна // ЯФ. 2010. Т.73. No.8. С.1489; V.K.Lukyanov, E.V.Zemlyanaya, K.V.Lukyanov, K.M.Hanna // Phys. At. Nucl. 2010. V.73. No.8. P.1443. 3. D.F.Geesaman et al. // Phys. Rev. C. 1981. V.23. No.6. P.2635.
57 A MODELING OF THE PION-NUCLEUS MICROSCOPIC OPTICAL POTENTIAL AT ENERGIES OF 33-RESONANCE AND IN-MEDIUM EFFECT ON THE PION-NUCLEON AMPLITUDE OF SCATTERING
V.K. Lukyanov, E.V. Zemlyanaya, K.V. Lukyanov, E.I. Zhabitskaya, M.V. Zhabitsky Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
Analysis is performed of differential cross sections of elastic scattering of pions on different nuclei at energies between 130 and 230 MeV. To this end the pion-nucleus microscopic optical potential (OP) [1] was constructed using the optical limit of a Glauber theory. Such an OP is defined by the corresponding target nucleus density distribution function and by the elementary πN-amplitude of scattering. Then the pion-nucleus cross sections were calculated by numerical solving the corresponding relativistic wave equation [2] with the above OPs. The three parameters of the πN scattering amplitude, total cross section, the ratio of real to imaginary part of the forward πN-amplitude, and the slope parameter, are firstly taken from existing experimental data on scattering of pions on free nucleons. As the next step these parameters were fitted to the data on the respective pion-nucleus cross sections [3],[4]. Thus, comparing the sets of “free” parameters to those obtained from pion-nuclear scattering data, one can estimate the “in-medium” effect on a pion surrounded by nuclear nucleons. The special procedure of the freely variation of parameters [5] was developed and applied to get the fast and effective χ2 minimization process. A difference between the best fit values of the in-medium and free parameters of the πN scattering amplitude is discussed. Conclusions on the mechanism of scattering at the 33-resonance energies are made.
1. В.К.Лукьянов, Е.В.Земляная, К.В.Лукьянов // ЯФ. 2006. Т.69. No.2. С.262; V.K.Lukyanov, E.V.Zemlyanaya, K.V.Lukyanov // JINR Preprint P4-2004-115, Dubna, 2004; Phys. At. Nucl. 2006. V.69. No.2. P.240. 2. В.К.Лукьянов, Е.В.Земляная, К.В.Лукьянов, К.М.Ханна // ЯФ. 2010. Т.73. No.8. С.1489; V.K.Lukyanov, E.V.Zemlyanaya, K.V.Lukyanov, K.M. Hanna // Phys. At. Nucl. 2010. V.73. No.8. P.1443. 3. B.M.Preedom et.al. // Nuc.Phys. A. 1979. V.326. P.385. 4. P.Gretillat et.al. // Nuc. Phys. A. 1981. V.364. P.270. 5. E.I.Zhabitskaya, M.V.Zhabitsky // Springer Lecture Notes in Computer Science. 2012. V.7125. P.328.
58 ACCELERATORS IN THE WORLD TODAY
A.P. Chernyaev, A.V. Belousov, A.S. Osipov, S.M. Varzar Department of Physics, Moscow State University, Russia E-mail: [email protected]
At first glance it seems that particle accelerator is very complicated invention of civilization that may be used only for the "deep science" - nuclear physics, elementary particle physics. Often there is a representation about the accelerator – as a very big installation. For example, such installations are well-known from the media Large Hadron Collider (LHC) – the largest accelerator in the world, or the proton synchrotron in Protvino, Russia. However, in life everything is not like that. Just a few of accelerators work in science. Though accelerators - complex high-tech product of human activity, were created primarily for scientific research, they have become part of our life and become an integral part of many industrial processes. The main part of all accelerators is used in radiation technologies in applied areas - industry, biology, medicine, ecology and agriculture. Currently, physicists have developed technologies that use accelerators for such exotic tasks as the definition of aging wine, change of the color of semi-precious stones, etc. The total number of active accelerators in the world is being estimated more than 33 thousand (moreover, this number does not include the accelerators used in enclosed works, particularly in the defense industry) and each year the number of accelerators increases on about 500 units. In science for research in nuclear physics and elementary particle physics about 3.5% (~ 1200) are used and in medicine about 10.5 thousand electron and 500 proton and ion accelerators operate for beam therapy and nuclear techniques. The world industry uses about 20.5 thousand accelerators for radiation technologies. Throughout the world the industrial accelerators are distributed approximately in the next proportion: North America – 26%; Europe – 25%; East Asia – 36%; rest of the world – 15%. The recent analysis of the accelerator equipment development gives next tendencies for the future: in the fundamental science new methods of particle acceleration are required to achieve higher energies; for industrial technologies the high current of the beam, the efficiency of beam generation and low cost of the equipment are most important factors; for beam therapy the major parameter is the accuracy of irradiation so the role of medical accelerators that provide stereotactic therapeutic and radiosurgical techniques should increase and the proton and ion accelerator will be more claimed.
59 CLUSTER STRUCTURE OF LIGHT RADIOACTIVE NUCLEI IN PROCESSES OF RELATIVISTIC FRAGMENTATION
P.I. Zarubin Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
The nuclear track emulsion technique retains a unique position with regard to the study of the fragmentation of relativistic nuclei due to a complete observation of fragment ensembles at a record spatial resolution. The purpose of the use of this fairly simple and generic method in the Becquerel Project [1] at the JINR Nuclotron is the searching for new clustering phenomena for an accessible variety of light nuclei. The most comprehensive analysis of cluster ensembles is achieved in the most peripheral interactions of projectile nuclei. These statements are particularly true for the light nuclei with an excess of protons like 7Be [2] and 8B [3]. An overview of recent results on major features of dissociation in nuclear track emulsion of 9Be [4-6], 9C [6, 7], 10C, and 12N nuclei of 1.2 A GeV is presented. The data presented for the nucleus 9Be can be considered as evidence that there is a core in its structure in the form of 0+ and 2+ states of the 8Be nucleus having roughly equal weights. Events of coherent dissociation 9C → 33He associated with the rearrangement of the nucleons outside the α-clustering are identified. Pairs of two 3He nuclei having unusually narrow opening angles are observed in channel 9C → 33Нe pointing to the possible two 3He resonance (dihelion) near the production threshold. A pattern of the charge fragment topology in the dissociation of 10C and 12N nuclei is obtained for the first time. Contribution of the unbound nucleus decays to the cascade process 10C → 9B → 8Be is identified.
1. The BECQUEREL Project, http://becquerel.jinr.ru/. 2. N.G.Peresadko et al. // Phys. Atom. Nucl. 2007. V.70. P.1266; nucl-ex/0605014. 3. R.Stanoeva et al. // Phys. Atom. Nucl. 2009. V.72. P.690; arXiv: 0906.4220. 4. D.A.Artemenkov et al. // Phys. Atom. Nucl. 2007. V.70. P.1222; nucl-ex/0605018. 5. D.A.Artemenkov et al. // Few Body Syst. 2008. V.44. P.273. 6. D.A.Artemenkov et al.// Int. J. Mod. Phys. E. 2011. V.20. P.993; arXiv: 1106.1749. 7. D.O.Krivenkov et al. // Phys. Atom. Nucl. 2010. V.73. P.2103; arXiv:1104.2439. 8. R.R.Kattabekov, K.Z.Mamatkulov et al. // Phys. Atom. Nucl. 2010. V.73. P.2110; arXiv:1104.5320. 9. D.A.Artemenkov et al. // Few Body Syst. 2011. V.50. P.259; arXiv:1105.2374.
60 STUDY OF EXCITATION SPECTRA BY PARTICLE-DECAY SPECTROSCOPY
О. Povoroznyk, О. Gorpinich Institute for Nuclear Research, Kyiv, Ukraine E-mail: [email protected]
The most of excited levels of lightest nuclei are unbound, short-lived and it decayed through emission nucleons and clusters. The exact knowledge of the excitation energy, time of life, modes of decay and spectroscopic parameters of excited states of light nuclei is suitable to test the nuclear models and also to develop astrophysical studies. However, present experimental information about the excitation spectra of lightest nuclei is enough contradictory [1, 2]. The most widespread methods of determination of energy characteristics of unstable excited states are measurement and analysis of inclusive spectra from quasi- two particle reactions and study elastic scattering of decay components. But by investigating particle decay spectra in kinematical complete correlation experiment one can to obtain more specific and more exact information about unbound level of lightest nuclei. The using our improved method particle decay[3, 4] spectroscopy for study the numerous three and four body reaction channels caused by interaction α-particle beams (Eα=27.2; 67.2 MeV) with hydrogen isotopes and carbon allowed us to specify energy splitting of ground and first excited states of 5He [5, 6] and 5Li [7], and structure of levels of these nuclei around 20 MeV [8, 9] excitation energy and to establish structure of excitation spectra of 6He [10] and 6Li [11, 12] above and below the break-up thresholds on t + t and 3He + t accordingly The used method of particle decay spectroscopy is powerful tool for investigation light nucleus and one can to provide data which might be generally useful in extracting information on nuclear forces.
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61 NEUTRINO CATALYSIS OF NUCLEAR FUSION IN COLD HYDROGEN
Yu.L. Ratis Institute of the Power Engineering for the Special Applications E-mail: [email protected]
The possibility of the existence of exotic neutral particles is proved. These particles are the quasi-stationary states of the quasi-bound neutrinos in the atomic nucleus. From the point of view of the Heisenberg uncertainty principle the hypothetical exotic neutrino atoms have the same status as the neutron, which has an opened channel of the decay into proton, electron and the electron antineutrino. However, the assertion that the neutron consists of the decay products is incorrect, since the Compton wavelength of the leptons in this case is much larger than the size of the neutron. It is shown that the exotic dineutroneum atom, which is a quasi-stationary quasi-bound state of two neutrons and neutrino [1, 2], is neutral nuclear-active particle, due to which the reactions of cold fusion and other exotic low-energy nuclear reactions. The lifetime of the dineutroneum at low energies in the case when the decay channels D n + are closed, are about 10 10 seconds. The size of the dineutroneum commensurate with the−3 size of−4 the deuteron. The mass푣 →of dineutroneum푎푛푦푡ℎ푖푛푔 is = 1876.0979650 MeV− . The generation of the dineutroneum D(e, e )D in gaseous deuterium target D푣 has a threshold of order 15-20 eV푀. ′ Reaction of the generation of dineutroneumv e + d D + in condensed matter has a threshold slightly more than 1 −eV. The cross section of the dineutroneum generation in the→ reactionv 푝ℎ표푛 D(e,표푛 e )D in gaseous deuterium is approximately 1 mbarn. ′ Based on the hypothesis of the existence of neutrino exotic atoms one couldv theoretically explain a) the prevalence of tritium in nature, and b) the ratio of the release tritium/neutron in the CF reactions ( / ~10 ); c) the release of heat and helium in the experiments of Y. Arata and Yue-Chang9 Zhang. 푇 푛 1. Yu.L.Ratis. http://es.arxiv.org/abs/0909.5561. 2. Yu.L.Ratis. The Old and New Concepts of Physics. 2009. V.6. No.4. P.525; http://www.conceptsofphysics.net/VI_4/525.pdf.
62 ALPHA-DECAY IN THE ELECTRONIC SURROUNDING
S.Yu. Igashov1, Yu.M. Tchuvil’sky2 1 All-Russia Research Institute of Automatics, Moscow, Russia; 2 Institute of Nuclear Physics, Moscow State University, Russia E-mail: [email protected]
The influence of the electronic surrounding (the electron shell of an atom or an ion and the electron gas in solids) on the alpha-decay widths is investigated. Both increasing of the penetrability of the potential barrier due to nonzero electron density in the internal (relatively to the outer turning point) area and the change of the outer boundary conditions on the resonance solution were taken into account. The latter effect is a consequence of the fact that the Coulomb parameter η of the asymptotic resonance wave function G(ρ)+iF(ρ) where G(ρ) and F(ρ) are irregular and regular Coulomb wave functions is determined by the potential acting between the alpha-particle and the residual system (a nucleus + electrons) and thus is not coincide with the alpha-nucleus Coulomb parameter η’. The Thomas-Fermi model is used for the description of the density of the electron shell. The numerical integration of the radial Schrödinger equation was performed directly by means of the Runge-Kutta and (for the reliability of the solution which is frequently-oscillating in very long interval of variation of the argument ρ) by the Stoermer methods. Equivalent results are obtained by these two approaches. The relationship between the sub-barrier amplitude of the resonance wave function and the alpha-decay width Γ presented in [1] is used for evaluation of the effect. This effect is not great. As an example the relative difference between the alpha-decay widths of the bare nucleus of 232Th and the Th atom turns out to be equal to 1.5 percent. Such a result is in a satisfactory quantitative agreement with the result obtained in the framework of one of the models used in [2] (very different results of two models are presented there). At the same time, a qualitative interpretation of the results is other than the one presented in [2], which attributes the effect to the influence of the solid state medium on the form of the potential barrier. Our calculations demonstrate that the effect is inherent for a separate atom. The relative difference decreases slightly with increasing of the alpha-particle energy. The possibilities for observation of the effect are discussed.
1. S.G.Kadmensky, W.I.Furman. Alpha-decay and related nuclear reactions. M.: Energoatomizdat, 1985 (in Russian). 2. N.T.Zinner // Nucl. Phys. A. 2007. V.781. P.81.
63 nd BREAKUP REACTION AS A TOOL FOR STUDYING NEUTRON-NEUTRON INTERACTION
E.S. Konobeevski, M.V. Mordovskoy, S.I. Potashev, I.M. Sharapov, S.V. Zuyev Institute for Nuclear Research of Russian Academy of Sciences, Moscow, Russia E-mail: [email protected]
The study of nd breakup reaction is a powerful tool of studying nn interaction. In view of absence of a free neutron target the use of deuterium target and neutron beam is, as a matter of fact, the unique effective way of studying nn interaction. Despite the simplicity of final pnn system the experiments can be performed in different kinematical arrangements of the three outgoing nucleons and their results can be compared with rigorous theoretical predictions. Important argument for continuation both experimental and theoretical works in this area are the clear discrepancies between the theory and existing data [1]. The strongest discrepancies occur in the nn quasifree scattering (QFS) and in the nd STAR (three nucleons are flying in the c.m. system with momenta of equal magnitude) geometries. The final state interaction (FSI) geometry is widely used for determination of singlet nn-scattering length characterizing the nn scattering at zero energy. Data for ann together with analogous data for pp scattering length app (difference ann – app) define a quantitative measure of the charge symmetry breaking (CSB) of nuclear forces. The goal of our study is the determining characteristic parameters of neutron- neutron interaction, as well as obtaining new accurate estimation of CSB effect. To study the n+d→p+n+n reaction the experimental setup allowing registration of all secondary particles in different kinematical arrangements was installed at neutron channel of Moscow Meson Factory of the Institute for Nuclear Research. The first preliminary data obtained in the neutron-neutron FSI and QFS geometries showed the possibility of our setup to obtain new data on neutron-neutron interaction in broad region of neutron energy.
1. H.Witala, W.Glöckle // J. Phys. G: Nucl. Part. Phys. 2010. V.37. 064003.
64 NEW DATA ON PARTIAL PHOTONEUTRON REACTIONS (γ, n), (γ, 2n) AND (γ, 3n)
V.V. Varlamov, B.S. Ishkhanov, V.N. Orlin, N.N. Peskov, M.E. Stepanov Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University, Russia E-mail: [email protected]
In the frame of program [1] of analysis and evaluation of total and partial photoneutron reaction cross sections the investigation of significant systematical disagreements between the results of various experiments were continued. New clear simple objective and absolute criteria of data reliability and authenticity - transitional photoneutron multiplicity functions
Fi = σ(γ, in)/σ(γ, xn) = σ(γ, in)/[σ(γ, n) + 2σ(γ, 2n) + 3σ(γ, 3n) + …], which have values not higher than 1.00, 0.50, 0.33,…., correspondingly were introduced [2, 3]. Additionally functions fi = σ(γ, in)/σ(γ, sn) = эксп эксп эксп σ(γ, in)/[σ (γ, n) + σ (γ, 2n) + σ (γ, 3n) + …] were used (fi < 1.0). That was shown that many experimental data obtained using various experimental methods of photoneutron multiplicity sorting are not reliable and authentic (for example, F2 > 0.5). The main manifestation of that is appearing of non-physical negative value regions in σ(γ, n) reaction cross sections. The new experimentally-theoretical treatment was proposed [2, 3] for partial reaction cross section data evaluation in which only experimental data for total neutron yield reaction cross section σэксп(γ, xn), free from the neutron multiplicity sorting problems, is used for partial reaction cross section theor evaluation together with functions Fi , calculated in the frame of modern model for photonuclear reactions [4, 5]. Evaluations of reliable and authentic data on cross sections for partial reactions (γ, n), (γ, 2n) and (γ, 3n) – σeval(γ, in) theor exp 90 115 181 208 = Fi ∙σ (γ, xn) - were carried out for Zr, In, Ta, Pb in addition to those for 112,114,116,117,118,119,120,122,124Sn [1, 2], 159Tb [1] and 197Au [1, 3]. New evaluated data are in agreement with the results of modern induced activity experiments free from neutron multiplicity sorting problems. Deviations of evaluated data from experimental ones are large, so the situation found out creates a lot of serious physical problems – many very important things for various applications must be reanalyzed. The work was partially supported by RBFR Grant 09-02-00368, scientific schools grant 02.120.21.485-SS and contract 02.740.11.0242.
1. V.V.Varlamov et al. // Conference «Nucleus 2011» Book of Abstracts (Sarov). 2011. P.265. 2. V.V.Varlamov et al. // Izvestiya RAN. Ser. Fiz. 2010. V.74. P.875. 3. V.V.Varlamov et al. // Izvestiya RAN. Ser. Fiz. 2010. V.74. P.884. 4. B.S.Ishkhanov et al. // Physics of Particles and Nuclei. 2007. V.38. P.232. 5. B.S.Ishkhanov et al. // Physics of Atomic Nuclei. 2008. V.71. P.493.
65 EXPERIMENTAL INVESTIGATIONS OF ATOMIC NUCLEUS PROPERTIES
SEARCH FOR NUCLEAR STABLE MULTINEUTRONS AND THEIR IDENTIFICATION IN THE CHANNELS OF THE MULTIPLE NEUTRONS CAPTURE
B.G. Novatsky, E.Yu. Nikolsky, S.B. Sakuta, D.N. Stepanov National Research Centre “Kurchatov Institute”, Moscow, Russia E-mail: [email protected]
A survey of the long standing search for the multineutrons (xn) in the ternary fission of 238U is presented. The fission was induced by α-particles with the energy of 62 MeV. The identification of xn was fulfilled by the activation method. The specific activity could be produced by the multiple transfers of k neutrons from neutron nuclei (if they exist) to the activated isotopes which were placed near the uranium target. The number of transferred neutrons could be from 2 to 5 in different experiments. A wide range of the activated samples was used including the light (19F, 25Mg, 26Mg, 34S), medium (45Sc, 92Sr, 127J, 132Te) and heavy (208Pb, 209Bi) isotopes. The main requirements for the choice of activated isotopes were: 1) acceptable half-lives (1-40 hours) for the measurements and 2) the availability of the intensive γ-rays from the produced β-active isotopes. The irradiation time of the uranium foil was about 7-8 hours at the beam intensity of 1.5 μA. After the irradiation the γ-spectra from activated samples were measured by the Ge- detector with the volume of 120 cm3. For the background suppression from the Compton scattering the detector was placed in the center of the surrounding NaJ(Tl) crystal (the active shield) and then they covered by lead with thickness of 10 cm (the passive shield). The analysis of the measured γ-spectra was carried out. The theoretical predictions which were made in the framework of the compound nuclear model were compared with the experimental results. The upper limits for the yield of multineutrons per one event of the binary fission of 238U were obtained.
66 8 STUDY OF HIGHLY EXCITED STATES OF THE Li ISOTOPE
B.A. Chernyshev, Yu.B. Gurov, L.Yu. Korotkova, S.V. Lapushkin, D.Yu. Markov, T.D. Schurenkova National Research Nuclear University “MEPhI”, Moscow, Russia E-mail: [email protected]
Study of highly excited states of the 8Li isotope was carried out in the inclusive 10B(π−, d)X, 11B(π−, t)X and correlation 12С(π−, pt)X, 12С(π−, dd)X, 14С(π−, tt)X measurements in stopped π−-mesons absorption reactions. The experiment was performed on the low energy pion beam of the LAMPF using the two-arm semiconductor spectrometer of charged particles [1]. Resolution of the missing mass in the registration of singly charged particles (p, d, t) is about 0.5 MeV in the inclusive measurements and about 1 MeV in the correlation ones. The accuracy of absolute calibration of the energy scale is 0.1 MeV in both types of measurements. Analysis of the missing-mass spectra showed, that there are ground state and two low-lying excited states and also the narrow state with Ex ≈ 6.5 MeV. The parameters of the observed excited states correspond to the world data [2] within experimental errors. In the correlation measurements the state with Ex ≈ 11 MeV was observed. The evidences of the presence of states with larger excitation energies were showed.
1. M.G.Gornov et al. // Nucl. Inst. and Meth. in Phys.Res. A. 2000. V.446. P.461. 2. D.R.Tilley et al. // Nucl. Phys. A. 2004. V.745. P.155.
67 CORRELATION STUDIES OF 10He LOW-ENERGY SPECTRUM
S.I. Sidorchuk1, A.A. Bezbakh1, V. Chudoba1,2, I.A. Egorova3, A.S. Fomichev1, M.S. Golovkov1, A.V. Gorshkov1, V.A. Gorshkov1, L.V. Grigorenko1,4,5, G. Kaminski1,6, S.A. Krupko1, E.A. Kuzmin5, E.Yu. Nikolsky5,7, Yu.Ts. Oganessian1, Yu.L. Parfenova1,8, P.G. Sharov1, R.S. Slepnev1, S.V. Stepantsov1, G.M. Ter-Akopian1, R. Wolski1,6
1Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia; 2Institute of Physics, Silesian University in Opava, Czech Republic; 3Bogolyubov Laboratory of Theoretical Physics, JINR, Dubna, Russia; 4GSI Helmholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; 5National Research Centre “Kurchatov Institute", Moscow, Russia; 6Institute of Nuclear Physics PAN, Krakow, Poland; 7RIKEN Nishina Center, Wako, Japan; 8Skobeltsyn Institute of Nuclear Physics, Moscow State University, Russia E-mail: [email protected]
The low-lying spectrum of 10He was studied in the transfer reaction 3H(8He, p)10He. The secondary 21.5 A MeV beam of 8He with intensity ~ 1.5×104 s–1 obtained with the fragment-separator ACCULINNA [1] (JINR, Dubna) hit a gaseous tritium target [2]. Tritium in the target cell cooled down to 26 K was kept at the pressure of about 1 atm. The 0+ ground state of the 10He nucleus was found at about 2.1 ± 0.2 MeV (Γ ~ 2 MeV) above the three-body 8He+n+n breakup threshold. Angular correlations observed for 10He decay products show prominent interference patterns allowing to draw conclusions about the structure of low-energy excited states. We interpret the observed correlations as a coherent superposition of the broad 1– state having a maximum at energy 4 - 6 MeV and the 2+ state above 6 MeV, setting both on top of the 0+ state “tail". This anomalous level ordering indicates that the breakdown of the N = 8 shell known in 12Be thus extends also to the 10He system.
1. A.M.Rodin et al. // Nucl. Phys. A. 1997. V.626. P.567c. 2. A.A.Yukhimchuk et al. // Nucl. Instr. Meth. A. 2003. V.513. P.439.
68 N AND Z DEPENDENCE OF NUCLEAR CHARGE RADII AND CORRELATION WITH OTHER SPECTROSCOPIC OBSERVABLES
K.P. Marinova1, I. Angeli2 1 Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia; 2 Institute of Experimental Physics, University of Debrecen, Hungary E-mail: [email protected]
An updated set of rms nuclear charge radii R =
1. I.Angeli, K.P.Marinova // At. Data Nucl. Data Tables. 2012 (in print). 2. I.Angeli et al. // J. Phys. G. 2009. V.36. P.085102.
69 THE RESULTS OF PERMANENT EXPERIMENTAL INVESTIGATIONS OF 60Co β-DECAY RATE CHANGE DURING 2010–2011
Yu.A. Baurov1, V.A. Nikitin2, V.B. Dunin2, N.A. Demchuk1, A.Yu. Baurov1, V.V. Tikhomirov2, C.V. Sergeev2, A.Yu. Baurov (junior)1 1 Central Research Institute of Machinery, Korolev, Moscow region, Russia; 2 Joint Institute for Nuclear Researches, Dubna, Moscow region, Russia E-mail: [email protected]
This report presents the results of long-term permanent experimental study of 60Co β-decay rate changes measured with the use of scintillation detectors on basis of LaBr3 crystals during 2010-2011 years. The experimental procedure was based on coincident records of γ-quanta with energies 1.17 and 1.332 MeV accompanying the 60Co β-decay. The data were pro- cessed by the statistical Kolmogoroff- Smirnoff’s criterion. In April 2010 and 2011 the results have shown an excess over the 0.01 significance level in the maximum difference between the the- oretical uniform and experimental ir- regular γ-quanta distributions in the course of 24 hours' observation. The maximum of pointed difference coin- cided for period March (11-21) in 2010 and 2011. (Fig. 1). A brief com- Fig. 1. The statistical Kolmogoroff- parison of the result obtained with the Smirnoff’s criterion for March (11-21) in earlier observational data for changes 2010 and 2011. Horizontal line – the value in the radioactive elements β-decay of criterion for indicated significance level rate is given [1-3]. (a = 0.02 for 2010, a = 0.1 for 2011).
1. Yu.A.Baurov et al. // Mod. Phys. Lett. A. 2001. V.16. P.2089. 2. Yu.A.Baurov et al. // Phys. At. Nucl. 2007. V.70. P.1825. 3. Yu.A.Baurov et al. // Appl. Phys. 2011. V.5. P.12.
70 STUDY OF THE DECAY 157Er → 157Ho
Yu.A. Vaganov, V.G. Kalinnikov, V.I. Stegailov, A.V. Sushkov, Yu.V. Yushkevich, N.Yu. Shirikova Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
The processing of gamma-gamma and electron-gamma coincidence spectra at YASSNAP [1, 2] experimental complex is continued to systematize the characteristics of the nuclear levels. The cascades of е-γ-t and γ-γ-t coincidences (see table) were detected.
Wind.(keV) E (keV) 40.8 (53.1), 121.5, (141.5), 236.6, 264.9, 308.3 53.14 40.8, 121.5, 150.5, 162.3, 180.0, (219.3), 264.9, 303.5, 305.5, 308.3, 349.0, (503.5), 652.0, 584.2, 638.4, 652.0, 1114.8, 1243.0, 1396.7 55.5 53.1, 121.5 57.2 (53.1), (121.5) 67.0 136.4, 161.8, 205.6, 503.5, 570.2, (644.3), (902.0) 68.9 84.6, 150.5 83.5 347.4, 527.9, 608.4, 648.1 121.5 40.8, 53.1, 180.0, 182.2, 183.4, 216.8, 344.0, 305.5, 308.3, 396.0, 451.9, 530.8, 587.2, 721.9, 734.6, 792.5, (1142.6) 141.5 40.8, 162.9 150.5 53.1, 68.9, 153.0, 171.0, 423.3, 488.1, 501.6, 614.8, 674.0 162.3 53.1, 55.5, 141.5, 236.6, 264.9, 308.5 180.0 53.1, 121.5, 640.6 182.2 53.1, 121.5 183.4 144.5, 211.9 303.5 53.1, 638.4 305.5 121.5 347.4 83.5
More than 20 new levels (keV) [1, 2] were supplemented in the scheme of the 157Er decay: 187.9, 203.6, 215.4, 272.5, 354.6, 356.8, 358.0, 451.7, 480.1, 523.9, 626.9, 691.8, 705.3, (731.6), 761.9, 818.5, 877.7, 896.5, 909.3, (944.8), 967.1, 995.3, 1064.6, 1161.5, 1289.4, 1430.9, 1481.7, 1507.0, 1597.0, 1759.1. The interpretation of the obtained results is carried out.
1. V.Andreitscheff, V.G.Kalinnikov, V.I.Stegailov, et al. // 28 Inter. Confer. L. 1978. P.78. 2. B.A.Alikov, V.Andreitscheff, A.Voizehovska, et al. // Nucleonika. 1979. V.24. P.1139.
71 STUDY OF THE DECAY 156Ho → 156Dy
Yu.A. Vaganov, Z. Hons, V.G. Kalinnikov, V.I. Stegailov, A.V. Sushkov, N.Yu. Shirikova Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected]
The excited levels of 156Dy were studied intensively by the method of nuclear reactions [1-2] and in beta-decay 156Ho [3-4] but there are many contradictions. The (γ-γ-t) spectra of the coincidences were measured by the HPGe-detectors. The found cascades of gamma-gamma coincidences are shown in the table. Now the interpretations of the found results are running.
Wind. (keV) E(keV) 266.0, 366.0, 666.2, 684.1, 691.1, 752.1, 764.1, 795.1, 931.1, 950.2, 960.2, 964.3, 1030.1, 1038.5, 1080.5, 111.2, 1122.3, 137.5 1155.5, 1175.3, 1205.3, 1222.5, 1230.1, 1730.5, 1734.4, 1793.4, 2035.0, 2085.1, 2271.5, 2354.5, 2417.8, 2430.5 366.5, 564.5, 582.5, 617.3, 666.3, 684.3, 754.3, 763.5, 931.5, 961.5, 965.5, 1002.5, 1033.2, 1039.5, 1156.5, 1190.5, 1205.3, 1223.5, 1235.5, 1272.2, 1292.5, 1301.5, 1309.5, 1315.5, 1380.2, 266.5 1390.5, 1415.5, 1421.2, 1453.5, 1526.5, 1536.5, 1545.5, 1643.2, 1649.2, 1669.5, 1734.5, 1902.5, 2029.5, 2035.2, 2049.5, 2053.5, 2086.3, 2238.3, 2414.2, 2419.3, 2494.5, 3279 278.0 752.2, 891.1, 1121.5 312.5 684.5, 763.2, 884.5, 1121.2, 1223.5, 1453.2, 1568.5 564.5, 667.5, 754.5, 1040.5, 1087.3, 1128.3, 1172.5, 1292.3, 366.4 1314.5, 1381.5, 1450.1, 1460.5, 1499.5, 1522.3, 1536.2, 1663.2, 1668.5, 2052.3, 3278.2
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72 EXPERIMENTAL AND THEORETICAL STUDIES OF THE STRUCTURE OF THE NONROTATIONAL STATES IN NUCLEI 155,157,159,161,163,165Но
P. Aleksa1, V.M. Gorozhankin2, Z. Hons2, V.G. Kalinnikov2, J. Kvasil3, V.I. Stegailov2, A.V. Sushkov2, N.Yu. Shirikova2 1 Department of Physics, Technical University of Ostrava, Czech Republic; 2 Joint Institute for Nuclear Research, Dubna, Russia; 3 Institute of Particle and Nuclear Physics, Charles University, Czech Republic E-mail: [email protected]
The behavior of the band head levels was established due to the results of the experimental study in nuclei 155÷165Ho [1–4]. However, there are discrepancies in the interpretation of some levels [5, 6]. The theoretical description of the experimental results is not sufficient [7]. To eliminate the existing discrepancies, the experimental studies of the decay of the erbium isotopes with A = 155, 157, 159, 161, 163 have been carried out for many years in Dubna. The calculations of the energies and the probabilities of the hand head levels 7/2–[523], 1/2+[411], 7/2+[404], 5/2+[402], 9/2–[514], 3/2+[411], 5/2+[413], 5/2-[532] were performed in the framework of the rotor-vibrational model with the Nilson potential [8]. The results for Ho isotopes are shown in the table (in keV).
[523] [404] [532] [540] [411] A exp. theor. exp. theor. exp. theor. exp. theor. exp. theor. 157 0 1 67 56 391 393 482 478 175 180 159 0 9.05 166 115 625 614 424 431 382 387 161 0 0 253 256 827 827 424 420 299 304 163 0 1 440 440 1114 1114 471 463 360 362 165 0 5 715 713 1415 1400 681 676 362 365
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73 PENETRATION EFFECTS IN THE E1 AND E2 HINDERED TRANSITIONS IN THE Sn NUCLEI
I.N. Vyshnevsky, S.S. Drapey,V.А. Zheltonozhsky, А.M. Savrasov Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kiev E-mail: [email protected]
Data on the existence of abnormal E1 and E2 transitions that allow to judge with confidence about the penetration effects in these transitions were obtained in a limited number of cases. A small number of such data was caused by the fact that the hindered transitions are required to detect the penetration effects. Our studies included penetration effects in the E1 and E2 hindered transitions in the Sn nuclei, which have a high degree of forbiddance according to Weisskopf. The experimental difficulties were caused by the fact that the contribution of the penetration effect is determined on the assumption of the difference between experimental and theoretical internal conversion coefficients. Herewith, contribution of the penetration effect usually averages to 1–3%, therefore it is necessary to conduct measurements with the level of accuracy <1%.
We used the αK determination method in terms of relative measurements of X-ray intensity and gamma transitions in the spectra of gamma-KX-coincidences for Sn, which provides the required accuracy.
As a result of the experiment, the following values of Sn αK were obtained:
th exp exp∗ Transitions αK αK αK E1 0.120 0.182±0,009 0.190±0.016 E2 0.218 0.245±0,012 0.220±0.015
Based on the obtained data, values of the penetration coefficients were determined
(keV) Nuclei Eγ FW λ1 120 Sn 89 18000 0.45±0.15 120 Sn 197 260 5±1
Discussions of the obtained data are in progress.
74 COMPETITION OF DECAY CHANNELS OF 90Zr GDR AND ITS ISOSPIN SPLITTING
E.A. Bychkova1, N.N. Peskov2, M.E. Stepanov1,2, V.V. Varlamov2 1 Faculty of Physics, Lomonosov Moscow State University, Russia; 2 Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected]
Data on 90Zr photodisintegration proton and neutron decay channels which define main parameters of giant dipole resonance (GDR) isospin splitting are investigated. New theoretical data obtained in the Combined Model of Photonucleon Reactions [1] and special transitional multiplicity function as criteria of data reliability F2=σ(γ, 2n)/σ(γ, xn) were involved in correction of results of two type of experiments carried out with quasimonoenergetic annihilation photons at Saclay (France) and Livermore (USA). New data on 90Zr GDR isospin splitting parameters (ΔE is energy of splitting, R is ratio of splitting components, E c.g. is energetic center of gravity of components with isospin T> and T<) were obtained on the base of joint analysis of data on GDR states appeared as resonances in photoneutron and photoproton reaction cross sections and possible channels of decay via states with various isospin values in neighboring nuclei.
Theory Evaluations
[2, 3] [4, 5] [6] Present work ΔE [MeV] 4.0 3.7 3.3 4.5 R [arb.units] 0.17 0.10 0.14 0.19 c.g. E > [MeV] 20.7 21.2 21.8 c.g. E < [MeV] 16.7 17.9 17.2
The differences in partial decay channels were eliminated in corrected data, therefore isospin splitting parameters are in better agreement with theoretical estimates now.
1. B.S.Ishkhanov, V.N.Orlin // Phys. At. Nucl. 2011. V.74. P.19. 2. S.Fallieros, B.Goulard, R.H.Venter // Phys. Lett. 1965. V.19. P.398. 3. R.O.Akyuz, S.Fallieros // Phys. Rev. Lett. 1971. V.27. P.1016. 4. K.Shoda, H.Miyase, M.Sugawara, et al. // Nucl. Phys. A. 1975. V.239. P.397. 5. K.Shoda // Phys. Rep. 1979. V.53. P.343. 6. V.V.Varlamov, N.N.Peskov, M.E.Stepanov // Phys. At. Nucl. 2009. V.72. P.241.
75 ALPHA-STABILITY OF SUPERHEAVY NUCLEI
N.N. Kolesnikov Moscow State University, Russia E-mail: [email protected]
In the region Z > 82, N > 126 the beta-stability line, whose equation is Z* = 0.356A + 9.1 [1, 2], deviates from the line A – 2Z = const, corresponding to α- decay. The nucleus formed after α-decay of nucleus (A, Z) approaches to the beta-stability line. For the latter ∆Z*/∆A = 0.356 and for the line of α-decay ∆Z/∆A = 0.5, so the nucleus (A – 4, Z – 2) approaches closer to the beta-stability line by ∆Z = (0.5 – 0.356)×4 = 0.576. Then as the energy of beta decay is Qβ± = ±k(Z – Z*) – D [2] where k = 1.13 MeV, the energy of α-decay of nucleus (A – 4, Z – 2) becomes lower, than that for nucleus (A, Z) by 0.576k = 0.65 MeV. At last from the (α, β) cycle including nuclei (A, Z), (A, Z + 1), (A — 4, Z — 2) and (A — 4, Z — 1) it follows that the alpha-decay energy of isobar (A, Z + 1) must be higher than that of (A, Z) by 0.65 MeV independently of parity [2]. This conclusion is very well confirmed by all (about 200 ) experimental dates for energy of α-decay (Qα), compiled in the tables [3], the rms deviation is 0.12 MeV at maximal deviation 0.25 MeV (see[2]). Then it follows from this that energy of α- decay of nucleus (A, Z) may be calculated as * Qα(A, Z) = Q α(A) + 0.65(Z – Z*), (1) * where Q α is the α-decay energy of a nucleus (fictitious) lying on the line of * beta-stability. The dependence of Q α on A is well approximated by a linear * function of A. In the beginning (for 210 < A < 230) Q α decreases according to * law Q α = —0.209A + 53.4 MeV, later (for 230 1. N.N.Kolesnikov // Izvestia AN SSSR. 1985. V.49. P.2144. 2. N.N.Kolesnikov // Preprint №8/2008. Physical Faculty. MSU. 3. R.B.Firestone et al. Tables Of Isotopes. 8-Th. Ed. New York. 1996. 4. Yu.Ts.Oganessian // J. Phys. G: Nucl. Phys. 2007. V.34. P.R165. 76 BETA-STABILITY OF SUPERHEAVY NUCLEI N.N. Kolesnikov Moscow State University, Russia E-mail: [email protected] As it follows from analyses of experiment [1,2] and is in conformity with many-particle shell model [3], the charge Z* of isobar (generally fictitious) possessing minimal energy, changes as a linear function of mass number (A). In particular for heavy nuclei (Z > 82, N > 126) ( see [1, 4]): Z*(A) = 0.356A + 9.1. (1) ± Moreover the energy Qβ± of β decay of the nucleus (A, Z) depends on its distance from beta-stability line as Qβ±(A, Z) = ± k (Z – Z*) + D, (2) where k and D are constants [1, 4]. Due to relations Qβ+(A, Z) = –Qβ–(A, Z—1) and Qβ–(A, Z) = –Qβ+(A, Z+1) it is convenient to consider only nuclei with even Z. The values of parameters in Eq. (1) are: k = 1.13 MeV, the parity correction D = 0.75 MeV for (odd Z, even N) nuclei and D = 1.9 MeV for (even Z, even N) nuclei. The confrontation of results of calculation according to Eqs. (2) and (1) with experiment is presented in the Fig.1. Despite of the use in sum only 5 parameters in Eqs. (1, 2) they assures sufficiently high accuracy for Qβ±: the rms deviation is about 0.3 MeV and maximal deviation is 0.6 MeV at inclusion of all experimental data of the table [2]. Fig.1. Dependence of Qβ on difference Z - Z*. 1. N.N.Kolesnikov // Preprint №8/2008. Physical Faculty, MSU. 2. R.B.Firestone et al. Table of Isotopes 8-th. ed. New York. 1996. 3. I.Talmi, A.De Shalit // Phys.Rev. 1958. V.108. P.376. 4. N.N.Kolesnikov // JETP. 1956. V.30. P.889. 77 NUCLEAR SHELLS AND THE STRUCTURE OF THE ENERGY SURFACE OF HEAVY ELEMENTS N.N. Kolesnikov Moscow State University, Moscow, Russia E-mail: [email protected] We proceed from the idea issued from experiments [1] that it is possible to divide the nuclear binding energy surface into the regions inside of which the binding energy of both protons (Bp ) and neutron (Bn)are presentable as a linear functions of number of protons (Z) and neutrons (N).Bounding lines between regions along Z = const or N = const are identified with (sub)magic numbers. The values of all parameters of energy surface and the (sub)magic numbers themselves were searched by means of solution of an inverse problem at requirement that these reproduce the experimental binding energy Bp and Bn for all heavy and superheavy nuclei compiled in [2] and in [3]. The method of solution and the final results are given in [1]. For convenience the results obtained for Bp and for Bn are reduced on the line of beta-stability (see [1]). Here in Fig. 1 the reduced energy Bn are presented; the lower curve refer to (even Z-even N) nuclei; the next line above — to odd-even nuclei; then follows line of odd-odd nuclei and the last of even-odd ones; moreover the line denoted as C corresponds to the line averaged over all parities. As it is seen from Fig. 1, after magic number N = 126 (fall by 2.1 MeV), most important subshells are N = 152 (fall 0.4 MeV) and N = 162 (fall 0.2 MeV). For protons after shell Z = 82 (fall 1.6 MeV) most important subshells are Z = 100 (fall 0.4 MeV) and Z = 92 (fall 0.3 MeV), see [1]. Fig. 1. Reduced binding energy of neutron. Neutron shell effects. 1. N.N.Kolesnikov // Preprint №8/2008. Physical Faculty. MSU. 2. R.B.Firestone et al. Tables of isotopes. 8-th. ed. New York. 1996. 3. Yu.Ts.Oganessian // J. Phys. G: Nucl. Phys. 2007. V.34. P.R165. 78 ALGORITHMS OF SEARCH FOR RARE DECAYS IN THE EXPERIMENTS ON THE SYNTHESIS OF SUPERHEAVY NUCLEI V.K. Utyonkov 1, M.V. Shumeiko 1,2 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Voronezh State University, Russia E-mail: [email protected] In the experiments performed in the Flerov Laboratory of Nuclear Reactions, JINR, Dubna, the superheavy nuclei were synthesized in the complete fusion reaction of 48Ca projectiles with 237U–249Cf target nuclei. Six new superheavy elements with atomic numbers 112−118 were observed for the first time. In these experiments the Dubna gas-filled recoil separator and detector system consisting of 12 focal-plane and 8 side detectors were employed. A set of codes was developed for quick calibration of the detector system and search for rare decay chains of heavy nuclei. In this paper the basic algorithms, principles and mathematic methods are discussed. The data accumulated in the experiment aimed at the synthesis of isotopes of element 115 in the reaction 243Am+48Ca were analyzed. Decay chains originating from 288115, the product of the 3n-evaporation channel, were found with the use of the new codes. One of the observed decay chains is shown in Fig. 1. Fig. 1. Decay chain of 288115 synthesized in the reaction 243Am(48Ca, 3n) at the excitation energy of the compound nucleus 291115 of 33 MeV. The energies, decay times, and positions of the detected events are given in the Figure. 79 EVALUATED OCCUPATION PROBABILITIES OF SINGLE-PARTICLE ORBITS IN MEDIUM RANGE NUCLEI O.V. Bespalova, E.A. Romanovsky, T.I. Spasskaya Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] exp Experimental occupation probabilities Nnlj for neutron and proton orbits near 40 124 the Fermi energy EF in stable even-even nuclei from Ca to Sn were obtained [1] by the joint evaluation of stripping and pick-up reaction data on the same nucleus. The data demonstrate shell closure when N, Z are equal to traditional magic number 20, 28, 50 and new magic number N=56 for Z=40. To evaluate occupation probabilities we used the formula of BCS theory. The Fermi energy EF was determined as half the sum of nucleon separation energy (with the opposite sign) from A and A+1 nuclei. The gap parameter ∆BCS for semi- closed shell nuclei determined by relativistic mean field theory + BCS was taken BCS exp exp from [2]. Good agreement of evaluated probabilities nlj EN nlj )( with Nnlj was achieved for stable nuclei (see Fig. 1, left). For unstable medium weight nuclei DOM the single-particle energies Enlj were calculated by dispersive optical model BCS DOM (DOM) and corresponding occupation probabilities nlj EN nlj )( were BCS DOM evaluated. In Fig 1 (right), occupation probabilities nlj EN nlj )( for the neutron single particle orbits of Ca isotopes with N from 20 to 50 are shown for the BCS example in comparison with the available experimental data. Occupations Nnlj , which correspond to the traditional magic number N=20, 28, 50, differ from that of the “new magic number” N=32, 34. Fig. 1. Occupation probabilities of neutron single-particle orbits in stable Sn isotopes (left) and neutron single-particle orbits in Ca isotopes with N from 20 to 50 (right). Data points – experimental data [1], lines with points – calculation using formula of BCS theory. 1. I.N.Boboshin. Magic numbers and shell structure evolution of atomic nuclei. Doctoral thesis (in Russian). Moscow. 2010. 2. S.Typel, H.H.Wolter // Nucl. Phys. A. 1999. V.656. P.331. 80 PROTON SHELL EVOLUTION OF NUCLEI WITH 20 ≤ Z ≤ 28 AND 20 ≤ N ≤ 50 AND DISPERSIVE OPTICAL MODEL O.V. Bespalova, T.A. Ermakova, A.A. Klimochkina, E.A. Romanovsky, T.I. Spasskaya Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] exp In [1], the experimental proton and neutron single-particle energies Enlj near the Fermi energy in the medium weight nuclei were obtained by the joint evaluation of the stripping and pick-up reaction data on the same nuclei. In the exp eval present work, in addition to Enlj , proton energies Enlj were evaluated using exp experimental neutron energies Enlj in the mirror nuclei. Then the evolution of the corresponding values of particle-hole gap G was identified for the isotopic and isotonic chains of nuclei with 20 ≤ Z ≤ 28 and 20 ≤ N ≤ 28. The gap G increases in double magic, magic nuclei, and nuclei with N=Z. exp,eval The proton energies Enlj were analyzed by dispersive optical model (DOM). The Fermi energy EF was defined as half the sum of nucleon separation energy (with the opposite sign) from A and A+1 nuclei. The parameters of dispersive optical model potential were determined and good exp DOM agreement between Enlj and Enlj was achieved. The parameters smoothly depend on N, Z and also take into account shell closure at N, Z magic numbers. A method to extrapolate dispersive optical model potential from stable isotopes to unstable ones up to drip-lines was elaborated. The method was applied to predict proton shell evolution of nuclei with 20 ≤ Z ≤ 28 and 20 ≤ N ≤ 50. 1. I.N.Boboshin. Magic numbers and shell structure evolution of atomic nuclei. Doctoral thesis (in Russian). Moscow. 2010. 81 EVALUATION OF NUCLEAR STRUCTURE AND DECAY DATA FOR A=146 MASS CHAIN Yu.L. Khazov, A.A. Rodionov B.P.Konstantinov Petersburg Nuclear Physics Institute, Russia E-mail: [email protected] This evaluation was carried out in the framework of activity of the Interna- tional Network of Nuclear Structure and Decay Evaluators, established in 1974 under the auspices of the IAEA. All data up to March 2012 were considered and compiled. The table shows the activity of the experimental research in the A=146 region. The main aim of the evaluation was to assemble consistent level schemes for all nuclei with A=146 and to recommend a set of the best parame- ters for a range of nuclear properties, such as level and gamma-ray energies, quantum numbers and lifetimes. Number of Number of Level energies were calculated by a least- Nuclide levels γ-transitions squares fit to transition energies using the pro- now / [1] now / [1] gram GTOL 7.2f [1] from ENSDF evaluator’s Xe 10/- -/- package. When transition energies were not agree Cs -/1 -/- Ba 49/43 85/76 (more then three standard deviations) with the en- La 60/49 245/231 ergy difference between the corresponding levels, Ce 118/118 321/317 they were not used in calculation. Usually, the Pr 10/9 23/21 normalized χ2 values are close to 1 for the evalu- Nd 300/292 352/279 ated level schemes. Pm 79/79 137/137 In several cases it was possible to develop Sm 216/168 480/389 more detail level schemes for a particular nuclide. Eu 71/36 107/44 For example, the 146Pm is not produced as a result Gd 245/197 317/190 − Tb 140/89 57/27 of β - decay or electron capture, but obtained 146 Dy 75/22 109/27 with the reactions in on-line. Pm level scheme Ho 1/1 -/- was studied in 146Nd(p, nγ) [2] and Er 1/1 -/- 136Xe(15N, 5nγ), 146Nd(d, 2nγ) [3] reactions. How- Tm 6/2 5/- ever, it was not enough experimental data to as- sign the characteristics of low-lying levels (< 873 keV). The authors had calcu- lated the reduced probabilities of γ-transitions with the program RULER [1] us- ing lifetimes of the 146Pm levels from [3], as well as had suggested the rotational structure for the levels connected by cascade of γ-transitions. As a result spins and parities of the lower excited states of 146Pm were assigned. 1. http://www.nndc.bnl.gov/nndcscr/ensdf_pgm/analysis/. 2. K.Uebelgunn, K.Farzine, U.Krumme, H.v.Buttlar // Z. Phys. A. 1992. V.341. P.465. 3. T.Rzaca-Urban, W.Urban, J.L.Durell, et al. // Nucl. Phys. A. 1995. V.588. P.767. 82 THE GAMMA-RAY INTENSITIES FROM THE 177mLu DECAY A.P. Lashko, T.N. Lashko Institute for Nuclear Research NASU, Kiev, Ukraine E-mail: [email protected] The relative intensities of γ-rays following the decay of 177mLu (Т1/2 = 160 days) were measured with a gamma-spectrometer that comprises two horizontal coaxial HPGe-detectors: GMX-30190 and GEM-40195, having the resolution of 1.89 and 1.73 keV for the γ1332-line of 60Co and efficiency of 33% and 43% respectively. The radioactive 177mLu sources were obtained in the (n, γ) reaction as a result of enriched 176Lu target irradiation with neutrons at the research nuclear reactor WWR-М. The measurements of gamma-ray spectra started two months after the 177 end of irradiation so that Lu (Т1/2 = 6.6 days), having much larger activation cross-section, must have decayed en masse. The results of these measurements are listed in Table. The gamma-ray energies were taken from Ref. [1]. Intensities Intensities Intensities Energies of Energies of Energies of of γ-rays, of γ-rays, of γ-rays, γ-rays, keV γ-rays, keV γ-rays, keV a. u. a. u. a. u. 105.3589 100 204.1050 109.2(16) 305.5033 14.11(29) 112.9498 173.0(25) 208.3662 482(7) 313.7250 9.9(3) 115.8682 5.12(14) 214.4341 51.8(7) 319.0210 83.1(23) 121.6211 48.2(8) 218.1038 26.8(5) 321.3159 10.3(4) 128.5027 126.1(18) 228.4838 296(5) 327.6829 145.9(28) 136.7245 11.47(23) 233.8615 44.5(7) 341.6432 13.8(4) 145.7693 7.65(13) 242.07 0.458(24) 367.4174 25.1(6) 147.1637 28.1(4) 249.6742 49.0(9) 378.5036 241(5) 153.2842 136.2(20) 268.7847 27.4(7) 385.0304 25.4(4) 159.7341 4.21(9) 281.7868 112.6(23) 413.6637 138.8(21) 171.8574 38.1(6) 283.609 3.23(26) 418.5388 171.7(23) 174.3988 100.8(14) 291.5429 8.14(30) 426.4726 3.64(16) 177.0007 28.6(4) 292.5266 6.75(10) 465.8416 19.8(3) 181.9093 0.77(7) 296.4584 39.8(8) 195.5602 6.60(12) 299.0534 13.11(29) The usage of different types of detectors allowed to determine the relative intensities of γ-rays for the energy range above 100 keV more precisely. Our data agrees to a great extent with the data of other researchers while having higher precision. 1. S.Matsui, H.Inoue, Y.Yoshizawa // Nucl. Instrum. Meth. Phys. Res. A. 1989. V.281. P.568. 83 PRECISE MEASUREMENT OF THE GAMMA-RAY ENERGIES FROM THE 175Hf DECAY A.P. Lashko, T.N. Lashko Institute for Nuclear Research NASU, Kiev, Ukraine E-mail: [email protected] The differences in energy for four pairs of γ-lines (γ245 - γ230, γ230 - γ205, γ433 - γ411, and γ468 - γ433) were measured with a gamma-spectrometer that comprises two horizontal coaxial HPGe-detectors: GMX-30190 and GEM-40195, having the resolution of 1.89 and 1.73 keV for the γ1332-line of 60Co, paired with the multichannel buffer ORTEC 919 SPECTRUM MASTER. One γ-transition from each pair is excited in the 175Hf decay, while the other one, which energy is known precisely, accompanies the 152Eu or 192Ir decay. 175 The radioactive Hf (Т1/2 = 70 days) sources were obtained in the (n, γ) reaction at a research nuclear reactor WWR-М. Natural hafnium targets were 152 192 used for the purpose. The reference Eu (Т1/2 = 13.5 years) and Ir (Т1/2 = 73.8 days) sources were also obtained in (n, γ) reaction as a result of irradiation of 151Eu and 191Ir samples by slow neutrons. Several composite radioactive sources (175Hf + 152Eu and 175Hf + 192Ir) with different ratios of nuclide radioactivity were prepared. The findings about energy values of the γ230 and γ433 keV transitions along with the data from our previous works [1, 2] and energy values of three transitions from Ref. [3] allowed us to calculate the energies of levels and corresponding γ-ray transitions in 175Lu. The abovementioned results are presented in the Table. Energies, eV levels γ-rays levels γ-rays 113800.8 ± 2.8 113800.8 ± 2.8 396322 ± 5 144863 ± 6 251459 ± 4 137658 ± 5 282521 ± 6 251459 ± 4 396322 ± 5 343410.2 ± 1.9 229609.2 ± 3.4 432772 ± 5 89362 ± 5 343409.8 ± 1.9 318971 ± 6 432771 ± 5 The values of energy for levels in 175Lu and deexciting γ-rays following the decay of 175Hf that we presented in this study agree to a great extent with the data of other researchers, however our data have higher precision. 1. A.P.Lashko, T.M.Lashko // Ukr. J. Phys. 2009. V.54. P.337. 2. A.P.Lashko, T.M.Lashko // Ukr. J. Phys. 2009. V.54. P.678. 3. J.D.Reierson, G.C.Nelson, E.N.Hatch // Nucl. Phys. 1970. A. V.153. P.109. 84 DETERMINATION OF THE PRECISE VALUE OF HALF LIFE OF 212Po V.A. Morozov, N.V. Morozova Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] This work has been undertaken for the purpose of half-life 212Po evaluation in various environments. Radioactive source in the first case was 228Th included in plastic scintillator (PS), in other cases [1] sources 212Po were prepared by implantation of products of 220Rn disintegration by electrostatic method in various targets – Ni, Pb and target Pb with additional layer of Pb after implantation of 220Rn. Measurements were carried out with an autocorrelation single-crystal scintillation time spectrometer [2]. Results of measurements are presented in table and on Fig. 1. 212 Observable difference of Т1/2 for Po included in plastic scintillator and metal matrixes, obviously, connected with features of electron-α interaction in atoms. Half-life of 212Po into different environments Matrix Pb Pb&Pb Ni PS NDS [3] T1/2, ns 295.7(3) 296.4(2) 296.8(2) 299.0(2) 299(2) 100000 212Po → 208Pb 1. Pb ∆t = 1.99 ns/ch 2. Pb & Pb 10000 3. Ni 4 T1/2 = 299.0(2) 4. PS 1000 1 3 2 100 Number of Counts of Number 10 1 0 1000 2000 3000 4000 Channel Number (t) Fig.1. Decay curves of 212Po. 1. V.L.Mikheev et al. // Let. Part&Nucl. 2008. V.5. No.4(146). P.623. 2. V.A.Morozov et al. // Nucl. Inst. Meth. A. 2002. V.484. No.1-3. P.225. 3. E.Brown //Nucl. Data Sheets. 2005. V.104. No.2. P.427. 85 EXPERIMENTAL INVESTIGATIONS OF NUCLEAR REACTIONS MECHANISMS LASER-INDUCED NUCLEAR REACTIONS AND TARGET RADIOACTIVITY WITH MODEST LASER PULSE ENERGY OF ~ 200 mJ N.I. Vogel1, V.A. Skvortsov2 1 Insitute of Physics, Chemnitz University of Technpology, Chemnitz, Germany; 2 Moscow Institute for Physics and Technology (State University), Dolgoprudny, Russia E-mail: [email protected] Nuclear activation has been observed in 181Ta – targets exposed to an exploding laser plasma at focused intensities only of order of 1015 W/cm2. It is well known, that at laser intensities greater than 1019 W/cm2 nuclear activation can be reached in laser-solid interactions from γ - ray induced reactions [1, 2], or from proton induced (p, n) reactions [3]. High level of nuclear activation observed in our experiments with a modest laser intensity can be caused by high energy multiple ionized Ta- ions, or by magnetic interaction between a monopole and a nucleon. The possible mechanism of light monopole generation [4] in laser plasma will be discussed in this presentation. Fig. 1. SEM image of Ta-target with a crater, EDX spectrum of sample, Tm – line was detected in vicinity of crater with 0.87 %. 1. M.H.Key et al. // Phys. Plasmas. 1998. V.5. P.1966. 2. M.I.Santala et al. // Phys. Rev. Lett. 2000. V.84. P.1459. 3. M.I.Santala et al. // Appl. Phys. Lett. 2001. V.78. P.19. 4. V.A.Skvortsov. N.I.Vogel // Megagauss XI. Proc. of 11th Int. Conf. on Megagauss Magn. Field Generation and Rel. Topics. London. 2007. P.419. 86 PARTIAL PHOTONEUTRON REACTION CROSS SECTIONS ON 115In AND NEUTRON MULTIPLICITY SORTING V.V. Varlamov, N.N. Peskov, M.E. Stepanov Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University, Russia; Centre for Photonuclear Experiments Data E-mail: [email protected] For isotope 115In the combined analysis was carried out for experimental data for cross sections of total photoneutron yield reaction σ(γ, xn) = σ(γ, n) + 2σ(γ, 2n) + 3σ(γ, 3n) + …and partial photoneutron reactions included obtained using bremsstrahlung and quasimonoenergetic annihilation photons. The systematic disagreements between the various experiments data were analyzed. Significant disagreements between various experiments data were revealed. For investigation of partial reaction cross section data reliability and authenticity the special transitional multiplicity sorting functions Fi = σ(γ, in)/σ(γ, xn) [1] were introduced. Those are clear simple and absolute criteria of neutron multiplicity sorting. Absolute values of Fi must be < 1.00 for i = 1, 0.55 for i = 2, 0.33 for i = 3, etc. and larger absolute values mean that neutron multiplicity sorting was carried out incorrectly — that resulted in appearance of non-physical ranges of negative values in σ(γ, n) cross section [2]. As the way of such kind problems taking into account and disagreements overcoming the new experimental-theoretical treatment to evaluation of partial reaction cross sections for σ(γ, n) and σ(γ, 2n) reaction cross sections free from shortcomings of experimental neutron multiplicity sorting methods was applied [3]. In that only σ(γ, xn) reaction cross section free from neutron multiplicity sorting problems was used as initial and for reliable description of various decay channels competition the equations of modern model [4, 5] of photonuclear eval theor exp reactions was used — σ (γ, in) = F i ∙ σ (γ, xn). New reliable and authentic evaluated cross section data for reactions 115In(γ, n)114In and 115In(γ, 2n)113In were obtained. Large (till 20 – 30 %) deviations of those from the experimental ones are discussed first of all from the point of view of important physical sequences. The work was partially supported by RBFR Grant 09-02-00368, scientific schools grant 02.120.21.485-SS and contract 02.740.11.0242. 1. V.V.Varlamov et al. // Conference «Nucleus 2011» Book of Abstracts (Sarov). 2011. P.265. 2. V.V.Varlamov et al. // MSU SINP Preprint-2010-8/864. 2010. 3. V.V.Varlamov et al. // Izvestiya RAN. Ser. Fiz. 2010. V.74. P.884. 4. B.S.Ishkhanov et al. // Physics of Particles and Nuclei. 2007. V.38. P.232. 5. B.S.Ishkhanov et al. // Physics of Atomic Nuclei. 2008. V.71. P.493. 87 THE CROSS-SECTIONS OF (γ, n) REACTIONS FOR 120Te AND 122Te ISOTOPES IN THE E1-GIANT RESONANCE ENERGY REGION V.M. Mazur, D.M. Symochko, Z.M. Bigan, P.S. Derechkey Institute of Electron Physics of NAS of Ukraine, Uzhhorod, Ukraine E-mail: [email protected] The raising interest for the studies of photonuclear reaction in the giant resonances energy region which can be seen for the last decade is driven by several factors such as the development of new facilities for producing the intensive monochromatic gamma beams and also by the urgent need of experimental information used as input in astrophysical calculations [1]. It is known that in the process of nucleosynthesis the nuclei heavier than iron are mainly produced through the neutron capture reactions. However there are few dozens of stable isotopes screened from the neutron capture processes by stable isobars. Such isotopes are produced via the chain of photonuclear reactions and are named as p-nuclei. Light Te isotopes are also included in the p-process. Current work is devoted to the investigations of the 120Te(γ, n)119Te and 122Te(γ, n)121Te reactions cross-sections. Experiment was done on the bremmstrahlung beam of microtron M-30 with the step ΔE=0.5 MeV. The reactions threshold energy region was treated with special attention and the measurements were carried out with the step ΔE=0.25 MeV. The induced activity was measured by 175 cm3 volume HPGe-detector. Obtained cross-sections have single-humped form with maximum at the ~15.5 MeV energy. The least-square fitting procedure was used to approximate our data with Lorentz curves: 22 Γ0 E σ(E )= σ0 ⋅ 2 22 2 2 ()EE−00 +Γ E 120 here σ0, Е0, Г0 are parameters. Fitting resulted in the following values: for Te 122 – σ0=262.6±2.1, E0=15.47±0.1, Γ0=5.33±0.11 and for Te – σ0=274.1±2.5, E0=15.27±0.1, Γ0=4.76±0.08. 1. C.Nair, A.R.Junghaus, V.Erhard et al. // Phys. Rev. C. 2010. V.81. 055806. 88 INVESTIGATION OF ISOMERIC YIELDS RATIOS IN (γ, n) REACTIONS ON 127Te NUCLEUS FOR THE 10-20 MeV ENERGIES V.M. Mazur, D.M. Symochko, Z.M. Bigan, P.S. Derechkey Institute of Electron Physics of NAS of Ukraine, Uzhhorod, Ukraine E-mail: [email protected] 128 127m,g The study of isomeric yields ratios d=Ym/Yg in the Te(γ, n) Te reaction was carried out with the use of activation technique. The Tellurium samples of natural isotopic composition were irradiated by bremmstrahlung produced on microtron M-30 of IEP NAS of Ukraine with endpoint energies 10-20 MeV and step ΔЕ=0.5 MeV. The induced activity was measured with gamma- spectrometer based on the HPGe-detector with 175 cm3 volume and ~2 keV energy resolutions for 60Co reference gammas. The decay of the 127Te ground π + state with J =3/2 and T1/2=9.3 hours was identified by the Е=417 keV peak in gamma-spectra. After the cooling period of 10 days the same gamma-line was used for the identification of the 127mTe isomeric state decay (Jπ=11/2—, T1/2=106.1 days). The experimental yields ratios energy dependence d=ƒ(Eγmax) have been approximated with Boltzmann curve by least-square method: EE− d=+− A( BA ) / [1 + exp0 ] , ∆E here A, B, E0, ΔE denotes the parameters. As a result of fitting the following optimal parameters values have been obtained: A=0.315(20), B = -0.0496(20), E0=13.92(19) and ΔE=1.99(20). Model calculations of the isomeric ratios were performed with TALYS-1.4 code. Calculated and experimental data are in satisfactory agreement within the limits of error. 89 THRESHOLD DEPENDENCE OF THE NUCLEON–EMISSION YIELDS IN REACTIONS INDUCED BY PHOTONS S.A. Karamian Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] Relative yields were measured in [1-4] for the bremsstrahlung induced nucleon emission from the moderately heavy targets. Now, they are systematized as a function of the (Ee – Tr – Bc) parameter containing an excess of the end-point energy Ee above the sum of reaction threshold Tr and Coulomb barrier Bc of the emitted particle. Bc values for proton emission are calculated using well-known Bass equation. For (γ, n) and (γ, p) reactions, systematic growth of the yields versus this parameter is established. The yield values are normalized to the most abundant yield of the (γ, n) reaction. Common behavior of the both neutron- and proton-emission yields may confirm a similar mechanism for nucleon release induced by electromagnetic radiation. The mechanism involves nucleon evaporation from the compound nucleus past photon absorption accompanied with some contribution from the direct-release mechanism. Such a regular behavior allows prediction of the unknown yields at the stage of the experiment proposal. The total yield of a definite reaction could be semi-quantitatively estimated calibrating to the measured yield of the neighbor product in the similar reaction with correction to the difference in thresholds. This possibility is especially useful for activation experiments at the cases when the product nuclei are stable in the ground (g) state and – radioactive in the isomeric (m) state. The latter state yield being measured by activity could serve to determine the isomer-to-ground state ratio m/g by means of the total yield estimate through the mentioned above systematic dependence of the yields. Another valuable use arises for the case when both states are radioactive and the isomer excitation energy is not low. Thresholds for formation of the m and g states are therefore different. Using the systematic dependence, one deduces a contribution of the threshold factor into the measured m/g ratio, and then, could isolate the threshold- and spin-factors separately from the observed m/g ratio. 1. S.A.Karamian et al. // Z. Phys. A. 1996. V.356. P.23. 2. B.S.Ishkhanov, S.Yu.Troschiev // Bull. Rus. Acad. Sci. Phys. 2011. V.75. P.603. 3. B.S.Ishkhanov, S.Yu.Troschiev, V.A.Chetvertkova // Ibid: P.594. 4. B.S.Ishkhanov, S.Yu.Troschiev, V.A.Chetvertkova // Abstracts of 61t Intern. Conf.: Nucleus 2011. Sarov. 2011. P.90. 90 PECULIAR BEHAVIOR OF THE YIELDS FOR DIFFERENT REACTIONS INDUCED BY PHOTONS S.A. Karamian Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] Unlike strongly interacting projectiles (nucleons and nuclei), the electromagnetic radiation perturbs nucleons in a target nucleus only slightly. Thus, the peculiarities in the yield of photon-induced reactions at relatively low energy may serve as a probe of the bonds and correlations between nucleons in a nucleus. In [1], there are presented evidences for regular dependence of the yield from the reaction threshold. This is visible for (γ, n) and (γ, p) reactions with moderately heavy target nuclei. Within the group of analyzed data, there are also yields of the (γ, 2n), (γ, pn) and (γ, α) reactions: see references in [1]. Their yields deviate from the regular threshold dependence. How to explain that and what conclusion follows? The (γ, 2n) reaction proceeds via sequential emission of two neutrons from the compound nucleus, when first neutron is evaporated with a great probability, and the emission of second one is defined by the residual excitation past first step. Thus, the yield ratio of (γ, 2n) to (γ, n) reactions is defined only by the bremsstrahlung spectrum, and the energy balance must be satisfied. Two neutrons are not emitted simultaneously. Therefore, neither 2n correlation, nor common threshold value influence the yield that typically exceeds the predicted value. The (γ, pn) reaction, in part, is going via direct emission of a deuteron, or simultaneous release of p and n. The consequent mechanism may add some little contribution, but much lower as compared to (γ, 2n). It is observed that (γ, pn) yield, in general, follows the threshold dependence being a little enhanced. Opposite, the (γ, α) yield is suppressed by two orders of magnitude as compared to (γ, p) reaction, even despite practically the same threshold. This means that the alpha pre-formation factor must be in account, similarly to the case of radioactive alpha decay. The conclusion follows that α-clusterization is incomplete within a nucleus. Nucleons remain nucleons inside the nuclear matter, and they are not dissolved to form a collective quark bag. The multi- quark correlations may take place but with restricted intensity. This conclusion is in agreement with the analyses undertaken for interpretation of the product spectra in reactions induced by protons at GeV energies. The “cumulative” component was isolated and its probability was estimated in [2]. 1. S.A.Karamian // 62 Int. Conf. “Nucleus 2012”. St.Petersburg. Solo, 2012. P.90. 2. V.I.Kukulin // Phys. of At. Nucl. 2011. V.74. P.1594. 91 REACTIONS WITH ISOMERS AS A PROBE OF THE LEVEL DENSITY AT INTERMEDIATE SPINS AND ENERGIES S.A. Karamian Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] Thermal-neutron capture reaction serves normally for control of the level density ρ at well defined energy E* and spin I values. This tool is very useful to deduce basic parameters of the statistical model and to calibrate the ρ(E*, I) landscape in an absolute magnitude. Relatively low spins, typically of about 5 units and lower, are populated with thermal neutrons. Neutron-absorption energy and spin of stable targets vary noticeably, thus, ρ(E*, I) dependence may be tested when the data for some set of nuclides are processed. However, the quality of results remains at a grade of interpolations corresponding to the selected group of the nuclides, not to the individual one. Reactions with charged projectiles (heavy ions) are efficient for population of the states in wide range of spins from 10 to 50 units and at residual excitations near 10-20 MeV. The level density could be integrally estimated, but specific variations of ρ as a function of (E*, I) coordinates are smoothed. Recently, the thermal neutron capture by the 178m2Hf isomer was studied [1] and it was stressed that a new area could be populated at the (E*, I) plane. With high-spin isomer target, the excitation energy of neutron resonances is shifted to higher energy due to the isomer energy. In spin coordinate, I π values may reach 31/2+ and 33/2+, or even higher. The populated area is again narrow the same as with stable targets, but spin range of 10-20 units becomes accessible. This is an intermediate position between typical neutron capture and heavy-ion induced reactions. One of the effects is manifested in the strongly enhanced isomer-to-ground state ratio for high-spin isomeric products, as is discussed in [1]. The reactions “from isomer to isomer” were touched originally in [2], and some experimental results were obtained. More extensive studies are promising, in particular, to probe the level density at the range of moderate spin and excitation energy. In literature, typically smooth ρ(E*, I) functions are assumed basing on the quasi-classics approach. But no one could exclude the great scale variations dependent on individual properties of the nuclides. For instance, an asymmetry in the level density for positive and negative parities or anomalously high spin for levels at low excitation may arise. The single particle structures in odd nuclei may generate such peculiarities, though they are not yet reliably confirmed in experiments. Reactions with isomers could throw some light to the nuclear structure at moderate spin and excitation energy. 1. S.A.Karamian, J.J.Carroll // Phys. Rev. C. 2011. V.83. 024604. 2. S.A.Karamian et al. // Z. Phys. 1996. V.356. P.23. 92 EXPERIMENTAL STUDY OF FISSION PRODUCTS YIELD DISTRIBUTIONS WITH JYFLTRAP D.A. Gorelov1,2, T. Eronen3, J. Hakala2, A. Jokinen2, A. Kankainen2, P. Karvonen2, V. Kolhinen2, I. Moore2, H. Penttilä2, I. Pohjalainen2, M. Reponen2, S. Rinta-Antila2, J. Rissanen2, V. Rubchenya1,2, A. Saastamoinen2, J. Äystö2 1 Saint-Petersburg State University, Russia; 2 University of Jyväskylä, Finland; 3 Max-Plank- Institut für Kernphysik, Heidelberg, Germany E-mail: [email protected] A new method to determine independent fission product yields was developed recently at the Accelerator Laboratory of the University of Jyväskylä [1]. The chemical universality of the ion guide technique has been combined with the unambiguous mass identification of ions using a Penning trap. The method was used to determine the independent yields in the proton-induced fission of 232Th and 238U at 25 MeV. The identification of the ions is based on their mass. The mass resolving power in such experiments usually is about 105 with the excitation time 400 ms. Nevertheless in some cases it is difficult to extract fission products yields due to population of isomeric states. There is not a large amount of experimental data available on the isomeric yield ratios and also fission theories do not often provide directly such information. However a special technique [2] allows improving the mass resolution and experimental determining isomeric yield ratios for some cases, like example in [3]. In this report the method for independent fission products yields will be described briefly. Experimental data for proton-induced fission of 232Th and 238U at 25 MeV will be presented. It will be discussed some possibilities to extend the present method, using Ramsey method, for a measurement of isomeric yield ratios. 1. H.Penttilä et al. // Eur. Phys. J. A. 2010. V.44. P.147. 2. T.Eronen et al. // Nucl. Instr. and Meth. B. 2008. V.266. 4527. 3. K.Peräjärvi et al. // Appl. Radiat. Isotopes. 2010. V.68. P.450. 93 ISOMERIC RATIOS IN 233U AND 241Am PHOTOFISSION FRAGMENTS V.А. Zheltonozhsky, А.M. Savrasov Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kiev E-mail: [email protected] Photofission by bremmsstrahlung photons has been investigated both 233U for the end point energies about: 17 and 10.5 МeV and 241Am for the end point energy about: 9.8 МeV. The gamma-spectra of the reaction products were measured by the semiconductor spectrometers based on HPGe-detectors which have energy resolution 2 keV for the 1332-keV γ-line of 60Co and detection efficiency of 18 % in comparison with a 3” × 3” NaI(Tl)-detector. The irradiations were done on the M-30 microtron of the Laboratory of Photonuclear Reactions at IEP, Uzhgorod. For the end point energy about 17 МeV at photofission the (γ, f) and (γ, nf) channels were opened when for the end point energies about 9.8 and 10.5 МeV only (γ, f) channel was opened. For the first time the isomeric yields ratios in the photofission fragments of 233U and 241Аm have been measured for the abovementioned end point energies of bremmsstrahlung photons. In photofission fragments the activities yields of the nuclides chain have been measured and isomeric yields ratios have been defined for isomeric pars shown in the table. Isomeric Ym/Yg Ym/Yg Ym/Yg para (Еbr = 10.5 МeV) (Еbr = 17 МeV) (Еbr = 9.8 МeV) 233U 233U 241Am 90m,gRb 0.9±0.3 0.7±0.3 1.1±0.3 133m,gTe 3.2±0.8 3.2±0.9 1.6±0.2 134m,gI 1.33±0.14 1.8±0.5 3.0±0.5 135m,gXe 0.14±0.02 0.38±0.04 0.18±0.01 From obtained data the average angular moments of photofission fragments have been calculated. The discussion is transacted about obtained data. 94 MASS DISTRIBUTION OF 238U PHOTOFISSION PRODUCTS S.S. Belyshev1, A.N. Ermakov2, B.S. Ishkhanov1,2, V.V. Khankin2, A.S. Kurilik1, A.A. Kuznetsov2, V.I. Shvedunov2, K.A. Stopani2 1 Faculty of Physics, M.V. Lomonosov Moscow State University, Russia; 2 Scobeltsyn Insitute of Nuclear Physics, Moscow State University, Russia E-mail: [email protected] In this work we study 238U photofission product yields with bremsstrahlung endpoint energy of 19.5, 29.1, 48.3, and 67.7 MeV. The experiment was carried out on the electron racetrack microtron RTM-70 at SINP MSU [1]. A sample was a natural mix of uranium isotopes coating on the aluminum disc. Identification of photofission products and determination of their quantitative characteristics were performed using gamma spectroscopy. Gamma spectra of the residual activity in the irradiated sample were measured with a high - purity germanium detector (HPGe). At this energy photofission and photonucleon reactions are possible. As a result we obtained independent and cumulative yields of photofission fragments and mass yield distribution for the photofission (Fig. 1). Additionally the ratio between asymmetric and symmetric modes of fission was measured (Fig. 2). Fig. 1. Mass yield distribution for the Fig. 2. Peak to valley ratio for the photofission of 238U with 67.7 MeV photofission of 238U in different bremsstrahlung. experiments depending on the bremsstrahlung endpoint energy. 1. V.I.Shvedunov et al. // Nucl. Instrum. Meth. A. 2005. V.550. P.39. 2. E.Jacobs et al. // Phys. Rev. C. 1979. V.19. P.422. 3. N.A.Demekhina, G.S.Karapetyan // Yad. Fiz. 2008. V.71. P.28. 95 ENERGY CHARACTERISTICS OF FISSIONABLE NUCLEUS IN SCISSION POINT FOR DIFFERENT FISSION MODES V.P. Pikul, Yu.N. Koblik, G.A. Abdullaeva, A.F. Nebesniy, A. P. Morozov Institute of Nuclear Physics Uz AS, Tashkent, Uzbekistan E-mail: [email protected] Within the model of balance [1] the analysis of potential energy and the form of fissionable system in a scission point for a super asymmetric mode of fission in a wide range of fission fragments kinetic energies (Ек) is carried out. As in the majority of models the {c,h,α}-parameterization is used, our calculations also have been executed depending from these parameters. Deformations parameters of both fragments changed at fixed values of Ек and relation of fragments masses and the minimum values of potential energy in scission point were defined. In distributions of potential energy depending on deformations are observed from 1 to 3 minima. The deepest minima correspond to the most probable fission and define the most probable Ек of heavy fragment and total kinetic energy ТКЕ. As for light fragments it is most probable Ек ∼ 98 MeV in case 235U fission in a wide range of mass numbers. Deformations parameters were calculate also as in [2-3]. The quantity of minima essentially depends on the sizes of a neck. Calculations for adjoining ellipsoids for the neck sizes from 1 to 3 fm and different relations of masses of formed fragments depending on Ек have been executed. The most probable fission occurs at the neck sizes 2.0-2.4 fm that corresponds to a losing of nucleus stability at the nucleus form with neck radius RN ≅ 0.3R0. At descent from saddle point to scission point the fissionable nucleus passes a bifurcation point after which the most probable fission has parameters βh ≈ 0.35 and βl ≈ 1.0 or βh ≈ 0.85-0.95 and βl ≈ 0.75-0.85. Descent with parameters βh ≈ 1.1-1.3 and βl ≈ 0.2-0.3 is possible also. These descents define excitation energy of formed fragments and neutrons emission. Comparison of experimental results [4, 5] with calculations results is carrying out. The most probable charges, kinetic energies and relative yields have good agreement. 1. B.D.Wilkins et al. // Phys.Rev. C. 1976. V.14. P.1832. 2. Yu.N.Koblik, V.P.Pikul et al. // Bull. of the Rus. Acad. of Scien. Physics. 2007. V.71. P.420. 3. Yu.N.Koblik, V.P.Pikul et al. // Bull. of the Rus. Acad. of Scien. Physics. 2011. V.75. P.1048. 4. J.L.Sida, P.Armbruster et al. // Nucl. Phys. A. 1989. V.502. P.233. 5. V.P.Pikul, Yu.N.Koblik et al. // Nucl. Phys. 2005. V.68. P.2. 96 CORRELATION FEMTOSCOPY OF KAONS IN THE SELEX EXPERIMENT G.V. Sinev, G.A. Nigmatkulov on behalf of the SELEX collaboration National Research Nuclear University “MEPhI”, Moscow, Russia E-mail: [email protected] 0 0 0 + 0 – + + – – Correlation femtoscopy of KS KS , KS K , KS K , K K and K K systems was studied in the SELEX experiment (Fermilab E781). The kaons used in this analysis were produced on carbon and copper targets via Σ–-beam at 610 GeV/c. Bose-Einstein correlations were measured as a function of the four-momentum difference (Q) of the kaon pairs. An enhancement of identical kaon pairs production at Q < 0.5 GeV compared to non-identical kaon pairs produced in the same Q range was observed. This enhancement was found to be consistent with Bose-Einstein statistics. The values of the radii of the source regions were obtained for both neutral and charged kaons. 97 LEVEL DENSITY PROBLEM IN NUCLEAR REACTION CODES. CALCULATIONS VERSUS EXPERIMENT A.V. Voinov, S.M. Grimes Physics and Astronomy Department, Ohio University, Athes, USA E-mail: [email protected] Current generation nuclear reaction codes including such publicly available systems as Empire [1] and Talys [2] are becoming a main tool for reaction cross section calculations in different applications including but not limited to astrophysics and nuclear data evaluation [3]. However, input parameters for such codes still need to be tested experimentally. The most uncertain input is the level density. Currently, reaction codes use several input level density options which give different results. The problem is that level density parameters have to be adjusted every time to be able to reproduce experimental cross section of a different reaction; therefore the predictive power of available reaction codes is severely limited. We will present comparison of calculations performed with different level density inputs against available experimental data. Prospective experiments targeting this problem will be discussed. 1. M.Herman, R.Capote, B.V.Carlson, et al. // Nucl. Data Sheets. 2007. V.108. P.2655. 2. A.J.Koning, S.Hilaire, M.C.Duijvestijn // Proceedings of the International Conference on Nuclear Data for Science and Technology. April 22-27, 2007, Nice, France. EDP Sciences, 2008. _P.211; http://www.talys.eu/. 3. M.B.Chadwick, P.Oblozinsky, M.Herman et al. // Nucl. Data Sheets. 2006. V.107. P.2931. 98 THE 238U PHOTOFISSION IN THE GIANT RESONANCE REGION L.Z. Dzhilavyan, V.G. Nedorezov Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia E-mail: [email protected] In order to prepare new experiments on photonuclear reactions at low excitation energies, in particular, with the use of powerful pulsed femtosecond lasers, the analysis of existing results and methods for measurement of 238U photofission cross sections is fulfilled. Analysis of the data covers the excitation energy range for 238U nuclei, corresponding to the giant resonances (GR) of different multipolarities (with the prevalence of the isovector electric dipole GR). Particular attention is paid to the method that uses the registration of fission fragments with solid state track detectors (SSTD) and with automatic track counting (ATC), providing large effectiveness, high selectivity and rather good convenience and reliability in operation. For the 238U photofission in the entire region of GR γ-quanta from as full spectrum bremsstrahlung for electrons, as annihilation in flight for positrons may be used (see [1-5] and references therein). However, because of the known difficulties of unfolding procedures for extracting the cross sections of photonuclear reactions from their measured yields (see, e.g., [2]), now cross section data for the 238U(γ, F)-reaction in the GR region [1, 3-5], obtained with annihilation photons (AP), are more preferable. And data from [1, 4] are the most complete ones among them for our purposes. Unfortunately, in [1, 4] there was used the questionable indirect method of measurements, based on multiplicity analysis for neutrons, produced by γ-quanta and detected after their slowing down. We undertook in [3] at AP energy 10 MeV the desirable independent verification of the pointed out method using registration of fission fragments with SSTD and with ATC. Since in this case it was necessary to reduce thickness of single 238U-target at about 104 times we had to use the multi-layered “sandwich” (238U-target – SSTD) of large area with a significant increase of used AP intensity. The measured by us in such a way value of the 238U(γ, F)-reaction cross section (65±12) mb is in a rather good agreement with the values ≈55 mb and ≈68 mb from [1] and [4] respectively, what removes away the doubts about the correctness of these works to a great extent. Later on this our result was confirmed in work [5], which authors also used at AP beam multi-layer “sandwich” (238U-target – parallel plate gaseous counter as direct detector of fission fragments). 1. A.Veyssiere et al. // Nucl. Phys. A 1973. V.199. P.45. 2. I.S.Koretskaya, L.E.Lazareva, V.G.Nedorezov et al. // Yad. Fizika. 1979. V.30. P.910. 3. L.Z.Dzhilavyan, V.G.Nedorezov et al. // Preprint INR P-0121. M. 1979. 4. J.T.Caldwell et al. // Phys. Rev. C. 1980. V.21. P.1215. 5. H.Ries et al. // Phys. Rev. C. 1984. V.29. P.2346. 99 ISOMERIC CROSS-SECTIONS RATIOS FOR 120m,gSb IN (p, n)-REACTION FOR NEARTHRESHOLD REGION I.N. Vyshnevsky, V.А. Zheltonozhsky, А.M. Savrasov Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kiev E-mail: [email protected] The isomeric cross-sections ratios have been measured at 120mSb π – 120g π + (T1/2 = 5.6 d., J = 8 ) and Sb (T1/2 = 16 m., J = 1 ) excitation by protons which have energies 3.8 and 3.9 MeV. The irradiations were done on the EGP-10K of Institute for Nuclear Research of National Academy of Sciences of Ukraine. The Sn targets from the natural isotopic composition were used for the irradiation. The gamma-spectra of the reaction products were measured by the semiconductor spectrometer based on HPGe-detector which has energy resolution 2 keV for the 1332-keV γ-line of 60Co and detection efficiency of 40 % in comparison with a 3” × 3” NaI(Tl)-detector. In the spectra the γ-transitions which follow the 120m,gSb decay are reliable identified for protons which have 3.9 MeV when for protons which have 3.8 MeV the 120mSb isomeric state is not populated. –4 The isomeric cross-sections ratio has been obtained: σm/σg = (9.1±2.3)∙10 for (р, n)- reaction for protons which have 3.9 MeV. The discussion is transacted about obtained data. 100 DOUBLE-DIFFERENTIAL AND INTEGRAL CROSS-SECTION OF (p, xp) REACTION ON 58Ni NUCLEUS AT Ep=29.9 MeV A. Duisebayev1, B.A. Duisebayev, T.K. Zholdybayev1, B.M. Sadykov1, K.M. Ismailov2 1 Institute of Nuclear Physics, National Nuclear Center, Almaty, Kazakhstan; 2 Nazarbayev University, Astana, Kazakhstan E-mail: [email protected] The role of new nuclear-physics experiments in the creation of nuclear databases and development of theoretical models in accordance with modern approaches is key in both fundamental and applied researches related in particular to the development of electro-nuclear plants (Accelerator Driven System, ADS) for the nuclear transmutation of long-lived radioactive nuclear waste and energy production [1]. The double-differential cross-section of (p, xp) reaction on 58Ni nucleus at Ep=29.9 MeV in angular range 30-135° with the step 15° have been measured on isochronous cyclotron U-150M of Institute of Nuclear Physics. To measure the cross-section in the whole range of the energy used two-detector telescope consisting of a thin silicon detector and total absorption detector based on the CsI(Tl) scintillator. The experimental data have been analyzed within the framework of the phenomenological exciton model of preequilibrium decay [2, 3] and microscopic theory of the multi-step direct and multi-step compound processes [4]. The satisfactory theoretical description of the double-differential and integral cross sections for (p, xp) reaction on 58Ni nucleus has been reached. The contribution of the preequilibrium mechanism to the (p, xp) reaction dominates and that is in agreement for both the exciton model and the quantum-mechanical theory calculations. 1. A.S.Gerasimov, G.V.Kiselev // PEPAN. 2001. V.32. P.143. 2. J.J.Griffin // Phys. Rev. Lett. 1966. №9. P.478. 3. C.Kalbach PRECO-2006: Exiton model preequilibrium nuclear reaction code with direct reaction. Durham NC 27708-0308, 2007. 4. M.Herman, G.Reffo, H.A.Weidenmüller. EMPIRE - statistical model code for nuclear reaction calculations (version 2.13 Trieste) // IAEA, 2000. 101 FROM SEQUENTIAL PROCESSES TO MULTIFRAGMENTATION IN PROTON REACTIONS WITH GOLD S.P. Avdeyev1, V.A. Karnaukhov1, V.V. Kirakosyan1, P.A. Rukoyatkin1, H. Oeschler2, W. Karcz3, E. Norbeck4, A.S. Botvina5 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Darmstadt University of Technology, Germany; 3 H. Niewodniczanski Institute of Nuclear Physics, Cracow, Poland; 4 Uiversity of Iowa, Iowa City, USA; 5 Institute for Nuclear Research RAN, Moscow, Russia E-mail: [email protected] The distributions of the relative angles between the intermediate mass fragments has been measured and analyzed for thermal multifragmentation in p+Au collisions at 2.1, 3.6 and 8.1 GeV. The analysis has been done on an event by event basis. The multibody Coulomb trajectory calculations of all charged particles have been performed starting with the initial break-up conditions given by the combined model with the revised intranuclear cascade (INC) [1] followed by the statistical multifragmentation model (SMM) [2]. Distributions of the excitation energy and residual masses after INC has been empirically modified to reach agreement with the data for the mean multiplicity. The measured correlation (Fig. 1) function was compared with the calculated one to find the actual time scale of the IMF emission. It was found transition from sequential evaporation for p (2.1 GeV) + Au to simultaneous multibody decay of a hot and expanded nuclear system in case of p (8.1 GeV) + Au. Fig. 1. Relative angle correlation function for IMF produced in p + Au collisions at 2.1 GeV. Points – experimental data. Lines correspond to INC + SMM calculations with mean time of secondary disintegration as a parameter. 1. V.D.Toneev et al. // Nucl. Phys. A. 1990. V.519. P.463. 2. A.S.Botvina et al. // Nucl. Phys. A. 1990. V.507. P.649. 102 PRODUCTION OF HADRONS AT LARGE TRANSVERSE MOMENTUM IN 50 GeV p-NUCLEUS COLLISIONS A.Yu. Bordanovskii, A.A. Volkov, D.K. Elumahov, V.P. Efremov, A.Yu. Kalinin, A.V. Korablev, A.N. Krinitsyn, V.I. Kryshkin, N.V. Kulagin, V.V. Skvortsov, V.V. Talov, L.K. Turchanovich Institute for High Energy Physics, Protvino, Russia E-mail: [email protected] To study quark structure of nucleus there are measured the high pT charged hadron production in collision of 50 GeV protons off nuclear targets (Be, Al, W) using double arm spectrometer. The single hadrons (π±, K±, р andpр) flying at 90° in c.m.s. and hadron pairs with high effective mass (produced back to back in c.m.s.) were recorded simultaneously. The results show that particles are produced due to different mechanism in different kinematical regions but the dominant process is parton-parton interaction. 103 EXPERIMENTAL INVESTIGATION OF 19F(n, α)16N REACTION EXITATION FUNCTION IN 4-7.35 MeV ENERGY REGION I.P. Bondarenko, T.A. Ivanova, V.A. Khryachkov, B.D. Kuzminov, N.N. Semenova, A.I. Sergachev State Scientific center of the Russian Federation - Institute for Physics and Power Engineering, Obninsk, Russia E-mail: [email protected] The interaction of neutrons with light nuclei is interesting for nuclear reaction mechanics understanding. Fluorine nuclei cross-section data are of a great importance due to the usage of fluorine-containing salts in advanced nuclear reactors. Their active zone is filled up with that molten salts, and so fluorine cross-section affects on nuclear chain reaction kinetics. The experimental investigation of 19F(n, α)16N reaction cross-section in 4-7.35 MeV energy region is represented in this work. Back-to-back ionization chamber with common cathode and Frisch grid in main chamber was used in this work. The detector was filled up with 95% Kr and 5% СF4 gas mixture, where СF4 was the gas target. Fast neutron beam collimating and digital signals processing allowed us to separate fixed gas sell in the detector sensitive volume, where observable reactions took place. Neutron flux was determined by fission fragments of 238U calculation. 104 NEW EXPERIMENTAL DATA FOR 10B(n, αt)4He REACTION T.A. Ivanova, I.P. Bondarenko, V.A. Khryachkov, B.D. Kuzminov, N.N. Semenova, A.I. Sergachev State Scientific center of the Russian Federation - Institute for Physics and Power Engineering, Obninsk, Russia E-mail: [email protected] The technique that allows to register reaction products with charge particles emission, proceeding on component of working gas under action of fast neutrons was developed. The present technique is unique because it allows studying reactions at which more than two charge particles are produced in the output channel. In case of solid target using for this kind of reactions the response function has difficult form, and extraction of useful events from background is a complicated problem. In the present work was researched the interaction of neutrons with 10B nuclei, where two alpha particles and tritium nucleus are formed as a reaction products. Slowing-down of three reaction products in the sensitive volume of chamber results to sharp line in the energy spectrum that correspond to the events of investigated reaction. 10B(n, αt)4He reaction was investigated in a neutron energy range from 4 to 7 MeV. The received data are below of estimation of ENDF B VII и JENDL 4. In the excitation function of the reaction there is some structure similar to structure in the Bonner’s work, which is not observed in existing estimations. 105 INVESTIGATION OF FAST NEUTRON INTERACTION WITH CHROMIUM NUCLEI V.A. Khryachkov, I.P. Bondarenko, T.A. Ivanova, B.D. Kuzminov, N.N. Semenova, A.I. Sergachev State Scientific center of the Russian Federation - Institute for Physics and Power Engineering, Obninsk, Russia E-mail: [email protected] In this work new method for low background measurement of (n, α) reaction cross section based on Fricsh grid ionization chamber and digital signal processing was used. This method was adopted for work with solid target placed in ionization chamber. Measurements of (n, α) reaction cross section for 50- and 52-chromium isotopes were carried out. It was shown that ratio between ENDF B VII estimation and obtained experimental data for chromium-50 can reach factor 20. Excitation function shape has unpredicted by estimation structure. It is remarkable that 52Cr(n, α) reaction cross section measurement was made in neutron energy region less than 14 MeV for the first time. 106 THE ORIENTATION PARAMETERS OF 24Mg(2+) FROM CORRELATION EXPERIMENTS 24 24 IN Mg(d, dγ) Mg REACTION L.I. Galanina, N.S. Zelenskaya, I.A. Konyuhova, V.M. Lebedev, N.V. Orlova, A.V. Spassky Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Russia E-mail: [email protected] The polarization tensors Tkyκ ()θ of aligned nuclei with spin J [1] are the essential physical characteristics that one can restored from correlation experiments. Tkyκ ()θ are defined in coordinate frame where quantification axis Z is orthogonal to reaction plane. The components with zero projection onto the quantification axis are the most significant. They are equivalent [2] to the orientation parameters up to a normalization factor [3]: (2J+ 1) ( JJ ++ 1)(2 3) FT2 = 20 ; (1) 5 JJ(2− 1) (2J+ 1) (2 JJJJ ++++ 3)(2 2)(2 4)(2 5) FT4 = 40 . (2) 6JJJJ (−−− 1)(2 1)(2 3) These parameters (k = 1, ..., 2J) are the expansion on power series from the average JZ and are normalized so that −≤11Fk ≤. Their physical sense is connected with the interaction energy of the quadrupole (hexadecapole) nuclear moment with a non-uniform electric field. Both experimental parameters and theoretical ones calculated by coupled channel model [4] depend from the final particles emission angle. This dependence is oscillating. The spin of nucleus 24Mg (2+) formed in inelastic deuterons scattering is oriented orthogonal to the axis Z mainly. But its precession around this axis takes place at some deuterons emission angles. 24 + Parameter F2 is negative in cases if Mg (2 ) spin is located in the reaction plane. Parameter F4 is negative practicaly for all angles of deuterons emission. This work was supported by RFBR. 1. L.I.Galanina, N.S.Zelenskaya, V.M.Lebedev, N.V.Orlova, A.V.Spassky // Bull. Russ. Acad. Sci. Phys. 2012. V.76. P.479. 2. L.I.Galanina, N.S.Zelenskaya // Bull. Russ. Acad. Sci. Phys. 1999. V.63. P.47. 3. G.P.Huzishvili // Sacc. Phys. Sci. 1954. V.53. P.381. 4. P.D.Kunz. http://spot.colorado.edu/~kunz/Home.html. 107 INVESTIGATION OF d-SCATTERING ON 24Mg AT Ed = 15.3 MeV L.I. Galanina1, N.S. Zelenskaya1, I.A. Konyuhova1, V.M. Lebedev1, N.V. Orlova1, A.V. Spassky1, S.V. Artemov2 1 Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Russia; 2 Institute of Nuclear Physics AS RUz, Ulukbek, Tashkent, Uzbekistan E-mail: [email protected] The angular dependences of the 24Mg(d, d)24Mg differential cross section for elastic (0+) and inelastic (to the 2+, 1.369 MeV state) scattering has been measured (SINP cyclotron U-120) at 15.3 MeV in the wide angular range (Fig. 1) from 21.5° до 161.5° (lab.). Fig. 1. Angular distributions of cross-sections for the elastic and inelastic d-scattering 24 on Mg at Ed = 15.3 MeV. Theoretical analysis of the scattering performed by the method of coupled channels on the assumption of rotational-vibrational model of the nucleus 24Mg (solid line, code ECIS [1]), as well as for the rotational model (dotted line, code CHUCK [2]). In the first case, take into account the lower three levels belonging to rotational bands with K = 0 and level 2+ (4.238 MeV) of the following γ-vibrational band with K = 2, while the second − only the coupling of the lower levels 0 → 2+. The optical potentials were included spin-orbit interaction. The resulting agreement with experiment for the calculation of ECIS can be considered satisfactory. The value of the 24Mg quadruple deformation parameter in this paper is chosen to be β2 = 0.45. Earlier in the analysis of inelastic scattering of α-particles on the same nucleus [3] we obtained β2 = 0.4. This work was supported by RFBR. 1. J.Raynal. http://www.nea.fr/abs/html/nea-0850.html. 2. P.D.Kunz. http://spot.colorado.edu/~kunz/Home.html. 3. L.I.Galanina et al. // Bull. Russ. Acad. Sci. Phys. 2011. V.75. P.588. 108 ENERGY AND ANGULAR DISTRIBUTIONS OF DEUTERONS FROM THE REACTION D + D → p + n + d O.O. Beliuskina, V.I. Grantsev, K.K. Kisurin, S.E. Omelchuk, G.P. Palkin, Yu.S. Roznyuk, B.A. Rudenko, V.S. Semenov, L.I. Slusarenko, B.G. Struzhko Institute for Nuclear Research of NAS of Ukraine, Kyiv E-mail: [email protected] The process of deuterons formation in the three nucleon breakup reaction D + D → p + n + d was studied experimentally and theoretically. Inclusive deuterons spectra in the energy range 5≤ Ed ≤37 MeV were measured on the deuterated polyethylene and carbon targets. The experiment was performed at the incident energy ED =36.9 MeV on the extracted beam from the cyclotron U-240 of the INR NAS of Ukraine. Deuteron energy spectra at small angles have broad intensive maxima shifted to the high energy edge and blurred less intensive maxima in the low energy range Ed <15 MeV. The observed structure in the energy spectra becomes less distinctive with a deuteron exit angle growth and is getting featureless continuum in the angle range θd>35°. Deuteron angular dσd distributions measured in the angular range 15°≤θd≤48° are characterized dΩ by a sharp exponential dependence on the exit angle θd. A comparison with the published data at the energy ED =60 MeV [1] is presented. The theoretical analysis of energy spectra and angular distributions at the deuteron incident energies ED =36.9 MeV and ED =60 MeV [1] was performed using the microscopic diffraction model with a final state interaction. Simple expressions for inner functions were used to facilitate calculations. The analysis made it possible to determine contribution to the experimental cross-section of both scattered deuterons following the target nuclei breakup and recoiled deuterons following the incident deuterons breakup. It was shown that the main contribution to the cross-section at small angles give scattered deuterons characterized by angular distribution with sharp decrease with the growth of exit deuteron angle θd. Recoil deuterons define the observed cross-sections in the energy range Ed <15 MeV. The sum theoretical cross-section of two referred above processes fits satisfactory with experimental cross-section both the shape and absolute value. 1. K.Fukunaga, T.Ohsawa, S.Kakigi et al. // Nucl. Phys. A. 1982. V.390. P.19. 109 COUPLED CHANNELS EFFECTS IN THE d, 3He AND α-PARTICLES SCATTERING ON 6Li NUCLEI S.B. Sakuta1, N. Burtebaev2, S.V. Artemov3, R. Yarmukhamedov3 1 National Research Center “Kurchatov Institute”, Moscow, Russia; 2 Institute of Nuclear Physics, National Nuclear Center, Almaty, Kazakhstan; 3 Institute of Nuclear Physics, Uzbekistan Academy of Sciences, Tashkent, Uzbekistan E-mail: [email protected] Existent experimental data on d, 3He and α-particles scattering by 6Li nuclei were analyzed in the framework of the coupled-reaction-channels method. The calculations were performed with code FRESCO [1]. The coupling of the ground (1+) and first excited (3+) states of 6Li as well as the cluster exchange mechanisms and spin-orbital interaction for the projectile and the target were taken into consideration. The found phenomenological potentials describe well the experimental angular distributions at all energies and in the full angular regions. Depths of the real and imaginary parts of nuclear potentials depend smoothly on the energy at fixed geometry parameters. Energy dependences of volume integrals (JV) for the real parts of potentials for the d, 3He and α-particles scattering agree well themselves, and are consistent with the analogues data for other systems (p + 6Li, 12C + 12C) and the microscopic theory predictions (see Fig. 1). Fig. 1. Volume integrals (JV) of the real parts of potentials as functions of the energy per nucleon (E/a) for different systems: d+6Li (■), 3He+6Li(◊) and α+6Li (○). Curves are approximations for the energy dependence 6 12 of JV for the p+ Li [2] (solid line) and C+ 12C [3] (dashed line) systems. It was shown that the coupled channels effects and the clusters exchange mechanisms play an important role in the cross sections behavior at large angles. Without taking into account these effects it is impossible to describe the scattering in this angular region with reasonable parameters. Physical reasonable potential parameters, as well as the spectroscopic factors and the deformation lengths which were found in the analysis show that main processes were taken into account and the contribution of other more complicated mechanisms is small. This work was supported by the RFBR (Grant No 08-02-90250) and CCSD under the Cabinet of Ministers of Republic of Uzbekistan (Grant No MP-29). 1. I.J.Thompson // Comput. Phys. Rep. 1988. V.7. P.167. 2. A.J.Koning, J.P.Delaroche // Nucl. Phys. A. 2003. V.713. P.231. 3. M.E.Brandan, G.R.Satchler // Phys. Rep. 1997. V.285. P.143. 110 CLUSTER STATES OF 11В WITH ABNORMALLY LARGE RADII A.S. Demyanova1, А.А. Ogloblin1, T.L. Belyaeva2, N. Burtebaev3, S.А. Goncharov4, Yu.B. Gurov5, А.N. Danilov1, S.V. Dmitriev1, Yu.G. Sobolev6, W. Trzaska7, G.P. Tyurin7, P. Heikkinen7, S.V. Khlebnikov8, R. Julin7 1 NRC Kurchatov Inst., Moscow, Russia; 2 Universidad Autonoma del Estado de Mexico, Mexico; 3 Nuclear Phys. Ins. Almati, Kazakhstan; 4 Skobeltzin Inst., Moscow, Russia; 5 MEPhI, Moscow, Russia; 6 Nuclear Phys. Ins., Rez, Czech Republic; 7 JYFL, Jyvaskyla, Finland; 8 Khlopin Radium Inst, St.-Peterburg, Russia E-mail: [email protected] There are predictions [1, 2] based on the antisymmetrized molecular dynamics (AMD) and alpha-condensate model that two states in 11B: E* = 1/2—, 8.56 MeV and 1/2+, (probably, 12.56 MeV), have RMS radii much larger than that of the ground state. Especially intriguing was the suggestion [2] that the radius of the 1/2+ level may exceed that of the Uranium nucleus! For testing these ideas we measured 11 B + α inelastic scattering at 65 and 11 40 MeV (the latter data were partly B + α (40 MeV) published in [3]) with the aim to extract 200 o Θ = 43 12.56 the radii values of the 11B excited states 180 14.04 with use of modified diffraction model 160 13.1 MDM [4]. The preliminary value of the 140 12.91 11.6 8.56 MeV level occurred to be 120 11.88 count count 1. Y.Kanada-En’yo // Phys. Rev. C. 2007. V.75. 024302. 2. T.Yamada, Y.Funaki // Phys. Rev. C. 2010. V.82. 064315. 3. N.Burtebaev et al. // Physics of Atomic Nuclei. 2005. V.68. 1356. 4. A.N.Danilov et al. // Phys.Rev. C. 2009. V.80. 054603. 5. A.S.Demyanova et al. // Int. J. of Modern Physics. E. 2011. V.20. 915. 6. H.Yamaguchi et al. // Phys. Rev. C. 2011. V.83. 034306. 111 INELASTIC SCATTERING WITH EXCITATION OF LOWER DENSITY HOYLE STATE Yu.A. Gloukhov1, A.A. Ogloblin1, S.A. Goncharov2, A.S. Demyanova1 1 Scientific Research Center «Кurchatov Institute», Moscow, Russia; 2 Institute of Nuclear Physics, Moscow State University, Russia E-mail: [email protected] + Alpha-condensate structure was predicted for the 0 2, 7.65 MeV Hoyle state in the 12С nucleus [1], however the available data are contradictory [2]. In order to check the model [1] we investigated inelastic scattering 12С + α. Elastic and + + – inelastic differential cross-sections (at excitation of the 2 1, 0 2 и 3 1 levels) were measured at the α-particles energy 60 MeV. The cross-sections of the Hoyle state excitation were compared with those calculated using the “exact“ wave function [3] which is considered [1] to be similar to the condensate one (Fig. 1). 104 4 12 + + He+ C Elab=60 MeV inelastic 01 --> 02 3 DWBA, Optics: Kamimura-DSMP 10 "far",W=0 102 ) 62.4 1 exp. 10 2 mb/sr ( Kamimura(0.131 ) Ω Ω 0 /d 10 σ d 10-1 10-2 10-3 0 20 40 60 80 100 120 140 160 180 θcm 12 + + Fig.1. The cross-sections С+α for 0 1 — 0 2 at Elab =60 МeV. The curves were calculated using the wave function [3]. The arrows denote probable Airy minima. Some conclusions can be done from this comparison: 1) the angular distribution of the Hoyle state excitation is not reproduced at the angles larger 60о; 2) the decomposition of the scattering amplitude into the near- and far-side components shows a dominance of the latter one at the middle and large angles; 3) the far-side component (W = 0) contains two Airy minima shifted relatively to the observed ones (marked with arrows); 4) the experimental ( θ ≈ 73о) and calculated (W = 0, θ ≈ 62о) minima are located at the larger angles than Airy minimum in the elastic scattering (θ ≈ 47о). Obtained result confirms nuclear density dilution in the Hoyle state and points out to not complete adequateness of the wave function [3]. It is important for understanding of the rainbow scattering mechanism with such kind of states. 1. A.Tohsaki et al. // Phys. Rev. Lett. 2001. V.87. P.192501. 2. A.A.Ogloblin et al. // 62 Int. Conf. “Nucleus 2012”. St.Petersburg. Solo, 2012. P.33. 3. M.Kamimura // Nucl. Phys. A. 1981. V.351. P.456. 112 NEUTRON EMISSION MECHANISMS IN 56Fe(α, xn) REACTION B.V. Zhuravlev, N.N. Titarenko, V.I. Trykova State Scientific Center of Russian Federation – Institute for Physics and Power Engineering, Obninsk, Kaluga Region, Russia E-mail: [email protected] Understanding of the nuclear interaction mechanisms is an overall objective of any nuclear reaction study. In spite of permanent interest to elaboration of fundamental approaches in the description of nuclear interaction in mega- electron-volt range of the energy, the complete understanding of nuclear reaction mechanisms yet it is not achieved. Accordingly the models are not developed, allowed to predict the differential cross-sections of interaction with accuracy achievable in experiment. Three types of the interactions described by mechanisms of equilibrium, pre-equilibrium and direct processes are traditionally distinguished. The equilibrium mechanism of reaction is strictly enough formalized in Hauser-Feshbach model, however big uncertainties arise at modeling of nuclear level density. Analysis of a non-equilibrium part demands more clear division between pre-equilibrium emission of particles and direct processes, especially one-step, as a rule negligible in the pre-equilibrium mechanism. Study of the non-equilibrium neutron emission in (α, xn) reaction is represented a little bit easier other reactions with complex particles as in this case the probability of preliminary formation of α-particles is not considered, lack of Coulomb barrier in output channel makes neutron decay predominated one, and the neutron optical potential is most investigated. In the present work neutron spectra and angular distributions in 56Fe(α, xn) reaction have been measured at α-particle energies of 12, 16, 18, 27, 45 MeV. The measurements were performed by time-of-flight fast neutron spectrometers on the pulsed accelerators. The analyses of the measured data have been carried out in the framework of equilibrium, pre-equilibrium and direct nuclear reaction mechanisms. The calculations are done using the exact formalism of the statistical theory as given by Hauser-Feshbach with the nuclear level densities of Ni isotopes, excited in this reaction, determined on the basis of new experimental data on the low-lying levels, the s-wave neutron resonance spacing and neutron evaporation spectra. The contributions of equilibrium, pre- equilibrium and direct mechanisms of neutron emission have been studied in a wide energy range of α-particles. 113 CROSS SECTIONS FOR ISOTOPES 43Sc AND 46Sc IN THE 45Sc+3He REACTION N.K. Skobelev1, A.A. Kulko1, Yu.E. Penionzhkevich1, E.I. Voskoboynik1, V. Kroha2, V. Burjan2, Z. Hons2, J. Mrázek2, Š. Piskoř2, E. Šimečkova2 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Nuclear Physics Institute, Řež, Czech Republic E-mail: [email protected] In the experiments carried out at the U-120M cyclotron of the Nuclear Physics Institute, Czech Academy of Sciences, an ion beam 3He was used to investigate the reactions 45Sc(3He, αn)43Sc (Q = —0.445 MeV), 45Sc(3He, α)44Sc (Q = 9.25 MeV) and 45Sc(3He, 2p)46Sc (Q = 1.042 MeV) in the 3He energy range from 5 to 24 MeV. The thin Sc foil stacks were irradiated on the extracted 3He beam. The yields of Sc isotopes of the induced target activities were measured using the activation technique. The measurement of the induced γ-activity in the target foils was performed using a high resolution HPGe detector. The figure shows the experimental values of the cross sections for the isotopes 43Sc, 44Sc and 46Sc as a function of the bombarding 3He energy (excitation functions for the reactions) obtained in this work. The curves in the figure are calculations of the cross sections for the same isotopes for the fusion reactions in the framework of the statistical model. A comparison of these experimental data with the calculations shows, as in the case of deuteron induced reactions, a strong contribution to the cross sections by direct nuclear 3 processes. Despite the low binding energy of He (Ebind/N = 2.572 MeV) and the positive reaction Q-values leading to the formation of the isotopes 44Sc and 46Sc, the behaviour of the excitation functions with the formation of these isotopes is different from the excitation functions for deuterons [1]. It should be noted that only the cross section for 44Sc reaches its maximum value at the Coulomb barrier of the reaction 45Sc+3He. Apparently this is due to the fact that the neutron from the target nucleus 45Sc is caught by the incoming 3He nucleus, transforming the projectile into the stable 4He system. The contribution of different reaction mechanisms to the cross sections of the isotopes 43Sc, 44Sc and 46Sc is also discussed. 1. N.K.Skobelev, A.A.Kulko, V.Kroha et al. // J. Phys. G: Nucl. Part. Phys. 2011. V.38. P.035, 106. 114 STUDY OF FUSION AND NUCLEON TRANSFER CHANNELS FOR THE REACTION 197Au +6He AT 6He ENERGIES UP TO 20 MeV/A N.K. Skobelev1, Yu.E. Penionzhkevich1, A.A. Kulko1, A.S. Fomichev1, N.A. Demekhina1, S.M. Lukyanov1, J.G. Sobolev1, V.A. Maslov1, E.I. Voskoboynik1, V. Kroha2, A. Kugler2, J. Mrázek2 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Nuclear Physics Institute, Řež, Czech Republic E-mail: [email protected] The cross sections of the fusion and transfer products of the nuclear reaction 6He +197Au were studied. 6He ion beams with an intensity of 106 1/s and an energy of 120 MeV were obtained at the separator AССULINNA of the Laboratory of Nuclear Reactions, JINR. A stack of thin gold targets (from 4 to 10 microns) was mounted on the path of the 6He beam. Yields of the fusion and transfer reaction products were measured by the activation of the irradiated targets. The cross sections for the reaction products of Au, Hg and Tl radioactive isotopes were determined in the 6He-beam energy range of 40-114 MeV. The analysis of the excitation functions of fusion reactions with the evaporation from the compound nucleus 203Tl from 5 to 10 neutrons shows that with increasing 6He energy the cross sections of 198-193Tl isotopes in the region of higher energies differ from the calculation within the statistical model [1]. This is probably due to the increase in the contribution of non-equilibrium processes that lead to an increase of the neutron number emitted prior to the establishment of statistical equilibrium. The excitation functions with the formation of 194Au and 196Au isotopes indicate that the knockout of neutrons from the target nucleus makes a significant contribution to the formation of these isotopes with increasing the 6He energy. The behaviour of the excitation functions of the 197Au(6He, pxn)192-197Hg reactions indicates that the isotopes of Hg in the ground and isomeric states could be formed not only in fusion reactions with the emission of charged particles and neutrons, but also in the process of direct transfer of the clusters and with the subsequent removal of the excitation by neutron evaporation. It should be noted that according to the energy balance some preference can be given for the reactions with the emission of deuterons compared to the reactions with proton and neutron evaporation. 1. Yu.E.Penionzhkevich et al. // Eur. Phys. J. A. 2007. V.31. P.185. 115 FUSION AND TRANSFER NUCLEAR REACTIONS IN THE INTERACTION OF 6He WITH 197Au N.A. Demekhina1, N.K. Skobelev2, Yu.E. Penionzhkevich2, T.V. Chuvilskaya3, A.A. Shirokova3 1 Erevan State University, Armenia; 2 Joint Institute for Nuclear Research, Dubna, Russia; 3 Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Russia E-mail: [email protected] The excitation function and isomeric cross section ratios was measured on the radioactive beam of 6He of the separator ACCULINA [1] with used of activation method [2]. It was obtained for the fusion reactions 197Au(6He, xn)203-xTl with up to 10 neutrons, and also for the transfer reactions with isotopes productions 194,196Au and 192,193,195,197Hg at the energy region of 6He E = 41 ÷ 115 MeV. The calculations of the cross sections of these reactions by codes EMPIRE – 2.18; 2.19 were performed. For the fusion reaction with 198,196Tl products it was a good agreement with the experimental and calculation values. For the transfer reactions with production of isotopes 194Au and 197Hg at this region of energies there is the shift of maximum of excitation function up to 20 MeV. As for 196Au isotope the discrepancy between experimental and calculated values of the cross section up to 10 times takes place. 1. A.M.Rodin et al. // Nucl. Instr. and Meth. In Phys. Res. B. 2003. V.204. P.114. 2. Yu.E.Penionzhkevich et al. // Eur. Phys. J. A. 2007. V.31. P.185. 116 FRAGMENTATION OF CARBON IONS AT INTERMEDIATE ENERGIES B.M. Abramov, P.N. Alexeev, Yu.A. Borodin, S.A. Bulychjov, I.A. Dukhovskoy, A.P. Krutenkova, V.V. Kulikov, M.A. Martemianov, M.A. Matsyuk, E.N. Turdakina, A.I. Khanov Institute for Theoretical and Experimental Physics, Moscow, Russia E-mail: [email protected] Momentum distributions of hydrogen, helium and lithium isotopes from 12C fragmentation at 3.5o were measured in an experiment FRAGM at ITEP TWA heavy ion accelerator. Fragments were separated by double focus beam line magnetic spectrometer with scintillation counters for momentum, dE/dx and TOF measurements. Results are presented for six projectile energies from 0.2 to 3.2 GeV/nucleon and four targets from Be to Ta. Main attention was given to the region of high momentum where fragment velocity exceeds the velocity of the projectile nucleus. The results obtained cover about six orders of the differential cross section magnitude and the value of x ≈ p/p0 up to x = 2.4. They were corrected for acceptance calculated using GEANT4-based simulation program. A transition from the Gaussian shape of the momentum spectra in projectile rest frame, expected for the evaporation mechanism, to the exponential shape, typical for the preequilibrium (cumulative) processes, is clearly seen. The x distributions for evaporation and cumulative regions for protons were reanalyzed taking into account experimental acceptance. In the framework of quark-gluon string model the probabilities of existence of two- and three- nucleon quark clusters in 12C nucleus are reestimated. The values are compared with the probabilities of existence of two- (three-) nucleon short range correlations in nuclei measured at TJNAF. Systematic uncertainties of the obtained probabilities are studied. 117 ELECTROMAGNETIC AND HADRONIC SIGNATURES OF QUARK-GLUON PLASMA IN HEAVY-ION COLLISIONS AT 62.4 GEV IN PHENIX EXPERIMENT AT RHIC Ya.A. Berdnikov1, D.A. Ivanishchev1, D.O. Kotov1, V.G. Riabov1, Yu.G. Riabov1, V.M. Samsonov1 1 St. Petersburg State Polytechnical University, Russia E-mail: [email protected] One of the first findings at the Relativistic Heavy Ion Collider (RHIC) was a very large hadron suppression at high pT (above 4–5 GeV/c) in √sNN = 130 and 200 GeV Au+Au collisions [1], attributed to the dominance of parton energy loss in the medium, i.e. to final state effects, but no suppression was observed in d+Au collisions [2] where formation of the hot, dense partonic medium is not expected, and initial state effects prevail. The current beam energy scan program with Au+Au collisions at RHIC provides an opportunity to study the transition from enhancement (RAA > 1) to suppression (RAA < 1) as a function of collision energy, centrality and pT. In this talk we present recent PHENIX results on p, π0-, φ-mesons invariant yields and RAA measurements by the PHENIX experiment at RHIC in Au+Au collisions at √sNN = 62.4 GeV. The possibility to measure electromagnetic signatures of quark-gluon plasma measurements with the innovation “hadron blind” detector will be discussed. This work is supported by federal target program “Scientific and scientific and pedagogical manpower of innovative Russia” through 2009–2013 years. 0 Fig. 1. Nuclear modification factor (RAA) of π -meson in most central 0-10% (a) and mid- peripheral 40-60% (b) Au+Au events measured at √sNN = 39, 62.4 and 200 GeV. 1. K.Adcox et al. // Nucl. Phys. A. 2005. V.757. P.184. 2. S.S.Adler et al. // Phys. Rev. C. 2006. V.74. 024904. 118 J/ψ-MESON DETECTION POSSIBILITY IN ULTRAPERIPHERAL Pb-Pb COLLISIONS AT √S=2.76 TeV Ya.A. Berdnikov, V.A. Rebyakova Saint Petersburg State Polytechnical University, Russia E-mail: [email protected] Coherent J/ψ mesons photoproduction in ultraperipheral Pb-Pb collisions at a LHC center-mass energy of 2.76 TeV per nucleon pair provide important information for investigations of the gluon density behavior in nuclei at small x down to x ≈ 10–5. The cross section of this process was calculated in Ref. [1] and equals ~10 mb. The Forward Muon Spectrometer of LHC detector ALICE can be used to detect J/ψ-meson through the dimuon decays in the polar angular range 171<<θ 178 (corresponds to the pseudo-rapidity range of −4.0 <η <− 2.5). While measuring the coherent J/ψ-meson photoproduction it is necessary to take into account contribution of background process – J/ψ-meson production in strong interaction. There is no dissociation of colliding ions in a process of coherent J/ψ-meson photoproduction. Therefore if we want to find of coherent J/ψ-meson photoproduction events in ALICE experiment it is required to use cuts on the charge particle number while data acquisition and analyzing. ALICE detectors allow to detect charge particle in the polar angular interval 0.7<<θ 177 (or −3.7 <<η 5.1). Probability of J/ψ-meson production in strong interaction of Pb-Pb ions and corresponding charge particle number were evaluated by using Monte Carlo generator HIJING [2]. The estimated contribution of strong interaction in described condition of event selection accounts less than 1% of J/ψ-meson photoproduction contribution in peripheral collision. According to this evaluated value of background processes the investigated J/ψ-mesons can be detected. It should be noted that also the contribution of electromagnetic lead nuclei dissociation with neutron emission at LHC [1] can be analyzed by using the Zero Degree Calorimeters of ALICE experiment, which detect neutral particles close to beam rapidity. This work was supported by the Ministry of Education of the Russian Federation, under the contract No. 02.740.11.0572 of the Federal task program “Research and educational community of innovative Russia” for 2009-2013. 1. V.Rebyakova et al. // arXiv:1109.0737v1 [hep-ph]. 2011. 2. X.N.Wang et al. // Comp. Phys. Comm. 1994. V.83. P.307. 119 DIELECTRON MEASUREMENTS IN HEAVY ION COLLISIONS AT 200 GeV IN PHENIX EXPERIMENT AT RHIC A.Ya. Berdnikov1, D.A. Ivanishchev1, D.O. Kotov1, V.G. Riabov1, Yu.G. Riabov1, V.M. Samsonov1 1 St. Petersburg State Polytechnical University, Russia E-mail: [email protected] High energy and density matter is created in ultrarelativistic heavy ion collisions [1]. Such dense thermalized medium is expected to emit thermal radiation in the form of direct photons and dielectrons. Electron-positron pairs are not affected by the strong interaction, and escape the dense medium without final state interaction. Therefore dielectron spectra can probe the time evolution and dynamics of the collision. Dielectrons can also be used to study the properties of low mass vector mesons in the medium, since their lifetime is shorter or similar to that of the medium. Their masses and widths inside the dense medium can be directly measured through their dielectron decay channels to study the effect of chiral symmetry restoration. Furthermore, production of photons can be measured through their conversion to dielectrons. The recent PHENIX results on e+e– pair continuum in Au+Au and p+p collisions at √sNN = 200 GeV over a wide range of mass and transverse momenta are presented in this talk. The e+e– yield is compared to the expectations from hadronic sources. In the mass region between φ- and the J/ψ-mesons, the yield is consistent with expectations from correlated сс production. In the mass region below the φ-meson, the p+p spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias spectrum in this region shows an enhancement by a factor of 4.7. At low mass (m < 0.3 GeV/c2) + – and high pT (1 < pT < 5 GeV/c) region an enhanced e e pair yield is consistent with production of virtual direct photons [2]. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the p+p is exponential with slope equal to 221 MeV. Hydrodynamical models with initial temperatures ranging from 300 to 600 MeV are in qualitative agreement with the direct photon data in Au+Au [2]. For low pT < 1 GeV/c the low mass region shows a further enhancement that increases with centrality and is underpredicted by theoretical models. This work is supported by federal target program “Scientific and scientific and pedagogical manpower of innovative Russia” through 2009–2013 years. 1. K.Adcox et al. // Nucl. Phys. A. 2005. V.757. P.184. 2. A.Adare et al. // Phys. Rev. Lett. 2010. V.104. 132301. 120 A-DEPENDENCE OF THE YIELDS OF THE DEUTERONS EMITTED IN STOPPED PION ABSORPTION B.A. Chernyshev, Yu.B. Gurov, L.Yu. Korotkova, S.V. Lapushkin, R.V. Pritula, T.D. Schurenkova National Research Nuclear University “MEPhI”, Moscow, Russia E-mail: [email protected] Experimental results on the yields and spectra of the deuterons emitted in stopped π— - mesons absorption by nuclei. The measurements were performed at the PNPI accelerator with two-arm semiconductor spectrometer of charged particles. A wide range of nuclei was investigated, which includes light nuclei 6,7Li, 9Be, 10,11B, 12C, the average nuclei 28Si, 40Ca, 59Co, 93Nb and heavy nuclei 169Tm, 181Ta, 209Bi, and also tin isotopes 114,117,120,124Sn. The spectra were measured in the range from 10 MeV to the kinematic reaction thresholds. The energy resolution over the whole range is 0.6 MeV. The accuracy of the absolute normalization is 7%. Analysis of high-momentum parts of the spectra of the fast deuterons indicates that the pion absorption on intranuclear 3He-clusters is of considerable importance in the fast deuteron production. In the framework of a phenomenological model defined contributions to the measured outputs of primary deuterons and deuterons formed in the pre-equilibrium and evaporation stages of reactions. A-dependences of the yields of deuterons and their components were received. The results are compared with the proton data obtained previously. This work has been supported by the Federal Program “Personnel of the innovative Russia” under contract for 2009-2013 SC № 14.740.11.0608. 121 MEASUREMENT OF THE EXCLUSIVE REACTION OF THE NEGATIVE PION PHOTOPRODUCTION ON POLARIZED DEUTERONS IN THE REGION OF THE LARGE VALUES OF THE FINAL PROTON MOMENTA L.M. Barkov2, V.V. Gauzshtein1, V.F. Dmitriev2, R.R. Dusaev1, A.Yu. Loginov1, S.I. Mishnev2, D.M. Nikolenko2, I.A. Rachek2, R.Sh. Sadikov2, A.A. Sidorov1, V.N. Stibunov1, D.K. Toporkov2, Yu.V. Shestakov2, S.A. Zevakov2 1 Tomsk Polytechnic University, Russia; 2 Budker Institute of Nuclear Physics, Novosibirsk, Russia E-mail: [email protected] Experimental investigations were carried out on internal tensor-polarized target of VEPP-3 electron storage ring by detecting of the two protons in coincidence [1 - 3]. The energies and trajectories of protons were measured by two hadron hodoscopes. Each hodoscope consists of three layers of plastic scintillators and three multilayer drift chambers. The scintillators were used for proton energy measurement and for particle identification. Target polarization was measured by LQ-polarimeter and beam luminosity was determined out by elastic ed-scattering. As a result T21 tensor analyzing power component was obtained for the γd→ ppπ− reaction as a function of photon energy, effective masses pp −, pπ− − , ppπ− − systems and proton momentum. These experimental results were compared with model predictions, issued in consideration of interparticle interactions at final state [4]. The mismatch between experimental and calculated behaviour of T21 component was found in both narrow and broad intervals of the kinematic variables. 1. D.M.Nicolenko et al. // Phys. Rev. Lett. 2003. V.90. No.7. 072501. 2. L.M.Barkov et al. // Bulletin of the Russian Academy of Sciences: Physics. 2010. V.74. No.6. P.743. 3. V.N.Stibunov et al. // Journal of Physics: Conference Series. 2011. No.295. P.012115. 4. A.Yu.Loginov et. al. // Phys. of Atom. Nucl. 2000. V.63. P.478. 122 CLAS COLLABORATION DATA BASE ON PHOTO- AND ELECTROPRODUCTION OF MESONS ON NUCLEONS AND NUCLEI V.D. Burkert1, V.V. Chesnokov 2, L. Elouadrhiri1, B.S. Ishkhanov2,3, V.I. Mokeev1,2, M.E. Stepanov2,3, V.V. Varlamov2 1 Thomas Jefferson National Accelerator Facility, Newport News, Virginia, USA; 2 Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia; 3 Faculty of Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] The data base on experimental results obtained by the International CLAS Collaboration was maintained and operated in collaboration between Hall B at Jefferson Lab and SINP at Moscow State University [1, 2]. CLAS Physics Data Base (CLAS DB) contains all results obtained with the CLAS detector beginning 1995, which represents model independent observables and, therefore, can be confronted with the respective results delivered by other groups worldwide. A large body of data on unpolarized cross sections, different polarization asymmetries of major meson photo and electroproduction channels off nucleons and nuclei measured in the kinematical area of the invariant masses of the final hadron system W < 3.0 GeV and at photon virtualities Q2 < 5.0 GeV2 are stored in the CLAS Physics DB. They keep extending continuously by new experimental results obtained by the CLAS Collaboration. The CLAS DB offers user friendly web-interfaces, which provide search for the particular observables in the user-selected reaction channels and kinematical areas, as well as the convenient tools for data submissions. The built-in fitting instruments for a simple on-line data analysis are available to determine integrated over the final state kinematical variables exclusive cross sections, as well as to access different structure functions in exclusive electroproduction processes. Available in the CLAS DB information is of particular interest for the high level physics analyses aimed to evaluate hadron elastic and transition form factors, different inclusive semi inclusive and fully exclusive GPD structure functions, as well as for comparison of the results on meson photo and electroproduction obtained by different groups worldwide, development of physical research program for the future experiments with the CLAS12 detector after completion of the JLAB 12 GeV Upgrade Project. 1. B.A.Mecking et al. // Nucl. Instr. & Meth. A. 2003. V.503. P.513. 2. CLAS Physics Database; http://www.jlab.org/Hall-B/; http://depni.sinp.msu.ru/jlab/. 123 CONTRIBUTIONS FROM EXCLUSIVE MESON ELECTROPRODUCTION CHANNELS TO THE INCLUSIVE STRUCTURE FUNCTIONS F1 AND F2 FROM THE CLAS PHYSICS DATABASE V.V. Chesnokov1, B.S. Ishkhanov1,2, V.I. Mokeev1,3, M.E. Stepanov1,2, V.V. Varlamov1 1 Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia; 2 Faculty of Physics, Lomonosov Moscow State University, Russia; 3 Thomas Jefferson National Accelerator Facility, Newport News, Virginia, USA E-mail: [email protected] The combination of a continuous electron beam and a 4π detector allows one to investigate most open channels of photo- and electroproduction of mesons on protons and nuclei during one cycle. The CLAS detector is the only experimental setup in the world with such possibilities. To date, data on most channels of meson electroproduction on protons at invariant masses W < 3.0 GeV of the finite hadronic system and photon virtualities 0.2 < Q2 < 5.0 GeV2 have been obtained on the CLAS detector, most of them for the first time. The CLAS data make it possible to determine the contributions of different exclusive channels to the inclusive structure function of electron scattering by protons. The information about the contributions of exclusive channels to the inclusive structure function is of great interest. It allows one to independently verify reliability of experimental data on both inclusive structure functions and the cross sections of exclusive channels integrated over the kinematic variables of final states. The contributions of exclusive π+n, π0p, and π—π+p channels to the inclusive 2 structure function F2(x, Q ) are determined for the first time from analysis of the CLAS collaboration data stored in CLAS Physics Database [1], developed in Collaboration between Hall B at JLAB and SINP at MSU. Reliability of the CLAS data on the inclusive structure function and single pion electroproduction channels is verified. The total contribution of the uninvestigated π+n and π0p channels to this function and the integrated cross sections of these channels at photon virtualities Q2 from 0.4 to 1.3 GeV2 are predicted. The contribution of the sum of π+π0n and π0π0p channels to the function 2 F2(x, Q ) and the integrated cross sections of the sum of these channels are predicted. Verification of these predictions in future experiments on electroproduction of the π+π0n and π0π0p final states is of great interest. 1. CLAS Physics Database; http://www.jlab.org/Hall-B/; http://depni.sinp.msu.ru/jlab/. 124 PHOTONUCLEAR REACTIONS ON PALLADIUM ISOTOPES S.S. Belyshev1, A.N. Ermakov2, A.S. Kurilik1, A.A. Kuznetsov2, K.A. Stopani2 1 Moscow State University, Russia; 2 D.V. Skobeltsyn Institute of Nuclear Physics, Moscow, Russia E-mail: [email protected] Natural palladium sample was irradiated with bremsstrahlung from tungsten target in the electron beam of RTM-55 microtron [1]. Electron beam energy was 55 MeV, average beam current was approx. 70 nA. Induced gamma radioactivity from photonuclear reactions products was then measured with a HPGe detector. Spectrums were saved in data acquisition system during the measurements and were analyzed to determine reaction yields. Photonuclear reactions up to (γ, 6n) are possible under the 55 MeV energy threshold. Peaks, coming from reactions up to (γ, 3n) and (γ, nб) were observed. The yields of 20 photonuclear reactions were calculated. Also isomeric ratios were found for four reactions (shown in the table). Isomeric ratio Reaction G.s. properties Isomer properties Ym/Yg.s. 102 99 Pd(γ, 2np) Rh 1.48 +/- 0.05 JP = 1/2– E = 64 keV, JP = 9/2+ 102 101 Pd(γ, p) Rh 2.8 +/- 0.1 JP = 1/2– E = 157 keV, JP = 9/2+ 104 102 Pd(γ, np) Rh 0.27 +/- 0.02 JP = (1–, 2–) E = 141 keV, JP = 6(+) 110 109 + Pd(γ, n) Pd 0.122 +/- 0.001 JP = 5/2 E = 189 keV, JP = 11/2 The obtained results were compared with the yields at 30 MeV that were determined in the previous experiment [4] using the RTM-70 microtron [5]. 1. A.I.Karev, A.N.Lebedev, V.G.Raevsky et al. // XXII Russian Particle Accelerator Conference RuPAC-2010, proceedings. P.316. 2. B.S.Ishkhanov, V.N.Orlin // Fiz. Elem. Chastis At. Yadra. 2007. V.38. P.84. 3. B.S.Ishkhanov, V.N.Orlin // Yad. Phys. 2008. V.71. P.517. 4. K.A.Stopani et al. // LX International Confenrence on Nuclear Physics “Nucleus 2010”. Proceedings. P.154. 5. V.I.Shvedunov, A.N.Ermakov, I.V.Gribov // Nucl. Instrum. Methods in Phys. Research. A. 2005. V.550. P.39. 125 EFFECT OF ELECTRON SCREENING IN THE MAIN THERMONUCLEAR REACTIONS S.N. Abramovich, S.M. Taova All-Russia Research Institute of Experimental Physics, RFNC-VNIIEF, Sarov, Russia E-mail: [email protected] Analysis of experimental data on the reactions of hydrogen and helium isotopes interaction with deuterons and tritons has been carried out. When performing the analysis there were considered data not only for gaseous targets but for deuterated metal targets as well. Being noticed at low energies the effect of electron screening in deuterated metal medium is much more intensive than in gaseous targets. The values of electron screening potentials are presented for the targets manufactured of aluminum, zirconium and tantalum with deuterium atoms implanted into them. Data presented in literary sources show great enough spread of electron screening potential values for the same kind of interaction. There is also a difference between experimentally obtained and theoretically predicted data on screening effect. The account of electron screening effect is necessary to perform qualitative calculations when designing different thermonuclear facilities. 126 MEASUREMENT OF THE TENSOR ANALYSING POWER COMPONENTS OF THE NEGATIVE PION PHOTOPRODUCTION ON DEUTERONS V.V. Gauzshtein1, R.R. Dusaev1, A.Yu. Loginov1, D.M. Nikolenko2, I.A. Rachek2, R.Sh. Sadikov2, A.A. Sidorov1, V.N. Stibunov1, D.K. Toporkov2, Yu.V. Shestakov2, S.A. Zevakov2 1 Tomsk Polytechnic University, Russia; 2 Budker Institute of Nuclear Physics, Novosibirsk, Russia E-mail: [email protected] The simultaneous measurements of three components of tensor analyzing power results are shown for exclusive negative pion photoproduction reaction, provided at the energy range 300-900 MeV [1]. The experiment was performed using internal polarized deuterium target at the VEPP-3 electron storage ring with coincidence proton registration [2]. From comparisons of obtained dependencies with theoretical predictions made in spectator model and in the impulse approximation with FSI one can consider that for pion photoproduction at large proton momenta, it is required to take into account in addition to πN and NN interactions, more complicated mechanisms of reaction, in particular, ∆N interaction at the intermediate states. 1. V.V.Gauzshtein et al. // Izv. Vuzov. Fizika. 2011. V.54. N.11/2. P.7. 2. M.V.Dyug et al. // Nucl. Instr. and. Meth. A. 2005. V.536. P.344. 127 SOME EXPERIMENTAL MANIFESTATIONS OF NEW TERNARY CLUSTER DECAY OF HEAVY NUCLEI D.V. Kamanin1, Yu.V. Pyatkov1,2, A.A. Alexandrov1, I.A. Alexandrova1, N.A. Kondratjev1, E.A. Kuznetsova1, V.E. Zhuchko1 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 National Nuclear Research University MEPHI, Moscow, Russia E-mail: [email protected] In the recent publications devoted to both experimental [1] and theoretical [2, 3] investigations of the new type of ternary decay of low excited heavy nuclei called collinear cluster tri-partition (CCT) the most populated modes of this process is under study. In the terms of conventional binary fission these modes are linked with the valley of the mass-asymmetric shapes of the fissioning system at the decent from the fission barrier. We have found that alternative valley of the mass-symmetric shapes can also give rise to the configurations provided ternary decay. Corresponding experimental data were obtained at two different time-of-flight spectrometers namely miniFOBOS based on the gas filled detectors and COMETA where micro-channels plates and PIN diodes are used for the detection of the fission fragments. The results presented demonstrate deep link between conventional binary fission and CCT processes. 1. Yu.V.Pyatkov et al. // Eur. Phys. J. A. 2010. V.45. P.29. 2. K.R.Vijayaraghavan et al. // Eur. Phys. J. A. 2012. V.48. P.27. 3. R.B.Tashkhodjaev et al. // Eur. Phys. J. A. 2011. V.47. P.136. 128 DIFFUSENESS PARAMETER FOR EVEN-EVEN NUCLEI WITH 58≤A≤250 AND THE COUPLED CHANNEL OPTICAL MODEL D.D. Zaikin, M.V. Mordovskoy, I.V. Surkova Institute for Nuclear Research of Russian Academy of Sciences, Moscow, Russia E-mail: [email protected] Earlier we obtained a description of low-energy neutron data for even-even nuclei with 58≤A≤250 using coupled channel optical model (CCOM) [1, 2]. A good description was obtained with the same parameters of CCOM (the depths of real and imaginary parts of CCOM potential). A parameter diffuseness, which enters our calculation through single-nucleon potential, is connected with the thickness of the surface layer of a nucleus and must not depend on the number of nucleons contained in a nucleus. As a matter of fact for a majority of 103 nuclei, considered here, such dependence was absent. A good description of low-energy neutron data was obtained at the same value of the diffuseness parameter a=0.65 fm, with exception of magic (as traditional and nontraditional) and deformed nuclei. For magic nuclei the best description was obtained for a=0.55-0.60 fm, for double magic ones — 0.50-0.55 fm, and for deformed — 0.70-0.75 fm. Such values are conceded with existing experimental data [3], and may be used for confirmation of finding nontraditional magic numbers. The present work contains a systematic for values of diffuseness parameter and an analysis of this parameter dependence on nucleon orbit filling. 1. D.A.Zaikin, M.V.Mordovskoy, I.V.Surkova // Eur. Phys. J. A. 1999. V.5. P.53. 2. D.A.Zaikin, M.V.Mordovskoy, I.V.Surkova // Izv. RAN. Ser. Fiz. 2002. V.66. P.727. 3. R.Schmidt, F.J.Hartmann, T.von Edigy et al. // Phys. Rev. C. 1998. V.58. P.3185. 129 EXCITATION OF ISOMERIC STATES IN REACTIONS (γ, n) AND (n, 2n) ON 113In AND 198Hg NUCLEI S.R. Palvanov1,2, G.S. Palvanova2, M. Kajumov3, O. Juraev3 1 Department of Physics, National University of Uzbekistan, Tashkent; 2 Institute of Applied Physics, National University of Uzbekistan, Tashkent; 3 Institute of Nuclear Physics, Tashkent, Uzbekistan E-mail: [email protected] In the present work results of investigation of the isomeric yield ratios and cross-section ratios of the (γ, n) and (n, 2n) reactions on nuclei 113In and 198Hg are presented. The isomeric yield ratios were measured by the induced radioactivity method. Samples have been irradiated in the bremsstrahlung beam of the betatron SB-50 of Institute of Applied Physics of National University of Uzbekistan in the energy range of 10÷35 MeV with energy step of 1 MeV. For 14 MeV neutron irradiation we used the NG-150 neutron generator of Institute of Nuclear Physics. As targets, we used indium and mercury in a natural mixture of isotopes. The gamma spectra reactions products were measured with a spectroscopic system consisting of HPGe detector CANBERRA with energy resolution of 1.8 keV at 1332 keV gamma ray of 60Co, amplifier 2022 and multichannel analyzer 8192 connected to computer for data processing. The filling of the isomeric and ground levels was identified according to their γ lines. For 113 112m,g 113 112m,g reactions In(γ, n) In and In(n, 2n) In values Ym/Yt it is equal 0.81±0.02 (at Eγmax=30 MeV) and 0.53±0.01(at En=14 MeV) respectively. The results are compared with the calculations made in the statistical Fermi-gas theory. 130 ISOMERIC YIELD RATIOS AND CROSS SECTION RATIOS OF THE REACTION (γ, 2n) ON 89Y, 113In AND 197Au NUCLEI S.R. Palvanov1,2, G.S. Palvanova2 1 Department of Physics, National University of Uzbekistan, Tashkent; 2 Institute of Applied Physics, National University of Uzbekistan, Tashkent E-mail: [email protected] In this work, the isomeric yield ratios and cross-section ratios of the photonuclear reaction of the (γ, 2n) type on nuclei of 89Y, 113In and 197Au is investigated by the induced radioactivity method. Samples have been irradiated in the bremsstrahlung beam of the betatron SB-50 of Institute of Applied Physics of National University of Uzbekistan in the energy range of 17÷35 MeV with energy step of 1 MeV. As targets, we used indium and mercury in a natural mixture of isotopes. To increase the dose power, we performed the irradiation inside the acceleration chamber of the SB-50 high current betatron at a distance of 12 cm from the tungsten braking target where the sample inside the special container was delivered with the help of a type K5-2A pneumatic transport setup. It took the transport setup ~4 s to deliver the sample to the irradiation site. The induced activities were examined by detecting and analyzing γ-rays with help of a 63 cm3 Ge(Li) semiconductor spectrometer equipped with a 4096 channel pulse height analyzer. The counting system had a resolution of ∼3.5 keV for the 1332 keV γ-line of 60Co. The filling of the isomeric and ground levels was identified according to their γ lines. Isomeric yield ratios were calculated according to the formula [1]. For reactions 89Y(γ, 2n)87m,gY and 113 111m,g In(γ, 2n) In values Ym/Yg at Eγmax=30 MeV is equal 0.45±0.02 and 0.13±0.01 respectively. The results are compared with the calculations made in the statistical Fermi-gas theory. 1. R.Vanska, R.Rieppo // Nucl. Instrum. Meth. 1981. V.179. P.525. 131 MASS DISTRIBUTION OF THE 241Am PHOTOFISSION FRAGMENTS O.A. Parlag1,2, T.V. Havrilec2, A.I. Lendyel1, V.T. Maslyuk1 1 Institute of Electron Physics, Uzhgorod, Ukraine; 2 Uzhgorod National University, Uzhgorod, Ukraine E-mail: [email protected] The semiconductor gamma-spectroscopy method [1] has been used for measuring the relative cumulative yields of 25 products of 241Am photofission for 22 mass chains at 14.5 MeV bremsstrahlung maximum energy. Bremsstrahlung irradiation was performed by electron accelerator – microtron M-30. During the target irradiation the beam energy instability not preceded 0.04 MeV. The bremsstrahlung was produced by the Ta - target. During the experiment the total absorption gamma-peaks identification was performed for the fission product: 88Kr, 91Sr, 91mY, 92Sr, 97Zr, 97Nb, 99Mo, 99mTc, 101Tc, 104Tc, 105Rh, 129Sb, 131I, 132Te, 133I, 134I, 135I, 138Cs, 139Ba,140La, 141Ba, 142La, 143Ce,146Pr, 149Nd. The cumulative yields were determined relative to 133I product reference. We have calculated the total chain yields of fission products summed for all mass chain with the help of semiempirical formula for the averaged charge distribution of fragments for given mass number [2]. The total error was estimated with taking into account the statistic errors of total absorption peaks intensity, time depending analysis, averaged means dispersion of different measures, efficiency interpolated values errors and nuclear constants (gamma line quantum yields, half decays). The total error of fission fragment cumulative yields is 7 - 15 %. The resulted mass distribution of heavy products shows the higher yields in the mass region 133 – 134, 138 – 140 and 143 – 154 which conforms to the similar experimental data for 232Th(γ, f), 238U(γ, f), 240Pu(γ, f), 237Np(γ, f) [3, 1] 241 and Am(nfast, f) [4]. On the basis of the multimodal fission [4] approach the asymmetric channels in the photofission process of 241Am were deduced. This decomposition allowed to get the estimation of contribution of different components. 1. O.Parlag et al. // Nuclear Physics and Atomic Energy. 2009. V.10. P.288. 2. A.Efimenko et al. // Nuclear data for science and technology. 1988. Mito, Japan. P.971. 3. H.Naik et al. // Nucl. Phys. A. 2011. V.853. P.1. 4. R.Iyer et al. // Nucl. Sci. Eng. 2000. V.135. P.227. 5. N.Demekhina, G.Karapetyan // Physics of Atomic Nuclei. 2010. V.73. P.24. 132 MASS DISTRIBUTION STRUCTURE OF THE 238U PHOTOFISSION O.A. Parlag1,2, T.V. Havrilec2, A.I. Lendyel1, V.T. Maslyuk1 1 Institute of Electron Physics, Uzhgorod, Ukraine; 2 Uzhgorod National University, Ukraine E-mail: [email protected] Experimental information on the yields of products of 238U photofission is important both for understanding the dynamics of the fission process and to address a number of applications involving the detection of nuclear materials, transmutation of minor actinide nuclear waste, making RIB and medical-isotope production etc. The semiconductor gamma-spectroscopy method has been used for measuring the relative cumulative yields of the 38 products of 238U photofission for 29 mass chains at 17.5 MeV bremsstrahlung maximum energy. During the experiment the total absorption gamma-peaks identification was performed for the fission product 85mKr (151.2; 304.9), 87Kr (402.6), 88Kr (196.3), 89Rb (1031.9; 1248.14), 91Sr (1024.3), 91mY (555.6), 92Sr (1384.1), 92Y (934.5), 93Sr (168.5), 95Zr (756.7), 97Zr (743.4), 97Nb (658.1), 99Mo (739.4), 99mTc (140.5), 101Tc (306.8), 103Ru (497.1), 104Tc (358), 105Ru (724.3), 129Sb (812.8), 131Te (149.7), 131I (354.5), 132Te (228.2), 133I (529.9), 134Te (272.9), 134I (847.0; 884.1), 135I (1131.5; 1260.4), 135Xe (249.8), 138Cs (1009.8; 1435.8), 139Ba (165.9), 140La (1596.2), 140Ba (537.3), 141Ba (190.3; 304.2), 141Ce (145.4), 142La (641.3), 143Ce (293.3), 146Pr (453.9), 147Nd (91.1), 149Nd (211.3). The cumulative yields were determined relatively to reference points 132Te (228.2 keV) and 133I (529.9 keV) products. We have calculated the total yields of fission products summed for all mass chain with the help of semiempirical formula for the averaged charge distribution of fragments for given mass number. The total error of fission product cumulative yields is 7 - 14 %. In the obtained mass distributing of photofission heavy products 238U there is an increased yield of fissions in the range of the masses 134, 138 and 142, which is consistent with the experimental data [1-3]. On the basis of the multimodal fission [4] approach the asymmetric channels in the photofission process of 238U were deduced. The heavy fragments peak of the mass spectrum was fitted by three Gaussians. This decomposition allowed to get the estimation of contribution of different components. 1. O.Parlag et al. // Nuclear Physics and Atomic Energy. 2009. V.10. P.288. 2. H.Naik et al. // Nucl. Phys. A. 2011. V.853. P.1. 3 R.Iyer et al. // Nucl. Sci. Eng. 2000. V.135. P.227. 4 N.Demekhina, G.Karapetyan // Physics of Atomic Nuclei. 2010. V.73. P.24. 133 PROMPT NEUTRON MULTIPLICITY PARAMETERIZATION OF ACTINIDE NUCLEI PHOTOFISSION O.A. Parlag1,2, T.V. Havrilec2, A.I. Lendyel1, V.T. Maslyuk1 1 Institute of Electron Physics, Uzhgorod, Ukraine; 2 Uzhgorod National University, Ukraine E-mail: [email protected] To estimate the fragment mass distribution by total yields of photofission product in the final state we need the form of neutron yields dependence on fission product mass. For this purpose we can use the parameterisation [1]. However, performing the analysis of the data on neutron yields of photofission of 232Th, 235U, 238U [2, 3], we concluded that for more detailed taking into account the peculiarities of the structure of neutron yields it is necessary to divide the whole mass plot into more than 2 bins [4]. We have constructed the function R(A)=νL,H(A)/νt(A). The parameterisation L LL of this function is Ri()() A=+− a ii b AAL for light fragment and HL Ri() A=1 − RAic () for heavy one, νL,H(A) is the light and heavy fission product neutron yields, respectively, i is the bin number (i = 1 or more), Aс is the conjugated mass number. We have fitted the function R(A) for photofission [4] with R(A) parameterisation taking into account fore bins (see Fig. 1). The free parameter number was significantly restricted due to the boundary conditions. One of the fitting results is shown on Fig. 1. 238 Fig. 1. Total neutron yield distribution of the U photofission: upper open circles – νt(A), middle open circles – νL,H(A), middle curve – result νL,H(A), bottom curve – R(A). 1. A.C.Wahl // Fission product yield data for the transmutation of minor actinide nuclear waste. Vienna. 2008. P.117. 2. M.Piessens et al. // Proceedings of the XV-th ISNP. Gaussig. 1986. P.92. 3. D.De Frenne et al. // Phys. Rev. C. 1982. V.26. P.1356. 4. A.I.Lengyel et al. // PAST (Nuclear physics and elementary particles). 2011. №3. P.14. 134 MEASUREMENT OF THE DIFFERENTIAL CROSS SECTIONS OF THE NEGATIVE PION PHOTOPRODUCTION ON DEUTERON AT LARGE PROTON MOMENTA L.M. Barkov2, V.V. Gauzshtein1, V.F. Dmitriev2, R.R. Dusaev1, A.Yu. Loginov1, S.I. Mishnev2, D.M. Nikolenko2, I.A. Rachek2, R.Sh. Sadikov2, A.A. Sidorov1, V.N. Stibunov1, D.K. Toporkov2, Yu.V. Shestakov2, S.A. Zevakov2 1 Tomsk Polytechnic University, Russia; 2 Budker Institute of Nuclear Physics, Novosibirsk, Russia E-mail: [email protected] The experimental differential cross section of the negative pion photoproduction on deuteron are presented as a function of the proton momentum. The experiment was carried out on internal deuteron target of the electron storage ring VEPP-3 [1, 2]. We studied the meson production by quasireal photons in forward peaking approximation. The detecting of the two protons with large momenta in coincidence puts down the spectral mechanism contribution increasing the role of the more complicated ones. The measured cross sections were compared with theoretical calculations for different photon energies. The elementary amplitude of the negative pion photoproduction on the nucleon in the modelling programm contains the Born terms, the contribution from the six nucleon resonances and vector meson exchanges [3]. The consideration of the πN and NN final state interaction in the theoretical calculations leads to quite good consent with experimental results. 1. L.M.Barkov et al. // Bulletin of the Russian Academy of Sciences: Physics. 2010. V.74. № 6. P.743. 2. V.N.Stibunov et al. // Journal of Physics: Conference Series. 2011. No.295. P.012115. 3. J.M.Laget // Phys. Rev. Lett. 1978. V.41. No.2. P.89. 135 MUON CAPTURE IN 12C N.S. Rumyantseva, V.G. Egorov Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] Analysis of experimental data obtained with µЕ4 and µЕ1 PSI muon beams is presented. Muonic X-rays and γ-rays following muon capture in both solid polyethylene and isobutane gas targets were registered with several HPGe-detectors. Specific shape of Doppler-broadened γ-lines was investigated taking into account slowing-down of the recoil 12B ions. As a result, lifetimes of corresponding excited levels of 12B were deduced. Precise analysis of the (1667-1673) keV doublet allows to separate these lines and to get their intensities. Using these data and the detector efficiency, we succeeded to extract partial µ-capture rates which strongly depend on induced form-factors and thus provide information about weak interaction. 136 THEORY OF ATOMIC NUCLEUS AND FUNDAMENTAL INTERACTIONS LIGHT NUCLEI WITH JISP-TYPE NN INTERACTION AND WITH OTHER MODERN STRONG INTERACTION MODELS V.A. Kulikov1, P. Maris2, A.I. Mazur3, A.M. Shirokov1,2,3, J.P. Vary2 1 Skobeltsyn Institute of Nuclear Physics, Moscow State University, Russia; 2 Department of Physics and Astronomy, Iowa State University, Ames IA, USA; 3 Pacific National University, Khabarovsk, Russia E-mail: [email protected] The NN interaction of the JISP (J-matrix inverse scattering potential) type provides better convergence of ab initio no-core shell model (NCSM) calculations as compared with other modern realistic NN interactions. The JISP-type NN interaction is obtained in the inverse scattering approach [1] which guarantees a perfect description of two-body nucleon-nucleon data. This potential is used in NCSM calculations of various observables in many-body nuclear systems. Based on these calculations, the interaction is modified in various partial NN waves by phase-equivalent transformations (PETs) [2,3] which do not affect the description of nucleon-nucleon scattering data while improve the description of multi-nucleon observables. As a result, a good agreement between theoretical predictions and experimental data on light nuclei (with mass A ≤ 16) can be achieved without making use of three-nucleon forces. Following this route, a realistic NN interaction JISP16 perfectly describing not only the NN data but also the binding energies and spectra of light nuclei was designed [3]. Recently a no-core full configuration (NCFC) method based on the extrapolation of the NCSM results to the case of infinite model space was introduced [4] improving essentially accuracy of theoretical predictions. These developments allow to achive a significant progress in ab initio description of light nuclei. We perform a detailed comparison of binding energies and spectra of light nuclei calculated by the NCFC method with JISP16 NN potential with ab initio results obtained with other modern two- and three-nucleon interactions. In particular, we concentrate on the description of unnatural parity states which were not studied with JISP16 before. 1. A.M.Shirokov, A.I.Mazur, S.A.Zaytsev, J.P.Vary, T.A.Weber // Phys. Rev. C. 2004. V.70. 044005. 2. A.M.Shirokov, J.P.Vary, A.I.Mazur, S.A.Zaytsev, T.A.Weber // Phys. Lett. B. 2005. V.621. P.96. 3. A.M.Shirokov, J.P.Vary, A.I.Mazur, T.A.Weber // Phys. Lett. B. 2007. V.644. P.33. 4. P.Maris, J.P.Vary, A.M.Shirokov // Phys. Rev. C. 2009. V.79. 014308. 137 NEW TREATMENT OF THE FEW-BODY BREAKUP O.A. Rubtsova Skobeltsyn Institute of Nuclear Physics, Moscow State University, Russia E-mail: [email protected] The new approach towards solution of few-body scattering problems and accurate treatment of few-body breakup is considered. The method is based on the few-body continuum discretization and solving the problem in the few-body L2 basis of stationary wave packets [1, 2]. After the projection into the wave- packet subspace, the operators take the finite-dimensional matrix forms and the integral scattering equations are reduced to algebraic ones. Simultaneously, the energy and momentum dependencies in kernels are smoothed by the averaging over the discretization bins. So the initial scattering problem is reduced to the matrix one with non-singular matrix kernel which can be solved directly on the real energy axis. Thus, this discrete approach allows to treat the intermediate and direct breakup reactions in terms of transitions between the states of the discretized continuum. To study the validity of the method, two areas of application are discussed: the direct nuclear reactions [1, 2] and few-nucleon systems [1]. One of the advantages of the discrete approach is that it can be adopted to different types of modern nucleon-nucleon and nucleon-nucleus interactions including tensor, non-local, multi-channel and complex non-Hermitian (e.g. optical) terms. Also the discrete approach allows to construct in an explicit form effective non-local potentials those take into account intermediate inelastic and breakup channels in composite particle collisions. As a numerical illustration, the 3N system is studied where different elastic and breakup observables are calculated. The obtained results are in good agreement with the results of the conventional approaches those based on the direct numerical solving of the Faddeev equations. At the same time the discrete approach has much more simple numerical scheme and all the calculations for realistic potentials are prepared on the ordinary personal computer in contrast to the conventional technique. 1. O.A.Rubtsova et al. // Phys. Rev. C. 2009. V.79. 064602. 2. O.A.Rubtsova et al. // Phys. Rev. C. 2011. V.84. 044002. 138 DESCRIPTION OF PROPERTIES OF QUADRUPOLE STATES IN 94Mo WITH SKYRME INTERACTION N.N. Arsenyev1, A.P. Severyukhin1, V.V. Voronov1, N. Pietralla2, Nguyen Van Giai3 1 Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Russia; 2 Institut für Kernphysik, TU Darmstadt, Darmstadt, Germany; 3 Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Orsay, France E-mail: [email protected] Many properties of the collective nuclear excitations can be described within the self-consistent quasiparticle random phase approximation (QRPA) with the Skyrme interaction. Such an approach describes the properties of the low-lying states less accurately than more phenomenological ones, but the results are in a reasonable agreement with experimental data. Due to the ahnarmonicity of vibrations there is a coupling between one-phonon and more complex states. The main difficulty is that the complexity of calculations beyond standard QRPA increases rapidly with the size of the configuration space, so one has to work within limited spaces. Using a finite rank approximation for the residual interaction resulting from the Skyrme forces that has been suggested in [1-3] one can overcome problems mentioned above. This approach is generalized to take into account a coupling between the one- and two-phonon components of wave functions [4]. To demonstrate an ability of the method, we examine the properties of the low-lying 2+ states in 94Mo [5]. The analysis of the 2+ states ++ ++ energies, the BE( 2;0gs→ 2 i ) and BM( 1; 2i → 21 ) - values will be discussed. This work was partly supported by the Heisenberg-Landau program and the RFBR grant № 110291054. 1. Nguyen Van Giai, Ch.Stoyanov, V.V.Voronov // Phys. Rev. C. 1998. V.57. P.1204. 2. A.P.Severyukhin et al. // Phys. Rev. C. 2002. V.66. 034304. 3. A.P.Severyukhin, V.V.Voronov, Nguyen Van Giai // Phys. Rev. C. 2008. V.77. 024322. 4. A.P.Severyukhin, V.V.Voronov, Nguyen Van Giai // Eur. Phys. J. A. 2004. V.22. P.397. 5. A.P.Severyukhin et al. // Nucl. At. Phys. 2011. V.74. P.1171. 139 INVESTIGATION OF SUPER DEFORMATION MANIFESTATIONS IN NUCLEI WITH EXTREME NEUTRON EXCESS K.A. Gridnev1,2, W. Greiner1, V.N. Tarasov3, S. Schramm1, D.K. Gridnev1, D.V. Tarasov3, X. Viñas4 1 Frankfurt Institute for Advanced Studies, J.W.G. University, Germany; 2 Institute of Physics, Saint Petersburg State University, Russia; 3 NSC Kharkov Institute of Physics and Technology, Ukraine; 4 University of Barcelona, Spain E-mail: [email protected] We investigated the properties of nuclei with extreme neutron excess at Z ≥ 80 including the region of transuranium elements. Our calculations are based on the Hartree–Fock (HF) method with Skyrme forces (SkM*, SkI2, SLy4, Ska) taking into account axial deformation and the BCS pairing approximation. In [1] we showed that the isotone chain at the neutron number N = 258 beyond the neutron drip line forms the peninsula of nuclei stable to the emission of one neutron. All the nuclides (for SkM* forses) of the isotone chain with N = 258 up to Z = 104 possess spherical symmetric neutron and proton density distributions. This result agrees with the idea about magic number 364 N = 258. However for Z = 106 ( Sg258) and SkM* forces the most bounded solution of HF equations corresponds to the solution with giant values of proton and neutron parameters of deformation βp = 0.854 and βn = 0.769. The giant values of β also occur for 360Rf (Z = 104) and 362Sg. These values of β are much bigger than the values of β~0.6 for superdeformed nuclei with extreme neutron excess such as 226-230Pb, 222-234Po and 222-236Rn. For some neutron rich superdeformed nuclei we have analyzed the potential energy curve as the function of the mass quadrupole moment E(Qm) through the constrained HF. 1. V.N.Tarasov et al. // 61 International Conference «Nucleus 2011» Abstracts. Sarov. 2011. P.42. 140 THE PENINSULA OF NEUTRON STABILITY OF NUCLEI IN THE NEIGHBORHOOD OF NEUTRON MAGIC NUMBER N = 126 V.N. Tarasov1, K.A. Gridnev2,3 , W. Greiner2 , S. Schramm2, D.K. Gridnev2, D.V. Tarasov1, X. Viñas4 1 NSC Kharkov Institute of Physics and Technology, Ukraine; 2 Frankfurt Institute for Advanced Studies, J.W.G. University, Germany; 3 Institute of Physics, Saint Petersburg State University, Russia; 4 University of Barcelona, Spain E-mail: [email protected] Calculations of the ground state properties of even-even nuclei with extreme neutron excess have been carried out beyond the theoretically known neutron drip line. These calculations are continuation of our investigations of nuclei with extreme neutron excess [1]. The Hartree–Fock method with Skyrme forces (Ska, SkM*, SLy4, SkI2) has been used with the accounts of axial deformations and the BCS pairing scheme. It is shown that the isotone chain with the neutron number N = 126 forms the peninsula of nuclei beyond the neutron drip line which are stable against one and sometimes two neutrons emission. The neutron and proton density distributions of nuclei belonging to this peninsula possess spherical symmetry. The mechanism of stability restoration beyond the neutron drip line is discussed. It has been shown that the formation the peninsula of stability beyond the neutron drip line while adding neutrons to extremely neutron-rich isotopes is stable to the choice of type of Skyrme forces. The localization the peninsulas of stability in the (N, Z) space take place at the same value of N = 126 irrelatively the type of Skyrme forces. The results for long isotope chains of Pd, Ru, Mo and Zr up to the neutron drip line are compared with the Hartree–Fock–Bogoliubov calculations [2]. 1. V.N.Tarasov et al. // Physics of Atomic Nuclei. 2012. V.75. P.19. 2. M.V.Stoitsov et al. // Phys. Rev. C. 2003. V.68. 054312. 141 CALCULATION OF NUCLEAR GROUND STATES PROPERTIES WITHIN THE STATISTICAL LEARNING FRAMEWORK Y. Martinez Palenzuela1, L. Felipe Ruiz1, A. Karpov1, V. Zagrebaev1, W. Greiner1 1 Frankfurt Institute for Advanced Studies, J. W. Goethe-Universität, Frankfurt, Germany; 2 Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia E-mail: [email protected] Using the macroscopic-microscopic approach with a Two-Center Shell Model potential a three-dimensional energy minimization is performed on the macroscopic shape coordinates of the model. The model is capable of reproducing the ground-state masses for a number of nuclei in the region 50 1. P.Moller, J.R.Nix, W.J.Swiatecki // Atomic Data Nucl. Data Tables. 1995. V.59. P.185. 2. V.Vapnik. The Nature of Statistical Learning Theory. New York:Springer-Verlag. 142 EFFECTS OF TENSOR INTERACTION ON GAMOW-TELLER STATES IN 118,120Sn A.P. Severyukhin1, V.V. Voronov1, H. Sagawa2, Nguyen Van Giai3 1 Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Russia; 2 Center for Mathematics and Physics, University of Aizu, Aizu-Wakamatsu, Japan; 3 Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Orsay, France E-mail: [email protected] The quasiparticle random phase approximation (QRPA) with the Skyrme interaction is a standard microscopic approach. Many charge-exchange versions of it were developed during the last decade. Their common feature is that they allow to relate the properties of the ground states and excited states through the same energy density functional. On the other hand, it would be desirable to extend the description beyond the QRPA scheme in order to include damping effects observed experimentally. Making use of separable residual interaction one can perform the spin-isospin excitation calculations in large configuration spaces since there is an opportunity to avoid matrices whose dimensions grow with the size of configuration space. For the same reasons, we develop the finite rank separable approximation for the Skyrme interactions [1-3] that enables one to perform the charge-exchange calculations in the large configuration space [4]. In this talk we briefly describe our method for the charge-exchange excitations and present our studies of properties of the Gamow-Teller resonances in some spherical nuclei. In particular, the effects of the tensor correlations on the strength distribution of Gamow-Teller resonances in 118,120Sn are discussed. Our results from the SGII Skyrme interaction in connection with the density-dependent zero-range pairing interaction are in reasonable agreement with the experimental data. This work was supported by the RFBR grant № 110291054. 1. Nguyen Van Giai, Ch.Stoyanov, V.V.Voronov // Phys. Rev. C. 1998. V.57. P.1204. 2. A.P.Severyukhin, V.V.Voronov, Nguyen Van Giai // Eur. Phys. J. A. 2004. V.22. P.397. 3. A.P.Severyukhin, V.V.Voronov, Nguyen Van Giai // Phys. Rev. C. 2008. V.77. 024322. 4. A.P.Severyukhin, V.V.Voronov, Nguyen Van Giai // Journal of Physics: Conference Series. 2011. V.267. P.012025. 143 SPIN AND ORBITAL NUCLEAR CURRENTS’ INTERFERENCE IN THE ELECTROEXCITATION OF 1f2p-SHELL NUCLEI N.G. Goncharova, Iu.A. Skorodumina Skobelzyn Institute of Nuclear Physics, Moscow State University, Russia E-mail: [email protected], [email protected] Successful microscopic description of E1 resonances at photopoint for calcium and titanium isotopes performed in «particle–core coupling» version (PCC) of multiparticle shell model [1] shows that the fragmentation of E1 strength is highly influenced by the hole distribution among the residual nuclei states. The investigation of E1 response in (e, e′) reactions at transferred momentum q > ω could be a good check of used model and as well the way to analyze the interference of spin- and orbital currents contributions. Relative roles of these currents in electroexcitation depend on q and ω and on wave functions’ configurations. At photopoint q = ω only the orbital current contributes to form factors; with growing q spin currents begin to dominate [2]. Destructive interference between the orbital and spin currents is responsible for the appearance of a non-diffraction zero at q≈0.4–0.6 fm-1 in all form factors for the single-particle transitions 1lj=l+1/2→1(l+1)j=l+3/2 [3] (Fig. 1 for 1f7/2→1g9/2 transition form factor). In the same q-region the single particle CJ form factors reach their maxima. Fig. 1. Fig. 2. The interference of spin- and orbital currents results in rebuilding of cross section distributions with growing q. At Fig. 2 the results of PCC calculations for electroexcitation of 48Ca at photopoint and at q=0.5 Fm-1 are shown. 1. N.G.Goncharova, Iu.A.Skorodumina // Bull RAS, Phys. 2011. V.75. P.1540; 2012. V.76. P.559. 2. N.G.Goncharova, A.A.Dzhioev // Nuclear Physics. A. 2001. V.290. P.247. 3. N.G.Goncharova, A.A.Dzhioev et al. // Phys. At. Nucl. 2000. V.63. P.1836. 144 SIMPLE ANALYTIC MODEL FOR ASTROPHYSICAL S-FACTORS A.I. Chugunov1, A.V. Afanasjev2, M. Beard3, M. Wiescher3, D.G. Yakovlev1,3,4 1 Ioffe Institute, St.-Petersburg, Russia; 2 Department of Physics and Astronomy, Mississippi State University, USA; 3 Department of Physics & The Joint Institute for Nuclear Astrophysics, University of Notre Dame, USA; 4 St.Petersburg State Polytechnical University, Russia E-mail: [email protected] Numerous nuclear reactions in the crust of accreting neutron stars are strongly affected by dense plasma environment. Simulations of superbursts, deep crustal heating and other nuclear burning phenomena in neutron stars require astrophysical S-factors for these reactions (as a function of center-of- mass energy E of colliding nuclei). A large database of S-factors is created for about 5,000 non-resonant fusion reactions involving stable and unstable isotopes of Be, B, C, N, O, F, Ne, Na, Mg, and Si. It extends the previous database of about 1,000 reactions involving isotopes of C, O, Ne, and Mg. The calculations are performed using the Sao Paulo potential and the barrier penetration formalism. All calculated S-data are parameterized by an analytic model for S(E) proposed before [1] and further elaborated here. For a given reaction, the present S(E)-model contains three parameters. These parameters are easily interpolated along reactions involving isotopes of the same elements with only seven input parameters, giving an ultracompact, accurate, simple, and uniform database. The S(E) approximation can also be used to estimate theoretical uncertainties of S(E) and nuclear reaction rates in dense matter, as illustrated for the case of the 34Ne+34Ne reaction in the inner crust of an accreting neutron star. This work is partially supported by JINA (PHYS-0822648) and by the U.S. Department of Energy under the grant DE-FG02-07ER41459 (Mississippi State University). AIC and DGY acknowledge support from RFBR (grant 11-02- 00253-a) and from the State Program of “Leading Scientific Schools of Russian Federation” (grant NSh 4035.2012.2). AIC acknowledges support of the Dynasty Foundation, of the President grant for young Russian scientists (MK- 857.2012.2), and of the RAS Presidium Program “Support for Young Scientists”; DGY acknowledges support of RFBR (grant 11-02-12082-ofi-m- 2011) and Ministry of Education and Science of Russian Federation (contract 11.G34.31.0001). 1. D.G.Yakovlev et al. // Phys.Rev. C. 2010. V.82. Id.044609. 145 BOSON MAPPING OF THE FERMION DYNAMICAL MODEL OF NUCLEI K. Baktybayev1, N. Koilyk1, K. Ramankulov2 1 Almaty al-Farabi University, Kazakhstan; 2 Abai Pedagogical University, Kazakhstan E-mail: [email protected] In the interacting boson model (IBM) boson degrees of freedom are introduced which are believed and, at least in some cases, have been shown, to be related to collective shell-model fermion pairs. The IBM with s-and d-boson has proven to be very efficient and useful in phenomenological description and correlating extensive pieces of experimental data. The formulation of fermion dynamical symmetry model (FDSM) on a description of collective states and relies on algebraic symmetry concepts is directly related to the shell structure. The building blocks of FDSM are correlated fermion pairs S, S' and D chosen as the pair creation and annihilation operators together with a set multipole operators close an Sp(6) or SO(8) and an SU(2) algebra. In the present work we investigate boson mappings [1, 2] relevant to the fermionic FDSM. We discuss several boson mapping procedures which transcribe an FDSM Hamiltonian into a boson one and compare the results. Hereby IBM-type Hamiltonians are constructed with an aim to test the applicability of different boson mapping procedures. Fermion theory was represented into boson’s space by Dyson, Belyaev- Zelevinski and Seniority methods. The solutions of represented boson equation were used to same platinum isotopes and it gave a good results. It was shown that FDSM and its boson representation gave a good explanation of experimental data. So it was shown that from the Hamiltonian of FDSM could be constructed boson type IBM-Hamiltonian by representation. So fermion theory gives microscopically base of phenomenological approaches. The results of the various mapping procedures are compare in different regions of the Z=50-82, N=82-126 shell. It should be notes that the correspondence between the IBM and FDSM has also been studied from a group theoretical point of view. 1. Ch.L.Wu, D.H.Feng et al. // Phys. Rev. C. 1987. V.36. P.1657. 2. I.Doleŝ, H.B.Geyer et al. // Phys. Rev. C. 1994. V.50. P.784. 146 FERMION MICROSCOPIC BASIS OF THE INTERACTING BOSON MODEL K. Baktybayev Al-Farabi Kazakh national University, Almaty, Kazakhstan E-mail: [email protected] The microscopic foundations of the interacting boson model (IBM), is to drive the parameters of the models microscopically, namely, from nucleon’s degrees of freedom [1]. The IBM, which can be analyzed in terms of an SU(6) group structure, has simulated considerable activity in the study of collective modes in nuclei from the point of view of dynamical fermion symmetries. Bosonic and fermionic descriptions for the nuclear many body system are complementary. Without distinguishing between proton and neutron bosons, it gave rise to successful phenomenology for medium and heavy nuclei, and is, built from the concept of dynamical symmetry whose genesis is a group chain. The fermion algebra, on the other hand, such as the fermion dynamical symmetry model (FDSM) [2], is necessarily more complex because it originates from the shall structure and uses protons and neutrons as building blocks. To study the microscopic basis of the IBM according to the Otsuka-Arima- Iachello (OAI) mapping, we have to clarify the validity of truncation of nucleon S- and D- pairs space from the entire shell-model space and the validity of the OAI – mapping up to first or second order Yoshinaga et al. use the single-j-orbit model, we can anticipate the better approximation of the OAI-mapping applied to the realistic case [3]. In this paper it is devoted to the introduction and discussion on the OAI-mapping in the realistic calculations and the definition of bosons. It is explained of OAI – mapping in detail, and showed how to determine the collective pairs and also some technical methods for calculating matrix elements. It is discussed the Hamiltonian for underlying nucleon system and the parameters of the boson Hamiltonian microscopically obtained. We study the microscopic calculation according to the OAI – mapping for the Xe-Ba isotopes. These isotopes of Xe-Ba are near spherical nuclei, and the OAI – mapping is expected to be good for them. It is important to explain the experimental data by IBM in a microscopic manner. 1. A.Arima, F.Iachello // Ann. of Phys. 1979. P.99. P.253. 2. T.Mizusaki, T.Otsuka // Progr. Theor. Phys. Suppl. 1996. №125. P.97. 3. N.Yoshinada et al. // Progr. Theor. Phys. Suppl. 1996. №125. P.65. 147 ON DISTRIBUTION OF THE ISOSCALAR MONOPOLE STRENGTH IN MEDIUM-HEAVY SPHERICAL NUCLEI M.L. Gorelik, M.H. Urin National Research Nuclear University “MEPhI”, Moscow, Russia E-mail: [email protected] Recent experimental data concerned with the (α-α')-scattering at small angles unexpectedly show existence of a rather strong resonance structure at high excitation energy (Ex ~ 24-25 MeV) in distribution of the isoscalar monopole strength for A ~ 90 region [1]. In the analysis of these data both the collective and microscopic energy-dependent transition densities [2] related to the isoscalar monopole giant resonance (ISMGR) are used although this resonance is located at Ex ~ 16-17 MeV. The method for calculating the microscopic energy-dependent transition density (MEDTD) is based on an extension of the Migdal's finite Fermi-system theory («continuum-RPA + spreading effect») and formulated in terms of an effective field [2, 3]. The use of such a method is justified in the energy region of a given giant resonance and in case of the ISGMR leads to the MEDTD whose radial dependence is close to that for the collective transition density [2]. For calculating the MEDTD, which is independent of an external field, in the presented work we use the particle-hole energy-averaged Green function. The basic equations of the method are given in Ref. [3]. Such a method, which is formulated for medium-heavy spherical nuclei and is valid in a wide excitation energy interval, allows us to take into account contribution to the isoscalar monopole MEDTD of both the ISGMR ant its overtone. The latter is expected to be located at Ex ~ 30-40 MeV for A ~ 90 region [2]. We hope that using the calculated isoscalar monopole MEDTD in an analysis of the data obtained in Ref. [1] will help to understand the problem raised in this reference. This work is partially supported by the Russian Foundation for Basic Research (grant no. 12-02-01303-a). 1. D.H.Youngblood et al. // submitted to Phys. Rev. Lett. 2. M.L.Gorelik, I.V.Safonov, M.H.Urin // Phys. Rev. C. 2004. V.69. 054322. 3. M.H.Urin // Phys. At. Nucl. 2011. V.74. P.1189. 148 RADII OF LAST PROTON POSITION IN SYMMETRICAL NUCLEI G.K. Nie Institute of Nuclear Physics, Tashkent, Uzbekistan E-mail: [email protected] Radius of the last proton position (RPP) in nucleus is an important characteristic. It can be used as a criterion in the task of determination of the single particle bound state potential. Empirical values of RPP have been obtained in the framework of an alpha-cluster model of nuclear structure based on representation of nucleus as a liquid drop of pn-pairs joint to alpha-clusters with using charge symmetry of nuclear force [1]. This model allows one to 1/3 calculate charge radii of nuclei by formula R=1.6 Nα where Nα =Z/2. The Coulomb energy is estimated as the sum of the differences between the binding energies of the neutron and the proton belonging to one pn-pair. The values RPP have been obtained by three different ways for the symmetrical nuclei with Z =5-45 with average difference 0.2 fm. With using the values the Coulomb radii in single particle wave function representation have 2 1/2 been estimated and the rms radii 1. G.K.Nie // Mod. Phys. Lett. A. 2007. V.22. P.227. 149 MICROSCOPICAL CALCULATIONS OF E2 EFFECTIVE CHARGES FOR IBM A.D. Efimov1, V.M. Mikhajlov2 1 Ioffe Physical Technical Institute, St.Petersburg, Russia; 2 Physical Institute of St.Petersburg State University, Russia E-mail: [email protected] Microscopical calculations of parameters for Interacting Boson Model (IBM) Hamiltonian [1] show that the quantitative agreement of theoretical and phenomenological values can be attained by taking into account the interactions of the most collective quadrupole two-quasiparticle phonons ( D ) with noncol- lective ones ( B ) possessing higher energies. The same has been established also in previous works exploiting other kinds of boson description in comparison with IBM. Here we consider the effect of these BD− interactions on E2− tran- sition probabilities which are calculated with admixtures of configurations | BDD+++> to state | D+ > , | BD++> to | DD++> and | B+ > to | DDD+++> . Besides, our modification of RPA results in a component | BD++> added to the phonon vacuum function (vacuum polarization). Because of the presence of B − phonons in fermion wave functions (for BE( 2) calculations B − phonons are mainly quad- rupole ones) the boson mapping on the space involving only quadrupole d - and scalar s -bosons of IBM gives rise to additional terms in the boson E2-transition operator Tˆ(E2) . One of these terms most essential for transitions along the yrast ˆ ˆ band (δT ) is used here and joined to the standard IBM operator (TIBM ). ˆ ˆ ˆˆ * + + +(2) ˆ * ++(0) ++(0) (2) T(E2)= TIBM +δ TT ;IBM = e ( sd ++ dsχ dd); δδ T = e (() s dd d+ d ()). dd s (1) Calculations of BE( 2) -values have been implemented for 126 Ba for which the IBM Hamiltonian parameters and the maximum d-boson number, Ω=13, are found in [1]. The distinguishing feature of our approach is the absence of effec- tive charges in the fermion E2-operator i.e. we adopt eeprot. = and eneutr. = 0 that, nevertheless, allows us to reproduce the absolute BE( 2) -values. We have ob- tained effective boson charges in (1): e*2=7.65 e ⋅ fm (or 6.22 if the vacuum po- larization is not included), δ e*2=0.90 e ⋅ fm . Empirical [2] and theoretical BE( 2) - values (in e24⋅ fm ) within the yrast band of 126 Ba are compared in Table. Calcula- tions with δ e* = 0 in (1) reduce the theoretical BE( 2) ’s which now average 0.6 of the values with δ e* ≠ 0 given above. Thus, the role of δTˆ in (1) is fairly vital ˆ and consists in compensation of the cutoff in TIBM produced by s -bosons. ++++ ++ ++ ++ ++ IIif→ 20→ 42→ 64→ 86→ 10→ 8 3400(100) 4830(100) 6620(300) 640 1000 BE( 2) , exp. 8040550 7300800 BE( 2) ,theor. 3600 5330 6190 6730 7060 1. A.D.Efimov, V.M.Mikhajlov // Bull. RAS. Ser. Phys. 2010. V.71. P.574; 2011. V.75. P.890. 2. A.Dewald, D.Weil et al. // Phys. Rev. C. 1996. V.54. R2119. 150 THE ANALYSIS OF THE MIXED TRANSITIONS IN 160Dy P.N. Usmanov1,2, A.I. Vdovin2, U.S. Salihbaev3, A. Urinov1 1 Namangan Engineering and Technology Institute, Uzbekistan; 2 Joint Institute for Nuclear Research, Dubna, Russia; 3 Institute of Nuclear Physics, Uzbekistan Academy of Sciences, Tashkent E-mail: [email protected] Many experimental researches have been devoted to studying of spectroscopic properties of the excited conditions in 160Dy [1-4]. In works [4 ,5] we had been carried out theoretical researches of rotational levels of the deformed nuclei and have been studied nonadiabaticities, manifesting in energies and reduced probabilities of Е2-and М1-transitions. In the given work, within the frame of phenomenological model [5], factors of the mixed transitions XI ( E 0 / E 2)=→→ BE ( 0; i f ) / BE ( 2; i f ) and multiple- mixture coefficients δI (E 2 /М 1) from rotational states of positive parity on levels of the ground band are studied. In table 1 comparison adiabatic and theoretical values of Rasmussen parameter Х(Е0/Е2) for rotational states β1 - and β2 - bands is shown. Numerical values of parameters m′ in the formula for reduced probabilities 0- transitions 0ν Е are defined using experimental data [1] which have appeared equal 2 m' = 7.76 fm2 and m' <0.236 fm . We will notice, that experimentally 02 e∙ 03 e observed K forbidden Е0 - transitions are also described within the frame of the given model. Possibility of presence of such transitions is explained by mixing of states γ1 - and γ2 - bands with levels β1 - β2 - bands. The calculated values of δI (E 2 /М 1) for transitions from β1 -, β2 -, γ1 -, γ2 -, + 160 and11 bands and their experimental values for Dy are presented in table 2. Table 1. X theor. X adiab. X theor. X adiab. I Iβ1 Iβ1 Iβ2 Iβ2 0 0.23 0.23 2.3 103 2.3 103 2 0.64 0.83 0.20 8.3 103 4 0.43 0.91 0.54 9.1 103 6 0.25 0.93 0.73 9.3 103 8 0.14 0.94 0.81 9.3 103 10 0.09 0.94 0.86 9.4 103 151 Table 2. IiKi IfKf Eγ(MeV) δexp. δtheor. –13+3–5 [1] + + 2 γ 2 gr 0.8794 –16.6±0.5 [2] –12.8(15) [3] –12.8 +5+20–11[2] 4+γ 4+gr 0.872 –0.70(30) [3] –6.15 6+γ 6+gr 0.8576 +5+6–2 [1] –3.69 –12.8+23–36 0.9623 [1] –12.46 3+γ 2+gr –13.8(3) [2] –37+17–109 [3] –13+4–10 [1] 3+γ 4+gr –13.8(9) [2] 0.7653 –9.0+24–50 [3] –9.5 1.0049 –13+3–7 [1] –7.26 5+γ 4+gr +7.1+8–10 [2] 5+γ 6+gr 0.7076 – –6.41 + + 2 β1 2 gr 1.2628 –1.5+7–20[2] 1.85 + + 2 β2 2 gr 1.4317 +2.9+21–10[1] –0.96 + + 1 11 2 gr 1.7179 –2.1+9–13 [1] –35.3 1. С.W.Reich // Nucl. Data Sheets. 2005. V.105. P.557. 2. A.M.Demidov, L.I.Govor, V.A.Kurkin, I.V.Mikhailov // YaPh. 2006. V.69 (7). P.1205. 3. I.J.Gromova, et al. // Izv. Akad. Nauk SSSR. Ser Fiz. 1979. V.43. P.53. 4. P.N.Usmanov, I.Adam, U.S.Salihbaev, A.A.Solnyshkin // Phys. of Atomic Nuclei. 2010. V.73. No.12. P.1990. 5. P.N.Usmanov, I.N.Mikhailov // Phys. Part. Nucl. 1997. V.28(4). P.349. 152 PROPERTIES OCTUPOLE STATES IN 160Dy 1,2 1 1 3 P.N. Usmanov , A.I. Vdovin , A.A. Solnyshkin , U.S. Salihbaev 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Namangan Engineering and Technology Institute, Uzbekistan; 3 Institute of Nuclear Physics, Uzbekistan Academy of Sciences, Tashkent E-mail: [email protected] The phenomenological model of nucleus [1] used for studying nonadiabatic effects in positive parity states [2], has been applied to research of properties of negative parity states in 160Dy. It is shown, that core of rotating nucleus for states of negative parity has 160 excellent inertial parameters J0 and J1 from states of positive parity. In Dy states of Kπ = 1–, 2– bands strongly mixing up and as it seems to us, for improvement of the description of energy between Kπ = 1–, 2– and 0–, 3– bands there should be a band having the quantum characteristic Kπ = 0–. The calculated values of energy spectrum, the reduced probabilities В(Е1) from states of Kπ = 0–, 1– and 2– bands on levels, the ground and γ-vibrational bands, as well as ratios of probabilities Е1 - transitions from states Kπ = 2– bands on levels of the ground band which are forbidden on quantum number K, will qualitatively be coordinated with experiment. The calculated values В(Е1) from states Kπ = 0–, 1–, 2– bands on levels of the ground band are resulted in comparison with experiment [3] in the table. Results of our calculations have shown that for the adequate description of levels of higher energies excitation expansion of basic states of the Hamiltonian is required. Also, it is necessary in Hamiltonian for model to include members describing directly mixing states of bands differing on ΔK = 2. π π KI ii KI ff В(Е1)exp. (W.u.) [3] В(Е1)theor. (W.u.) 2–2 2gr >4,6∙10–6 4,6∙10–6 3–2 4gr 31∙10–5(9) 40∙10–5 3–2 2gr 42∙10–5(12) 50∙10–5 2–1 2gr 3,03∙10–8(16) 3,06∙10–5 1–0 2gr 7,6∙10–3(15) 7,6∙10–3 1–0 0gr 3,8∙10–3(7) 3,6∙10–3 2–2 2+2 >4,9∙10–4 1,0∙10–4 2–2 3+2 >2,0∙10–4 0,6∙10–4 3–2 4+2 1,0∙10–4(4) 1,0∙10–4 3–2 3+2 1,3∙10–4(6) 1,3∙10–4 3–2 2+2 7∙10–5(5) 7∙10–5 2–1 3+2 2,44∙10–7(13) 4,2∙10–7 2–1 2+2 1,85∙10–7(10) 2,8∙10–5 1. P.N.Usmanov, I.N.Mikhailov // Phys. Part. Nucl. 1997. V.28(4). P.349. 2. P.N.Usmanov, I.Adam, U.S.Salihbaev, A.A.Solnyshkin // Phys. of Atomic Nuclei. 2010. V.73. No.12. P.1990. 3. C.W.Reich // Nucl. Data Sheets. 2005. V.78. P.610. 153 ROLE OF QUASIPARTICLE STRUCTURE IN ALPHA DECAYS OF THE HEAVIEST NUCLEI A.N. Kuzmina, G.G. Adamian, N.V. Antonenko Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] The investigation of transfermium elements expands our knowledge of the single-particle structure, location of the shell closures, and decay modes of the heaviest nuclei. Existing microscopic-macroscopic approaches supply the basis for the intensive calculations of the properties of heavy nuclei. The contribution of an odd nucleon, which occupies a single-particle state |μ› with energy eμ, to the energy of a nucleus is described by the one-quasi-particle energy 2 2 ½ ((eμ − eF ) + ∆ ) . Here, the Fermi energy eF and the pairing-energy gap parameter ∆ are calculated with the BCS approximation. One-quasiparticle 2 2 ½ 2 2 ½ excitations Eμ = ((eμ − eF ) + ∆ ) + ((e'μ − eF ) + ∆ ) where e'μ is the single- particle energy of occupied level below the Fermi-level energies. Calculating the potential-energy surface as a function of collective coordinates with the two center shell model (TCSM), we find the ground-state potential minimum in which the energies of the low-lying one-quasiparticle states are obtained [1-3]. The details of the calculations of binding energies of nuclei in the ground states are presented in Ref. [3]. By using these energies, we calculate the Qα values for the α-decays from ground-state-to-ground-state. In order to estimate the α-decay half-lives Tα with found Qα and one-quasiparticle spectra, we use the expression recently suggested in Ref. [4]. The calculations performed with the modified TCSM reveal good agreement between calculated and most of the experimental values of Qα . Based on the calculated one-quasiproton spectra and energies for α-decays, one can explain why the α-decay chain of 291117 or 287115 is terminated by spontaneous fission of 267Db. It is shown that, in the α-decay chain of 293117, the α decay of 281Rg is hindered by the structure effects and because of this, the 281Rg nucleus undergoes spontaneous fission instead of α-decay. In addition, the number of isomeric states in the heaviest odd-Z nuclei is predicted. 1. G.G.Adamian, N.V.Antonenko, W.Scheid // Phys. Rev. C. 2010. V.81. 024320. 2. A.N.Kuzmina, G.G.Adamian, N.V.Antonenko // Eur. Phys. J. A. 2011. 47. 145. 3. A.N.Kuzmina, G.G.Adamian, N.V.Antonenko, W.Scheid // Phys. Rev. C. 2012. V.85. 014319. 4. A.Parkhomenko, A.Sobiczewski // Acta Phys. Pol. B. 2005. V.36. 3095. 154 QUANTUM TRANSPARENCY OF BARRIERS IN RESONANCE TUNNELING OF COUPLED PAIR OF PARTICLES OR IONS P.M. Krassovitskiy1, A.A. Gusev2, S.I. Vinitsky2, O. Chuluunbaatar2 1 Institute of Nuclear Physics NNC RK, Almaty, Kazakhstan; 2 Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] The multichannel scattering problem has been formulated in a center-of-mass system for quantum tunneling problem of pair of particles (or ions) on a line coupled by potential with infinite wells through Coulomb-like or short-range [1] potential barrier. For solving the boundary-value problems with Schrödinger-type equations the KANTBP program [2] that realize a computation scheme based on Kantorovich method and finite-element method is elaborated. The analysis of quantum transparency effect is presented. This effect is nonmonotonic dependence of transmission coefficient versus energy of coupled particles [1]. The result for transmission through short-range potential barriers agrees with previous calculations [1]. Fig. 1. Upper panels: The transmission coefficient for resonance tunneling of coupled ions through repulsive barriers with Coulomb-type potential. Lower panels: Profiles of the total wave functions of the continuous spectrum in the yx plane with Z1=Z2=0.5, m1=m2=1 at resonance energies E=8.1403 a.u. (left panel) and E=9.4748 a.u. (right panel), demonstrating resonance transmission and total reflection, respectively. 1. F.M.Pen'kov // Phys. Rev. A. 2000. V.62. 044701. 2. O.Chuluunbaatar et al. // Comput. Phys. Commun. 2008. V.179. P.685. 155 MUON-γ-NUCLEAR SPECTROSCOPY: DISCHARGE OF METASTABLE NUCLEI DURING µ– CAPTURE A.V. Glushkov 1 Odessa State University – OSENU, Odessa-9, Ukraine E-mail: [email protected], [email protected] A negative muon µ captured by a metastable nucleus may accelerate the discharge of the latter by many orders of magnitude [1, 2]. For a certain relation between the energy range of the nuclear and muonic levels a discharge may be followed by µ ejection and µ– participates in discharge of other nuclei. We present relativistic energy approach to a discharge of a nucleus with emission of γ quantum and further µ conversion, which initiates this discharge [2]. Besides, the external raser effect on cited processes is studied. The decay probability is linked with imaginary part of the "nucleus core+ external nucleon+µ–" system energy. One should consider 3 channels: 1) radiative purely nuclear 2j–poled transition (probability P1; this value can be calculated on the basis of known traditional formula); 2) non–radiative decay, when a proton transits into the ground state and µ– leaves a nucleus with energy E=E(p–N1J1) – E(i), where E(p–N1J1) is an energy of nuclear transition, E(i) is the bond energy of µ– in 1s state (P2); 3) a transition of proton to the ground state with µ– excitation and emission of γ quantum with energy E(p–N1J1) – E(nl) (P3). Under condition E(p–N1J1)>E(i) a probability definition reduces to QED calculation of probability of autoionization decay of 2–particle system. As example, data on probabilities for Sc, Tl nuclei (within the Dirac–Woods–Saxon model) are presented. The probabilities of µ––atom decay for different transitions: 15 12 14 P2(p1/2–p3/2)=3.93⋅10 , P2(p1/2–f7/2)= 3.15⋅10 , P2(p3/2–f7/2)=8.83⋅10 . Here the nucleus must transit the momentum no less than 2.4 and 2 according to the – momentum and parity rules. If a µ –atom is in the initial state p1/2, than the cascade discharge occur with ejection of µ– on first stage and secondly the γ quantum emission. To consider a case when the second channel is closed and the third one is opened, suppose: E(p1/2) – E(p3/2)=0.92 MeV. Energy of nuclear transition is not sufficient to transit µ– to continuum state and it may excite to 2p – state. Then, there is the proton transition p1/2 – p3/2 with virtual µ excitation to states of nd series and γ quantum emission ħω=Ep(p1/2)+Eµ(1s) – Ep(p3/2) – Eµ(2p). The dipole transition 2p–1s occurs with 13 –1 P3=1.9⋅10 s (more than P(p1/2–p3/2), P(p1/2–f7/2 ) transitions without radiation. 1. V.I.Gol'dansky, V.S.Letokhov // JETP. 1974. V.67. P.513; L.N.Ivanov, V.S.Letokhov // JETP. 1976. V.70. P.19; A.V.Glushkov, L.N.Ivanov // Phys. Lett. A. 1992. V.170. P.33; Preprint ISAN, NAS-4, Moscow-Troitsk, 1992. 2. A.V.Glushkov // Low Energy Antiproton Phys. 2005. V.796. P.206; A.Glushkov et al. // Adv. in Theory of Quant. Syst. in Chem. and Phys. (Berlin, Springer). 2011. V.22. P.51. 156 RESONANCE EXCITATION OF THE NUCLEAR ISOMER VIA RESONANCE CONVERSION IN THE IONS OF Th-229 F.F. Karpeshin1,2, M.B. Trzhaskovskaya3 1 Weizmann Institute of Science, Rehovot, Israel; 2 Saint-Petersburg State University, Russia; 3 Petersburg Nuclear Physics Institute, Russia E-mail: [email protected] The unique isomer of 229mTh with the energy of a few eV arose a considerable interest in the past decade. 1) It has a good prospect to serve as standard for creation of the atomic clock. 2) Resonance conversion accompanying deexcitation of the isomer may be used for studying structure of crystals. It will help to receive information on redistribution of the electronic density on the thorium atoms embedded in a crystal of CaF2. 3) A possibility of creation of gamma laser on the basis of the nuclear isomer is of great interest. To realize these and other opportunities, it is necessary to solve the practical problem of obtaining the nuclide in a metastable state. This question is essentially considered in [1, 2]. Numerical calculationы [1, 2], however, were performed for the isomer energy of 3.5 eV, while data appeared in recent years that the energy can be somewhat larger, about 7.6 eV [3]. This does not change the concept. Regrettably, recent theoretical calculations e.g. [4], still demonstrate incompetence of the authors in matters of theory of internal conversion and others, which makes it advisable to return to this issue. Recall that in [1, 2] it was justified the use of laser pumping of the isomer via resonance atomic transition 7s-8s. In singly ionized atoms of Th II, discussed in [1], its energy is just close to the energy of 7.6 eV, so the arguments remain valid. This transition is optimum due to the combination of high internal conversion coefficient with the large cross section of photoexcitation. It can be initiated by the absorption of the second laser harmonic. We also conduct the calculations of the probability of discrete conversion in the ions of 229mTh, which can be used in the experiments mentioned above. 1. F.F.Karpeshin, I.M.Band, M.B.Trzhaskovskaya, M.A.Listengarten // Phys. Lett. B. 1996. V.372. P.1. 2. F.F.Karpeshin, I.M.Band, M.B.Trzhaskovskaya // Nucl. Phys. 1999. A. V.654. P.579. 3. B.R.Beck et al. // Phys. Rev. Lett. 2007. V.98. 142501. 4. S.G.Porsev, V.V.Flambaum, E.Peik, Chr.Tamm // Phys. Rev. Lett. 2010. V.105. 182501. 157 HEISENBERG TRANSFORMATION AND BORN APPROXIMATION IN PROBLEM SHAKING OF ATOMIC ELECTRONS UNDER BETA DECAY Yu.I. Sorokin Institute for Nuclear Research RAS, Moscow, Russia E-mail: [email protected] Formulation mathematical part problem shaking of atomic electrons under beta decay may be illustrated by Heisenberg transformation – formal solution Schrödinger equation. Kernel of integral representation this formal solution – propagator – may be represented by functional with Feynman path integral [1]. Feynman propagator contains integral of Lagrangian. Lagrangian contains as initial potential, and its subatomic change, that may be separated change nuclear potential and impact escape particle charge. New nuclear potential define new propagator, which may be record due, as for Schrödinger equation, other for Dirac equation. Impact escape particle charge may be taken, or as minimum, estimated, by Feynman path integral. It may give, as minimum, limiting accuracy of first, “precise”, nuclear contribution. At the same times, it is difficulty examine convergence Born approximation of Dyson equation solution, because of neglected expansion term contain required solution and so include sum of previous expansion term. Expanded form of propagator, as path functional, and its illustration - Heisenberg operator, may be useful, as quantum description Hall effect [2, 3], other description decay of nucleus giant dipole resonance: photo-neutron [4] and photo-proton [5] reactions. 1. Ю.И.Сорокин // Вестник РУДН, сер. физика. 2005. №1(13). С.113. 2. Yu.I.Sorokin // Proceedings of the XII International Seminar on Electromagnetic Interaction of Nuclei. EMIN-2009. Moscow, September 17-20, 2009. Moscow. 2010. P.146. 3. Yu.I.Sorokin // International Conference on Nuclear physics "NUCLEUS 2010". Method of Nuclear Physics for Femto- and Nanotechnologies. Book of abstracts. July 6-9, 2010. Saint-Petersburg, Russia. Saint-Petersburg. 2010. P.239. 4. Ю.И.Сорокин, Б.А.Юрьев // ЯФ. 1974. Т.20. Вып.2. №.8. P.233. 5. Ю.И.Сорокин, В.А.Хрущёв, Б.А.Юрьев // ЯФ. 1971. Т.14. Вып.6. С.1118. 158 BETA-DECAY 229U→ 229Pa A.A. Kurteva Institute for Nuclear Research, Kyiv, Ukraine E-mail: [email protected] The energies, spectroscopic factors, magnetic dipole and electric quadrupole moments of the ground and excited states of 229Pa, as well as reduced probabilities of electromagnetic transitions between them have been calculated in the framework of dynamic collective model. The method from [1] has been used for the calculation of β+ decay 229U → 229Pa. Multy-phonon states (up to ten phonons) of main band of even-even core and the influence of vacuum fluctuations of quasiparticles on the renormalization of one-particle moments and effective forces are taken into account. The basis used in 228U calculation is presented in p n figure; λ denotes the position 0 p d 3/2 s3/2 of the chemical potentials f 1/2 5/2 g7/2 (proton and neutron), while the E, MeV f7/2 d j 5/2 letters and indices denote the -4 i13/2 15/2 λ i11/2 orbital moments and the total h λ 9/2 g moments of one-particle states, s 9/2 + -8 1/2 respectively. β decay takes d p1/2 3/2 f place because the proton h11/2 5/2 d p3/2 chemical potential lies above 5/2 i -12 g 13/2 the neutron one. The 7/2 f 7/2 difference between chemical h9/2 p1/2 potentials correlates with g -16 9/2 energy of β decay p 3/2 s 1/2 Q = 1305 keV. f 5/2 β decay goes from the -20 ground state 2/3 + of 229U in which the contribution give almost all subshells with the even orbital moments from filled shell, but the maximum contribution gives i 2/11 . Therefore the β transition occurs with + 229 maximum intensity and probability to 2/5 1 state of Pa, formed by bonding of + one-quasiparticle state 13 2/ 1 with phonon states of even-even core with full moments R = 4, 6, 8. The calculated value lg ft for β transition to this state is equal 5.69, experimental lg ft = 5.6. The renormalization of constants of weak interaction in this calculation was the same as for the nuclei with A ≈ 100. 1. I.N.Vishnevskii, G.B.Krygin, A.A.Kurteva, et al. // Yad. Fiz. 1994. V.57. No.1. P.17. 159 THE SEARCH FOR NEUTRINOLESS DOUBLE BETA DECAY WITH THE GERDA EXPERIMENT K.N. Gusev1,2,3 for the GERDA collaboration 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Russian Research Center “Kurchatov Institute”, Moscow, Russia; 3 Technische Universität München, Munich, Germany E-mail: [email protected] The GERmanium Detector Array (GERDA) is designed to search for neutrinoless double beta decay of 76Ge. The main special feature of GERDA is the use of cryogenic liquid argon (LAr) as a shield against gamma radiation, the dominant background in earlier experiments. High purity germanium detectors, made from material enriched in 76Ge, are immersed directly in the cryogenic liquid which also acts as the cooling medium. By operating HPGe detectors GERDA has an energy resolution FWHM ~ 4 keV at Qββ. The experiment is foreseen to proceed in two phases. In Phase I, enriched Ge detectors which were previously operated by the Heidelberg-Moscow and IGEX collaborations have been redeployed (in total 15 kg of 76Ge). In Phase II, new detectors based on the design of Broad-Energy Germanium (BEGe) detector will be installed. GERDA is situated in Hall A of the National Gran Sasso Laboratory (LNGS). In November 2011 all existing enriched detectors have been immersed in the GERDA cryostat and Phase I data taking started. The presentation will focus on the results of background studies performed during the ongoing phase of the experiment and previous commissioning runs. The background (preliminary estimated) in GERDA Phase I is < 0.02 counts/ (keV∙kg∙year), which is significantly lower than the background achieved in preceding experiments Heidelberg-Moscow and IGEX (0.16 counts/(keV∙kg∙year)). The status of Phase II preparations will be also presented. 160 ROLE OF ENDOTHERMIC BETA DECAYS IN ABUNDANCE FORMING PROCESSES OF 113In AND 115Sn NUCLEI I.V. Kopytin, T.A. Krylovetskaya, Imad A. Hussain Voronezh State University, Russia E-mail: [email protected] The 113In and 115Sn isotopes are referred to a category of p-nuclei because their observed abundances have the quantities corresponding to this category of nuclei. In addition as it has turned out these isotopes may not be received in neutron capture s-processes. In fact, the 113Cd→113In and 115In→115Sn β-decays are forbidden β-decays of the fourth orders and the 113Cd and 115In parent nuclei are stable practically. The efforts to give an explanation of this isotope origin in models investigating a nuclear synthesis by the supernova star explosives were not successful. Therefore for the solution of the 113In and 115Sn isotope origin problem any physical mechanism which allows realizing the 113Cd→113In and 115In→115Sn β -transitions is interesting for researchers. In this paper the role of the endothermic β -transitions (collisional beta decay [1] and photobeta decay [2]) is estimated. These transitions may be realized into the hot substance of a star in various stages of its evolution. It is supposed that a 113 115 certain amount of the Cd (Qβ=322 keV) and In (Qβ=499 keV) parent nuclei have been accumulated in the star substance. Their ground states have spin values 1/2+ and 9/2+ respectively. In the 113In daughter nuclear there is the first excited state with a 391.7 keV energy and 1/2– spin and in the 115Sn daughter nuclear there is the second excited state with a 612.8 keV energy and 7/2+ spin. The 1/2+→1/2– (the forbidden β-decay of the first order) and 9/2+→7/2+ (the allowed β-decay) endothermic β-transitions are possible in these states within the hot substance. As a result the 113Cd →113In and 115In →115Sn β-decay are occurred respectively. It may be the collisional beta decays and the photobeta decays as well activated by the star thermal field. The rate temperature dependences of the indicated β-transitions are calculated in the 1·108÷5·109 K temperature range. The collisional β-decay rates are calculated in conformity with Paper [1], the parent nuclear collisions with protons and α-particles are taken into account. The photobeta decay rates are calculated in conformity with Paper [2], electromagnetic radiation with Planck spectrum is used. The comparison of the β-rate quantities for endothermic β-decays and thermal β-decays (see this collected theses) demonstrate that the 9/2+→7/2+ collisional β-transition for a pair of the 115In, 115Sn isotopes is able to give the appreciable correction only. 1. I.V.Kopytin, T.A.Krylovetskaya // Physics of Atomic Nuclei. 1998. V.61. P.1479. 2. I.V.Kopytin et al. // Physics of Atomic Nuclei. 2004. V.67. P.1429. 161 THERMAL BETA DECAY AND PROBLEM OF P-NUCLEI 113In AND 115Sn I.V. Kopytin, T.A. Krylovetskaya, Imad A. Hussain Voronezh State University, Russia E-mail: [email protected] It is known the models in which a stage of supernova star explosion is used for p-nuclear origin problem solution are very perspective (see [1, 2] e.g.). However in this approach there are a number of the problem nuclei which cannot be produced in a sufficient amount, in particular the 113In and 115Sn isotopes. While developing a p-element explosive synthesis model a presupernova stage is very important in massive star evolution. The chemical element concentrations which already exist in the star substance in this stage determine the starting conditions in the system of the kinetic equations by nuclear explosive synthesis. These concentrations determine the final yields of s- and - p-nuclei. It is usually assumed that the p-nuclear concentrations are practically equal to a zero in the presupernova stage including the “problem” p-isotopes. However they may be accumulated in a quasi-equilibrium stage of massive star evolution in various physical processes. The thermal β-decay is the one of them. Its role may be substantial in the quasi-equilibrium stages when a star substance temperature is above 109 К. The temperature dependence of 113In and 115Sn isotope β-decay rates is investigated. The canals of 113Cd →113In and 115In →115Sn natural β–-transitions are practically closed because these transitions are forbidden β-decays of the fourth orders. However the excited levels of the parent nuclei are populated in the heated medium. Therefore the allowed β-transitions and forbidden β-transitions of the first orders from the excited states of 113Cd and 115In parent nuclei into the ground and excited states of 113In and 115Sn daughter nuclei respectively are feasible. All the thermal allowed β-transitions and forbidden β-transitions of the first orders among the nuclear states with energies up to 1.0 MeV for the pair of 113Cd, 113In isotopes and with energies up to 0.5 MeV for the pair of 115In, 115Sn isotopes. The β-decay matrix elements are calculated by a nuclear shell model. It is received that in both cases the allowed β-transitions give the largest contribution to a total rate of the thermal β-decay. β-rate temperature dependences in the 108 К÷1010 К range are calculated. They make it possible to estimate the yields of 113In and 115Sn isotopes if the abundances of the 113Cd and 115In parent s-nuclei respectively, temperatures and quasi-equilibrium stage time lengths of massive star evolution are known. 1. E.M.Babishov, I.V.Kopytin // Astronomy Reports. 2006. V.50. P.569. 2. E.M.Babishov, I.V.Kopytin // Physics of Atomic Nuclei. 2008. V. 71. P.1207. 162 ON P- AND T- SYMMETRIES VIOLATION IN POLARIZED NEUTRINO-PROTON ELASTIC SCATTERING M.Ya. Safin People Friendship University of Russia, Moscow, Russia E-mail: [email protected] We study here differential cross sections and spin asymmetries for the processes of elastic electroweak scattering of the neutrino by polarized proton target. In the calculations we take into account initial and final neutrino helicities, charge radius and magnetic moment of the Dirac neutrino, electroweak form factors, including neutral weak Pauli magnetic, as well as P-and T/CP-symmetries violating anapole and electric dipole proton's electromagnetic form factors. Angular and energy distributions of the recoil protons, which are obtained for the cases of helicity conserving ( ν→ν LL ) and helicity changing ( ν→ν RL ) neutrino scattering, contain P- and T-symmetries violating correlations between target proton spin and momenta of the incoming neutrino and recoil proton. Fig. 1. Influence of interference and pure Fig. 2. Angular dependence of reduced electromagnetic contributions to the cross transverse T-violating asymmetry of the cross section on the longitudinal asymmetry due to section due to electric dipole moment of the P-symmetry violation. proton. Comparative study of the pure weak, electroweak interference, and electromagnetic spin asymmetries in dependence of angle, energy and form factors parameters provide a possibility to get supplementary new information about the structure of the proton's electroweak interaction with neutrino, and about the electromagnetic properties of the neutrino. 1. B.K.Kerimov, M.Ya.Safin // Izvestiya Ros. Akad. Nauk. Ser.Fiz. 2010. V.74. P.854. 2. B.K.Kerimov, M.Ya.Safin // Neutrinos: Properties, Sources and Detection. N.Y.: Nova Science Publishers, 2011. P.1. 163 WEAK INTERACTION AND PARITY NONCONSERVATION EFFECT IN HEAVY FINITE FERMI-SYSTEMS: RELATIVISTIC NUCLEAR MANY-BODY THEORY O.Yu. Khetselius Odessa State University – OSENU, Ukraine E-mail: [email protected] During the past two decades, the nuclear and atomic-optical experiments to detect parity nonconservation (PNC) have progressed to the point where PNC amplitudes can be measured with accuracy on the level of a few percents in certain heavy atoms [1] and significantly worse in some nuclei (Mössbauer spectroscopy). Nowdays the PNC in atoms has a potential to probe a new physics beyond the Standard model. Promising idea (Forston) is to apply the techniques of laser cooling and ion trapping to measurement of the PNC in + 6s S1/2-5d D3/2 transition for the Ba ion. In our paper we systematically apply the nuclear-QED many-body perturbation theory formalism [2] to precise studying PNC effect in heavy atoms with account for nuclear, correlation and QED corrections. There are determined the PNC radiative amplitudes for a set of nuclei (atoms): 133Cs, 137Ba+, 205Tl, 173Yb with account of exchange- correlation, Breit, weak е-е interactions, QED and nuclear (magnetic moment distribution, finite size, neutron “skin”) corrections, nuclear-spin dependent corrections due to anapole moment, Z-boson ( (AnVe) current) exchange, HFS-Z 133 205 exchange ((VnAe) current). The weak charge is found for Cs, Tl and firstly 173Yb and comparison with Standard model is done. Using the experimental PNC value ∆E1 /β==39mV/cm (Веrkeley, 2009; Tsigutkin et al.) [1] and our value 173 9.707⋅10(-10) eaB one could find for Yb (Z=70, N=103) the weak charge value QW= – 92.31, that differs of the SM QW= – 95.44. The received data are compared with known earlier and recent results by Flambaun-Dzuba etal, Johnson-Safronova et al., by Johnson-Sapirstein-Blundell et al. The role of the nuclear effects contribution (core-polarization ones, which are induced by valent protons of a nucleus), spatial distribution of magnetization in a nucleus (effect of Bohr-Weisskopf) and non-accounted high order QED corrections is analyzed [2]. We discuss a new improved possibility for observing P and PT violation using a nuclear magnetic resonance (NMR) frequency shift in a laser beam too [1, 2]. 1. O.Sushkov // Phys. Scripta. 1993. V.T46. P.193; W.Johnson, M.S.Safronova, U.I.Safronova // Phys.Rev. A. 2003. V.69. 062106; V.V.Flaumbaum, G.Ginges// Phys. Rev. A. 2005. V.72. 052115; K.Tsigutkin et al.// Phys. Rev. Lett. 2009. V.103. 071601. 2. O.Yu.Khetselius // Phys.Scripta. 2009. V.T135. P.014023; Int. J. Quant. Ch. 2009. V.109. P.3330; A.V.Glushkov, O.Yu.Khetselius, L.Lovett // in: Recent Advances in Theory of Atomic and Molec. Systems. Series: Progress in Theor. Chem. and Physics. Berlin: Springer, 2010. V.20. P.125. 164 THE DESCRIPTION OF THE WEAK LEPTONIC PROCESSES ON THE BASIS OF THE CURRENTS WITH THE COMPLEX COUPLING CONSTANTS Yu.I. Romanov Moscow State University of Design and Technology, Russia E-mail: [email protected] The total cross sections of elastic and inelastic (anti) neutrino-election scattering, the neutrino annihilation of e+e– (µ+e–) pairs, the energy distributions of the particles emitted in the (µ-e) decay and its full width are obtained and analyzed within the framework of leptonic currents interaction with the real and complex or pure imaginary vector gV and axial-vector gA coupling constants. Among presented results the electron spectrum in the νee scattering described by the formulas 2 dσ G 22 2 =11 +h m + h E2 +−() ET − 2 {( ν) ee( )( νν ) dT 4π pν 2 22 −−1h mTm +22 +− 1h m 1h − ⋅ 2m − ( ee)()ν( νν) ( e) e 2 −+1 h E + 4Re h Re hT2E()− Tm ( ee) ννe e} obtained on the basis of the Lagrangian G LNC = νγ+γνγ+γαν()1h5 e α() 1, he5 2 e νν e e ν e where ν = ggh VA , = Ae ggh V , = ggGG VVF , GF is the Fermi constant, Eν , pν and mν are the total energy, momentum modulus and mass of initial neutrino, me , Ee and T are the mass, total and kinetic energies of the recoil electron. Considering the spectrum at hν =1, mν = 0 we should note that in case of low energy transfer to an electron (T< 165 EXTENSION OF EQUATIONS-OF-MOTION METHOD TO THE MULTILEVEL SYSTEMS WITH PAIRING A.K. Vlasnikov, V.M. Mikhajlov St. Petersburg State University, Russia E-mail: [email protected] Last several years the finding of the exact eigenvalues of the Bardeen-Cooper- Schriffer Hamiltonian ( HBCS ) has taken special interest partly in connection with nuclear physics problems and mainly owing to studying the nanocluster superconductivity. In nuclear physics one of effective enough approaches (the equations-of-motion method) has been investigated for spherical systems [1]. We consider hear a broadening of this method to systems with twofold (spin) degeneration of single-particle levels, for which HBCS can be written in the form + ++ +++ ++ HBCS =ε−∑ tt n gA A ; nt= aa tt + aa tt; AA= ∑ t ; At= aa tt. (1) t t The equations-of-motion method consists of successive calculations of transfer amplitudes + µ by using the commutator , + that results in a system EAt HABCS t ++ + (2ε−tE + Eµ ) EA t µ= gEA t µ+∑ EA tt ν ν n µ, (2) ν E is one of eigenfunctions of HBCS (with eigenvalue E) for (k+1) particle pairs with zero seniority (k+1-system), µ (or ν ) is a similar function for k pairs (k-system), Eµ is a corresponding energy. Matrix νµnt in (2) is defined on the previous step of calculations for k-system. The important problem of this method is removal of spurious states and reduction of the order of the energy matrix. Indeed, the number of eigenstates of k-system is the number of distributions of k pairs over Ω single-particle levels mk =Ω!! kk() Ω− ! Therefore, the number of amplitudes equals Ω⋅mk , whereas the number of eigenvalues of k+1-system is mk +1 and Ω⋅mmkk −+1 >1. Solving system (2) for small values of Ω and k indicates that km⋅ k solutions are spurious, after their exclusion the obtained equation gives each E with k+1 multiplicity. The reason of this awkwardness in determination of energies lies in linear + dependence of EAt µ . Application of equations ++ EAnttµ=∑ EAt ν ν n t µ=0, (3) ν ++ + ∑∑EAqνν A pq A µ= EAp νν() n q2 µ (4) νν separates the independent quantities. Eq. (3) allows us to cut off the basis µ keeping in it only ()()Ω−1!kk ! Ω− − 1! low energy states. By virtue of Eq. (4) only + amplitudes of (Ω–k) operators At can be considered to be independent (their total + amount is Ω). Thus, the number of restrictions on amplitudes EAt µ is such that the order of the equation for E gains the necessary value mk +1 . 1. F.Andreozzi, A.Covello et al. // Phys. Rev. C. 1990. V.41. P.250. 166 PROPERTIES OF ROTATIONAL BAND STATES WITH Kπ≤2+ IN 170,172,174Yb ISOTOPES A.A. Okhunov1, Ph.N. Usmanov2, H. Abu Kassim1 1 Department of Physics, University of Malaya, Kuala Lumpur, Malaysia; 2 Namangan Engineering-technological Institute, Uzbekistan E-mail: [email protected] An extensite research interest in the properties of deformed nuclei has risen in recent years with the exploration of a new collective isovector magnetic dipole mode [1, 2]. The measured values of excited energy of magnetic mode are found to be not so high in an excited spectrum, and consideration of mixing with low-lying exciting states appear to lead to an interesting physical phenomena [3,4]. The nuclei 170,172,174Yb have been well studied. It is important to note that these are investigated in a number of ways such as radioactive decay of 170,172,174Lu, and different nuclear reactions. In these isotopes, many 1+ states and Kπ=0+, 2+ bands have been observed. Present paper focuses on low-lying states of positive parity of isotopes 170,172,174Yb. The calculation are conducted by utilizing a phenomenological model [3] which accounts Coriolis mixture all of the states experimentally known low-lying rotational bands with Kπ≤2+. The energy and structure of wave functions of excited states are calculated. The reduced probabilities of E2– and M1– transitions are also calculated and comprised with experimental data which are gives satisfactory result. The reduced probability of M2– transitions are presented in Table. The results of the calculations reveal considerable hybridization of states with various values of quantum number K that occurs even at low values of spin. This leads to non-adiabaties in the probability of electromagnetic transitions from states of rotational bands. Probability of M1– transitions of 172Yb 1;( → IKIMB )0 → IKI 0 ffii ffii Exp. [5] Theory + + −3 −3 2 → 2020 1 0.6 ⋅10 (2) 1.8⋅10 + + −4 −3 3 → 2020 1 1.2 ⋅10 (7) 1.1⋅10 + + −2 −3 1 → 2022 1 1.7 ⋅10 (2) 0.2⋅10 + + −2 −3 1 → 4042 1 9 ⋅10 (6) 3.1⋅10 + + −5 −5 2 → 2022 1 5.2 ⋅10 (27) 4⋅10 1. D.Bohle et al. // Phys. Lett. B. 1988. V.4,5(148). P.411. 2. A.Zilges et al. // Nuc. Phys. A. 1990. V.507. P.399. 3. Ph.N.Usmanov, I.N.Mikhailov.// Fiz. Elem. Chastits At. Yadra. 1997. V.28. P.887. 4. Ph.N.Usmanov et al. // Physics of Particles and Nuclei Letters. 2010. V.7(3). P.185. 5. B.Singh // Nucl. Data Sheets. 1995. V.75. P.199. 167 + INFLUENCE OF 1 STATES ON THE gR-FACTORS OF GROUND-STATE BAND IN 160Dy AND 170,174Yb ISOTOPES Ph.N. Usmanov1,2, A.A. Okhunov1, H. Abu Kassim1 1 Department of Physics, University of Malaya, Kuala Lumpur, Malaysia; 2 Namangan Engineering-Technological Institute, Uzbekistan E-mail: [email protected] In the work [1] has studied the state of the ground band up to spin I=16 isotopes 160Dy and 170,174Yb using 85Kr ions with energy of 350 MeV for the Coulomb excitation. The finding reveals that with an increase of angular momentum gR–factor is decreases. In this paper, we study the reasons for reducing the experimental values of the gR–factor with spin. A simple phenomenological model [2] which takes into π+ account the Coriolis mixing of states of the ground and K =1ν bands is proposed. With the use the theory of perturbations, corrections for the wave functions of states are determined. An analytical expression for gR–factor of the states of ground rotational band has been obtained. The model parameters are identified from the experimental values of gR–factor. Accuracy of the approximation is verified. The reduced probabilities of E2– transitions within ground band are calculated which provides favored correspondence with experimental data. It is shown that magnetic characteristics of ground band 160Dy and 170,174Yb has been found to more sensitive than that of electric properties. Fig. 1. Intrinsic B(E2)– transitions of ground bands of isotopes 170,174Yb respectively. 1. H.R.Andrews, O.Hausser et al. // Phys. Rev. Lett. 1980. V.43(23). P.1835. 2. Ph.N.Usmanov, I.N.Mikhaylov // Fiz. Elem. Chastits At. Yadra. 1997. V.23. P.887. 168 NON-STATIONARY PROCESSES IN RADIOACTIVE OXIDES WITH DYNAMIC POLARIZATION AS POSSIBLE EXHIBITING OF DISCRETE SYMMETRY VIOLATIONS V.M. Kartashov The Institute of Nuclear Physics RK, Almaty, Kazakhstan E-mail: [email protected] The interpreting of precision electronic-spectroscopic experiment results always demands high quality of radiation source making and deep comprehension of processes, descending in their template. As was found out recently, it is especially important at use of sources in the form of oxides, where dependence of their properties from descending in them processes of ordering and disordering of structural formations well shows. The exhibiting in experiments of the Doppler broadening of spectrum lines (at any rate – its parametric part) quite often directs a realization of dielectric-ferroelectric phase transition in oxide films. The change of dispersing properties of the medium complicates this picture. The spectral picture, observed in dynamics from radioactive oxides, following (on the one hand) to the law of the radioactive decay, with another – reminds about existence of autocatalytic reactions leading to non-stationarity of taking place processes. According to the Brewster law because of connection between refractive index and angle of radiation incidence, at which the electrons reflected from the dielectric surface are completely polarized, medium gyrotropy and, in particular, birefringence and rotation of the plane of polarization showed. The developing method of multipolar parameterizations of dipole mediums now categorizes them so: electrical and magnetic mediums, and also - polar and axial toroidal mediums. We supervised a self-organizing autocatalytic reaction in the radioactive lutetium oxide resulting to formation of solid phase structures in the source template due to changes in the shell of ytterbium atoms (especially M4- and M5-subshells). The local macroscopic properties of such structures are variable relative specular reflections. The processes taking place in the lutetium oxide, as it was observed experimentally by us, detect right and left asymmetry, and, accordingly, their performances are featured variously. In particular, the gyrotropy can be specified by space parity violation in weak interactions, i.e. by chirality. The detailed examinations made by other authors in other gyrotropic mediums have shown, that some effects are connected to the sign change at the time reversion, that is violation of time invariance. The arguing of this important physical problem with the representatives of other experimental and theoretical directions of examination would become useful. 169 RESONANCE STATES OF COMPOUND SUPER-HEAVY NUCLEUS AND EPPP IN HEAVY NUCLEUS COLLISIONS A.V. Glushkov Odessa State University – OSENU, Ukraine E-mail: [email protected], [email protected] Existence of a narrow e+ line in the positron spectra obtained from heavy ions collisions near the Coulomb barrier (see, e.g., [1, 2]). Here a consistent unified quantum mechanics and QED approach is used for studying the electron- positron pair production (EPPP) process in the heavy nuclei collisions and treating the compound nucleus in an extreme electromagnetic (electric) field. The positron spectrum narrow peaks as a spectrum of the resonance states of compound super heavy nucleus are treated. Resonance phenomena in the nuclear system lead to structurization of the positron spectrum produced. To calculate the EPPP cross-section we used the modified versions of the relativistic energy approach, based on the S-matrix Gell-Mann and Low formalism [2, 3]. The nuclear and electron subsystems are considered as two parts of the complicated system, interacting with each other through the model potential. The nuclear system dynamics is treated within the Dirac equation with an effective potential. All the spontaneous decay or the new particle (particles) production processes are excluded in the 0th order. The calculation results for cross-sections at different collision energies (non-resonant energies and resonant ones), corresponding to energies of s-resonances of the compound 238U+238U, 232Th+250Cf and 238U+248Cm nuclei are presented. Calculation with the two- pocket nuclear potential is carried out and led to principally the same physical picture as the calculation with the one-pocket one [2], besides an appearance of some new peaks. 1. J.Reinhardt, U.Muller, W.Greiner // Z. Phys. A. 1981. V.303. P.173; V.Zagrebaev, Yu.Oganessian, M.Itkis, W.Greiner // Phys. Rev. C. 2006. V.73. 031602(R). 2. A.V.Glushkov, L.N.Ivanov // Phys. Lett. A. 1992. V.170. P.36; Preprint ISAN. No.5, Moscow-Troitsk, 1991; Preprint ISAN, NAS-1. Moscow-Troitsk, 1992; A.V.Glushkov et al. // Nucl. Phys. A. 2004. V.734. P.E21. 3. A.V.Glushkov et al. // Frontiers in Quantum Systems in Chem. and Phys. Berlin: Springer, 2008. V.18. P.505; Theory and Applications of Comp. Chem. (AIP). 2009. V.1102. P.168; Int. J. Mod. Phys. A. 2009. V.24. P.611. 170 RELATIVISTIC ENERGY APPROACH TO COOPERATIVE ELECTRON-γ-NUCLEAR PROCESSES: NEET EFFECT O.Yu. Khetselius Odessa State University – OSENU, Ukraine E-mail: [email protected] A consistent relativistic energy approach (REA) to calculation of the cooperative electron-gamma-nuclear processes combined with the relativistic many-body perturbation theory PT [1] is presented. The nuclear-excitation – electron transition (NEET) effect is studied [2]. The fundamental parameter of the cooperative NEET process is a probability PNEET. It can be determined as the probability that the decay of the initial excited atomic state will result to the excitation of and subsequent decay from the corresponding nuclear state. Within REA the probability is connected with an imaginary part of energy shift for the system (nuclear subsystem plus electron subsystem) excited state. The latter can a N be expanded to a series on the known parameters ωIFR e , ωIFR N . The effects of purely nuclear transition, purely electron-(hole) transition and combined electron – nuclear transition can be distinguished. The calculation results are 189 193 197 presented in table for the atomic/nuclear systems 76Os , 77 Ir , 79 Au and compared with available theoretical and experimental data [3]. Studying the cooperative electron- gamma-nuclear process such as the NEET effect is expected to allow the determination of nuclear transition energies and the study of atomic vacancy effects on nuclear lifetime and population mechanisms of excited nuclear levels. Table. Theoretical and experimental data on probabilities РNEET (M1) for the 189 193 197 isotopes of 76Os , 77 Ir , 79 Au Nucleus Energy of nuclear Experiment [3] Theory [3] Present excitation (keV) work 189 –10 –10 –10 76Os 69.535 <9.5⋅10 1.2⋅10 1.9⋅10 1.3⋅10–10 193 –9 –9 –9 77 Ir 73.04 (2.8±0.4) ⋅10 2.0⋅10 2.7⋅10 197 –8 –8 –8 79 Au 77.351 (5.7±1.2) ⋅10 3.4⋅10 4.6⋅10 (4.5±0.6) ⋅10–8 4.5⋅10–8 1. O.Yu.Khetselius // Phys.Scripta. 2009. V.T135. P.014023; Int. J. Quant. Ch. 2009. V.109. P.3330; Frontiers in Quantum Systems in Chemistry and Physics. Series: Progress in Theor. Chem. and Physics. Berlin: Springer, 2012. V.24. 2. M.Morita // Progr. Theor. Phys. 1973. V.49. P.1574; V.S.Letokhov, V.I.Goldanskii // JETP. 1974. V.67. P.513; V.I.Goldanskii, V.A.Namiot // Phys. Lett. B. 1976. V.62. P.393. 3. E.V.Tkalya // Nucl.Phys. A. 1992. V.539. P.209; Phys. Rev. A. 2007. V.75. 022509; I.Ahmad et al. // Phys. Rev. C. 2000. V.61. 051304; S. Kishimoto et al. // Phys. Rev. Lett. 2000. V.85. P.1831; Phys. Rev. C. 2006. V.74. 031301. 171 THE BRINK MODEL WITH TETRAHEDRAL ALPHA-CLUSTERS FOR THE THREE-BODY FORCES V.S. Kinchakov Computer Center, Far East Division, Russian Academy of sciences, Khabarovsk, Russia E-mail: [email protected] Three-particle interaction is introduced in the modification of Brink model that takes into account the localization of the nucleons inside the clusters [1]. At the same time a class of variational single-particle functions considerably is broadened by replacing the traditionally used one gaussoid on sum up K of gaussoids. It is shown that the potentials of increasing the binding energy of nuclei 4He, 8Be, 12C almost exhaust in case two (K=2) gaussoids in the single- particle function for Volkov interaction number 2 [2]. For the BKN interaction [3] four gaussoids provide a good upper variational estimate of the result [4] of the Hartree-Fock approximation for the nucleus 4He. The clusterization in the excited state 3– of the nucleus 12C is greater compared with clusterization of the ground state for these potentials. Short-range C2/C1 components of opposite sign relative to the major components are present in the single-particle functions of nuclei for BKN interaction. This component simulates to some extent effects of inclusion of short-range correlations in the many-body wave function. 1. V.S.Kinchakov // Bull. of the Rus.Acad. of Sciences: Physics. 2009. V.73. P.1472. 2. A.B.Volkov // Nucl. Phys. A. 1965. V.74. P.33. 3. P.Bonche et al. // Phys. Rev. C. 1976. V.13. P.1226. 4. S.Takami et al. // Prog. Theor. Phys. 1996. V.96. P.407. 172 ABOUT VALIDITY OF USE OF STUDENT’S t − CRITERION FOR EXPERIMENTAL PROOF OF RESTORATION OF WIGNER’S SU(4) SPIN–ISOSPIN SYMMETRY IN ATOMIC NUCLEI A.M. Nurmukhamedov The Institute of Nuclear Physics, Tashkent, Uzbekistan E-mail: [email protected] In the work [1] was given the proof of restoration of Wigner’s spin-isospin SU(4)-symmetry in the field of heavy nuclei with odd mass numbers and isospins ≥ 53 2/ by using -criterion of Student. For that proof experimental Tz t values of the factor Franchini-Radicatti R were calculated, and these values were checked up on compliance with the exact theoretical formula for R . The applied Student’s t-criterion significance is optimal, i.e. it provides the highest reliability of statistical conclusions only in cases if sampling was extracted from the universal set with normal distribution. In cases of large deviation from normal distribution, the accuracy of the t-criterion substantially falls. Therefore, in order to use Student’s t-criterion, it is necessary to verify the assumption of normal distribution of universal population. The given work uses the fitting criterion of Shapiro-Wilk [2] to verify the normality of distribution of universal set R . That allows to locate deviations even with the volume of sampling n ≈10 . The calculation of fitting criterion of Shapiro-Wilk was performed with standard method using formula: Wsn=22( − 1) D , (1) where n is a volume of sampling, D is dispersion, s is a certain amount. The analysis of obtained results reveals that 84 tested groups of nuclei with identical had only 3 cases (~3.5 %) of substantial deviation of normal Tz distribution. These distortions were related to the field of light nuclides. In all other cases, R has normal distribution or deviations are not substantial. The conclusion is that results obtained in the work [1] were based on the highest reliability of Student’s t − criterion, and the method used for proof of restoration of Wigner’s symmetry in the field of heavy nuclei was valid. 1. A.M.Nurmukhamedov // Phys. Atom. Nucl. 2012. V.75. P. 27. 2. S.S.Shapiro, M.B.Wilk // Biometrics. 1965. V.52. P.591. 173 ABNORMAL VALUES OF EMPIRIC FUNCTION bA() OF THE MASS FORMULA OF WIGNER IN THE FIELD OF LIGHT NUCLEI A.M. Nurmukhamedov The Institute of nuclear physics, Tashkent, Uzbekistan E-mail: [email protected] The work [1] state that values of empiric functions Ab )( in the field with < 2/5 quickly declining along with decline of and )( changes sign to Tz Tz Ab negative while is shifting from = 2/1 to −= 2/1 . Tz Tz Tz In order to calculate specific values of empiric function Ab )( , the given work extends the range of reviewed nuclei and uses experimental values of nuclear mass along with surplus of mass developed by authors of [2] through research of mass surface and identification of systemic trends. Figures 1 and 2 describe dependency of empiric functions Ab )( from amount of neutrons N for nuclei with odd and even mass numbers. Values of Ab < 0)( for nuclei with isospin of basic state < 0 . Tz Empiric function Ab )( defines contribution of effective bi-particle spin- isospin interaction into nuclear mass. That is why negative values of Ab )( should be interesting to researchers. This interaction connected to energy of symmetry as well as pair energy included into Wigner’s mass formula [3]. )( )( Fig. 1. Dependency of Ab from Tz for Fig. 2. Dependency Ab from Tz for odd A . even A . 1. A.M.Nurmukhamedov // Phys. Atom. Nucl. 2009. V.72. P.401. 2. G.Audi et al. // Nucl. Phys. A. 2003. V.729. P.337. 3. A.M.Nurmukhamedov // Phys. Atom. Nucl. 2009. V.72. P.1435. 174 NUCLEAR VERTEX CONSTANTS AND ASYMPTOTIC NORMALIZATION COEFFICIENTS FOR 8Be RESONANT STATES FROM THE αα SCATTERING EFFECTIVE-RANGE FUNCTION EXPANSION Yu.V. Orlov, L.I. Nikitina Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] We study properties of the ground and first excited resonant states of 8Be nucleus which is very important in astrophysics. The nuclear vertex constants (NVC) for the synthesis (decay) αα↔8Be and asymptotic normalization coefficients (ANC) of the corresponding Gamov wave functions are calculated 2 using the α-particle model and the effective-range function Kl(k ) expansion up to k4 with the Coulomb interaction taken into account [1, 2]. In [3] for the 8Be ground s-state (l=0) the experimental [4] resonant energy E0 and width Γ0±∆Γ0 are used as an input as well as a phase shift value δ0(Eα) [5] within the cm energy Eα region defined by the singularity position (Eα≅−4.76 МэВ) for the two-pion exchange scattering amplitude. We give a good description of the experimental behavior δ0(Eα) at Eα ≤ 5 MeV. The resonance energy E2 in the d-wave αα scattering is also situated within 2 the convergence area, but the related K2(k ) parameters and δ2(Eα) energy dependence are very sensitive to the adopted values of E2 and Γ2. With the experimental values E2 = 3.03±0.01 MeV, Γ2=1.49±0.02 MeV [4] and 2 δ2(2.63) = 37.5°±2° [5], when the δ2 uncertainty is minimal, the K2(k ) parameter 2 fitting leads to the function K2(k ) whose shape even differs from the experimental one. When the experimental δ2(Eα) energy dependence is only fitted, we obtain the resonance energy E2 and Γ2 shifting to the somewhat smaller values (E2 ≅ 2.87, Γ2 ≅ 1.42 MeV). Correspondingly, we obtain NVC 2 2 (fm) ReG2ren ≅ 0.012, ImG2ren ≅ −0.016 which can be compared with 2 2 −4 −1/2 ReG0ren ≅ 0.56, ImG0ren ≅ −1.5 10 . The respective ANC (fm ) have a much smaller difference: C2 ≈ 1, C0 ≈ 1.5. This study was partly supported by funding from FTsP “Kadry” (1.1 “Scientific research implementation by teams of science and education centers” contract 02.740.1.0242) and by the Russian Foundation for Basic Research, project no. 10-02-00096. 1. V.O.Eremenko, L.I.Nikitina, Yu.V.Orlov // Izv. RAN. Ser. Fiz. 2007. V.71. P.819. 2. Yu.V.Orlov, B.F.Irgaziev, L.I.Nikitina // Yad. Fiz. 2010. V.73. P.787. 3. Yu.V.Orlov, L.I.Nikitina // Izv. RAN. Ser. Fiz. 2012. V.76. №4. P.512. 4. D.R.Tilley, J.H.Kelley et al. // Nucl. Phys. A. 2004. V.745. P.155. 5. S.A.Afzal, A.A.Z.Ahmad, S.Ali // Rev. Mod. Phys. 1969. V.41. P.247. 175 SPECTROSCOPY OF THE HADRONIC ATOMS AND SUPERHEAVY ISOTOPES: ENERGY SHIFTS AND WIDTHS AND STRONG K-, π-N INTERACTION CORRECTION I.N. Serga, Yu.V. Dubrovskaya, D.E. Sukharev Odessa State University – OSENU, Ukraine E-mail: [email protected], [email protected] In the last few years transition energies in pionic and kaonic atoms have been measured with an unprecedented precision [1]. The spectroscopy of hadronic hydrogen allows to study the strong interaction at low energies [2] by measuring the energy and width of the ground level with a precision of few MeV. The light hadronic atoms can additionally be used to define new low-energy X-ray standards and to evaluate the pion mass using high accuracy X-ray spectroscopy. Paper is devoted to studying spectra for hadronic (kaonic and pionic) atoms and some superheavy isotopes. Ab initio QED approach [3] with an accurate account of relativistic, nuclear, radiative effects is used in calculating spectra of the hadronic (pion, kaon) atoms. One of the main purposes is establishment a quantitative link between quality of nucleus structure modeling and accuracy of calculating energy and spectral properties of systems. The wave functions zeroth basis is found from the Klein-Gordon or Dirac equation. The potential includes the SCF ab initio potential, the electric and polarization potentials of a nucleus (the RMF, Fermi and Gauss models for a charge distribution in a nucleus are considered). For low orbits there are the important effects due to the strong hadron-nuclear interaction. The energy shift is connected with a length of the hadron-nuclear scattering. For superheavy isotopes (ions) the correlation corrections of high orders are accounted for within the Green function method. The Lamb shift polarization part – in the Uhling-Serber approximation and the self-energy part – within the Green functions method. We present the data on: 1) energy levels for superheavy isotopes Z=113,114; 2) shifts and widths of transitions (2p-1s, 3d-2p, 4f-3d etc) in some pionic and kaonic atoms (H, He, N, W, U). The calculated X-ray transitions spectrum for kaonic He and estimate of 2p level shift due to the strong K-N interaction 1.57 eV are in the reasonable agreement with experimental data (cited shift 1.9 eV) by Okada et al. (2008; E570; KEK 12GeV, RIKEN Nishina Centre, JAPAN) and differ (about order) of other experimental data by Wiegand-Pehl (1971), Batty et al. (1979), Baird et al. (1983). 1. D.Gotta // Progr. in Part. and Nucl. Phys. 2004. V.52. P.133; G.Beer et al. // Phys. Lett. B. 2002. V.535. P.52; R.Deslattes et al. // Rev. Mod. Phys. 2003. V.75. P.35; M.Trassinelli, P.Indelicato // arXiv:phys/0611262v2 (2007). 2. C.J.Batty et al. // Phys. Rev. C. 1989. V.40. P.2154; T.Ito et al. // Phys. Rev. C. 1998. V.58. P.2366; S.Okada et al. // Phys. Lett. B. 2007. V.653. P.387. 3. A.V.Glushkov et al.// Frontiers in Quantum Systems in Chem. and Phys. Berlin: Springer, 2008. V.18. P.505; Theory and Applications of Comp. Chem. (AIP). 2009. V.1102. P.168; Int. J. Mod. Phys. A. 2009. V.24. P.611. 176 THE ANALYSIS OF STRUCTURE OF 6He AND 8He NUCLEI 1 2 3 E.T. Ibraeva , O. Imambekov , I. Tleulessova 1 Institute of Nuclear Physics of NNC RK, Almaty, Kazakhstan; 2 Al-Farabi Kazakh National University, Almaty, Kazakhstan; 3 L.N.Gumilyov Eurasian National University, Astana, Kazakhstan E-mail: [email protected] The study of the structure of the 6Не and 8Не isotopes showed that they consist of α-particle core and valence nucleons, which form the skin, and which radius is equal to 0.9 fm [1, 2]. After the comparison of data obtained by different methods, the following conclusion can be made: the calculation of three-particle wave functions leads to the root mean square (rms) radius 0.1- 0.2 fm larger than the calculation with the single-particle densities [3]. The analysis shows that the increase in radius is due to the intrinsic composite structure of many-particle wave functions and their extended asymptotic behavior. At present the most accurate method of determining the nuclear charge radius is the laser-spectroscopic method [4, 5]. The comparison of the rms matter and charge radii of the 6Не and 8Не isotopes carried out in [5] shows an interesting picture: the radius of the matter of 8Не is more than 6Не, while the 8He 6He charge radius is less. The fact that RRmm> is clearly explained by the large 8He 6He number of nucleons. The reverse inequality for the charge radii RRch < сh is due to the internal structure of these isotopes. The two excess neutrons in 6Не are correlated in such a way that is more likely to find them in the dineutron configuration. As a result, the movement of the α-core in relation to the correlated pair of neutrons spreads the charge distribution over a larger volume. In contrast, in 8He four excess neutrons are distributed more in the spherically symmetric manner in the halo and the spreading of the charge in the core, respectively, smaller, which leads to a decrease in the charge radius. It turns out that the addition of a larger number of valence nucleons to α-partial core prevents further spatial swelling of the nucleus, as determined by the ratio of the charge radii of 6Не and 8Не. 1. J.S.Al-Khalili, J.A.Tostevin // Phys. Rev. C. 1998. V.57. P.1846. 2. L.Giot et al. // Phys. Rev. C. 2005. V.71. 064311. 3. S.B.Neumaier et al.// Nucl. Phys. A. 2002. V.712. P.247. 4. L.-B.Wang et al. // Phys. Rev. Lett. 2004. V.93. 142501. 5. P.Mueller et al. // Phys. Rev. Lett. 2007. V.99. 252501. 177 CLUSTER STATES IN THE NEUTRON EXCESS NUCLEI S.Yu. Torilov, K.A. Gridnev, T.V. Korovitskaya Saint-Petersburg State University, Russia E-mail: [email protected] The study of the neutron-rich light nuclei has constantly represented a challenge for nuclear spectroscopy, mainly due to the unclear question about the role of the cluster configurations in the different kinds of the rotational bands of these nuclei. As it well known [1], we have a lot of the “good” cluster states in the nuclei like 16O, 20Ne and in the other self-conjugated nuclei [2]. Generally, the structure of nearby even-even nuclei bear marked similarities to one another. It gives as the possibility to compare the recent results which were obtained for the neutron-rich nuclei with the predictions of the simple binary cluster model. In a recent study the sets of the rotational bands in the nuclei 18O [3], 20O [4], 22Ne [5] were observed. In the present work we compare our predictions to data on rotational bands for a series of O, Ne, Ar, Ca and Ti isotopes. The different kinds of the potential wells were used. It was founded that we have good agreement with experimental results for local mass-depended potential which can give us not only right position of the states, but as well as the energy splitting between positive and negative parity bands, widths and reproduce alpha-particle elastic scattering angular distribution. 1. H.Horiuchi, K.Ikeda // Progr. Theor. Phys. 1968. V.40. P.277. 2. T.Yamaya et al. // Progr. Theor. Phys. Suppl. 1998. V.132. P.73. 3. W.von Oertzen et al. // Eur. Phys. J. A. 2010. V.43. P.17. 4. W.von Oertzen et al. // AIP Conference Proceedings. 2009. V.1165. P.19. 5. S.Yu.Torilov et al. // Eur. Phys. J. A. 2011. V.47. P.158. 178 NUCLEAR REACTIONS THEORY MANIFESTATION OF QUARK DEGREES OF FREEDOM IN BACKWARD pd SCATTERING M.N. Platonova, V.I. Kukulin Skobel’tsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] It is well known that the nucleon-deuteron scattering observables at low momentum transfers can be well reproduced by solving the exact Faddeev equations (at low and moderate energies) or by approximate methods like Glauber diffraction model (at higher energies). However, at larger momentum transfers, there exist strong discrepancies between theoretical predictions and experimental data. These discrepancies are usually attributed to the three- nucleon force effects but the inclusion of conventional 3N forces (2π exchange with excitation of an intermediate Δ-isobar) improves the agreement with the data only partially. On the other hand, it is clear that high momentum transfers are related to the short NN distances where nucleons loose their individuality and quark degrees of freedom should manifest themselves. Incorporating the 6q objects explicitly may influence the effective short-range behaviour of both NN and 3N forces. However previous attempts to include 6q bags in 3N calculations were ad hoc and not connected to the basic NN forces. In the talk we present the first calculations of backward pd scattering on the basis of the dressed bag model of nuclear forces. In this model proposed by the Moscow-Tuebingen group some time ago quark degrees of freedom are taken into account through the formation of an intermediate 6q bag dressed by a strong scalar field. This mechanism of the short-range NN interaction leads to the emergence of new two- and three-body forces, which are shown to give significant contributions to the large-angle pd scattering. In particular, a noticeable enhancement in the high-momentum components of the deuteron wave function has been predicted. Using this modified deuteron wave function leads to much better description of the pd experimental cross sections in the large-angle region. Thus, from the results obtained for the backward pd scattering, a suggestion can be made that the proposed mechanism of the short-range NN interaction is very likely responsible for the large amount of processes with high momentum transfers. 179 (d, p) REACTIONS AS A PROBE FOR NEUTRON HALO IN EXCITED STATES OF NUCLEI T.L. Belyaeva1, A.S. Demyanova2, S.A. Goncharov3, A.A. Ogloblin2 1 Universidad Autonoma del Estado de Mexico, Mexico; 2 NRC Kurchatov Institute, Moscow, Russia; 3 Skobeltzin Institute of Moscow State University, Russia E-mail: [email protected] Neutron halos have been almost exclusively observed in ground states of some neutron-rich radioactive nuclei located close to the neutron drip line. Nevertheless, an appearance of neutron halos in the excited states of the stable + 13 nuclei, for instance, in the first (1/2 , Ex = 3.089 MeV) state of C was discussed in the 1990s. The enlarged rms radius of 13C in this state was found by the asymptotic normalization coefficient (ANC) method [1] and within the modified diffraction approach [2]. The talk will discuss the current state of neutron transfer reactions that remain a useful tool for investigating nuclear structure. A rebirth of interest to their studies is related, in particular, to the possibility of finding neutron halos in the radioactive nuclei using inverse kinematics. We present the calculations of the angular distributions, rms radii, spectroscopic factors Sexp, and ANCs for the (d, p) reactions leading to the formation of the stable 13C nucleus and the radioactive 11Be and 12B nuclei in the excited states, where the existence of neutron halos is implied. A comparison is made with the states having normal densities. Three complement models are used in calculations: the coupled reaction channels model for the direct neutron transfer at all energies, the Hauser- Feshbach compound nucleus formalism at low energies, and CDCC calculations for the deuteron breakup at higher energies. We have found that the neutron transfer dominates at all energies (an example is shown in Fig. 1) and demonstrated that the states with enlarged radii are formed in the reactions of a peripheral type, which satisfy to the criterion of a 2 2 peripherality: C =Sexpb =const, where Fig.1. The contribution of the direct C is the ANC and b is the neutron transfer (solid lines) comparing with the experimental data Refs. [1,3]. “single-particle” ANC. 1. Z.H.Liu et al. // Phys. Rev. C. 2001. V.64. 034312. 2. A.A.Ogloblin, A.N.Danilov, T.L.Belyaeva, et al. // Phys. Rev. C. 2011. V.84. 054601. 3. H.Obnuma // Nucl. Phys. A. 1985. V.448. P.205. 180 7,9 THE ANALYSIS OF (t, p) REACTIONS ON Li ISOTOPES L.I. Galanina, N.S. Zelenskaya Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Russia E-mail: [email protected] Differential cross sections of the (t, p) reaction on nuclei 7,9Li are considered in order to restore the spatial structure of the initial and final nuclei by means of determining the various mechanisms contributions dependence from the spatial configurations of excess neutrons. 1p-shell nuclei featuring two excess neutrons may have two spatial configurations differing in the position of the neutrons with respect to the core — a two-neutron configuration, and a cigar-like configuration [1]. As a theoretical approach that is able to reveal each of the above two spatial configurations, we proposed [2] analyzing angular dependences of cross sections for reactions involving the production of neutron- rich nuclei with allowance for one and two-step reaction mechanisms illustrated by pole and box diagrams (Fig. 1). As is seen from the Fig. 2, both mechanism contributions to the total cross section are comparable. This fact indicates that both possible two neutron configurations of nucleus 9Li should appear in this reaction. Fig. 1. Diagrams illustrating the Fig. 2. The differential cross section of 7Li (t, p)9Li mechanisms of transfer dineutron cluster reaction: dotted curve – independent neutrons in 7Li (t, p)9Li reaction: a – stripping transfer contribution, thin solid – dineutron dineutron, b – independent neutron stripping, solid – their coherent sum. Circles – transfer mechanism. experiment [3]. Two neutron peripherals in the nucleus 11Li in reaction 9Li(t, p)11Li not actually seen. This result is confirmed by calculations of the (t, p) reaction cross section and data [4] on the 11Li structure, obtained under the scattering of protons with 1 GeV energy on this nucleus. 1. A.A.Korsheninnikov. Nuclear exotics near and abroad stability. Thesis for the degree of doctor of phys.- math. sciences. Мoscow, 1996. 170 p. 2. L.I.Galanina, N.S.Zelenskaya // Phys. Atom. Nucl. 2007. V.70. P. 308. 3. L.N.Generalov, S.N.Abramovich, Yu.I.Vinogradov // Bull. Rus. Acad. Sci.: Phys. 2009. V.73. P. 156. 4. E.T.Ibraeva, M.A.Zhusupov, O.Imambekov, Sh.Sh.Sagindykov // Phys. Atom. Nucl. 2008. V.71. P.1272. 181 NUCLEAR REACTIONS AT THE Δ-ISOBAR EXCITATION REGION Yu.L. Ratis Institute of the Power Engineering for the Special Applications E-mail: [email protected] We consider the interference effects are manifested in nuclear reactions with the -isobar excitation. Fig. 1 shows the experimentally measured value of the ratio ( , ) at = 0.8 GeV, = 0 significantly less than the theoretical value ∆ = 3, and near the upper kinematic0 limit of the spectrum the observed is 푛 푛 푛 푛 almost푅 of푇 orderθ less푇 than θ. This effect was qualitatively explained [1] by the 푡ℎ푒표푟 푅presence of constructive interference of virtual and - isobars for 푅the 푅theor reaction n + p n + and destructive interference of+ the and0 - isobars for ∆ ∆ the process p + p n + . However, the clear quantative++ explanation+ of this effect is absent→ [1]. 푋 ∆ ∆ It have been studied→ 푋 the effects of interference and -isobar ( и -isobar), excited in the reactions p + p n + (n + p ++p + ) at+ the projectile+ ∆ ∆ ∆ energies0 0.8 10GeV [2]. Calculations were carried out for OSET, JAIN and DMIT-∆ parameter sets of the vertex functions.→ Description푋 → of sets푋 , see [2]. As one can≤ 푇see ≤ (Fig. 1), the ratios ( , ) has a similar angular and energy dependence for all three sets, despite the fact that the numerical values of the theoretical cross sections for p +푅 p푇 휃 n + (n + p p + ) reactions at > 1.5 GeV significantly differs ( (DMIT) > (OSET) > (JAIN)). The angular dependence of the integral relationship → is not푋 significant→ and푋 differences of the푇 magnitudes for JAIN, OSET orσ DMIT- σset less thanσ 10%. If energy increasing, the interference effects for 〈푅 и〉 - isobar at n + p p + reaction 푇푛 vanishes, thus 3. + 0 We demonstrate that for the reactions∆ at∆ the - isobar excitation→ 푋region the superposition principle〈푅〉 → holds with a high degree of accuracy and, consequently, the theory of such processes should be linear. ∆ Fig. 1. The ratio of the cross sections for the charge exchange reactions. 1. B.J.VerWest, R.A.Arndt // Phys. Rev. C. 1982. V.25. P.1979. 2. F.A.Gareev, E.A.Strokovsky, J.S.Vaagen, et al. // YaF (rus). 1994. V.57. No.2. 182 RESCATTERING EFFECTS IN PROTON ELASTIC SCATTERING FROM 15N NUCLEUS E.T. Ibraeva1, O. Imambekov2, P.M. Krassovitskiy1, A.L. Koslovsky3 1 Institute of Nuclear Physics NNC RK, Almaty, Kazakhstan; 2 Al-Farabi Kazakh National University, Almaty, Kazakhstan; 3 L.N. Gumilev Eurasian National University, Astana, Kazakhstan E-mail: [email protected] Protons scattering on nuclei is a proven method for studying the internal structure of nuclei and proton-nucleus interactions. For the present the exact nucleon-nuclear interaction is not known, the theoretical data analysis is made in various models. Typically, the optical model is used at low energies, the Glauber theory of multiple scattering (from hundreds MeV to GeV) is used at higher energies. The purpose of this paper is consideration of higher collisions multiplicity (rescattering) in the calculation of protons elastic scattering amplitude on nucleons 15N nucleus within the Glauber diffraction theory and calculation of differential cross section (DCS) taking into account the amplitudes of single, double and triple collisions and their interference. It is shown that in the approximation of triple scattering using the shell wave function 15N (where the ground state is the level of negative parity with J π,Т = 1 2− ,1/2 with (1s)4(1р)11) configuration , the amplitude of р15N-scattering can be calculated analytically. Differential cross section calculation is made at two energies of incident protons 0.2 and 1.0 GeV in the angular range 40°>θ >0°, where the Glauber’s theory is applicable. Rescattering effects in DCS occur throughout the angular range, but their importance increases with the energy of incident particles, because the more energy the deeper protons can penetrate into the internal area of nucleus and rescatter on larger number of nucleons. If double rescattering slightly reduces DCS in the region of small scattering angles, they (and triple ones) become dominant and determine the behavior of cross section at large angles. 183 RATIO OF THE NEUTRON ASYMPTOTICAL NORMALIZATION COEFFICIENT TO THE PROTON’S ONE FOR MIRROR NUCLEI 11B AND 11C FROM ANALYSIS OF DIRECT REACTIONS S.V. Artemov, G.K. Nie, M.A. Kayumov, E.A. Zaparov Institute of Nuclear Physics, Tashkent, Uzbekistan E-mail: [email protected] In this work two pairs of mirror reactions 10B(d, n)11С and 10B(d, p)11B, 11B(d, t)10B and 11B(3He, d)11C, where a neutron and a proton transfer causes the bound states 11B и 11C, are investigated. The analysis of experimental data taken from literature is made in DWBA approach advanced with using asymptotic normalization coefficient (ANC) [1, 2, 3]. In the case the charge symmetry of nuclear force is applied as a demand of equivalence of neutron and proton nuclear potentials in the nuclei 11B and 11C [4]. Besides, for the elastic mirror channels the same optical potentials are used to describe nuclear interactions of the isobars. Using the feature of nuclear force allows one to calculate the ratio of the neutron asymptotic normalization coefficient to the proton’s one with deviation in ±1% [4]. Besides, this approach gives an opportunity to select proper optical potentials upon a new criterion, which is a good description of angular distributions of both mirror reactions. Analysis shows that the reactions 11B(d, t)10B and 11B(3He, d)11C at the main peak of the angular distribution are pure peripheral ones, which allows one to obtain the neutron and proton ANCs with error in 25% mostly determined by using different optical potentials. Unlike the reactions 11B(d, t)10B and 11B(3He, d)11C, the reactions 10B(d, n)11С and 10B(d, p)11B at the main peak of the angular distribution have amplitudes including internal part of the nucleus, which makes the bound state potential parameters important in obtaining the values ANCs. The values of the neutron and proton ANCs of the bound states 11B и 11C obtained from the analysis of both reaction pairs are in agreement. The ratio of the empirical neutron and proton ANCs is obtained in less deviation than it is supposed to be according to the deviations of the ANCs and it is in agreement with the theoretical value. 1. Л.Д.Блохинцев, И.Борбей, Э.И.Долинский // ЭЧАЯ. 1977. Т.8. С.1189. 2. I.R.Gulamov, A.M.Mukhamedzhanov, G.K.Nie // Phys. At. Nucl. 1995. V.58. P.1689. 3. S.V.Artemov et al. // Phys. At. Nucl. 1996. V.59. P.454. 4. G.K.Nie, S.V.Artemov // Bull. Russ. Acad. of Sc.: Physics. 2007. V.71. P.1762. 184 HADRON PRODUCTION IN HADRON-NUCLEUS INTERACTIONS AT HIGH ENERGIES Ya.A. Berdnikov1, A.E. Ivanov1, V.T. Kim1, V.A. Murzin1 1 Saint-Petersburg State Polytechnic University, Saint-Petersburg, Russia E-mail: [email protected] Hadron production in lepton-nucleus interactions at high-energies is considered in framework of developing Monte Carlo (MC) generator HARDPING (HARD Probe INteraction Generator). Such effects as formation length, energy loss and multiple rescattering for produced hadrons are implemented into the HARPING. Available data from HERMES on hadron production in lepton-nucleus collisions are described by the current version of the HARDPING generator in a reasonable agreement. Hadronisation of quarks and gluons is one of the most intriguing parts of nonperturbative QCD. Use of nuclear targets may allow to reveal important features of space-time picture of hadronisation, like hadron formation length and energy loss, see, e.g, for a review [1] and references therein. The understanding of quark propagation in nuclear medium is crucial for the interpretation of ultrarelativistic heavy ion collisions, as well as high energy proton-nucleus and lepton-nucleus interactions. To simplify interpretation of observable effects one can consider, at the beginning, hadron production in lepton scattering off nuclei. In case of deep inelastic scattering of lepton on nucleus there can be three stages of hadronisation. The first stage is when after hard scattering a struck quark propagates through the nuclear medium being in point-like parton state experiencing a little attenuation. This effect is known as Landau-Pomeranchuck- Migdal effect in QCD [2]. In the second stage, a pre-hadron state (a color dipole or constituent quark) is formed [3]. In this stage cross section of such pre-hadron state is smaller than hadron cross section. There is finally formed hadron at the third stage. Depending from the formation length the hadronisation process can evolve beyond the nucleus at any stage. In this talk the developing of Monte Carlo event generator HARDPING is discussing. It includes hadron production in lepton-nuclei interactions. It takes into account effects on formation length, energy loss and multiple soft rescatterings. Using experimental data from HERMES and EMC Collaborations on lepton-nuclei interactions and simulations by HARDPING one can study different stages of hadronisation process. This work was supported by the Ministry of Education of the Russian Federation, under the contract No. 02.740.11.0572 of the Federal task program “Research and educational community of innovative Russia”' for 2009-2013 1. B.Z.Kopeliovich // Nucl. Phys. A. 2004. V.740. P.211. 2. R.Baier // Nucl. Phys. B. 1997. V.484. P.265. 3. A.Accardi // Nucl. Phys. A. 2003. V.720. P.131. 185 ON THE DIRECT AND SEMIDIRECT RADIATIVE CAPTURE OF NEUTRONS BY MEDIUM-HEAVY NUCLEI B.A. Tulupov1, M.H. Urin2 1 Institute for Nuclear Research, RAS, Moscow, Russia; 2 National Research Nuclear University «MEPhI», Moscow, Russia E-mail: [email protected]; [email protected] Based on the finite Fermi-system theory equations for the effective fields [1] the continuum random phase approximation (cRPA) approach is used for the study of some features of the fast neutron radiative capture accompanied by excitation of the isovector giant dipole and quadrupole resonances (IVGDR and IVGQR, respectively). The suggested so-called semimicroscopic approach (see Ref. [2] and references therein) takes into account all the main giant-resonance relaxation modes (the Landau damping, coupling with the single-particle continuum, the spreading effect). The last one is taken into account phenomenologically with the help of the imaginary part (with the intensity α) of the effective optical-model potential directly used in the cRPA equations. In the present work the extended version of the approach is proposed. The extension consists in (i) the explicit use of the isovector part of (separable) momentum-dependent forces (with intensity k’L (L=1, 2)); (ii) account of the giant-resonance energy shift due to the spreading effect [3]; (iii) the use of the version of the phenomenological partially self-consistent mean field [4]. Three specific parameters (α and k’L) are adjusted to describe the experimental photoabsorption cross section in the considered energy region for a given (spherical) nucleus. Then, the partial (n, γ)–reaction cross sections in the IVGDR energy region as well as the asymmetry (relatively 90o) of the differential (n, γ)–and inverse reaction cross sections in the IVGQR energy region (together with the main properties of the IVGQR) are calculated without the use of free parameters. The calculation results obtained for a number of magic and semimagic nuclei are compared with available experimental data. 1. A.B.Migdal. Theory of Finite Fermi Systems and Properties of Atomic Nuclei. M.: Nauka, 1965 (in Russian); A.B.Migdal. Theory of Finite Fermi-Systems and Applications to Atomic Nuclei. New York: Interscience, 1967. 2. M.H.Urin // Nucl. Phys. A. 2008. V.811. P.107. 3. B.A.Tulupov, M.G.Urin // Phys. At. Nucl. 2009. V.72. P.737. 4. S.Yu.Igashov, M.G.Urin // Bull. RAS. Phys. 2006. V.70. P.186. 186 ISOTOPIC TRENDS OF CAPTURE CROSS SECTION AND MEAN-SQUARE ANGULAR MOMENTUM OF CAPTURED SYSTEM R.A. Kuzyakin1, V.V. Sargsyan1, G.G. Adamian1, N.V. Antonenko1, E.E. Saperstein2, S.V. Tolokonnikov2,3 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Kurchatov Institute, Moscow, Russia; 3 Moscow Institute of Physics and Technology, Russia E-mail: [email protected] By using the quantum diffusion approach [1], the isotopic trends of capture cross sections and mean-square angular momenta of captured systems are studied in the reactions 4He, 16O, 36S, 48Ca + 196,200,204,208Pb. The nuclear parts of the nucleus-nucleus interaction potentials were calculated by using the double- folding procedure with the density-dependent effective NN interaction [2] constructing with an averaging procedure from the TFFS (Theory of Finite Fermi Systems) effective interaction. For density distributions of interacting nuclei, we used the two-parameter symmetrized Fermi functions. For the lead isotopes, the Fermi-distribution parameters were found to fit to the self- consistent density distributions calculated with the DF3-a functional [3] within the EDF (Energy Density Functional) method [4]. The available experimental data at energies above and below the Coulomb barrier are well described. The isotopic trends are attributed to the deformation effects, neutron transfer, and nucleus-nucleus interaction. As demonstrated in our calculations, in the case of the same deformations of colliding isotopes and minor effect of neutron transfer, the neutron number of the target nucleus strictly influences the height of the Coulomb barrier, but not the width of the barrier. Thus, the height Vb of the calculated Coulomb barrier can be adjusted to the experimental data for the capture cross sections at Ec.m.>Vb to take effectively into account the change of nuclear interaction with neutron number. The width of the nucleus-nucleus interaction potential can be calculated with any realistic diffuseness parameter because the width is rather insensitive to its value. Indeed, this procedure is often used for calculating the sub-barrier fusion and capture. It was applied to the reactions 16O + 70,72,74,76Ge. As found, the increase of the number of neutrons in Pb assists the capture process. The isotopic dependence is rather weak in the reactions with 4He and 16O because the nucleus-nucleus potential weakly depends on the mass number of the target in very asymmetric reactions. In the reactions with 36S and 48Ca the isotopic trend is more pronounced. The slope of the capture cross section at deep sub-barrier energies is not sensitive to the neutron number of the system. 1. V.V.Sargsyan et al. // Part. Nucl. 2010. V.41. P.175. 2. G.G.Adamian et al. // Int. J. Mod. Phys. E. 1996. V.5. P.191. 3. S.V.Tolokonnikov et al. // Phys. Atom. Nucl. 2010. V.73. P.1684. 4. S. A.Fayans et al. // Nucl. Phys. A. 2000. V.676. P.49. 187 Р-ODD ASYMMETRIES FOR PRODUCTS OF SPONTANEOUS FISSION OF ORIENTED NUCLEI S.G. Kadmensky, L.V. Titova Voronezh State University, Russia E-mail: [email protected] Experimental investigations of the Р-odd asymmetries in angular distribu- tions of fission fragments were carried out only for (n, f) reactions of induced fission for non-oriented target-nuclei by cold polarized neutrons. The possibility of the Р-odd asymmetry observation for oriented in strong magnetic fields at low temperatures nuclei was considered in paper [1] with usage of the represen- tation about sufficient difference of the fission barriers penetrability factors for the states with opposite parities. Mentioned representation contradicts with con- clusions of the paper [2], where it was shown that, because of the existence of the octupole deformation of asymmetrically fissioning nuclei in the saddle point of its deformation potential, these factors are close to each other. Spontaneous fission of oriented nuclei with spin I and its projections M and K onto z axis of laboratory frame and onto symmetry axis correspondingly, from its’ ground states with K=I, which is analyzed in [3], can be described by spin density ma- I ()21Q + IM' II trix in the form: ρδ' = MM '∑ C C pIQ (), where the orienta- MM Q ()21I + IQM00 IQI tion axis of the nucleus is chosen along z axis of laboratory frame and pIQ () is degree of orientation. Then the coefficient Р-odd asymmetry with usage of the quantum fission theory methods [4] can be presented as: 2 θ= α II 2+ 1 cosθ , where α ~10–7 is admixture param- D() ∑ pQQ() IC()IQI0 ()() Q P Q−неч eter for the states with opposite parities, cosθ is Legandre polynom and pa- PQ () rameter Q has only odd values. The term with Q = 1 corresponds to Р-odd asymmetry with structure ()pk, LF [2, 4], where kLF is unit wave vector of light 255 fission fragment, p is nuclear polarization vector. For nuclei Es (I=7/2) and 257 Fm (I=9/2) [3] in the case of their total polarization, when pIQ () =1 for all values Q, coefficients D()0 remarkably change for taking into account values Q > 1 in comparison with case Q = 1. So the values of coefficient D()0 for Q = 1 are 2.33·10–7 and 2.45·10–7; and for Q=1, 3, 5, … are 4·10–7 and 5·10–7, correspondingly. The work is supported by RFBR 12-02-00218-а. 1. V.V.Vladimirsky, V.N.Andreev // JETPH. 1961. V.41. P.663. 2. О.P.Sushkov, V.V.Flambaum // UFN. 1982. V.136. P.3. 3. G.M.Gurevich et al. // Abstract «Nucleus-2003». S.-Petersburg. 2003. P.36. 4. S.G.Kadmensky // Yad. Fiz. 2003. V.66. P.1739. 188 T-ODD ASYMMETRIES FOR THE REACTION OF TERNARY SPONTANEOUS FISSION OF ORIENTED NUCLEI S.G. Kadmensky, L.V. Titova Voronezh State University, Russia E-mail: [email protected] Experimental investigations of Т-odd asymmetries in angular distributions of the ternary fission products have been carried out only for the (n, f) reaction of induced fission of non-oriented target-nuclei by cold polarized neutrons. The investigation of the analogous asymmetries for spontaneous fission of oriented in strong magnetic fields at low temperatures nuclei is in undoubted interest. Spin density matrix of oriented nucleus in ground state with spin J and its projection K=J onto nucleus symmetry axis, when the orientation axis is directed along y axis of laboratory frame, can be presented as JJ21Q MJ' π 3π 4π J ρδ' MM '0 CYJQMq Qq , CpJJQJ Q , where pQ J is MM Qq 21J 22 21Q orientation degree of nucleus of order Q. Using methods [1, 2] with taking into account the influence of the Coriolis interaction of the spontaneous fissile nucleus spin with the orbital moment of the prescission α-particle, emitted in ternary fission, the coefficient D of the Т-odd asymmetry corresponds to ROT-type for Q 1 can be expressed in form: 2 DIdAdAAθ ~ θ cosφθθθ(0) (0) (0) θ, where A(0) θ is the module of the non-perturbed by Coriolis interaction amplitude of the α-particle angular distribution, and the effective angle I of the rotation of the polarized nucleus axis for Q 1 has structure JJJJpJ 2321 1 , where J is fissile nucleus moment of inertia, is rotation time. Taking into account that the angle is proportional to polarization vector of compound nucleus [1, 2], and using the values of rotation angle n 0.23 for the case of fission of non-oriented target-nucleus 235U with spin I=7/2 by cold polarized neutrons [2], which is defined as n 2 JpJJpJJ 11 , where indexes > and < corresponds to the values of the fissile nucleus spin 255 JI 1/2 and JI 1/2, the estimation of the angle for nuclei Es 257 (I=7/2) and Fm (I=9/2) can be obtained: I 4.67 n 1.08 and I 5.03 n 1.16 , correspondingly. Because of similarity of α-particle 2 angular distributions A(0) for different actinide-nuclei, the coefficient D for spontaneous fission has about 5 times higher values than for the case of induced fission by cold polarized nuclei. The work is supported by RFBR № 12-02-00218-а. 1. V.E.Bunakov, S.G.Kadmensky // Phys. of At. Nucl. 2008. V.71. P.1200. 2. I.S.Guseva, Yu.I.Gusev // Bull. of RAS. 2007. V.71. P.367. 189 THE P-ODD ASYMMETRIES FOR THE REACTIONS OF BINARY FISSION OF ORIENTED TARGET-NUCLEI BY COLD POLARIZED NEUTRONS S.G. Kadmensky1, L.V. Titova1, V.Е. Bunakov2 1 Voronezh State University, Russia; 2 Saint-Petersburg Institute of Nuclear Physics, Gatchina, Russia E-mail: [email protected] In papers [1, 2] the P-odd asymmetries in binary fission of non-oriented target-nuclei with spin I by cold polarized neutrons and in [3] of oriented nuclei by non-polarized neutrons have been investigated. It is remained undecided, what new terms, describing P-odd asymmetries, appear in the differential cross- section in binary fission of oriented target-nuclei by cold polarized neutrons. The spin density matrix for compound nucleus, which takes into account the interference of fission amplitudes for different pairs of s-neutron resonances sJ and sJ'', excited in mentioned nucleus, can be presented as: JJ ' JM'+ ()21Q + Ff Ff ρ=MM ' ∑∑()()() −1 4 π 2JJ '1 + 2 + 1 C''− C × 22+ 1 JJ M M Qq1 − qn Q≥1, q Ff ()I qn =±1 (1) 111 22 II ×CIQI01 p Q() IpY n q()ΩΩ n Y Qq () I IQ, n J' JF where pIQ () ( pn ) is module of vector pIQ () ( pn ), which gives the degree of target-nucleus orientation (neutron polarization) of order Q , and solid angles Ωn and Ω define the direction of target-nucleus orientation and neutron polarization axes in laboratory frame. Using methods [2, 3] and expressions for products of three spherical functions [4] with taking into account spin density matrix (1), where index F has odd values, the additional terms into differential cross-section of the investigated reaction are presented as new forms: dσnf ∆~ A11( kLF ppInn, 1 () +)() A12 ( pk,LF− 3() pIk 2() , LF() ppI n , 2 () ) + ..., (2) dΩLF where kLF is unit wave vector of light fission fragment, coefficients A1Q depend on the phases of the interfering neutron resonances. The experimental investigation of the new correlations in formula (2) is of interest. The work is supported by RFBR № 12-02-00218-а. 1. О.P.Sushkov, V.V.Flambaum // UFN. 1982. V.136. P.3. 2. S.G.Kadmensky // Yad. Fiz. 2003. V.66. P.1739. 3. S.G.Kadmensky, V.E.Bunakov, L.V.Titova // Abst. of “Nucleus-2011”, P.129. 4. A.L.Barabanov. Symmetries and spin-angular correlations in reactions and decays. M.: Fizmatlit, 2010. 520 p. 190 INFLUENCE OF THE POTENTIAL BARRIER HEIGHT ON THE RATE OF THE THERMAL DECAY OF THE METASTABLE STATE N.E. Aktaev, I.I. Gontchar Omsk State Transport University, Russia E-mail: [email protected] A decay of the metastable state is the most important theoretical model for study of the different physical phenomenons. As a striking example of this phe- nomenon is the fission of the atomic nucleus. The nuclear structure evolution on the fission is described by master kinetic equation. But frequently it does happen to move to Fokker-Plank equation by the agency of the Kramers-Moyal forward expansion [1]. The solution of this equation for the appointed approximation (fundamental − high fission barrier) was received by H.A. Kramers [2]. At pre- sent the Kramers result (Kramers formula) is active to apply in nuclear physics for the description of the fission of exited atomic nuclei [3, 4]. The modern experiments for synthesis of the superheavy elements (see for ex. [5]) to set the problem of the modeling of the nuclear fission on the assump- tion of the fission barrier height is comparable with the temperature. In this case usability conditions of the conventional Kramers formula are disturbed. It is necessary to obtain a new expression by means of which may to describe the fis- sion rate at the low value of the potential barrier height. The first attempt to take of this expression is belong to V.M. Strutinsky (Strutinsky formula) [6]. But numerical research of this formula doesn’t perform and this formula doesn’t ap- ply for the modeling of the atomic nuclear fission. Our research is the logical continuation of the works [7, 8] where the fission process of the exited atomic nuclei is studied. Attempt is to detect of the general regularity behavior of the fission rate at the low and rather high values of the fis- sion barrier height. Moreover the corrections in the formula for the decay rate at the low barrier to improvement of the agreement with the result of the numerical modeling are suggested. 1. J.Randrup, P.Muller, A.J.Sierk // Phys. Rev. C. 2011. V.84. 034613. 2. H.A.Kramers // Physica. 1940. V.7. P.284. 3. K.Mazurek et al. // Phys. Rev. C. 2011. V.84. 014610. 4. S.G.McCalla, J.P.Lestone // Phys. Rev. Lett. 2008. V.101. 032702. 5. Yu.Ts.Oganessian et al. // Phys. Rev. Lett. 2012. V.108. 022502. 6. V.M.Strutinsky // Phys. Lett. B. 1973. V.47. P.121. 7. I.I.Gontchar et al. // Phys. Rev. C. 2010. V.82. 064606. 8. N.E.Aktaev, I.I.Gonchar // Bull. of the RAS. Physics. 2011. V.75. P.994. 191 EFFECT OF NEUTRON TRANSFER IN FUSION REACTIONS WITH WEAKLY BOUND NUCLEI AT SUB-BURRIER ENERGY V.A. Rachkov1, A. Adel2, A.V. Karpov1, A.S. Denikin1, V.I. Zagrebaev1 1 Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia; 2 Physics Department, Faculty of Science, Cairo University, Giza, Egypt E-mail: [email protected] Many theoretical and experimental studies are devoted to analysis of the fusion reactions. Reactions of sub-barrier fusion of the neutron-rich nuclei with stable nuclei are of special interest. In these reactions an increase of the fusion cross section at energies below the Coulomb barrier is observed. The processes of the rearrangement of valence neutrons with positive Q-values (that leads to a gain in the kinetic energy of the colliding nuclei) may substantially increase the sub-barrier fusion cross section. It should be noted that a large enhancement of the fusion cross section at energies below the Coulomb barrier was observed in the nuclear reactions with light neutron-rich weakly bound nuclei [1]. Further investigation in this field might be rather important as well for the astrophysical primordial and supernova nucleosynthesis. Theoretical analysis of the role of weakly bound nucleons in the process of sub-barrier fusion is very complicated, because it requires a simultaneous account for the break-up, neutron transfer and total fusion channels within one model. In this work an empirical channel coupling model (ECC model) [2, 3] is used for description of the sub-barrier fusion reactions with neutron rearrangement. Within this approach the total penetrability of the fusion barrier is calculated taking into account the probabilities of transfer of a single or several neutrons (up to four neutrons), averaged over the parameterized barrier distribution function. The sub-barrier fusion cross sections is discussed for different combinations of colliding nuclei, such as 4He + 64Zn and 6He + 64Zn, 9Li + 208Pb and 11Li + 206Pb, 6,7,9,11Li + 152Sm. In all the cases, the sub-barrier fusion proves to be more probable for the combinations, where intermediate neutron transfer with positive Q-values is possible. The theoretical calculations show a good agreement with available experimental data. Predictions of the fusion cross section for several combinations of colliding nuclei have been made. These results may be useful in planning and data analysis of the corresponding experiments. 1. Yu.E.Penionzhkevich, V.I.Zagrebaev, S.M.Lukyanov, R.Kalpakchieva // Phys. Rev. Lett. 2006. V.96. 162701. 2. V.I.Zagrebaev // Phys. Rev. C. 2003. V.67. 061601. 3. V.I.Zagrebaev, A.S.Denikin, A.V.Karpov, et al. // Fusion code of NRV, http://nrv.jinr.ru/nrv/. 192 DIFFUSION COEFFICIENTS IN HEAVI-ION REACTIONS WITH DEEP INELASTIC NUCLEON TRANSFER V.E. Bunakov1,2, G.M. Gindin1 1 St. Petersburg State University, Russia; 2 Petersburg Nuclear Physics Institute, Gatchina, Russia E-mail: [email protected] The mass and charge transport in deep- inelastic heavy-ion collisions is studied on the basis of Fokker-Plank equation. The mean interaction time of the forming binuclear system is calculated by the solution of the classical equations of motion. Theoretical angular distributions of the reaction products for the reaction 40Ar (288 MeV) + 232Th are compared with the experimental data for the first time. We found, that the angular distributions obtained using the standard assumption about constancy of drift and diffusion coefficients do not coincide with the experimental data. However, if one takes charge distribution averaged over the emission angles, it will be in a rather good agreement with the experimental data. For better agreement between theoretical angular distributions of the reaction products and experimental data it was necessary to assume that drift and diffusion coefficients strongly decrease with time. 193 YIELDS AND ANGULAR AND ENERGY DISTRIBUTIONS OF THE LIGHT PARTICLES IN TRUE QUATERNARY FISSION S.G. Kadmensky, L.V. Titova Voronezh State University, Russia E-mail: [email protected] Using methods of the quantum theory of true quaternary fission [1] the yield of the prescission third and fourth particles pair N3,4 in the true quaternary fission (1) (2) (1) (2) with respect to the binary fission is defined as N3,4 = NN34()()34+ NN 43 , ()i ()i where N3 ( N4 ) – the yield of the third (forth) particle emitted first (i =1) or se- cond (i = 2 ) in time of the flight, and can be transformed to formula: (1) (1) N3,4 = NN34( g4()()3+ g 3 4) / 2; where g3(4) , g4 (3) – descent factor for flight prob- ability in unit time for the second (i = 2 ) particle with respect to the analogous probability for the first corresponding particle. With taking into account that the (1) (1) (1) yields N3 and energy WE3 () and angular W3 ()Ω distributions of the emitted first particle are similar to the analogous characteristics of the corresponding par- ticle in the true ternary fission and using experimental data of yields N3,4 for the pairs of identical (α, α), (t, t) and different (α, t) particles in quaternary fission of 234,236 252 –2 nuclei U and Cf [2, 3] the values of the factors gα ()α≈(1.9±0.6)×10 and (9.3±3.2)×10–2 for nuclei 234,236U and 252Cf correspondingly, and factors -2 −2 234 gtt ()≈(11.2±3.8)×10 and gtα ( )≈±×() 5.42 0.47 10 for nucleus U have been obtained. It has been noted, that the sufficient change of the descent factor gα ()α under the transition from nuclei 236U, 234U to the nucleus 252Cf is connected not with the nuclear fissility growth in the given sequence of nuclei, as it was as- sumed in paper [3], but with the different character of the neck shell structure re- construction in mentioned above fissile nuclei after the first α-particle flight. Us- ing full experimental distributions WE3 () (WE4 () ) and W3 ()Ω (W4 ()Ω ) of the third (fourth) particle in true quaternary fission the calculation scheme for energy (2) (2) (2) (2) WE3 () (WE4 () ) and angular W3 ()Ω (W4 ()Ω ) distributions of the third (fourth) particle emitted second in time has been presented. It has been shown that (2) (2) distributions WE3 () and W3 ()Ω have maximum shift to the smaller energies (1) and angles and widening in comparison with the similar distributions WE3 () and (1) W3 ()Ω of analogous third particles in ternary fission. It has been demonstrated that in contrast to [2, 3], the distributions WE3 () and W3 ()Ω should be described by unsymmetrical Gauss functions with larger width of the left branch than of the (2) (2) right branch owing to the properties of the WE3 () and W3 ()Ω . The work is supported by RFBR № 12-02-00218-а. 1. S.G.Kadmensky, О.V.Smolyansky // Izv. RAN. Ser. fiz. 2007. V.71. P.350. 2. P.Jesinger et al. // in Proc. of Symp. Nucl. Clusters, Rauischholzhauseb, 2002. P.289. 3. P.Jesinger et al. // Eur. Phys. J. A. 2005. V.24. P.379. 194 TRANSITION FISSION STATES FOR HEATED NUCLEI S.G. Kadmensky1, V.Е. Bunakov2, S.S. Kadmensky1 1 Voronezh State University, Russia; 2 Saint-Petersburg Institute of Nuclear Physics, Gatchina, Russia E-mail: [email protected] The induced nuclear fission reactions usually have a resonance character, when at the capture of the incoming particle by target-nucleus the compound nucleus is formed in the first well of its deformation potential, for which the equilibrium sta- tes are described at the sufficiently high excitation energies E by temperature T. The fission process for compound nucleus is connected with its deformation coll- ective motions and is described in the framework of the adiabatic approximation by vibration wave functions υ with energies E ()υ [1]. The internal wave func- tion of the compound nucleus i in the Wigner random matrixes framework [1] is presented as the superposition of the products of the wave functions for the quasi- particles states n with exitation energies En() and named above vibration states υ with energies E()()υ = E − En [2]. The weight of the state n in the function i exponentially increases with the growth of the energy En() , so the penetrabili- ty factors P()υ of deformation barriers for the states υ with EB()υ ≥ are equal 1 and exponentially falls down with decrease of E ()υ in the region EB()υ < , where B exceeds averaged height of fission barriers B on some MeV. Then the probabilities of subbarrier induced fission, when EB< , are defined by transition fission states in saddle points vicinity, coinsiding with few-quasiparticle cold sta- tes K with energies EK() , where K is projection of the nucleus spin onto its symmetry axis, and vibration states υ, K with energies E()()υ, K= E − EK and with penetrability factors PEK()() depending on K . It is shown that the probabilities of overbarrier induced fission, when the exci- tation energy E is sufficiently higher than B , with taking into account the decrease of E to EE < (cooling the temperature T to TT < ) because of the emitting from the nucleus prescission evaporation neutrons are mainly defined by transition fis- sion states, which correspond to thermalized many-quasiparticle states n with energies En() = E − B charactarized by temperature TTT<< and by vibration sta- te υ with energy EB()υ = and penetrability factor P()υ =1 and. It is demonst- rated that the nonadiabac character of the collective deformation motion of the nucleus near its scission point leads to the exitation in the nucleus only the non- equilibrium «door-way» states, which don’t change the nuclear temperature T . Therefore the projections K near scission point are approximately described by Gibbs distribution with temperature T . The work is supported by RFBR № 12-02-00218-а. 1. A.Bohr, B.Mottelson. Nuclear Structure. N.-Y.: Benjamin, 1974. 2. S.G.Kadmensky, V.P.Markushev, V.I.Furman // Yad. Fiz. 1983. V.37. P.277. 195 CALCULATION SCHEME OF HE AVY-ION COLLISIONS WITHIN THE FRAMEWORK OF A MODIFIED HYDRODYNAMIC APPROACH A.T. D’yachenko1, K.A. Gridnev2 1 Petersburg State Transport University, Russia; 2 Saint Petersburg State University, Russia E-mail: [email protected] The hydrodynamic model of heavy-ion collisions, which can be successfully applied both at medium and high-energies, needs further validation and refinement. An example of this approach is the consideration of the mechanism of the hydrodynamic evolution of a hot spot, used in [1] and extended in [2, 3]. In the present paper, we have taken into account in more detail the sidelong motion of nuclear matter with the formation of a shock wave at the compression stage. We have also considered the expansion stage in a different way from in [1]. The formed shock wave differs from the shock wave introduced by W. Greiner and co-workers in [4]. In our approach, the front of the shock wave changes as a function of time. We emphasize that the degree of compression of the resulting hot spot, obtained as a function of time for the central collisions of 16O +16O nuclei at energies Ecm = 100 MeV and Ecm =1000 MeV in the system of the center of mass, is different and more realistic than the one presented for the same energies in [4]. This suggests the need for refinements in the calculation of heavy-ion collisions in the hydrodynamic model taking into account the emission of secondary particles, which is conducted in this paper. 1. A.T.D’yachenko // Phys. At. Nucl. 1994. V.57. P.1930. 2. A.T.D’yachenko, K.A.Gridnev // Bull. Russ. Acad. Sci. Phys. 2011. V.75. P.970. 3. A.T.D’yachenko, K.A.Gridnev // J. Mod. Phys. 2011. V.2. P.8. 4. W.Scheid, H.Müller, W.Greiner // Phys. Rev. Lett. 1974. V.32. P.741. 196 THE RELATIONS BETWEEN THE DIFFERENTIAL CROSS SECTIONS FOR DIFFRACTIVE PROCESSES OF HALO- NUCLEUS CORE STRIPPING AND NUCLEON STRIPPING V.E. Pafomov, V.A. Sergeev, V.P. Zavarzina Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia E-mail: [email protected] The core stripping reaction of a halo nucleus characterized by instantaneous violent core-target interaction was investigated with fast radioactive beams in a number of works (see [1]), some theoretical estimations being done. In the recent work [2] the core stripping and nucleon stripping reactions of the single- nucleon halo nucleus were studied on the basis of common approach using a potential model of diffractive processes [3]. It was shown particularly that the differential (in longitudinal momentum of the observed particle) cross section for core stripping contains more complete information on the unperturbed wave function of the weakly bound system core+nucleon. Comparison between the core stripping and nucleon stripping is simplified due to the fact that the difference of the differential cross sections for these reactions is proportional to the longitudinal momentum distribution directly related to the unperturbed wave function. In the present work a comparative analysis of the stripping reactions of the halo nucleus is given in a more complicated case when transverse momentum distributions of the observed particles are calculated, the same model being used. Then the above relation (properly modified) between the differential cross sections is not fulfilled rigorously. Our calculations performed for 11Be and a light target allow to evaluate inaccuracy of this relation at different transverse momenta. In accordance with geometrical considerations the cross section value for halo-nucleus core stripping is significantly greater than that for nucleon stripping. It can be concluded from all calculations that both transverse and longitudinal momentum distributions of nucleons for core stripping are less distorted by constituent absorption in a target than the distributions of core- fragments for nucleon stripping. Results obtained by using other approaches are discussed. 1. S.Grevy et al. // Nucl. Phys. A. 1999. V.650. P.47. 2. V.E.Pafomov, V.A.Sergeev. // Izv. RAN. Ser. Fiz. 2011. V.75. P.490. 3. K.Hencken et al. // Phys. Rev. C. 1996. V.54. P.3043. 197 CALCULATION OF TRANSURANIUM ELEMENTS YIELDS UNDER CONDITIONS OF NEUTRON PULSE Yu.S. Lutostansky1, V.I. Lyashuk 2, I.V. Panov 3 1 Russian Research Center "Kurchatov Institute", Moscow, Russia; 2 Institute of Nuclear Research Russian Academy of Sciences, Moscow, Russia; 3 Institute of Theoretical and Experimental Physics, Moscow, Russia E-mail: [email protected] The earlier developed model [1] of transuranium isotopes creation under the condition of pulse nucleosynthesis in intensive neutron flux 1024 ÷ 1025 neutron/cm2 [2] is used for calculation of new elements production rate. An explosive nature of the process allows to separate it into two parts: the process of multiple neutron captures (t < 10–6с) and the following β-decays of neutron- rich nuclei. Along with U-238 the binary mixture of U-238 and Pu-239 are used as a start isotope substance. Transuranium yields are obtained from nucleosynthesis equations as additive solution of two systems of equations, generated by the pair of starting isotopes. The radioactive neutron capture rates are calculated according to the statistical model [3]. Half-life periods, probability of emission for one and two delayed neutrons, probability of delayed fission for neutron rich isotopes calculated taking into account the β-decay strength function, which obtained from the finite-Fermi system theory [4]. The results of nucleosynthesis modelling in experiments “Par” and “Mike” for two-component model of target allowed to obtain the better fit of the calculation results to the experimental data. Calculations were done for different relations between initial concentrations of uranium and plutonium. It was obtained that distributions registered for large time delay after the pulse can strongly differ from distributions for several hours and minutes time delays. It was showen, in particular, that with uptodate experimental tecknique the yields of transuranium elements formed on the first stage of the pulse nucleosynthesis can be measured up to atomic numbers A=270 [5]. It must be note that, according to our calculations, as early the samples will be extracted and analyzed the more heavier isotopes can be investigated. The work is supported by the RFBR grant № 11-02-00882. 1. Yu.S.Lutostanskii, V.I.Lyashuk, I.V.Panov // Bull. Russ. Acad. Sci. Phys. 2011. V.75. P.533. 2. G.I.Bell // Phys. Rev. 1965. V.139. P.1207. 3. I.V.Panov et al. // Nucl. Phys. A. 2005. V.747. P.633. 4. Yu.V.Gaponov, Yu.S.Lutostansky // Phys. At. Nucl. 2010. V.73. P.1360. 5. Yu.S.Lutostansky, V.I.Lyashuk // Bull. Russ. Acad. Sci. Phys. 2012. V.76. P.530. 198 CLUSTER MODEL OF FORMATION OF SUBNUCLEAR AND SUBATOMIC OBJECTS E.E. Lin Russian Federal Nuclear Center – All-Russia Research Institute of Experimental Physics, Sarov, Russia E-mail: [email protected] Results [1] of the development of the asymptotical model for forming objects (clusters) of subnuclear (quark) and subatomic (nuclear) matter are given in the paper. Asymptotical properties of the density function ϕ()at, of clusters distribution in sizes “a” were determined on the basis of a general kinetic approach; the relations were obtained for the most probable cluster sizes and for the dependences of average cluster sizes upon the time t. Some evaluations were obtained for the transition time of u- and d-quarks from asymptotic freedom in the condition of confinement as well as for the formation time of stable hadron jets. There was gained a correspondence between the asymptotical behavior of ϕ and composition of a jet formed at frontal collision of protons. The calculations were carried out for the most probable mass numbers A of clusters- nuclides in the whole range including transfermium elements on the strength of notions concerning vibrations of nucleons. By using a shell model of nucleus the author calculated the mass characteristics and the time characteristics of the following processes of approaching to equilibrium in nuclear reactions: cluster radioactivity, deep inelastic interactions between heavy ions, spontaneous fission, and synthesis of superheavy elements. The assessments are presented for the average mass number A ≈ 330 for superheavy elements to be formed under nucleosynthesis in stars as well as the mass number Afin ≈ 470–490 for a final nuclide. The obtained results are in keeping with the well-known notions [2-6] including the notions about lines and islands of nuclides stability. In addition, the possibility has been displayed formally for nuclides formation having –22 A = 10-300 in the times of t ~ 10 s under “rapid” excitation of vibrational shells. 1. E.E.Lin. Qualitative models for kinetics of formation of compact objects with strong inner bonds. Monograph. Sarov: RFNC-VNIIEF, 2011. 2. I.P.Selinov. Structure and Systematization of Atomic Nuclei. Moscow: Science, 1990. 3. V.M.Kulakov // Physical Values: Reference Book. Moscow: Energoatomizdat, 1991. P.993. 4. I.V.Panov, I.Yu.Korneev, F.-K.Thielemann // Journal of Nuclear Physics. 2009. V.72. No.6. P.1070. 5. Yu.S.Zamyatnin, S.G.Kadmensky, S.D.Kurgalin, et al. // Journal of Nuclear Physics. 1994. V.57. No.11. P.1981. 6. A.I.Obukhov, I.S.Grigoriev // Physical Values: Reference Book. Moscow: Energoatomizdat, 1991. P.1094. 199 EFFECTIVE RANGE EXPANSION AND VERTEX CONSTANTS FOR 6Li L.D. Blokhintsev1, D.A. Savin1 1 Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] Vertex constants (VCs) and asymptotic normalization coefficients (ANCs), which are proportional to VCs, are important nuclear characteristics. They determine cross sections of radiative capture processes at astrophysical energies. Their knowledge is necessary for solving the inverse scattering problem. The 6Li nucleus in the α+d channel is one of the most interesting systems for which it is important to know VCs and ANCs. The ANC values for this system determine the cross section of the radiative capture 4He(d, γ) 6Li, which is the only process of 6Li formation in the Big Bang model. The available data on the 6 values of the VCs Gl for the Li→ α+d channel (l=0, 2) are characterized by a large spread. In the given work, the Gl values were found by analytic continuation in energy of the effective range expansion for the dα scattering to the pole corresponding to the bound 6Li state. Both one- and two-channel [1] versions of the effective range expansion were employed. Several sets of scattering phases were used as an input: the phase-shift analysis made in [2] with neglect of the coupling of l=0 and l=2 channels (set 1), results of Faddeev calculations neglecting the Coulomb interaction [2] (set 2), and the phase-shift analysis made in [3] with account of the channel coupling (set 3). The calculations were performed with and without the preassigned (fixed) value of the 6Li binding energy ε. Several numerical results are listed below. 2 Set 1 with ε fixed results in G0 = 0.435 fm. Set 2 with ε fixed and 2 disregarding the channel coupling gives G0 = 0.319 fm. Finally, set 2 with ε 2 fixed and account of the channel coupling leads to G0 = 0.314 fm and 2 –5 G2 = 1.6∙10 fm. The sign of G2 (relative to G0) turned out to be negative. It follows from the above-listed and other numerical results obtained that the absolute values of Gl increase with increasing ε as well as with taking account of the Coulomb interaction. Account of the channel coupling affects only slightly the G0 value. On the other hand, account of that coupling is absolutely necessary to get the reliable G2 value. 1. L.D.Blokhintsev // Yad. Fiz. 2011. V.74. P.1008. 2. L.D.Blokhintsev, V.I.Kukulin, A.A.Sakharuk, et al. // Phys. Rev. C. 1993. V.48. P.2390. 3. W.Grüebler et al. // Nucl. Phys. A. 1975. V.242. P.245. 200 SHELL STRUCTURE EFFECTS OF NUCLEI IN р15C AND р15N SCATTERING IN DIFFRACTION THEORY M.A. Zhusupov2, E.T. Ibraeva1, A.L. Koslovsky3, B.А. Prmantaeva3, А.М. Zhigalova3 1 Institute of Nuclear Physics NNC RK, Almaty, Kazakhstan; 2 Al-Farabi Kazakh National University, Almaty, Kazakhstan; 3L.N. Gumilev Eurasian National University, Astana, Kazakhstan E-mail: [email protected] The calculation of differential cross sections (DCS) of elastic and inelastic 15 scattering at protons level ( JTπ+,= 52 ,32) on С nucleus and elastic scattering on 15N nucleus was made within the Glauber’s diffraction theory. The calculation was performed in the approximation of double scattering at energies of 0.2, 0.6 and 1 GeV/nucleon. Using the wave functions (WFs) of nuclei in the shell model allowed not only to calculate DCS analytically but also to calculate the contribution from protons scattering on nucleons at different shells. The wave functions of 15С are presented by the following configurations: 15 (1sp )4 (1 ) 10 (2 s ) 1 for the ground state С and (1sp )4 (1 ) 10 (1 d ) 1 for the excited state. The main difference between WFs of the ground state and the first excited state of 15C nucleus is the location of the last neutron: when it fills the 2s 21 -orbital, the root mean square radius and the total neutron density sharply increase in comparison with the case when the last neutron fills the 1d 25 -orbital 15 ( Rh = 5.666 fm for 2s 21 and Rh = 3.845 fm for 1d 25 , [1]). The WF of N, where the ground state is the level of negative parity with J π = 21 − , has the configuration as s р)1()1( 114 . Having calculated the dependence of DCS from collisions on nucleons from different shells for elastic р15С- and р15N-scattering we showed that the contribution from protons scattering on 1s-shell nucleons in the region of front angles is smaller by order than the scattering on 1р-shell nucleons and double sp-scattering. Physically this is explained by the fact that the larger impulse (more than for 1р-shell nucleons) is required for scattering on internal 1s-shell nucleons, and the larger the transmitted momentum the greater the scattering angle. For inelastic р15С-scattering only the scattering on 1d-shell nucleon contributes to single scattering. The contribution of scattering on nucleons from different shells is calculated for double collisions, for which scattering on р-shell nucleons is dominant. 1. T.Dong, Z.Ren, Y. Guo. // Phys. Rev. C. 2007. V.76. 054602. 201 DYNAMIC POLARIZATION OF 6,7Li NUCLEI IN α-PARTICLE ELASTIC SCATTERING R.S. Kabatayeva1, O.A. Rubtsova2, V.I. Kukulin2 1 Al-Farabi Kazakh National University, Almaty, Kazakhstan; 2 D.V.Skobeltsyn Scientific Research Institute for Nuclear Physics, M.V.Lomonosov Moscow State University, Russia E-mail: [email protected] We investigated the role of the excited intermediate states of the 6Li target in the framework of the three-particle model for the (α + 6Li)-scattering process. The simple general physical considerations show that these α–d continuum states should provide an essential contribution to elastic and inelastic α + 6Li cross sections, and also in radiation capture α + 6Li → 10B + γ reaction. Since the direct solution of the scattering problem in the three-particle (α + α + d)–system at low energies is too tedious and time-consuming because of the large Coulomb effects, we carried out the wave-packet reduction [1] of the problem. So, we projected the states of the three-particle continuum onto the discrete basis of the wave packets and employed, instead of the solution of the three particles Schrodinger equation, the coupled channel problem. Thus, we used the method of stationary wave packets as applied to the (α + α + d) three-body coupled- channel scattering case. We limited here by the intermediate αd–continuum with ℓ = 0. The account of the states of the intermediate continuum was found to smooth noticeably [2] the sharp oscillations of the differential cross sections, typical for the folding model potential and makes the obtained cross sections closer to the empirical ones found on the base of potentials extracted from solution of inverse scattering problem. Thus, account for the intermediate continuum essentially approximates the exact solution of the three-particle model. At low energies of order of several MeV the account of the dynamic polarization of particles in the reactions of elastic scattering and radiation capture affects cross sections even stronger [3]. The present authors are planning in the near future to carry out the similar calculations for elastic scattering of α-particles on 6Li nuclei with account of d-wave of the αd–continuum, and also for scattering of α-particles on 7Li nuclei. 1. V.I.Kukulin, V.N.Pomerantsev, О.А.Rubtsova // Theor. Math. Phys. 2007. V.150. P.473. 2. R.S.Kabatayeva et al. // Vestnik of al-Farabi KazNU. 2011. V.4(39). P.15. 3. V.S.Vasilevsky et al. // Proc. 3rd Int.Conf.“Curr.Probl. in NP & At.En.”. 2010. Kiev. 202 ELASTIC SCATTERING OF NEUTRONS ON 7Li NUCLEUS AT LOW ENERGIES M.A. Zhusupov1, E.T. Ibraeva2, R.S. Kabatayeva1, S.K. Sakhiyev3 1 Al-Farabi Kazakh National University, Almaty, Kazakhstan; 2 Institute for Nuclear Physics, National Nuclear Center, Almaty, Kazakhstan; 3L.N.Gumilyov Eurasian National University, Astana, Kazakhstan E-mail: [email protected] In order to consider the elastic scattering of neutrons on 7Li nucleus the cluster folding-model is used for calculation of interaction potentials. Earlier it was successfully applied for calculation of α9Ве elastic scattering at 6 7 Еα = 50 MeV [1], and also for elastic scattering of α-particles on Li and Li isotopes [2]. At construction of n7Li-potential the nucleus 7Li was being considered in the simple αt-model [3], which well reproduces all characteristics of the nucleus. In this case interaction of projectile neutron with constituents of 7Li nucleus – α-particle and triton – was averaged by the wave functions of 7Li nucleus. For nα- and nt-potentials the central potential was used, and this potential takes into account the splitting by orbital momentum parity, and the spin-orbital interaction was added to it. The parameters were chosen to find the corresponding elastic phase shifts. With the obtained n7Li-potential there were carried out calculations of elastic scattering of neutrons at En = 3.35 and 4.83 MeV, for which more or less hopeful experimental date are available [4]. A comparison with the experiment points to the important role of account of spin-orbital potential. 1. M.A.Zhusupov, S.K.Sakhiyev, Sh.Sh.Sagindykov // Bull. Russ. Acad. Sci. Physics. 2000. V.64. №1. P.127. 2. N.A.Burkova, M.A.Zhusupov, R.S.Kabatayeva // Bull. Russ. Acad. Sci. Physics. 2012. V.76. №4. P.506. 3. S.B.Dubovichenko, M.A.Zhusupov // Phys. At. Nucl. 1984. V.39. №6. P.1378. 4. J.C.Hopkins, D.M.Drake, H.Conde // Nucl.Phys. A. 1968. V.107. No.1. P.139. 203 CALCULATION OF SCATTERING LENGTH FOR NUCLEAR THREE-BODY PROBLEM USING HYPERSPHERICAL BASIS EXPANSIONS V.I. Kovalchuk Taras Shevchenko National University of Kiev, Ukraine E-mail: [email protected] The equation that describes continuum spectrum for the system of three spinless particles [1] has been investigated and solved for the case of d-α scattering. The corresponding S-wave phase shifts are shown in the Fig. 1. Fig. 1. S-wave phase shifts as a function of alpha-particle energy, Eα. PSA data are designated: ● – from [2], Δ – from [3]. Theoretical curves are calculated using such a αN-potentials: Grinyuk-Simenog [4] (dash curve), Satchler [5] (dash-dot curve), and Sack-Biedenharn-Breit [6] (dot curve). Solid curve is taken from [7]. The best fitting, as seen from Fig. 1, achieved for the Grinyuk-Simenog αN-potential. It have been calculated the S-wave scattering lengths, there are 1.242 fm (Grinyuk-Simenog potential), 3.202 fm (Satchler potential), and 2.830 fm (Sack-Biedenharn-Breit potential). 1. V.I.Kovalchuk et al. // Phys. At. Nucl. 2011. V.74. P.693. 2. E.V.Kuznetsova, V.I.Kukulin // Phys. At. Nucl. 1997. V.60. P.528. 3. B.Jenny et al. // Nucl. Phys. A. 1983. V.397. P.61. 4. B.E.Grinyuk, I.V.Simenog // Phys. At. Nucl. 2009. V.72. P.10. 5. G.R.Satchler et al. // Nucl. Phys. A. 1968. V.112. P.1. 6. S.Sack et al. // Phys. Rev. 1954. V.93. P.391. 7. V.I.Kukulin et al. // Phys. Rev. C. 1998. V.57. P.2462. 204 ENERGY DEPENDENCE OF (P–Ay) SPIN OBSERVABLES IN ( pp, ′ ) SCATTERING AND KNOCK-ON EXCHANGE TREATMENT A.V. Plavko1, M.S. Onegin2, V.I. Kudriashov3 1 St. Petersburg State Polytechnic University, Russia; 2 Petresburg Nuclear Physics Institute, Gatchina, Russia; 3 St. Petersburg State University, Russia E-mail: [email protected] The discrepancy of the values of the (P–Ay) observables obtained in the + 12 ( pp, ′) scattering at a variety of energies Ep for the excited 1 , T=1 state in C is pointed out in [1]. To achieve a better understanding of it, we have analyzed a whole region of the so-called energy window for the nuclear structure: from ~100 MeV to 500 MeV (Fig. 1). Our detailed presentation makes it more evident, than in [1], that the algebraic values of (P–Ay), near their pronounced extremes, decrease in magnitude with increasing beam energy. In [1] an assumption is made that (P–Ay) is driven primarily by tensor exchange contributions. It could be based on the fact that such contributions are expected to become less important at higher Ep and more significant at lower energies. The nonzero values of (P–Ay) can be attributed to the nonlocal or exchange nature of NN interaction. As is shown in [3], the exchange terms arise from the tensor force. The above assertions can be confirmed by the evidence that in our description of (P–Ay) (Part A in Fig. 1), we had to make exact finite-range calculations, using the DWBA 91 program of Raynal at lower energies (as we did in our other abstract in the present book). As for higher Ep of 400 and 500 MeV (Part B in Fig. 1), the zero-range treatment of knock-on exchange in LEA of Kelly appeared to be more adequate, or at least sufficient. The Cohen–Kurath shell-model wave functions adjusted to reproduce the available electromagnetic data have been employed for all our microscopic calculations of the (,pp ′ )− scattering. This made it possible to extract effective radial dependences of particle, spin, spin-orbit, and current transition densities for the 1+, T=1 state in the 12C nucleus to further understand its structure. Studies of the energy dependence of (P–Ay) data may provide a better insight of the nonlocality (or velocity dependence) of the effective coupling between projectile and target nucleons. 1. A.K.Opper et al. // Phys. Rev. 2001. C. V.63. 034614. 2. K.Hosono et al. // Supl. to Jour. Sos. of Japan. 1986. V.55. P.618. 3. T.A.Carey et al. // Phys. Rev. Lett. 1982. V.49. P.266. 4. S.P.Wells et al. // Phys. Rev. 1995. C. V.52. P.2559. 5. K.H.Hicks et al. // Phys. Lett. B. 1988. V.201. P.29. 6. X.Y.Chen et al. // Phys. Rev. 1991. C. V.44. P.1991. 7. K.W.Jones et al. // Phys. Rev. 1994. C. V.50. P.1982. 205 12 + A) C 1 T=1 B) 12C 1+ T=1 DWBA91, Geramb, g-matrix exp., Ep=400 MeV 1,5 exp., Ep=200 MeV 0,6 exp., Ep=500 MeV exp., Ep=200 MeV LEA, Geramb, g-matrix 1 0,4 0,2 0,5 y y 0 P-A 0 P-A -0,2 -0,5 -0,4 -1 -0,6 0 10 20 30 40 0 0,5 1 1,5 2 2,5 ο -1 Θ c.m. q, fm DWBA91, Geramb, g-matrix exp., Ep=398 MeV 1,5 exp., Ep=150 MeV 0,8 LEA, Geramb, g-matrix 1 0,4 0,5 y y 0 A 0 P-A -0,4 -0,5 -1 -0,8 0 10 20 30 40 50 0 0,5 1 1,5 2 2,5 o -1 Θ c.m. q, fm exp., Ep=80 MeV exp., Ep=398 MeV DWBA91, 120 MeV 1,5 10 LEA, Geramb, g-matrix 1 1 , mb/sr Ω 0,5 d 0,1 σ/ d y 0 0,01 P-A -0,5 0,001 -1 0,0001 0 10 20 30 40 50 0 0,5 1 1,5 2 2,5 o -1 Θ c.m. q, fm Fig.1. The experimental data (dots) we have systematized are as follows. Part A: proton energies are 80 [2], 150 [3], 200 MeV (• from [1], ∆ from [4]). Part B: for the (P–Ay) data, proton energies are 400 [5], and 500 MeV [6]; for the Ay and dσ/dΩ, data, proton energy is 398 MeV [7]. The curves represent our calculations. In Part B we also show the description of the cross sections dσ/dΩ and the analyzing power Ay, with the same distortions, the same type of the effective interaction (von Geramb, g-matrix) and the same wave functions (Cohen– Kurath), as in the description of the (P–Ay) data at 400 MeV. The case of (P–Ay) at 80 MeV is analyzed in detail in our other abstract (present book, p.207). 206 EXCHANGE APPROXIMATIONS IN THE CALCULATIONS OF THE ( pp, ′) SCATTERING USING THE DWBA 91 AND LEA PROGRAMS AT ENERGIES NEAR 100 MeV A.V. Plavko1, M.S. Onegin2, V.I. Kudriashov3 1 St. Petersburg State Polytechnic University, Russia; 2 Petresburg Nuclear Physics Institute, Gatchina, Russia; 3 St. Petersburg State University, Russia E-mail: [email protected] To test exchange approximations, we have analyzed the ( pp, ′) scattering at energies Ep near 100 MeV, i.e., near the lowest limit of the so-called energy window for nuclear structure studies, where distortions are still relatively small and multistep processes are suppressed. One-step processes within the distorted- wave method are shown in Fig. 1– two types of curves calculated with the use of two programs: DWBA 91 of Raynal and LEA (linear expansion analysis) of Kelly. These programs differ from the point of view of their treatment of exchange processes. LEA uses the zero-range exchange approximation (ZREA), assuming that the knock-on exchange is dominated by momentum transfers, nearly equal to the incident momentum. As is seen in Fig. 1, ZREA cannot describe the difference between polarization and the analyzing power (P–Ay). Therefore, other treatment of exchange is required for the exited 1+, T=1 state in 12C. The use of a more accurate finite-range program such as DWBA 91 for the exchange part of the scattering gives good agreement with the experimental data from [1], as is seen in Fig. 1, at least for the (P–Ay) observables. In the case of the differential cross section, two types of exchange approximations are practically indistinguishable. Though both descriptions are not very satisfactory here, we have achieved a significantly better agreement between the experimental data for the cross section at 120 MeV (not shown) and the same parameter set of the effective interaction of von Geramb. However, in the description of the Ay data at both 80 and 120 MeV, these parameters are quite acceptable (not shown). 12 + exp., Ep=80 MeV C 1 T=1 DWBA, 120 MeV 1,5 1 10 LEA, 120 MeV 1 0,5 b/sr ) m 1 y 0,5 Θ ), ( y 0 0,1 Θ 0 ( A P-A -0,5 -0,5 σ 0,01 -1 -1 0,001 0 10 20 30 40 50 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 o o ο Θ c.m. Θ c.m. Θ c.m. Fig.1. Angular distributions of the difference function (P–Ay), analyzing power (Ay), and differential cross section (σ) for the ( pp, ′) scattering to the 1+, T=1 state in 12C. 1. K.Hosono et al. // Suppl. to Jour. of Phys. Sos. of Japan. 1986. V.55. P.618. 207 THE INFLUENCE OF THE ELASTIC AND INELASTIC CLUSTER TRANSFER ON THE ELASTIC SCATTERING OF 16O+12C AND 16O+16O K.A. Gridnev, N.A. Maltsev, N.V. Leshakova Saint Petersburg State University, Russia E-mail: [email protected] The aim of this work was the description of the elastic scattering reactions 12C(16O, 16O)12C and 16O(16O, 16O)16O and the analysis of the influence of elastic and inelastic cluster transfer channels on the elastic cross-section. It is known, that for the certain reactions the particle transfer gives the sizeable contribution to the backward hemisphere. At the same time, the study of the inelastic transfer channels is important because, for example, actually the pick-up process of an α-particle from 16O gives the first excited state (2+, E=4.44 MeV) of 12C with a strength, which is four times stronger than the ground state [1]. Within the framework of the model, the elastic and inelastic transfer channels have been calculated with code Fresco [2]. Fig. 1 shows the experimental elastic cross-section and the theoretical elastic cross-section with and without elastic α-cluster transfer. Apparently, that the elastic cross-section with the inclusion of the elastic α-cluster transfer term well reproduces the angles greater than 140 degrees. On the other hand, it is known that, the peak of the transfer cross-section depend on the angular momentum of the transfer cluster. Then pick-up process of an α-particle from 16O with the formation of the first excited state (2+, E=4.44 MeV) of 12C will probably give a contribution to the range of angles which does not describe with elastic α-cluster transfer. 12 16 16 12 Fig 1. Angular distribution of the elastic scattering C( O, O) C at Elab=181MeV: dots – experimental data, dashed line – without elastic α - cluster transfer; solid line – with elastic α - cluster transfer. 1. S.Szilner, W.von Oertzen, Z.Basrak et al. // Eur. Phys. J. A. 2010. V.13. No.3. P. 273. 2. I.J.Thompson // Comput. Phys. Rep. 1988. V.7. P.167. 208 CORE EXCHANGE AND 16O+12C ELASTIC SCATTERING S.N. Fadeev, K.A. Gridnev, N.A. Maltsev St. Petersburg State University, Russia E-mail: [email protected] For the scattering of light nuclei, cluster exchange might be of great importance leading for instance to enhancement at backward angles in the elastic angular distribution. In [1, 2] the influence of α-cluster transfer on angular distributions was examined for 16O+12C scattering. The DWBA method was used for the calculation of the transfer amplitude. In this work we consider alternative mechanism to take into account exchange of clusters: exchange of 12C core between nuclei. Possible types of the exchange are presented on Fig. 1. The wave function of 16O in cluster representation is given by 1/2 ϕ16 O =Syαα ϕϕC ()r . The contributions of exchanges (a) and (b) are defined by nonlocal potentials ˆ *3 Vua (r )= Sα ∫ y ( γ ((1 −ν )rr + '))VCC ( γν ( rr − '))y ( γ ((1 −ν ) r ' + r ))u ( r ') dr ' , ˆ *3 VubC(r )= Sαα∫ y ( γ ((1 −ν )rr + '))V ( γ ((1 −ν )rr + '))y ( γ ((1 −ν ) rr ' + ))u ( r ') d r ' 2 ν=mmmαα/ ( +C ), γ= 1 / (1 − (1 −ν ) ) . The potential corresponding to (c) is similar ˆ to Vb . The core-core potential VCC depends on − rr ', as a consequence, ˆ equivalent local potential for Va doesn’t depend on parity (Wigner type ˆ potential) [3]. In expression for Vb the α-core potential Vα C depends on sum + rr ' as result the equivalent local potential depends on parity (-1)l (Majorana- type potential). ˆ ˆ The expressions for Va , Vb give a possibility to determine α-spectroscopic factor Sα from the analysis of elastic scattering angular distributions by adding the exchange potentials to the local potential of optical model. Fig.1. Various types of core exchange. Wavy line represents interaction between clusters, loop – core exchange. 1. K.A.Gridnev, E.E.Rodionova, S.N.Fadeev // Phys. At. Nucl. 2008. V.71. P.1262. 2. Sh.Hamada et al. // Nucl. Phys. A. 2011. V.859. P.29. 3. H.Horiuchi // Prog. Theor. Phys. 1980. V.64. P.184. 209 FEW-NUCLEON TRANSFERS AND WEAKLY-DISSIPATIVE PROCESSES IN GRAZING-MODEL OF LOW-ENERGY NUCLEAR REACTIONS V.V. Samarin Joint Institute for Nuclear Research, Dubna, Moscow region, Russia E-mail: [email protected] At enough large spacing distances smin between surfaces of colliding atomic nuclei probabilities of nucleons transfers and collective excitations are small. This allows to use the approximated approaches (perturbation theory, linear parts of decomposing in series, trial-and-error models etc.). Designed by A.Winther [1,2] model of few nucleons transfers processes with a small dissipation of energy responds conditions of large and intermediate values smin . This model is realised in the GRAZING code [3], which accessible on the Internet-server NRV, JINR [4]. For low-energy reactions, including of representative set of nuclei, the satisfactory similarity with experimental data (see Fig. 1) is obtained by variation of some parameters, mainly, of parameter of nucleon levels density near to a Fermi level. a b Fig. 1. Total cross sections for pure neutron pick-up (a) and one-proton stripping (b) 40 96 channels at Ca + Zr reaction for Elab=152 MeV. The triangles are the experimental data [5] and the circles are the calculation performed with the code GRAZING by selection of density of nucleon levels near to a Fermi level. This work was supported in part by the Russian Foundation for Basic Research (RFBR) through Grant No 11-07-00583-а. 1. A.Winther. // Nucl. Phys. A. 1995. V.594. P.203. 2. A.Winther // Nucl. Phys. A. 1994. V.572. P.191. 3. http://personalpages.to.infn.it/~nanni/grazing/. 4. http://nrv.jinr.ru/nrv/. 5. S.Szilner et al. // Phys Rev. C. 2007. V.76. 024604. 210 TIME-DEPENDENT QUANTUM DESCRIPTION OF FEW NUCLEONS TRANSFERS AT NUCLEAR REACTIONS 40Са + 96Zr, 40Са + 208Pb, 90Zr + 208Pb K.V. Samarin Chuvash State University, Cheboksary, Russia E-mail: [email protected] Time-dependent Schrödinger equations is numerically solved by difference method [1, 2] for external nucleons of spherical nuclei 40Са, 96Zr, 208Pb at their grazing collisions for energies near to a Coulomb barrier. The probabilities of transfer of neutrons (Fig. 1 a, b) and protons (Fig. 1 b) are determined as function on minimum internuclear distances rm , quantum numbers of initial nucleons states and module Ω of nucleon moment projection on an internuclear axis at closed approach of nuclei . It is found, that the transfers of nucleons with small values Ω=1 2, 3 2 are most probable. a b Fig. 1. Probabilities of neutrons pick-up by a nucleus Са from different external shells of a nucleus Pb in reaction 40Са + 208Pb (a), neutrons pick-up by a nucleus Са (solid lines) and protons stripping from nucleus Са (dashed lines) in reaction 40Са + 96Zr (b) as function on minimum nuclear distance rm and quantum numbers nlj, , of initial nucleones states. 1. V.V.Samarin, K.V.Samarin // Bull. Russ. Acad. Sci. Phys. 2010. V.74. P.567. 2. V.V.Samarin, K.V.Samarin // Bull. Russ. Acad. Sci. Phys. 2011. V.75. P.964. 211 MC ESTIMATION OF DANSS SENSITIVITY TO THE NEUTRINO OSCILLATIONS M.V. Fomina, I.V. Zhitnikov, Yu.A. Shitov Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] Possibility of the DANSS detector application to searching for the short- range antineutrino oscillations is considered. Monte Carlo simulations of these oscillations at the distance of 1-25 meters from the WWER 1000 reactor core are presented. Influence of the reactor size and burning distribution, as well as the detector energy resolution on the final effect is investigated. In order to check the MC predictions, a “pilot” version of the detector (DANSSino) has been made. Results of the tests performed in the laboratory with radioactive sources, as well as at the reactor site with the real neutrino flux, are presented. 212 TECHNIQUE AND METHODS OF EXPERIMENT AND APPLICATIONS OF NUCLEAR-PHYSICAL METHODS ENHANCEMENT OF DOSE FIELD DURING RADIATIVE EXPOSURE OF HETEROGENEOUS BIOLOGICAL SUBSTANCE WITH NANOPARTICLES I.S. Batkin1, M.A. Dolgopolov2, I.V. Kopytin2 1 Ottawa University, Canada; 2 Voronezh State University, Russia E-mail: [email protected] It has been shown before for radiotherapy that in general a possibility for the radiation amplification effect of a dose field due to the presence of nanoparticles into a biological medium [1, 2]. The model in which the calculation of dose field characteristics is performed supposed that a biological substance is homogeneous and there selected a zone of specified shape (of a cylinder form for example) evenly filled with nanopaticles. The enhancement coefficient for the dose field depended on the charging number of atoms in the nanoparticle structure and for example it is three times increased for the nanopaticles containing platinum atoms. In this paper a physical model of a forming process of dose fields in a biological substance with a heterogeneous distribution of nanoparticles is developed. The model allows the defining of spatial dependence of the radiation exposure enhancement coefficient. The method of statistical simulation and the elementary quantum processes of the ionizing radiation interaction with the substance are used in the model. Besides the radiative transport process by the characteristic photon cascade occurring owing to the photo effect on atoms from the nanoparticle structure is taken into consideration. Linear, Gaussian and Fermi functions are used for the description of the nanoparticle heterogeneous distribution form in the biological substance. The modeling is performed with the magnetite, argentums and platinum nanoparticles. The maximum mass concentration of the nanopaticles in the biological substance does not exceed 1%. Spatial distributions of an absorbed energy are obtained. We conclude that the forms of the nanoparticle distribution in the substance and the absorbed energy are noticeably different. This result is explained by the nonlocal behavior of the radiation absorption in the substance. The zones where the enhancement coefficient is more than 2 are determined. 1. I.S.Batkin et al. // LX international conference on nuclear physics “Nucleus 2010”. July 6-9, 2010, Saint-Petersburg, Russia. Book of abstracts. P.428. 2. M.A.Dolgopolov et al. // Proceedings of Voronezh State University. Series: Physics. Mathematics. 2011. №1. P.5. 213 TRANSFORMATION OF HARD X-RAYS IRRADIATION INTO CHARACTERISTIC IRRADIATION IN BIOLOGICAL SUBSTANCE WITH HEAVY NANOPARTICLES I.S. Batkin1, M.A. Dolgopolov2, I.V. Kopytin2 1 Ottawa University, Ottawa, Canada; 2 Voronezh State University, Russia E-mail: [email protected] We have shown before [1, 2] that the efficiency of photons absorption of an external irradiation is considerably enlarged in biological medium with nanoparticles. The effect is caused by a sharp dependence of cross section of a nuclear photo effect on the charging number of atoms in the structure of the nanoparticles. Accordingly, the intensity of characteristic radiation which is directly bound to the quantity of photoelectrons from the atoms of the nanoparticles will increase. Such transformation of an initial radiative irradiation into a softer characteristic of it opens a new possibility for a dose field formation within a biological object. Taking into account the dose field formation problem the yield of a characteristic X-ray radiation from the nanoparticles is solved by the method of statistical simulation with regards of the quantum processes accompanying propagation of radiation in the substance. It is supposed in the model that the irradiated area is a soft biological tissue into which an up to 2 mm thick nanopartcle layer is introduced. The cascades of characteristic radiation from all atomic shells of elements from nanoparticle structure are considered. The nanoparticles from Ag atoms or FePt particles are surveyed. A spatial distribution of the absorbed energy in soft biological tissues behind a nanoparticle layer is investigated. The energy of initial radiative irradiation and the thickness of the layer are varied parameters. It is shown that the absorbed dose created by 1 mm deep characteristic radiation exceeds the dose created by primary radiation at least by 30 % for nanoparticles from Ag atoms and from FePt particles. Thus, the transformation of the initial hard X-ray radiation into characteristic radiation within the nanoparticle layer applied on a tissue surface frames a basic possibility for intensification of radiative influence on the area near surface. The irradiative load on healthy tissues simultaneously decreases. 1. I.S.Batkin et al. // LX international conference on nuclear physics “Nucleus 2010”. July 6-9, 2010, Saint-Petersburg, Russia. Book of abstracts. P.428. 2. M.A.Dolgopolov et al. // Proceedings of Voronezh State University. Series: Physics. Mathematics. 2011. №1. P.5. 214 ACOUSTIC PRESSURE TEMPERATURE DEPENDENCE OF HEAVY CHARGED PARTICLE RADIATION MOVING IN CONDENSED MEDIUM A.N. Almaliev1, I.S. Batkin2, M.A. Dolgopolov1, I.V. Kopytin1, P.V. Lukin1, T.A. Churakova1 1 Voronezh State University, Russia; 2 Ottawa University, Canada E-mail: [email protected] In the proton therapy long-term session the heating of the biological tissue which is irradiated by a proton beam takes place. It is known that the medium parameters such as the coefficient of volumetric expansion β, specific heat capacity Cp and sound velocity c depend on the temperature of the medium [1-3]. These characteristics of the medium enter the heterogeneous wave equation ∂22p cQβ∂ −2 ∆= 2 cp , (1) ∂t Ctp ∂ which describes the sound thermal-radiation generation by the heavy charged particle moving in the condensed medium. In Eq. (1) p is an acoustic pressure, a quantity Q. is a penetrating radiation energy release [4]. At present the experimental investigation accuracy is such that the temperature dependence of the acoustic signal amplitude from the 200 MeV energy proton motion in water may be measured (see [2], e.g.). In this paper an acoustic pressure is calculated (see Eq. (1)). The temperature dependences of sound velocity, specific heat capacity and the volumetric expansion coefficient are taken into account. The 200 MeV energy proton motion in water is considered. It is shown that the acoustic pressure quantity is varied within the range of 10% if the temperature of the medium is changed by 1° K. This result accuracy allows carrying out the experimental verification of the theory. 1. I.M.Hallaj et al. // J. Acoust. Soc. Am. 2001. V.109. Pt.1. P.2245. 2. V.I.Albul et al. // Instr. and Exper. Techniques. 2004. V.47. P.507. 3. K.Graf et al. // Int. J. Mod. Phys. A. 2006. V.21S1. P.127. 4. L.M.Lyamshev // Advances in Physical Sciences. 1992. V.162. P.43. 215 POSSIBLE MECHANISM OF ABSORBED RADIATION DOSE ADJUSTMENT AT PROTON RADIATION THERAPY A.N. Almaliev1, I.S. Batkin2, M.A. Dolgopolov1, I.V. Kopytin1, P.V. Lukin1, T.A. Churakova1 1 Voronezh State University, Russia; 2 Ottawa University, Canada E-mail: [email protected] A beam collimation and energy release in the assigned range are open problems of the proton therapy. The detection of the ultrasonics which is generated by a proton motion owing to the thermal-radiation mechanism [1] is the possible way of the solution of the problem. In this paper the method of the radiation dose decrease which the tissue around the target obtains is suggested. It consists of a preliminary calibration of the system by the low power impulses. Before every insertion of the main proton beam (this is a therapeutic impulse) the device generates a weak impulse. Its intensity must be far less compared to the medical impulse. This is a guidance procedure. It is supposed that the acoustic response amplitude from such a “test” impulse must be more than the minimal amplitude of the signal which the ultrasonic detector can record. A weak proton beam emission must be performed for some time until the device aims exactly at the target. It is usually an object measured by a few millimeters. After that the main proton beam is injected into a biological tissue. It is proposed that the relative positions of the proton source and tissue radiated segment are not changed for a short time interval between the generations of the final “test” impulse and radiating one. At the same time between the therapeutic impulses the displacements of the target or the device can take place. Our calculations demonstrate that modern hydrophones can record an acoustic wave from the proton beam which carries in the dose three orders of magnitude less than the therapeutic dose. Such a proton beam is not able to do a significant harm to the biological tissue. In addition one proton can not destroy a living cell because the linear energy transfer coefficient for the light nuclei is small. 1. A.N.Almaliev et al. // 61 Intern. Conf. «Nucleus-2011» on Problems of Nucl. Spectrosc. and Structure of Atom. Nucl. Abstr. 10-14 October, 2011. Sarov. P.186. 216 INFLUENCE OF PHOTONUCLEAR REACTIONS PRODUCTS ON BIOLOGICAL EFFICIENCY OF PHOTON AT THE THIN LAYERS IRRADIATION A.V. Belousov, A.S. Osipov, A.P. Chernyaev Lomonosov Moscow State University, Physics Department, Russia E-mail: [email protected] The considerable quantity of secondary particles is formed at passage photon radiation through a biological matter, their type an energy spectrum defined by photons energy and matter characteristics. Biological action is characterized by experiments measured value of relative biological effectiveness (RBE). Experimental values are defined at thin layers of cultures irradiation by a wide beam photons. The thickness of irradiated objects is so small, that it is possible to neglect interaction of scattering components with matter of a layer and to consider, that all photons have single interaction in a layer or do not have it at all. Under these conditions, the formed absorbed dose in the big degree can be defined by the heavy charged particles having high value of quality factor (QF). QF there is the regulated value of RBE established on the basis of experimental data. The purpose of the present work is the estimation of energy dependence of average QF of the protons formed as a result of photonuclear reactions and average QF mixed radiation induced at passage through thin layers of biological matter photon radiation. Absorbed dose Dγ, caused by passage of primary photon radiation, can be presented in the form of the sum of components Dl, the caused particles type l: the heavy charged particles, neutrons and the nuclear recoil resulting photonuclear reactions; electronic and secondary photon components — DDγ = ∑ l . The equivalent dose H formed in matter by mixed radiation, is l defined as the sum of equivalent doses of various kinds of radiation l, having quality factor wl and creating absorbed dose Dl: H= ∑ wDll. The average factor l of quality of mixed radiation KK can be defined as KK= ∑∑ wll D D l. ll The model is developed, allowing to estimate average value of protons formed as a result of photonuclear reactions at passage of photon radiation through thin layers of biological environments QF and average value QF of mixed radiation induced by photons. At a thickness of an irradiated layer of 1 mm biological action of bremsstrahlung and the mixed radiation induced by it including products of photonuclear reactions, described in terms QF, reaches values 1.45 at end-point energy 30 MeV. Estimations QF strongly depend on a thickness of a layer and its element structure and, less considerably, from the form of bremsstrahlung spectrum. Presence of QF dependence from a thickness of an irradiated layer can explain distinction in RBE value at experiments on an irradiation of identical cultures of cells. 217 DETERMINATION OF KERMA IN BIOLOGICAL TISSUE IRRADIATED BY NEUTRON BEAM OF WWR-SM REACTOR G.A. Abdullaeva, Yu.N. Koblik, G.A. Kulabdullaev, K. Belasarov, Sh. Saytjanov Institute of Nuclear Physics Uz AS, Tashkent, Uzbekistan E-mail: [email protected] At the horizontal channel of WWR-SM reactor of Uz AS authors create the beam of epithermal neutrons for development of neutron capture therapy (NCT) method [1]. About the spectral characteristics of beam calculated with use MCNP 4C code [2] and results of their measurements it was informed in [3]. The experimental data of neutron flux measurements on channel exit have al- lowed determining neutron kerma for a biological tissue. For neutron kerma cal- culations the method from [4] was used. Calculations by definition of neutron 16 12 1 kerma factor — k(En) for a biological tissue ( O – 70.8%; C – 14.3%; H – 10.2%; 14N –3.4%; 31P – 0.3%; S – 0.3%, Cl – 0.2%) depending from energy in the range from thermal neutrons to 20 MeV are executed. Dependence k(En) is obtained with use of nuclear physical databases ICRU 63 and JENDL-3.2 [5-6] and presented at figure. 1E-10 /n 2 1E-11 1E-12 k, Gr cm 1E-13 1E-14 1E-15 1H 12 1E-16 C 14N 1E-17 16O 1E-18 31P S (nat.) 1E-19 Cl (nat.) 1E-20 biological tissue 1E-10 1E-9 1E-8 1E-7 1E-6 1E-5 1E-4 1E-3 0.01 0.1 1 10 E, MeV Using the obtained dependence k(En) and data of neutron flux measurements integration within an experimental spectrum of neutrons is executed. Neutron kerma value K=8.11×10–5 Gr/sec for biological tissue irradiated by epithermal neutron beam of specialized reactor horizontal channel was calculated. 1. G.A.Abdullaeva et al. // Bull. of the Rus. Acad. of Sci. Physics. 2009. V.73. P.512. 2. J.F.Briestmeister // CCC-700 MCNP4C. 2000. 3. G.A.Abdullaeva et al. // 2010. ISBN 978987-1323-19-7. P.421. 4. A.F.Tsyb et al. // MRRC RAMS, Obninsk. 2003. 5. ICRU 63. Bethesda, 2000. 6. JENDL-3.2 // J. Nucl. Sci. Technol. 1995. V.32. P.1259. 218 INVESTIGATIONS AND DEVELOPMENT OF THE SUPPRESSION METHODS OF THE BACKGROUND IN THE LArGe LOW-BACKGROUND TEST FACILITY FOR THE GERDA EXPERIMENT A.V. Lubashevskiy1,2 on the behalf of the GERDA collaboration 1 Max-Plank-Institut fur Kernphysik, Heidelberg, Germany; 2 Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] In Phase-I of the GERDA experiment [1] liquid argon is used as a passive shield only. For the next phases of GERDA additional methods of further reduction of background are required. LArGe test facility operates bare germanium detectors submersed into liquid argon (1m3, 1.4 tons), which in addition is instrumented with photomultipliers to detect argon scintillation light. The main goal of the LArGe is development of methods aimed to reduce background of Ge detectors by using anticoincidence with LAr scintillation signals. Another goal of LArGe is to develop and test methods of pulse shape discrimination (PSD) with naked semi-coaxial HPGe detectors immersed in liquid argon as well as with a new type of Ge detectors (BEGe Broad Energy Germanium detector) which are planned to use in Phase-II of the GERDA experiment. First results of the GERDA commissioning runs showed the need to study concentration and volume distribution of the cosmogenic isotope 42Ar and its daughter 42K in liquid argon. This task was also under the thorough investigation in LArGe. Well-known activity of 42Ar was produced in 40Ar(7Li, p)42Ar reactions and the sample with activity (5.2 ± 0.9) Bq was transferred into the LArGe cryostat. Measurements were performed with semi- coaxial HPGe detector completely encapsulated with three layers of PTFE/copper/PTFE. It is possible to apply HV from –3000 V to +3000 V in order to attract/repel of the 42K ions to/from the detector. Intensity of the 1525 keV line depending on voltages applied on copper surface of encapsulation from –3000 V to +3000 V in time has been studied. The results of measurements are compared to 3-D simulations of the electric field together with ion drift calculations and simulations for the detection efficiency of the 1525 keV gammas. After that naked BEGe detector was immersed into LArGe aimed to investigate surface events induced by 42K beta decay nearby the detector and their suppression efficiency by PMT veto together with PSD. 1. GERDA collaboration, I.Abt et al. // Letter of Intent (2004), hep-ex/0404039v1. 219 RADON IN LSM UNDERGROUND LABORATORY E.A. Yakushev1, V.B. Brudanin1, D.V. Filosofov1, A.V. Lubashevskiy1, S.V. Rozov1, S.S. Semikh1 1 Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] Noble radioactive gas radon due to its very high mobility together with exceptional penetration power represents a real danger for all low background experiments. The talk represents radon problem in LSM deep underground laboratory [1], place of world leading experiments for direct dark matter search (EDELWEISS) and search for neutrinoless double beta decay (NEMO 2,3, SuperNEMO, TGV). Approach to reduction of radon level in the laboratory is based on 1) ventilation of the laboratory with clean air taken outside of the mountains with several volume exchanges per hour; 2) using anti-radon factory [2] for further reduction of radon in air supply to experiments. In reported here study we performed measurements of radon level in air on all it way to EDELWEISS experiment [3]. This detailed study has been performed with using high sensitive radon detector developed by JINR (Dubna) with sensitivity to 222Rn on a level 1 mBq/m3 of air [4]. In particular measurements were performed in the air intake place (Usine-B of Frejus road tunnel), in the pipe supplying clean air to LSM, in the main hall of LSM, in clean room of EDELWEISS experiment and finally inside of the shielding of EDELWEISS experiment. Received values for radon levels are tabulated below. Place of measurement Rn-222 level, Bq/m3 Air intake for LSM ventilation system 7÷13 Air supply pipe 8÷16 LSM main hall 10÷15 EDELWEISS clean room 5÷12 Inside of EDELWEISS shields <0.05 By this study it was found that the radon level in air of the LSM laboratory is completely defined by natural radon level in air supplied by the ventilation system (when this system is ON). Anti-radon factory is able to provide factor 100 and better for radon reduction for closed spaces inside of experiment’s shields. This work has been partly supported by RFBR (grants 11-02-00442 and 10-02-93105). 1. LSM laboratory web site // http://www.lsm.in2p3.fr. 2. R.Arnold et al. // NIM. A. 2005. V.536. P.79. 3. E.Armengaud et al. // Phys. Lett. B. 2011. V.702. P.329. 4. E.A.Yakushev, A.V.Lubashevskiy // Izvestiya.Vuzov. Fizika. 2010. V.53. P.67. 220 NUCLEAR REACTIONS ON Si AND Al INDUCED BY COSMIC PROTONS AND α-PARTICLES N.G. Chechenin, T.V. Chuvilskaya, A.G. Kadmenskii, A.A. Shirokova Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Russia E-mail: [email protected] The calculations of the products of the reactions induced by protons of energy region up to 100 MeV on isotope 28Si and Al were performed. The code TALYS was used for these purposes. This code has the possibility to calculate the cross sections and spectra of recoils of the products of the nuclear reactions with the number ejectails up to 13 for neutrons and 9 for protons. As a test of the code the reaction induced by protons on the natural Fe was used. Early by us calculations by code EMPIRE were carried out. The comparison of the obtained results was performed. The preliminary results for the reaction 28 Si(α, xn, yp) at Eα energy region up to 100 MeV are presented. The given results are important taken into account the interaction of the cosmic rays with the materials of the border electronic. 221 RADIATION-TECHNOLOGICAL PROCESSES BASED ON LOW-ENERGY RADIATION IN PRODUCTION OF PRODUCTS WITH STRUCTURE “METAL-OXIDE-SEMICONDUCTOR” V. R . Gitlin Voronezh State University, Russia Е-mail: [email protected] Radiation-technological processes (RTP) of the precision adjustment of the threshold voltages of MOS transistors using soft X-ray (≤ 20 keV) and UV of near range (≤ 6 eV) radiation are developed. The possibility of realization of these processes is based on the formation of thermostable charge controlled by radiation in gate oxide containing phosphorus impurities. The results of the successful implementation of the technology based on the use of ionizing radiation in a full-scale production of serial MOS integrated circuits were summarized and had a major economic effect. To implement a set of precise methods of controlling the parameters of MOS structures associated with their geometry and the planar heterogeneity of the surface potential of the semiconductor has been developed automated measuring device. The meter is designed to develop RTP in new perspective development of ICs. A model of the structure of poli-Si-SiO2(P)-Si, taking into account the presence of intrinsic and extrinsic defects in the layer of SiO2(P) and surface states at the SiO2 (P)-Si, adequately describes the processes occurring in the MOS structures in the course of developed RTP. In view of complexity of the structure and technology of its formation, changes in the geometrical factors, the use of materials and layers with new electrophysical characteristics of the model is suitable for RTP description in the production of new advanced MOS. In view of complexity of the structure and technology of its formation, changes in the geometrical factors, the use of materials and layers with new electrophysical characteristics of the model, it is suitable for the description of RTP in the production of new advanced MOS ICs. The technique of radiation resistance of the MOS ICs prediction in the fields of low intensity ionizing radiation (cosmic radiation) is proposed, that is based on the analysis of response of structure poli-Si-SiO2(P)-Si to the effects of high dose rate radiation, and solving the system of equations describing the model proposed in the processes of accumulation of radioactive charge in the gate oxide structure and its relaxation due to tunneling and thermal emission. 1. V. R . Gitlin et al. // Microelectronics Reliability. 2001. V.41. №2. P.185. 2. М.Н.Левин и др. // Микроэлектроника. 2006. Т.35. №5. С.382. 3. М.Н.Левин и др. // Изв. РАН. Сер. Физ. 2009. Т.73. №2. С.264. 222 MATHEMATICAL SIMULATION OF RADIATION IMPACT ON NANOSTRUCTURES E.N. Voronina, L.S. Novikov Skobeltsyn Institute of Nuclear Physics Lomonosov Moscow State University, Russia E-mail: [email protected] In the near future various nanostructures (carbon and boron nitride nanoеtubes, graphene, graphene nanoribbons, etc.) will be widely used in spacecraft constructions both as separate materials and as fillers of composites [1, 2]. One of the main requirements for spacecraft materials is their resistance against the space radiation [3]. The data concerning the processes of the radiation damage in nanostructures and nanomaterials are quite limited. Radiation effects that occur under the influence of ionizing radiation in nanostructures and materials based on them have a number of features due to the primarily small quantity of energy transmitted by the incident particle, constraints of the displaced atom movement and efficient recombination of vacancies and displaced atoms in nanostructures. The features described above, in particular, explain high resistance of CNTs to the formation and accumulation of radiation defects. To this resistance also contributes the fact that most of the carbon atoms which are knocked out of the host hexagonal cells, leave the nanotube without interacting with other atoms. In this paper the analysis of various methods for mathematical simulation of radiation impact on nanostructures is given. The processes of radiation damage of nanotubes by particles of hot magnetosphere plasma with energies up to 200 eV and the migration of displaced atoms on the nanotubes surface were simulated with the density functional tight-binding (DFTB) method [3]. An example of the simulation of forming vacancies in a carbon nanotube is given on Fig. 1. 3 2 4 1 Fig. 1. Vacancy formation in a carbon nanotubes under the impact of an hydrogen atom: 1, 2 – vacancies formed in the nanotubes walls; 3, 4 – sputtered carbon atoms. 1. L.S.Novikov, V.N.Mileev, E.N.Voronina / AIP Conf. Proc. 9th International Conference on Protection of Materials and Structures From Space Environment, ICPMSE-9, Toronto, May 2008. Ed. J.IKleiman. New York, 2009. P.550. 2. Е.Н.Воронина и др. // Изв. РАН. Сер. физ. 2011. Т.75. С.1594. 3. L.S.Novikov et al. // Journal of Surface Investigation: X-Ray, Synchrotron and Neutron Techniques. 2009. V.3, P.199. 223 SIMULATION OF A RADIATION SHIELDING FOR THE MANNED MARS MISSION V.K. Grishin1, A.A. Kuznetsov2, K.A. Stopani2 1 Moscow State University, Russia; 2 D. V. Skobeltsyn Institute of Nuclear Physics, Moscow, Russia E-mail: [email protected] The negative impact of galactic cosmic rays is one of the concerns of manned interplanetary space missions. Atomic nuclei with kinetic energy of several GeV and greater have a high degree of penetrability; and their effect on biological tissues is not completely understood [1]. The main types of radiological shielding considered as possible designs for the Mars spacecraft are traditional passive shielding and active shielding based on deflection of cosmic ray particles by an artificial magnetic field. The results of passive shielding simulations were presented in the previous work [2]. The present work focuses on the efficiency of the active shielding. A system of superconducting coils was studied as a means of producing circular magnetic field. GEANT4 was used to calculate doses in a phantom behind the shielding. The figure shows the field dependence of equivalent (squares) and absorbed (circles) annual doses in the phantom. The comparison with previously made calculations [3] suggests that the production of secondary particles greatly influences the obtained doses. 1. F.A.Cucinotta, M.Durante // The Lancet Oncology. 2006. V.7. Iss.5. P.431. 2. V.K.Grishin et al. // LIX International Confenrence on Nuclear Physics “Nucleus 2009”. Book of Abstracts. P.323. 3. D.Kh.Morozov et al. // Some aspects of active shielding against the radiation in space. CERN-71-16 (Vol. 1 and 2), From International congress on protection against accelerator and space radiation; Geneva, Switzerland (26 Apr 1971). 224 PHOTOACTIVATION INFLUENCE ON CATALYTIC CHARACTERISTICS OF ZnO NANOPARTICLES DURING CONVERSION OF METHANOL N.P. Dikiy1, A.N. Dovbnya1, E.P. Medvedeva1, D.V. Medvedev1, D.S. Bakay1, Yu.V. Lyashko1, V.L. Uvarov1, I.D. Fedorets2, N.P. Khlapova2 1 NSC “Kharkov Institute Physics and Technology”, Ukraine; 2 V.N. Karazin Kharkov National University, Ukraine E-mail: [email protected] Transformation of rich carbon substances (natural gas, coal, and biomass) at the presence of catalysts in hydrocarbons is perspective process for wide use in the industry. The process of methanol transformation was investigated in the presence of ZnО nanoparticles (d = 40 nm) which were activated by bremsstrahlung with 65 66 65 Emax = 23 MeV. The decay Zn which obtained by reaction Zn(γ, n) Zn is accompanied by Auger electrons with Е = 0.92 keV (I = 126.7%) and 7.03 keV (I = 47.5%). Auger electrons have large linear energy transfer 10−27 keV/µm. Initial and γ−activated ZnO nanoparticles were investigated by method of X-ray diffraction. Character of an arrangement interference maxima, their width and intensity specified on high crystalline researched samples. Presence of the peaks of other ZnO phase or an impurity was not observed. That specifies high cleanliness of researched ZnO samples (99%). High concentration of 1 hydrated electrons, hydroxide • ZnO powder radicals (ОН ), Н2О2 and ZnO nanopowder, • irradiated radicals НО2 in order to the D ZnO powder, photochemical reactions are irradiated generated in consequence of 0,1 large linear energy transfer of Auger electrons on a surface of nanoparticles ZnО. These free 200 300 400 500 600 radical products intensify λ, nm formation of hydrocarbons out Fig. 1. Spectra absorption of products of conversion of methanol (diethyl ether, transformation methanol. olefins, propane). Catalysis transformations of methanol on activated ZnО nanoparticles were investigated by UV/Vis spectroscopy (Fig. 1) and by quantum-metric method with respect to residual compounds in methanol (dienes, λ = 200-245 nm; dimerized alkenyl carbenium ions, λ = 323 nm; monodienylic carbocations, λ = 360-370 nm; small aromatic cations, λ = 430 nm). Catalysis transformations of methanol on activated ZnО nanoparticles are as realization of chemical dimensional effect for utilization of methane out of coal mine. 225 PHOTONUCLEAR METHOD OF Cu-67 MANUFACTURE FOR NUCLEAR MEDICINE N.P. Dikiy, A.N. Dovbnya, M.A. Dolzhek, Yu.V. Lyashko, E.P. Medvedeva, D.V. Medvedev NSC “Kharkov Institute Physics and Technology”, Ukraine E-mail: [email protected] The isotope 67Cu allows carrying out therapy of many cancer diseases. The efficiently separation of 67Cu is achieved by using diantipyrylpropylmethane (DАPPМ). Experimental separation of 67Cu from sulphuric solution (1 mol./l) of zinc (2 mol./l) with addition potassium iodide (0.1 mol./l) is realized with help DAPPM (0.02 mol./l) which dissolve in chloroform. The 84.4% 67Сu was extracted from water phase of ZnSO4 into organic phase (solution DAPPM in chloroform). The 67Сu remainder in organic phase amount 4.6%. Table 1. № Yield 67 рН solution Part activity 65Zn Content Zn in re- Content Сu in test Сu, % re-extract in re-extract extract, µg/ml re-extract, µg/ml 1 0.7 2 < 2⋅10−4 20.8 0.0757 2 0.8 2.5 < 6⋅10−5 3.92 0.132 3 33.7 4.5 < 2⋅10−5 0.45 0.0052 4 39.0 5 < 2⋅10−5 0.05 0.0045 5* 5.6 7 < 2⋅10−5 − − 6** 4.6 − < 2⋅10−5 − − 5* - solution NaOH for quantitative re-extract, 6** - solution DAPPM in CHCl3 after re- extract Effective extraction of protonated forms of reagent and ionic associate of metal+halide was realized by means of antipyrin forms in acid halide solution. The decrease of acidity of a water phase is necessary for effective re-extraction. Re-extraction was fulfilled by consecutive washing of organic phase (DAPPM in chloroform) by distilled water. Some amount of ZnSO4 in process of extraction gets in an organic phase that causes a low level re-extraction in first two tests. These tests re-extraction have low values рН. Measurement of activity of initial solution ZnSO4, an organic phase and re- extraction tests was carried out with help Ge(Li)-detector of volume of 40 cm3 with the energy resolution 3.2 keV for line 1332 keV. Re-extraction 67Сu from solution DAPPM in chloroform is carried out consistently four times by distilled water (Table 1). The activity of 67Сu in third and fourth re-extraction tests was 72.7%. The fifth quantitatively re-extraction of 67Сu was carried out by means of caustic soda solution (рН=7) and its activity was 5.6% from initial activity 67Сu. 226 NON BOGOLUBOV CONFUSING OF SWIFT CHARGED PARTICLES IN A CRYSTAL. ANTICHANNELING A.G. Kadmenskii FGUP Central Research Institute of mashine building, Korolev, Moscow region E-mail: [email protected] The effective so-called continuous potential arising in cross-section space at special coherent dispersion of fast charged particles on a atomic string (АS) of a crystal with transfer to a lattice of an impulse, equal to zero, supposes generalisation on all crystal in the form of the additive sum of potentials of two-dimensional lattice АS. The model of carrying over of protons and ions in such crystal in a wide range of entry conditions taking into account coherent dispersion (with preservation of cross-section movement energy E⊥ ) and not coherent processes of scattering modified at its presence on electrons and nucleus of the atoms participating in thermal fluctuations of a lattice (proceeding with change as E⊥ , and full energy E of a particle), in particular, possible display of effects “antichanneling” (AC) [1] and the superdensity [2], the linear transmissions of energy connected with absolute maxima for protons and ions in crystals with excess of normal values is presented in 2. . 3 times observed in a range (1… 3)θcr outside of Lindhard’s critical angle θcr for axial channeling. In previous researches it was used for entry conditions of axial channeling [1, 2, 3]: Hamilton’s dynamics ( E⊥ , E – const) not relativistic protons in cross-section space for lattice AS has shown effects of stochastic dynamics [3, 4] types of dynamic chaos and separately regular movement (modes normal and double channeling — NC and DC, accordingly). Absence of attenuation of autocorrelation momentum function for DC has proved an inconsistency of known Lindhard’s hypothesis [5] about fast phase confusing — base of the existing statistical theory of channeling. The account for these modes of not coherent processes for protons with change E⊥ , E by their averaging on a trajectory in the field of continuous AS potential (in the form of universal functions from E⊥ , E and aim parameter of collision) has allowed to investigate features of these modes in a wide range of thickness up to particle stopping and to observe at computer simulation transitions between all revealed modes as examples of diffusion of Arnold. A number of the experimental facts which do not have the descriptions in statistical theory of channeling, in particular, effect AC on the basis of revealed heterogeneity of distributions of aim parameters in a crystal, and various for modes NC and DC has been explained. 1. N.G.Chechenin, A.G.Kadmenskii, M.I.Panasyuk, et al. // Int. Conf. on Swift Charged Particles Interactions with Crystals. Moscow, 27 May- 2 June, 2011. Abstracts. P.3. 2. A.L'Hoir, L.Adoui, F.Barrué, et al. // NIM. B. 2006. V.245. P.1. 3. A.G.Kadmenskii, V.V.Samarin, A.F.Tulinov // Physics of Particles and Nuclei. 2003. V.34. No.4. P.411. 4. A.G.Kadmenskii, A.F.Tulinov // Tech. Phys. Lett. 2004. V.30. No.7. P.541. 5. J.Lindhard // Kgl. Dan. Vid. Selsk. Mat.-Fys. Medd. 1965. No.14. 49 p. 227 RESEARCH BY METHOD POSITRON ANNIHILATION SPECTROSCOPY OF CONDENSED MATTER WITH ITS OWN RADIATION V.I. Grafutin, O.V. Ilyukhina, E.P. Prokopev NRC «Kurchatov Institute», FSBU «SNC RF – ITEP», Moscow, Russia E-mail: [email protected] The irradiation of condensed matter with its own radiation by positrons (e.g., radioactive substances, etc.) are negatively charged and neutral point or extended defects with sizes in the angstrom and nanometer range, which may serve as trapping centers of positrons and positronium atom [1]. This fact, as shown by experimental data and calculations are carried out by us, a profound impact on changes in the basic characteristics of positron annihilation spectra, allowing detection of these nanodefects in experiments and to study their influence on the properties of condensed matter with its own radiation [2]. It is known that positrons effectively probe the free volume of nano-objects with dimensions in the angstrom and nanometer ranges in metals and alloys, as well as in semiconductors. Of particular importance is the possibility of determining the size of nano-objects in condensed matter (materials) with its own radiation and materials irradiated with protons, neutrons, and α - particles. This requires comprehensive studies of the defect structure in these materials containing nanometer and angstrom cavity sizes (vacancies, vacancy clusters, pores) using different methods of positron annihilation spectroscopy. This allows us to establish links between the experimentally measured parameters and characteristics of the annihilation spectra nanodefects (type, size R , density N ) in these materials. The behavior of radiation nanodefects is very important. Performing such studies will contribute to the accumulation of fundamental knowledge of radiation damage in these materials, the development of theoretical models describing the properties and behavior of these defects. It is shown that one of the most effective methods for determining the average size of cylindrical and spherical nano-objects (the free volume of pores, cavities, voids, etc.), their average values R , N of concentration and chemical composition at the site of positron annihilation in defective materials (metals and alloys) is the method of positron annihilation spectroscopy [3]. This allows us to determine the average percentage of free space is formed in these environments during their operation. We discuss the idea of searching for 3 correlations between the values Vrad =(4 / 3) π RNand mechanical and other properties of such media (e.g., strength and brittleness of metals and alloys irradiated by neutrons, protons, and α - particles). 1. V.I.Grafutin I.N.Meshkov, E.P.Prokopev, et al. // Microelectronics. 2011. V.40. №6. P.428. 2. V.I.Grafutin, E.P.Prokopev, et al. // Nucl. Phys. 2011. V.74. №2. P.195. 3. http://www.portalus.ru/modules/science/data/files/prokopiev/Prokopev-pos- Report.doc. 228 STUDYING OF SUPRA-AТОMIC STRUCTURE OF THE REACTOR IRRADIATION ALUMINIUM ALLOYS BY SMALL-ANGLE NEUTRON SCATTERING TECHNIQUE V.M. Lebedev, V.T. Lebedev, S.P. Orlov Petersburg Nuclear Physics Institute, Gatchina, Russia E-mail: [email protected] Modern nuclear technologies need the advanced methods for investigation and examination of physics-chemistry properties of substance. The nondestructive small-angle neutron scattering technique creates new opportunities for studies of irradiated metals and alloys, composites, nanostructures and other materials. One of important problems it is the study of an ageing process of the reactor materials in the strong neutron and gamma fields. Aluminum alloys were used widely in atomic machine-building. The samples were irradiated in the WWR-M reactor of PNPI with fast neutrons at a fluency of 2×1021 neutron/cm2 at a temperature not higher then 60oC in of ~14 years. The supra-atomic structure of the CAВ-1 alloy (Al-Mg-Si) samples was studied on a MEMBRANA-2 diffractometer using small-angle neutron scattering (wavelength λ=0.3 nm and Δλ/λ=0.3). In the initial and irradiated samples, there are defects, namely, pores with a characteristic radius ~8 nm observed as individual pores and as clusters with the radii ~20 nm and ~40 nm. In irradiated sample the summary volume fraction of the defects increases by ~10%, and the total surface area of the defects increases by ~40 %. The irradiation decreases the volume fraction of coarse scattering regions with the radius ~40 nm and, along with this, increases the fraction of the scattering regions with the radius ~ 8 nm and ~20 nm, which is explained by fragmentation of the coarse regions. 229 NEW OTPC DETECTOR AT THE ACCULINNA SEPARATOR A.A. Bezbakh1, S.A. Baraeva1, A.S. Fomichev1, W. Dominik2, M.S. Golovkov1, A.V. Gorshkov1, L.V. Grigorenko1, V. Chudoba1, Z. Janas2, G. Kaminski1,3, S.A. Krupko1, C. Mazzochi2, S. Mianowski2, M. Pfützner2, M. Pomorski2, S.I. Sidorchuk1, R.S. Slepnev1, G.M. Ter-Akopian1, R. Wolski1 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Faculty of Physics, University of Warsaw, Poland; 3 Institute of Nuclear Physics PAN, Krakow, Poland E-mail: [email protected] The OTPC is a gaseous detector for charged particles allowing the reconstruction of particles' tracks in three dimensions [1]. It was developed at the Faculty of Physics, University of Warsaw in order to study rare decay channels of exotic nuclides in which emission of charged particles occurs. The first tests and research program of studying the exotic decays of nuclei far from stability were started at the ACCULINNA separator [http://aculina.jinr.ru/] in 2006. Later this detector was successfully used for a detailed study of the two-proton (2p) radioactivity of 45Fe [2], providing the first full correlation picture for protons emitted in such a decay. Recently, it served as the key instrument for the observation of rare decay branches of 8He* [3] and in the discovery of the 2p decay of 48Ni [4]. The principle of operation is based on the recording of optical signals by CCD camera representing the ionization tracks of charged particles emitted in the active gas volume. By combining a CCD camera image with the electron drift-time profile measured by a photomultiplier, it is possible to reconstruct trajectories of particles in three dimensions. The new OTCP detector is planned to build at ACCULINNA separator in FLNR, as a perspective device for further study of the radioactive decays of exotic nuclei. The main advantage of using the active target at the ACCULINNA facility is the possibility to use the hydrogen or deuterium as the gas target and the variety of light neutron-rich radioactive beams like 8He, 11Li, 15B and others. 1. K.Miernik et al. // Nucl. Instr. and Methods. A. 2007. V.581. P.194. 2. K.Miernik et al. // Phys. Rev. Lett. 2007. V.99. 192501. 3. S.Mianowski et al. // Acta Phys. Pol. B. 2010. V.41. P.449. 4. M.Pomorski et al. // Phys. Rev. C. 2011. V.83. 061303(R). 230 DETECTION OF LOW-INTENSITY GAMMA-NEUTRON FLUXES FROM STATIC AND DYNAMIC MULTIPLYING SYSTEMS BY POLYSTYRENE-BASED SCINTILLATION DETECTORS A.A. Sushko Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics, Sarov, Russia E-mail: [email protected] A method for processing data of experiments on static and dynamic multiplying assemblies with detector irradiation by non-parallel non- monoenergetic low-intensity mixed gamma-neutron fluxes is presented. This method uses calculations of light output in the detector scintillator providing an unambiguous relationship between data obtained in calibration measurements and experiments. Application of high-power nanosecond neutron pulses for external initiation of the chain reaction enables high-accuracy measurements of criticality parameters in dynamic and static multiplying assemblies. In Figs. 1, 2, computational and experimental output is compared for static and dynamic multiplying assemblies. 60 50 40 Д1, расчет 30 Д1, эксперимент Сигнал, В Сигнал, 20 10 0 2 3 4 5 6 7 8 9 10 Время, мкс Fig. 1. Comparison of normalized Fig. 2. Comparison of computational computational and experimental and experimental output for dynamic output for static multiplying multiplying assembly. assembly. 231 A NEUTRINO DETECTOR AT THE BIGR PULSED REACTOR A.A. Sushko, A.N. Babaikin, I.A. Ivanin, V.N. Yanovsky Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics, Sarov, Russia E-mail: [email protected] BIGR is one of the world’s highest-power pulsed reactors with about 300 MJ output energy per pulse. With a closed core, BIGR [1] is a hollow vertically oriented cylinder having an outer diameter of 76 cm, inner diameter of 18 cm, and height of 67 cm. The reactor is fueled with a pressed homogeneous mixture of uranium dioxide and graphite. Enrichment in 235U is 90%, and the nuclear ratio of carbon to 235U is ∼16. Under the BIGR room, at a depth of ∼2 m from AZ, there is a nearly empty 10x11x3.2 m room in the basement, where the detector will presumably be installed. Detection of antineutrinos from the reactor is based on the reaction ~ + ν e + p → n + e . (1) We are going to use a liquid scintillator with cadmium or gadolinium to absorb neutrons produced by the reaction (1). Detection is based on a set of time-delayed triple coincidences: first, we detect two simultaneous weak pulses from two annihilation γ-photons, and then, with a μs delay, γ-photons emitted by gadolinium, which absorbs the neutron. When choosing the detector geometry, we should take into account that the minimum number of light photons arriving at photomultipliers and necessary for pulse detection is 3-10 photons, the cross section of (1) β-decay in 235U is –43 2 σf=6.08∙10 cm /fission±8.5% [2], and the number of fission events per reactor pulse is up to 9.3∙1018. Thus, if we divide the detector into 2х2х2 m cubes and install photomultipliers at their apexes looking at the cube center, then at least two photomultipliers will see the flash from the reactions (1). In this case, four antineutrino events will occur in the cube per reactor pulse. At the first stage, we are going to make four of such cubes and detect 16 antineutrino events per pulse. Over a period of one year, with 70-80 BIGR pulses, we will have ∼1000 antineutrino events (1). 1. V.F.Kolesov. Non-repetitive pulsed reactors. Sarov, RFNC-VNIIEF, 1999. 1032 p. (in Russian). 2. A.I.Afonin, A.A.Borovoi, Yu.L.Dobrynin, et al. // Letters to JETF. 1985. V.41. Iss.8. P. 355 (in Russian). 232 HIGH EFFICIENCY HPGe γ-SPECTROMETER FOR THE INVESTIGATIONS OF ββ DECAY TO EXCITED STATES N.I. Rukhadze1, V.B. Brudanin1, Ch. Briancon2, P. Čermák3, O.I. Kochetov1, F. Mamedov3, P. Loaïza4, F. Piquemal4, E.N. Rukhadze3, I. Štekl3, G. Warot4, E.A. Yakushev1, M. Zampaolo4 1 Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; 2 Centre de Spetromėtrie Nuclėaire et de Spetromėtrie de Masse, Orsay, France; 3 Institute of Experimental and Applied Physics, CTU, Prague, Czech Republic; 4 Laboratoire Souterrain de Modane, Modane, France E-mail: [email protected] A new ultra low background HPGe γ-spectrometer produced by Canberra was installed at the Modane underground laboratory (LSM, France, 4800 m w.e.). The base of the spectrometer is the P type coaxial Ge detector with the sensitive volume of ~600 cm3 and the efficiency of ~160%. The energy resolution of the detector is ~1.2 keV at 122 keV (57Co) and ~2 keV at 1332 keV (60Co). Detector is mounted in U type ultra low background cryostat. The distance between the crystal and the end cap is ~ 4 mm. The cryostat and all constructive details surrounding detector are made from materials with low radioactive contaminations. Electronic modules (high voltage power supply, spectroscopy amplifier, Multiport II ADC) and data acquisition (Genie 2000) of the spectrometer are produced by Canberra. Some measurements were also performed by using Canberra Digital Signal Analyzer Lynx. Detector part of the spectrometer is surrounded by several layers of lead shielding. Two inner parts of lead shielding with the thickness of ~70 mm are made from archeological lead and may be removed to measure samples with a big volume. Marinelli boxes and bobbins are used to measure investigated samples. Radon free air from the anti-radon facility is blown through the passive shielding in order to decrease the concentration of Radon. The main goal of the spectrometer is to search for double beta decay processes to excited states of daughter nuclei. These decays will be accompanied by emission of γ-rays which will be detected by the spectrometer with high efficiency. Such decays are for example resonant neutrinoless double electron capture (0νEC/EC) decay of 106Cd – 106Pd (KL, 2741 keV, or KK, 2718 keV, or KL, 2737 keV, …) [1], double beta decay of 100Mo – 100Ru (0+, 1130 keV) [2] and others. The sensitivity of the spectrometer for such measurements is on the 21 22 level of T1/2 ~10 -10 years. The spectrometer is also used for measurements of radiopurity of materials, details and foils used in experiments of double beta decay (Nemo-3, SuperNemo, TGV-2) and dark matter (Edelweiss). This work was partly supported by RFBR under grant № 11-02-00813. 1. N.I.Rukhadze et al. // Nucl. Phys. A. 2011. V.852. P.197. 2. A.S.Barabash et al. // Phys. Lett. B. 1995. V.345. P.408. 233 USING OF PIXEL DETECTORS IN INVESTIGATIONS OF EC/EC DECAY N.I. Rukhadze1, V.B. Brudanin1, P. Čermák2, J. Čermák2, J.M. Jose2, V. Král2, F. Mamedov2, S.V. Rozov1, E.N. Rukhadze2, A.V. Salamatin1, Yu.A. Shitov1, I. Štekl2, E.A. Yakushev1 1 Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; 2 Institute of Experimental and Applied Physics CTU, Prague, Czech Republic E-mail: [email protected] A new generation of spectrometer intended for the search for double electron capture decay (EC/EC) is under development. It will be based on silicon pixel detectors (SPD) and will upgrade of the TGV-2 experiment [1]. The hybrid pixel detectors Timepix [2] (256×256 pixel matrix, 55µm pitch, size 1.4×1.4 cm2, thickness 300 µm) developed in CERN by Medipix collaboration will be used. Within each pixel of this device an analog circuitry and a digital counter are integrated. Operated in Time Over Threshold (TOT) mode Timepix detectors can use counters as a Wilkinson type ADC providing a spectroscopic capabilities in each individual pixel. Timepix device operated at room temperature has high efficiency to detect two correlated low energy X-rays (15-30 keV) emitted in 2νEC/EC decay. The ability of SPD to identify α, β, γ particles and localize them precisely leads to effective background discrimination and thus considerable improvement of the signal-to-background ratio. Series of low background measurements were performed at Modane underground laboratory (LSM, France, 4800 m w.e.). Background of Timepix detector shielded by 5 cm of lead has been measured in the 19-23 keV energy range, which is the region of interest (ROI) in searching for EC/EC decay of 106Cd. After 20 days of background measurement no pair events was obtained in ROI. Radiopurity of individual parts of Timepix has been also measured with low background screening HPGe technique. It was found that the standard printed circuit board (PCB) FR4 was the most radioactive piece of the Timepix device. Special PCB has been developed for the next SPD prototypes on the base of Cuflon, which is pure Teflon based material. A new EC/EC silicon pixel telescope (SPT) will be a multi-detector close- geometry spectrometer with neighboring detectors working in coincidence mode. The tests of SPT prototype will be performed at LSM during this year. This work was partly supported by RFBR under grant № 11-02-00813. 1. N.I.Rukhadze et al. // Bull. Russ. Acad. Sci. Phys. 2011. V.75. P.879. 2. P.Cermak et al. // JINST 2011. V.6. C01057. 234 DEVELOPMENT OF LOW ENERGY THRESHOLD HPGe DETECTORS IN JINR S.V. Rozov1, D. Borowicz1,2, V.B. Brudanin1, D.V. Filosofov1, Yu.B. Gurov1,3, V.G. Sandukovskiy1, S.S. Semikh1, E.A. Yakushev1 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Institute of Nuclear Physics, Krakow, Poland; 3 National Research Nuclear University (MIPhI), Moscow, Russia E-mail: [email protected] With an aim of direct light WIMP search JINR(Dubna) developed innovative detectors with energy threshold at few hundred eV. Main element of further setup for light WIMP detection is HPGe detector with modified p-contact, made by implantation of boron in the center of germanium crystal. The diameter of the implanted p-contact is 3 mm. By developed by JINR technology three HPGe detectors with masses 4, 241, and 446 grams were created. The implanted contact is surrounded by a guard ring having depth and width at 2.5 mm. All remained surface of the mono-crystal is the n-contact made by diffusion of lithium. Thickness of the diffusion level is about 0.5 mm. The first cascade of preamplification is located directly under the detector holder (Fig. 1). It’s made from 2N4416 FET with resistive or optical feedback. Such configuration provides the detector capacitance on a level below 1 pF. WIMP search for low WIMP mass region will be targeted with build detectors in frame of EDELWEISS experiment [1]. In 2011 a test of one such detector with weigh ~200 g has been started at the EDELWEISS site. This work has an aim to start in 2012 measurements with 400 g detectors in a low threshold mode (with threshold at few hundred eV) to be competitive with the CoGeNT experiment [2]. This work has been partly supported by RFBR (grants 11-02-00442 and 10- 02-93105). Fig. 1. HPGe detector with low registration threshold with mass 241 g: scheme of the detector (left); photo of the detector and a test holder (right). 1. E.Armengaud et al. // Phys. Lett. B. 2011. V.702. P.329. 2. C.E.Aalseth et al. // arXiv:1106.0650, 2011. 235 THE NEUTRON BEAM SPECTROMETER BASED ON SCINTILLATION DETECTOR WITH n-γ PULSE SHAPE DISCRIMINATION E.S. Konobeevski, M.V. Mordovskoy, S.I. Potashev, I.M. Sharapov, S.V. Zuyev Institute for Nuclear Research of Russian Academy of Sciences, Moscow, Russia E-mail: konobeev @inr.ru The study of the deuteron breakup reaction is performed at the neutron channel RADEX of the Institute for Nuclear Research. To obtain the absolute values of the cross-sections we need both monitoring the neutron beam and determination of its spectral composition in the energy range of 10-80 MeV. To solve this problem spectrometer of the neutron beam, based on a scintillation detector is installed and tested. As this neutron detector will operate in the presence of background gamma-ray, it is necessary to apply scintillators, which allow pulse-shape discrimination of neutrons and gamma rays. In our work we tested various scintillators based on stilbene crystal and liquid scintillators. The difference in the slow decay component of the light emission induced by neutrons and gamma-rays is the basis of digital pulse-shape discrimination (PSD) in the scintillating detectors. The data obtained with PuBe source as well as those obtained by irradiation of scintillators at the neutron channel show good n-γ discrimination in the energy range considered. We have tested a variety of methods most suitable for the n-γ discrimination. In Fig. 1 one can see spectra of various discrimination parameters – PSD (based on comparison of the charge collected from different parts of the pulse) and TAU - factor obtained from the approximation of the trailing edge of the pulse and characterizing the slow decay component of the light emission. Fig. 1. The spectra of various discrimination parameters: a – PSD with figure of merit (FOM) about 1.0 and b – TAU with FOM ~ 1.2. After the separation procedure the part of the total spectrum corresponding to the neutron irradiation will be used to reconstruct the energy spectrum of incident neutrons by solving the inverse problem [1]. 1. С.В.Зуев, Е.С.Конобеевский, М.В.Мордовской, И.М.Шарапов // Изв. РАН. Сер. физ. 2012. Т.76. №4. С.46. 236 THE SETUP FOR STUDYING QUASIFREE nn SCATTERING IN ENERGY RANGE OF 20-60 MeV Yu.M. Burmistrov, E.S. Konobeevski, M.V. Mordovskoy, S.I. Potashev, I.M. Sharapov, S.V. Zuyev Institute for Nuclear Research of Russian Academy of Sciences, Moscow, Russia E-mail: [email protected] To study the neutron-neutron quasifree scattering (QFS) in the energy range of 20-60 MeV the experimental setup was installed and tested at the neutron channel RADEX of the Institute for Nuclear Research. A beamstop of 200-MeV protons of INR linear accelerator is used as a neutron source. Neutrons produced in a 60-mm-thick tungsten target are collimated at an angle of 0º on a length of 12 m, forming a beam with a diameter of ~50 mm at the measuring CD target. In our setup liquid deuterated scintillator EJ-315 (Eljen Technology Company) is used not only as the target but also as a detector of secondary protons in the nd→pnn reaction. The signal produced by proton serves as well as a start signal for time-of-flight spectrometer of secondary neutrons. Neutrons in the setup are detected by a two-arm hodoscope consisted of five detectors located at angles of 29º – 42º on the left and a single detector at an angle of ~55º on the right of the incident neutron beam axis. Registration of two neutrons in the right and in one of the left detectors at an additional condition of low energy of the proton (proton-spectator) allows us to investigate the reaction of quasifree nn scattering in a wide range of primary neutrons energy and at different combinations of scattering angles. 237 NEUTRON DETECTION USING DOUBLE-SCATTERING METHOD S.S. Verbitsky1, A.M. Lapik2, A.V. Rusakov2, A.N. Tselebrovsky1 1 Institute of Energy Problems of Chemical Physics, Moscow, Russia; 2 Institute for Nuclear Research, Moscow, Russia E-mail: [email protected] The structural features and the results of the testing experiments of the device prototype for fast-neutron and gamma-rays detection using double-scattering concept are presented here. The device prototype consists of two position-sensitive liquid-scintillation detectors and the digitization and data processing system. The device characteristics are the following: detector active areas are 1380 and 990 cm2, with thickness of 5 cm, and the distance between scintillators is about 100 cm. After two consecutive scatterings the following particle characteristics can be determined: – particle energy deposited in both liquid-scintillation detectors, – type of the particle scattered in the detector (neutron or gamma-quantum) by pulse shape discrimination method, – coordinates of the points of the scattering in both detectors [1], – particle time-of-flight between the points of scattering. During the testing the following parameters were obtained: energy resolution for 10 MeV neutrons equals to ~7 %, for 4 MeV gamma-rays — equals to ~16 %, the coordinate resolution in the central area equals to ~1 cm, the angular resolution in the best geometry is about 0.1 rad, the gamma-rays background in the neutron detection region is less than 0.1 %. The energy distributions from the neutron source Pu-Be, gamma-rays source 60Co, neutron and gamma-rays natural background were obtained. Device can be used for a wide range of fundamental research and practical applications [2], related to neutron detection in the conditions of gamma-rays background. 1. S.S.Verbitsky et al. // Prib. Tekh. Eksp. 2002. № 3. P.34. 2. S.S.Verbitsky et al. // Izv. RAN. Energ. 2002. № 6. P.140. 238 THE NEUTRON SCATTERING INSTALLATIONS COMPLEX FOR CONDENSED MATTER RESEARCH AND NANO- DIAGNISTICS BASED ON THE PULSED SPALLATION NEUTRON SOURCES RADEX AND IN-06 AT INR RAS R.A. Sadykov1,2, A.A. Alekseev1 , V.S. Litvin1, E.S. Clementyev1,4, S.N. Axenov1, D.N. Trunov1, A.S. Kononyhin 1 , S.F. Sidorkin1, Y.V. Ryabov1, M.I. Grachev1, V.A. Fedchenko1, A.P. Artyushin1 , V.K. Gorbunov1, E.V. Ponomareva 1, V.A. Kutuzov1, A.V. Feshenko1, V.L. Serov 1, S.P. Kuznetsov3, I.V. Meshkov3, Yu.A. Lapushkin3, P.A. Alekseev4, A.P. Bulkin5, V.A. Ulianov5, V.A. Trunov5, E.A. Koptelov1, L.V. Kravchuk1 1 Institute for Nuclear Research RAS, Moscow, Russia; 2 Institute for High Pressure Physics, Troitsk, Moscow Region, Russia; 3 Lebedev Physical Institute RAS, Moscow, Russia; 4 NRC "Kurchatov Institute", Moscow, Russia; 5 Petersburg Nuclear Physics Institute, Gatchina, Russia E-mail: [email protected] A two new pulsed neutron sources for condensed matter and nanosystems research based on the high-current linear proton accelerator at INR RAS was constructed. The first stage of the neutron installations was accomplished. The experimental spectra of direct neutron beams and some neutron diffraction patterns were measured. 800 220 250 311 600 200 331 400 150 400 222 111 100 200 50 Intensity (counts) Интенсивность 0 0 200 400 600 800 1000 1200 0 400 800 1200 1600 ChannelA Channel (8 µs/ch) Fig.1. Neutron diffraction pattern of Fig.2. Neutron diffraction pattern of the polycrystalline abrasive on the basis zero alloy TiZr for high pressure cells of synthetic diamond (carbonado), and containers for the samples. measured at installation of "Hercules". 239 ABOUT GENERATION OF STRONGLY DIRECTED COHERENT NEUTRON RADIATION V.A. Skvortsov1, N.I. Vogel2 1 Moscow Institute for Physics and Technology (State University), Russia; 2 University of Technology, Chemnitz, Germany E-mail: [email protected] Results of experimental investigations on generation of strongly directed (with the angle divergence up to 2∙10–3 steradian) neutron beams are represented, which had been emitted (with variable intensities) a long time from laser-activated metallic targets. Fig. 1 shows the interference picture, which was carried out after neutron beam transition (with reflection) across of silicon crystal. The time exposition was 1 h 30 minutes and started after few minutes of finishing of nuclear activation (during 1 h 15 minutes) of Ta-181 target by using radiation of pulsed-periodic Nd YAG laser (with intensity in focal spot I ≈ 1014 W/cm 2, the frequency of pulse repetition was 4 Hz, energy of main pulse ≈ 100 mJ, its half-width pulse duration τ =100 ps, and wavelength λ= 1.06 µm). A similar neutron beams we could obtain and observe with more big time delay (hours, days), among them by using spherical target from iron with thin copper envelope. a) b) Fig. 1. The negative of interference picture from beam of coherent neutrons (a), and its stylized computer graph (b). Here 1 pixel = 1.667∙10–3 cm. This work was supported by DAAD. 240 PHYSICS OF NUCLEAR ACTIVATION OF METALLIC TARGETS BY LASER RADIATION V.A. Skvortsov1, N.I. Vogel2 1 Moscow Institute for Physics and Technology (State University), Russia; 2 University of Technology, Chemnitz, Germany E-mail: [email protected] Contrary to [1], when nuclear reactions had been initiated and investigated in processes of laser radiation influence on metallic targets, in present work the effect of induced radioactivity is considered after pulse-periodic interaction of intensive laser radiation with metallic targets (see parameters of used laser beams in [1, 2]). Results of experimental investigations are completed by results of theoretical calculations, which are carried out by using radiative MHD model [3], as well as by numerical solution of Fokker-Plank equation under calculations of energy specters of ions and electrons in plasmas with strong electric and magnetic fields. Fig. 1 demonstrates typical picture for spatial distribution of electric filed tension under condition of the development of explosive instability in laser- produced plasmas. The acceleration of ions in strong fields leads to intensive bombard of metallic targets and hence to it nuclear activation. This work was supported by DAAD. a) b) Fig. 1. The scheme of relative vectors of electric field tension in plasma for t=534 ps and Ez- component in 10 kV/cm (here R, Z in cm)- a); Ez (kV/cm) – b), where on R, Z – are numbers of cells of non equidistant calculation grid. This is a case of Al-target in hydrogen atmosphere. 1. V.A.Skvortsov, N.I.Vogel // Proc. MEGAGAUS-XI. London. 2006. Sarov, 2010. P.419. 2. V.A.Skvortsov, N.I.Vogel // 62 Int. Conf. “Nucleus 2012”. St.Petersburg. Solo, 2012. P.240. 3. V.A.Skvortsov. The physics of matter under high energy densities. Moscow: MIPT, 2007. 241 POWERFUL ANTINEUTRINO SOURCE ON THE BASE OF ACCELERATOR AND LITHIUM CONVERTER Yu.S. Lutostansky1, V.I. Lyashuk 2 1 Russian Research Center "Kurchatov Institute", Moscow, Russia; 2 Institute of Nuclear Research Russian Academy of Sciences, Moscow, Russia E-mail: [email protected] The developed conception of the powerful antineutrino source with hard 7 – ν e -spectrum is based on (n, γ)-activation of Li and subsequent β -decay 8 (T½ = 0.84 s) of Li isotope with emission of high-energy ν e with Eν up to 13 MeV [1]. The 8Li isotope is the perspective source for neutrino investigation taking into account that at the such energy the cross section of neutrino 2 interactions is depend as σ ~ Eν and increases significantly compare to the reactor ν e -spectrum. The source can operate as in static regime [2] by covering the active reactor zone with high purified 7Li-blanket and also in dynamic regime. The source can be realized [3, 4] on the base of metallic high purified 7Li (in order to prevent the parasitic neutron absorption on the 6Li) and on the 7 base of several chemical Li-compaunds (Li2C2, Li2CO3, heavy water solution . of LiOD, LiOD D2O, LiD and another). Compare to pumping of lithium in the metallic state the heavy water solution of 7Li allows to decrease the mass of high purified lithium in two orders of values and more for the same efficiency of the converter. As a neutron source for this purpose not only the nuclear reactors (of steady- state flux or pulse regime) and also accelerators can be used. Construction of beam dumps at large accelerators [5] also is perspective for creation of neutrino factory. Different realizations of accelerators as boosters for the lithium converters are considered. The advantages of such nuclear installations compare to ones based on nuclear reactors are discussed. Some directions for physical investigations on the antineutrino source (neutrino factory) are presented. The possibility to carry out a simple laboratory experiment with lithium converter is considered. The work is supported by the RFBR grant № 11-02-00882. 1. Yu.S.Lutostansky, V.I.Lyashuk // Bull. Russ. Acad. Sci. Phys. 2011. V.75. P.504. 2. Yu.S.Lutostansky, V.I.Lyashuk // Nucl. Sci. Eng. 1994. V.117. P.77. 3. Yu.S.Lutostansky, V.I.Lyashuk // Phys. Atomic Nucl. 2000. V.63. P.1288. 4. Yu.S.Lutostansky, V.I.Lyashuk // Phys. Particl. Nucl. Lett. 2005. V.2. P.226. 5. Yu.Ya.Stavissky // Uspekhi Fizicheskikh Nauk. 2006. V.176. P.1283. 242 THE DUAL-ENERGY METHOD IN X-RAY CT D.O. Spirin, Ya.A. Berdnikov Saint-Petersburg State Polytechnical University, Russia E-mail: [email protected] Dual-energy method allows to obtain the atomic number and density by linear attenuation coefficient examination at two different energies [1]. The possibility of the dual-energy method application in X-ray CT was examined with the use of X-ray CT simulating. The software complex was developed for full-scale realistic modeling of the X-ray tomograph from a stage of reception of projective data till restoration of the image of investigated object. Three material rods were chosen as a measurement sample. The diameter of the sample was 20 mm. The dual-energy method verification was conducted by materials discrimination of three kinds of metal (aluminum, titanium, iron). Two different X-ray images at low-energy (90 keV – 150 keV) and high-energy (90 keV – 250 keV) spectra were obtained. Fuzzy clustering algorithm was considered and introduced in dual-energy method in X-ray tomography. Shown (Fig. 1) approach allows to improve accuracy of element structure identification. Fig. 1. Effective atomic number and material density distributions for chosen samples. 1. D.O.Spirin et al. // NTV SPbSPU. 2009. V.73. №1. P.269. 2. D.J.MacKay. Information theory, inference, and learning algorithms. Cambridge: Cambridge University Press, 2003. 640 p. 3. H.J.Zimmermann. Fuzzy Set Theory and Its Applications. Kluwer Academic Publishers, 1996. 435 p. 243 THE STAND FOR TEST VLSI IN THE FIELD, MODELLING RADIATING FIELDS IN SPACE VEHICLES 1 1 2 M.V. Anokhin , V.I. Galkin , А.Е. Dubov 1 Skobeltsyn Institute of Nuclear Physics MSU, Russia; 2 SKB kosmicheskogo priborostroenia ISR RAN E-mail: [email protected] The present work is conducted on the basis of simple and obvious preconditions. 1. The basic processes leading to change of properties of materials radiation- sensitive elements of VLSI occur in the vicinity of tracks of the particles forming a radiation field. 2. Mechanisms of occurrence of such processes are diverse: a) the track core in the detector can present a new phase of substance [1, 2] and, as a result of action of δ -electron cloud around the track, the islets of a new phase or dot defects [3] can be formed and also ruptures of intermolecular binds can occur; b) a thermal wedge can be formed [4, 5]; c) with a high probability a Coulomb explosion [4], shock waves [6], acoustic effects [7] can arise; d) occurrence of amorphous areas in crystals and crystalline microstructures in amorphous materials [1] is possible; e) emission of substance from the axis of a track is possible which can lead to the formation of cavities along the axis and dot defects round them [1]; f) there can be a competition between various mechanisms, for example, rupture or joining of intermolecular binds, but sometimes synergetic effects can arise at the formation of the local response [8, 9]. 3. For a condition estimation in track volume it is productive to use Geizenberg uncertainty relation [10] from which the basic criteria parameters of radiation field for the research of the character of the radiating response in VLSI or other radiation-sensitive devices are deduced. On the basis of this concept a test desk was elaborated including a 239Pu-Be neutron source. Using a multicomponent converter a radiation field is formed which spectrum of the specific absorbed energy on a micrometer scale is similar to such spectrum inside a spacecraft. A "back illuminated" CMOS matrix is used as a radiation monitor. 1. S.Furuno et al. // NIM. B. 1996. V.107. P.223. 2. Yu.Didyk et al. // Nukleonika. 2005. V.50(4). P.149. 3. F.F.Komarov // UFN. 1992. V.173. No.12. P.1287. 4. R.L.Fleisher et al. // Nuclear Tracks in Solids. Berkeley: Univ. of Cal. Press, 1975. 5. F.F.Komarov, A.A.Komarov. Model of thermal picks in application to an appearance of track formation in A3B5 semiconductors under high-energy ionic implantation. Iss. 8. 2003. P.22. 6. T.Turovsky, W.Enge // Rad. Meas. 2001. V.34. P.27. 7. B.L.Beron, R.Hofstadier // IEEE Trans. Nucl. Sci. 1969. V.23. N.4. P.638. 8. L.T.Chadderton // Rad. Meas. 2003. V.36. P.13. 9. V.A.Belyi, F.F.Komarov // Zh. Tekh. Fiz. 1998. V.68. P.42. 10. V.A.Ditlov. Sess. Dep. Nucl. Phys. RAS, IТEPh, 2009; R.Katz // 7-th Int. Colloq. Corp. Photography and Visual Solid Detectors. Barcelona, 1970. P.1. 244 SELF-RECOMBINATION AND 2Δ-PHONON EXCHANGE IN STJ X-RAY DETECTORS V.A. Andrianov1, V.P. Gorkov2 1 Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia; 2 Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, Russia E-mail: [email protected] Detectors based on superconducting tunnel junctions (STJ detectors) have high energy resolution and low energy threshold and can be used in the precision X-ray, ultraviolet and optical spectroscopy [1]. Unfortunately, the real energy resolution is noticeably worse than the theoretical predictions. The main mechanism of the energy resolution degradation is self-recombination of the excess quasiparticles, generated in superconducting absorber after X-ray quantum absorption [2]. In this work the effects of self-recombination are studied for the STJ-detectors of a special type, detectors with a killed electrode. The detectors were described by the formula Ti/Nb/Al-AlOx/Al/Nb/NbN, where Al/Nb/NbN is the main multilayer electrode and Ti/Nb is the killed electrode. The signal amplitudes and the temporary shape of the signals were studied as a function of the bias voltage and the energy of the quanta. The signals related to the quantum absorption in the main electrode and in the killed one were considered. The data were analyzed on the basis of 2D-diffusional model with self recombination terms. It is shown that the self-recombination and 2Δ-phonon exchange between detector electrodes cause the strong nonlinearity of the detector response as a function of the energy of the quantum. These mechanisms also change the temporal shape of the detector signals. The ways of decreasing of these effects are discussed. 1. P.Lerch, A.Zender // Topics in applied physics. 2005. V.99. P.217. 2. V.A.Andrianov et al. // Semiconductors. 2007. V.41. P.215. 245 18F PRODUCTION IN THE 19F(γ, n) REACTION S.S. Belyshev1, L.Z. Dzhilavyan2, A.N. Ermakov3, B.S. Ishkhanov1,3, V.V. Khankin3, A.S. Kurilik1, A.A. Kuznetsov3, V.I. Shvedunov3, K.A. Stopani3 1 Faculty of Physics, M.V. Lomonosov Moscow State University, Russia; 2 Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia; 3 Scobeltsyn Insitute of Nuclear Physics, Moscow State University, Russia E-mail: [email protected] 18F isotope is widely used in nuclear medicine for positron emission tomography. In our recent work [1], its production via the 23Na(γ, αn) reaction was studied and promising results for achieving required levels of total and specific activities were obtained. In the present work, as a continuation of the experimental study of opportunities to produce 18F for medical purposes in photonuclear reactions, 19F(γ, n) reaction with largest integrated cross sections for 18F production was investigated. This work was carried on a pulsed race-track microtron with electron beam energy of 55 MeV [2]. PTFE targets with thicknesses up to several g/cm2 were irradiated by bremsstrahlung photons produced in 2.5 mm thick tungsten radiator. Average beam current was 50 nA with irradiation times up to 1 hour. After the irradiation, targets were measured on a HPGE spectrometer and 18F activity was calculated from the decay of 511 keV annihilation line. According to estimations obtained by the method described in [3], results of this work for total produced 18F activities and, respectively, value of σ-1 ≈ 8.9 mb is in reasonable agreement with known data for maximum γ-quanta energies up to ~28 MeV [4]. 1. S.S.Belyshev, L.Z.Dzhilavyan, A.N.Ermakov et al. // Vestnik MGU (to be published). 2. A.I.Karev et al. // Proc. XXII Russian Particle Accelerator Conf. RuPAC-2010. P.316. 3. L.Z.Dzhilavyan, A.I.Karev, V.G.Raevsky // Yad. Fizika. 2011. V.74. P.1728. 4. S.S.Dietrich, B.L.Berman // Atomic Data and Nuclear Data Tables. 1988. V.38. P.199. 246 MEASUREMENT OF THE ATOMIC NUMBER BY MEANS OF ELECTRON ACCELERATOR A.N. Ermakov1, A.S. Kurilik1,2, K.A. Stopani1 1 Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Russia; 2 Faculty of Physics M.V.Lomonosov Moscow State University, Russia E-mail: [email protected] Development of systems for nondestructive inspection of the content of trucks and containers acquired a great importance in the last decade [1, 2]. We propose a method of cargo inspection based on a multi-energy electron accelerator, that provides enhanced capabilities to recognize the elemental composition of an object. The volume of unknown content is X-rayed with several bremsstrahlung beams with different upper energies. An electron accelerator with switchable beam energy is used as a source of photons. Then a gamma-radiation detector is used to register the photons that passed through the object. The difference in the energy dependence of the photon absorption cross-section for different elements is used to find the anomalous content of light and heavy elements. Computer simulations have been made with GEANT4 [3] code to study the details of the multi-energy technique for material recognition and to produce software for raw detector information processing. The proposed method [4] was compared with the method of two energies. It was shown that our method allows to determine the atomic number without ambiguity, unlike the method of two energies, which in some cases does not permit to distinguish high Z fissile materials from low Z light materials. Our computations show that the multi-energy method has a higher true detection rate and a lower false alarm rate than the method of two energies. 1. P.J.Bjorkholm // Port Tech. Int. 2002. V.17-08. P.36. 2. S.Ogorodnikov, V.Petrunin // Phys. Rev. STAB. 2002. V.5. 104701. 3. http://geant4.cern.ch. 4. Б.С.Ишханов, А.С.Курилик и др. // Изв. РАН. Сер. физ. 2008. Т.72. №6. С.908. 247 TIME CORRELATION OF THE PMT NOISE IMPULSES V.A. Morozov, N.V. Morozova Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] The purpose of the work consisted in an establishment of time correlation of the PMT noise impulses in nanosecond range. In measurements there were used the autocorrelation time spectrometer of the delayed coincidences [1] and photo multipliers XP2020, XP2232B, XP1021, FEU-85, FEU-87, FEU-93, FEU-130. Results of measurements with ХР2020 with and without a radioactive source are presented on Fig. 1.The presented results lead to following conclusions: 1. It is observed the time correlation of the noise pulses in nanosecond range in exponential form connected with registration process in PMT. The distribution of noise impulses with T1/2 ~ 20 nanoseconds are produced by the thermoelectrons from photocathode PMT. This conclusion follows from the fact of registration of the ion feedback afterpulses (AP). 2. At measurements with a radioactive source the registered decay time is considerable less due the dead time of TAC as a result connected with effect of the TAC blocking. 3. The exponential part of noise impulses is connected with dynode system of PMT because it is disappears at increase of a threshold of the discriminator while registration of AP’s is continued. 100000 T1/2 = 25,2(3) ns 4.3(1) ns XP2020 65,5(7) ns Vpmt = 1800 V 10000 241Am → 237Np AP 1000 3 2 100 Number of counts of Number 1 10 1 0 400 800 1200 1600 t(ns) Fig.1. 1 — Vd=4 keV, 2 — Vd=40 keV, 3 — Vd=4 keV. 1. V.A.Morozov et al. // Nucl. Inst. Meth. A. 2002. V.484. No.1-3. P.225. 248 POSSIBLE DEVELOPMENT OF A PROBLEM OF PHYSICS, CHEMISTRY AND TECHNOLOGY OF ANTIMATTER FOR PROJECTS OF SPACESHIPS E.P. Prokopev Research Center "Kurchatov Institute". Federal official body of the "State Research Center of Russian Federation - Institute of Theoretical and Experimental Physics." FGBU "SSC RF - ITEP", Moscow, Russia E-mail: [email protected] The big interest represents a possibility of reception of intensive streams of positrons (probably and other antiparticles) at reorganization of physical vacuum in strong fields (for example, in an electric field of modern super-power laser beams [1] and on accelerators. Speech can possibly go about creation of space solar factories on the Moon or asteroids, etc. with use of the transformed energy of radiation of the Sun to electric energy and uses of a space for manufacture and storages of positrons. The essence of a method should consist in reception by means of the transformed energy of the Sun on accelerators or any other methods of streams of fast positrons with their subsequent delay up to temperatures of the order 0.5 K in some closed area of a space. Thus, very significant stocks of positrons could be created. Gathering of such positrons in magnetic traps in conditions of a space can become rather effective method of accumulation of antimatter by means transformations of energy of the sun [2]. On a modern level of development of technologies about lots of received antimatter to speak it is not necessary. Besides this process of reception is very dear. Therefore probably really to speak only about tens or hundreds nanograms received antimatter. This quantity of antimatter, apparently, would suffice for creation of space vehicles (SV) with the sizes in nano-or a micron range [3]. This fantastic assumption is not deprived sense in a context of modern development of nanotechnologies in the World. All the sizes long devices and details such SV should not exceed the sizes of nano- and micron ranges. 1. E.Prokopev. http://infox.ru/science/lab/2008/11/18/antimatter.phtml. 2. E.Prokopev. http://www.portalus.ru/modules/science/data/files/prokopiev/Project- Prokop-Paper.pdf. 3. E.Prokopev. http://www.portalus.ru/modules/science/data/files/prokopiev/Antimatter- Positronics-_ProektEngRus.doc. 249 TDPAC SPECTROMETER FOR THE STUDY OF HYPERFINE INTERACTIONS IN A CONDENSED MATTER AT LOW TEMPERATURES AND HIGH PRESSURES 1 2,4 3 1 A.V. Salamatin , A.V. Tsvyashchenko , M. Budzynski , A.I. Velichkov , 1 2 2 2 V.N. Trofimov , D.A. Salamatin , A.V. Fedorov , L.N. Fomicheva , G.K. Ryasny4, D.V. Karaivanov1 1 Joint Institute for Nuclear Research, Dubna, Russia; 2 Vereshchagin Institute for High Pressure Physics, Troitsk, Russia; 3 Institute of Physics, M. Curie-Sklodowska University, Lublin, Poland; 4 Skobieltsyn Institute of Nuclear Physics, MSU, Moscow, Russia E-mail: [email protected] A four-detector spectrometer [1] for study gamma-gamma PAC was equipped with an optical four-window cryostat “JANIS” (model SHI-950). The cryostat designed to operate from below 4 K to room temperature. In the modified channel of cryostat is set high-pressure chamber type piston-cylinder [2], capable of generating a sample pressure of 2 GPa. The refreshed PAC spectrometer allows us to study the magnetic phase diagrams of systems with strong electron correlations in a wide range of pressures and temperatures. In the first test experiments at 4 K was measured hyperfine magnetic field in 111 the cubic Laves phase GdCo2 at probe nuclei Cd, which are localized in spherically symmetric sites of gadolinium (see Fig. 1). Under pressure 1.8 GPa was measured dependence of the quadrupole frequency in the temperature range 111 from 4 K to 300 K in compound ZrZn2, in which the probe nuclei Cd were located in Zn site. Fig. 2 shows the spectrum of the anisotropy at 4 K and 1.8 GPa. This work was supported by the Program authorized representative of Poland at JINR. R(t) Амплитуда [у.е.] -0.16 -0.12 20 111In in ZrZn ; N 3034; T = 4 K; p=18 kb 111 ωm = 40.3(5) МГц 1.9 -0.12 Cd in GdCo 16 2 300 K νQ = 144.1(4) MHz 12 -0.08 8 -0.08 -0.04 4 (t) 0 160 2 G -0.12 2 111 ωm = 50(1) МГц A Cd in GdCo2 4 K 12 -0.08 -0.04 8 -0.04 4 0 0 0 100 200 300 0 0.2 0.4 0.6 0.8 1 0 t [нс] ω [Град/с] 0 100 200 300 t [ns] 111 111 Fig. 1. Time spectrum for Cd in GdCo2. Fig. 2. Time spectrum for Cd in ZrZn2. 1. V.B.Brudanin at al. // NIM in Physics Research. A. 2005. V.547. P.389. 2. A.N.Voronovski at al. // ZETF. 1979. V.77. P.1119; Sov. Phys. JETP. 1979. V.50. P.564. 250 ON THE THEORY OF NUCLEAR FORCES, ELEMENTARY PARTICLES AND «UNLIMITED» ENERGY CUMULATION V.A. Skvortsov Moscow Institute for Physics and Technology (State University), Russia E-mail: [email protected] In numerical solution of Maxwell’s equation in matter (under conditions of laser radiation influence, when thermo magnetic or explosive MHD instabilities take place) a soliton-like pulse magnetic and electric fields had been discovered. These objects are very similar to quasi atoms with large number of electrons and ions – «magnetoms» with freezing magnetic fields [1]. In the vicinity of such vortex systems (on micron and sub micron regions, as well as in atoms) there is exists extremely high pressures, super strong electric and magnetic fields. Very high internal energy densities take place in observed short living toroidal vertexes [1]. Example of such «shooting vertex» is represented on Fig. 1, for case of picosecond laser influence on aluminum target in argon (having initial room temperature and pressure P=0.56 atm). The intensity of laser beam in focal spot riches up to 3.53 1016 W/cm2 for shown time t = 54.47 ps. Similar vortex can evaluated into miniature black holes [1]. Contrary to calculations, which were produced by American scientists predicting physically non real MeV’s electron temperatures in “fireballs”, in our case the temperature of electron was not higher then 20 keV (due to bremsstrachlung), but ion temperature can be extremely high due to gyro relaxation heating in strong variable fields. So one could say that “quark-gluon” plasma must be produced in laser plasma. Nevertheless, in present paper will be shown that another kind of particles are generated [2], namely they must be responsible for nature of nuclear forces, and for physics of “order of mesons”. To the point, mesons can be really multiple generated during decay of «shooting vortex”, and its physics [3] is very similar to physics of mentioned above laser “magnetoms” [1]. It is not surprisingly: the Maxwell’s equations in matter have the same closed symmetry as Dirac’s equation in quantum mechanics [4]. a b Fig.1. Spatial distribution of magnetic field induction and ion temperature in calculation region (400×650 µm, on r, z– are numbers of cells of non equidistant grid). The time form of laser pulse see in [1], P.116. 1. V.A.Skvortsov. Physics of matter under high energy densities. M.:MIPT, 2007. 2. V.A.Skvortsov, N.I.Vogel // Particle Physics in Laboratory, Space and Universe. Singapore: World Scientific, 2005, P.373. 3. E.Fermi. Elementary particles. London:1951. 4. V.I.Fushich, V.G.Nikitin. The symmetry of quantum mechanics equations. M.:Nauka. 1990. 251 CONVERTERS FOR MÖSSBAUER RESONANCE DETECTORS V.M. Vakhtel1, A.M. Khoviv1, S.V. Kannykin1, V.A. Rabotkin1, A.N. Kharin1, O.V. Serbin2, S.V. Rosnovskiy3 1 Voronezh State University, Russia; 2 LLC “Institute of Modern engineering”, Voronezh, Russia; 3 Novovoronezh Nuclear Power Plant, Russia E-mail: [email protected] The main problem with investigation of nanostructured materials by Mössbauer spectroscopy is complicated or unresolved hyperfine spectrum structure and little quantity of resonance absorption in the studied material. The most effective way to solve the problem is to apply resonance detectors (RD) [1, 2]. Alloys Fe50Al50 having natural line width and f-factor ~ 0.6 possess the best experimental parameters as a RD converters’ material. The research demonstrates converters production procedure for proportional gas RD, the design and working principle of which are discussed in [3]. Thin films of Fe–Al system of equimolar composition of 20-40 nm in thickness were deposited by magnetron sputtering at UVN-71P unit onto wafer surface of oxidized monocrystalline silicon of orientation (111) without being preheated. The cathode material is a target prepared in advance of Fe–Al system with the components’ ratio 1:1. In order to stabilize the alloy composition within its thickness heat treatment of the obtained wafers in vacuum at 300-600° С was performed. The obtained wafers were cut up to the required sizes at the cutting unit of semiconductor wafer by the skive with edge thickness of 30 micrometers. The obtained films’ thickness and elemental composition were controlled by SEM, energy dispersive analysis and Auger-electron spectroscopy. The technique was developed as well as optimal regimes for production of materials for RD converters were determined. Using the synthesized structures the corresponding Mössbauer spectra were obtained. 1. К.P.Mitrofanov, V.N.Plotnikova, V.S.Shpinel // Scientific Instruments and Methods. 1963. №3. P.49. 2. A.A.Belyaev, S.M.Irkaev, V.V.Panchuck, et al. // American Institute of Physics Conference Proceedings. 2008. V.1070. P.147. 3. А.А.Belyaev, V.S.Volodin, S.M.Irkaev, et al. // Scientific Instrument Engineering. 2009. V.19. №3. P.41. 252 COLLECTIVE OPTICAL BREMSSTRAHLUNG GENERATED NARROW BEAM OF GAMMA QUANTA F.F. Valiev St.Petersburg State University, Russia E-mail: [email protected] The optical bremsstrahlung (OB) of the ensemble of electrons which appears inside the transparent medium is examined. It is experimentally and theoretically investigated in [1]. We used the method of the simulation of interaction of the stationary flux o of the primary gamma radiation within a liquid or gaseous medium. We obtain the energy and space-time distributions of the ensemble of electrons resulting from the interaction. Within the model, we calculated the effective pulse of the electron current, which is shown to move with the speed of light in the vacuum. It is produced by the contribution of the Compton, photo- and other electrons generated by electromagnetic processes. The work is an extension of [2], where collective bremsstrahlung generated by the interaction of a focused pulse of ionizing radiation with matter are discussed within the framework of the model of a linear electrical current without filling. As a result, it was found that all the electrons give a contribution to the collective (OB), whose movement is started by the first ionization electron. The influence of the electrons formed can explain the experimentally observed intensity of optical radiation in the aquatic environment generated by a beam of gamma rays [3]. 1. Yа.Ruzicka. Ph. D. Thesis. Dubna, 1993. 2. F.F.Valiev // LX Intern.Conf on Nuclear Physics. 2009. Saint-Petersburg. P.317. 3. P.A.Cherenkov // Trudy FIAN. 1944. V.2. №4. 253 X-RAY SENSITIVITY OF IRON-DOPED CdIn2S4 SINGLE CRYSTALS S.N. Mustafaeva1, M.M. Asadov2, D.T. Guseinov1 1 Institute of Physics, National Academy of Sciences of Azerbaijan; 2 Institute of Chemical Problems, National Academy of Sciences of Azerbaijan E-mail: [email protected] The search for new X-ray-sensitive semiconductors applicable in vidicons and radiographic information carriers is an important problem of semiconductor physics and technology. One of the most important ideas underlying the occurrence of X-ray conductivity is high absorptivity of the semiconductor material in the X-ray spectral region. In this regard, of special interest are high-resistance II III VI II semiconductor materials. These are compounds of A B2 C4 type (A = Zn, Cd; BIII = Al, Ga, In; CVI = S, Se, Te). Among the representatives of this class of materials are CdIn2S4 single crystals. Information on luminescence and photoelectric properties of these single crystals can be found in the literature; however there are no data on their X-ray conductivity. The objective of this study is the investigation of X-ray electric properties of CdIn2S4 single crystals doped by iron. CdIn2S4 254 RADIATION CURRENT TRANSFER IN METAL-DIELECRTIC-SEMICONDUCTOR STRUCTURES M.N. Levin1, А.S. Tatarintsev1, V.М. Мaslovskiy2 1 Voronezh State University, Russia; 2 FSUE NIIFP named after F.V. Lukin, Zelenograd, Moscow, Russia Е-mail: [email protected] The analysis of charge transport processes in the dielectric MDS-structures based on the numerical solution system of equations describing the processes of spatio-temporal evolution of the charge, occurring in the dielectric MDS-structures under the action of X-ray and UV radiation was carried out. The analysis was taken at the test MDS transistors with the geometry of 3.2×200 mkm2, with the oxide thickness d = 100 nm, grown at 1050° C, with the electrode of the polysilicon doped with phosphorus and with a thickness of 0.5 microns. It was found out by the change of the stationary subthreshold current-voltage characteristics (CVC) that under the action of the UV irradiation the radiation- induced charge in the gate dielectric and the surface states of short channel MDPT changes. Thus, the effectiveness of UV depends on the ratio of the area gate MOS structure to the perimeter. The result indicates the peripheral nature of the interaction. The penetration of UV under the opaque MDST gate is apparently due to the fact that the oxides in the MDS elements are optical fibers for UV radiation. Radiation exposure was carried out by X-rays with photon energies 5 Ex ≈ 25 keV and a dose of 5∙10 R. Subsequent isothermal annealing was carried out at a temperature of 700 K for one hour. The charge was completely annealed at the surface states and small trapping levels. The source of UV radiation is a xenon lamp DKSSh-1000 with a continuous spectrum in the closest UV region. Irradiation was carried out through a monochromator MDR-24 of the KSVU complex with an adjustable output gap. An original technique for determining the spatial distribution of the radiation of a charge in the dielectric of the MIS structures was used. The method includes determining of potential barrier height and the magnitude of the effective charge at the respective border of MIS-structure of the experimental characteristics of the photoemission current and photoemission CVC and comparison of the obtained values with the calculated characteristics. The experimental results of applying the developed technique to study the spatial distribution of radiation-induced positive charge in the structure of poly-Si-SiO2-Si have shown its high efficiency. 1. М.Н.Левин и др. // Вестн. Ворон. госунив-та. Сер. Физ. Мат. 2004. №2. С.16. 2. М.Н.Левин и др. // Электр. техника. Сер.7. 1990. №6(163). С.23. 255 EDGE EFFECTS IN MOS-STRUCTURES UNDER THE ACTION OF THE LOW-ENERGY RADIATION EXPOSURE M.N. Levin, V.R. Gitlin, A.V. Tatarintsev Voronezh State University, Russia Е-mail: [email protected] On the basis of two-dimensional numerical calculation of drain-to-shutter and drain-to-output voltage characteristics of MOST and in view of the charge in the oxide and the surface states it was established, that the presence of SS leads to a dependence of the threshold voltage of the drain voltage VT (VD) for MOST with a long channel and strengthening of this relationship for the short channel MOST. The observed dependence is due to the effect of two-dimensional separation of SS into parts shielded by shutter and output. Type of VT (VD)-dependence is determined by the SS distribution near the drain. The determination method of the charge characteristics of the interface in the SiO2-Si MOS transistor with radiation effects of short-channel and planar heterogeneity is developed. The method includes determination of the density of the SS from measurements of the charge pump currents and the calculation of the effective charge in the dielectric fluctuations of MOST and its share of the measured output and transfer CVC MOST and the experimental dependence of the threshold voltage of the drain voltage. The criterion of applicability of the proposed method is the constancy of the slope of CVC MOST at the subthreshold area at the voltage change at the drain of the transistor. Direct experiments on irradiation of MOST by focused electron beam in a scanning electron microscope (SEM) confirmed the results of numerical calculations, modeling of radiation effects in the short-channel MOST. It is established that as a result of MOST irradiation there is a dependence that is absent into parts initial samples, which increases with the accumulation of radiation dose and linear for uniform irradiation of MOST with VD=0. Linearity is disturbed by irradiation of the transistor with displacement at the drain or with the local irradiation near-the-drain area. The use of SEM for this purpose makes it possible to influence some parts of MOST structures in order to identify the causes of radiation degradation of their parameters and imitation of various effects. 1. M.N.Levin et al. // Письма в ЖТФ. 2004. Т.30. №2. Вып.9. С.73. 2. M.N.Levin et al. // Вестн. Воронеж. гос. ун-та. Сер. Физика. Математика. 2005. №2. С.30. 256 RADIOECOLOGICAL MEASUREMENTS IN LENINGRAD REGION V.A. Sergienko, A.I. Zippa, V.A. Danilenko Saint Petersburg State University, Russia E-mail: [email protected] The Chernobyl disaster that occurred on 26 April 1986 was a nuclear accident of catastrophic proportions. As a result more than 30000 PBq of radioactive isotopes were thrown out into the atmosphere. Long-lived isotopes 90Sr and 137Cs were among them. Both the isotopes have a long radioactive half- life period, about 30 years. 137Cs also emits gamma quanta, except of its beta- radiation, so it is possible to carry out the research using gamma-spectrometer. Areas with soils polluted by 137Cs were also found in the southwest of Leningrad region. It is supposed that the pollution is connected with Chernobyl disaster. There was a research made in 1991 that estimates the quantity of the pollution of the soils by 137Cs as 1–5 Ci/km2 (or 37–185 GBq/km2) [1]. We supposed that specific activity of the pollution had reduced to a second since 1986 because of the radioactive decay and also the washout of the soil deeper in the soil. We carried out the research of estimation of quantity of 137Cs in the soil samples that were taken in Kotelsky village. The village is located in the polluted area of Leningrad region. The research was carried out using HPGe detector “Canberra” with relative efficiency 20% and resolution 1.8 keV at the peak of 60Co 1333 keV. The efficiency calibration was made by the method of the “effective center of the detector” [2]. To evaluate concentration of 137Cs, we used the presence of line 1460 keV 40K in the gamma-spectrum. Average activity of 40K in soils is equal to 300–450 Bq/kg [3]. Then a specific activity of 137Cs can be estimated using comparison with 40K by the formula ACs-137 =(ε1460/ε662)·(I1460/I662)·(N662/N1460)·AK-40, where A is activity of radionuclides (Bq/kg), ε is absolute efficiencies, N is count rates (count/s) in the peaks 662 and 1460 keV. Background of 40K in the laboratory was taken into account. Hence 137Cs activity in the soil is 42-63 Bq/kg. Taking the soil density equal to 1.2 g/cm3 and thickness 20 cm, we obtain value of soil pollution by 137Cs is approximately equal to 10-15 GBq/ km2. 1. Leningrad region. The map of the radioactive pollution of the area (by Cs-137). 1992. 2. A.Notea // Nucl. Instrum. Meth. 1971. V.91. P.513. 3. V.K.Sakharov. Radioecologia (in Russian). 2006. 257 FUNDAMENTAL PROBLEMS OF NUCLEAR POWER AND NUCLEAR TECHNOLOGIES. EXPERIENCE AND PROBLEMS OF QUALITATIVE TRAINING OF RUSSIAN AND FOREIGN SPECIALISTS IN FIELD OF NUCLEAR PHYSICS, ATOMIC POWER ENGINEERING AND NUCLEAR TECHNOLOGIES INVESTIGATION OF ELEMENT COMPOSITION OF THE DUST ON THE GLOBUS-M TOKAMAK V.M. Lebedev, V.A. Smolin Petersburg Nuclear Physics Institute, Gatchina, Russia E-mail: [email protected] Globus-M is the first Russian spherical tokamak built at A.F. Ioffe Physico- Technical Institute in 1999. It can operate with high deuterium plasma density up to 1020 m–3 and high specific power deposition in to the plasma volume up to a few MW/m3. Almost 90% of the inner vacuum vessel (austenitic stainless steel) surface area, which is directly faced to plasma, is now covered by RGTi tiles. The inner surfaces of tokamak chamber were protected by B/C:H films using procedures of the boronization. The maximum density of the evolved power takes place of exit of the separatrix into the divertor plates. The element composition and structural-phase analysis of mixed layers deposited during primary boronization procedure and following modification during plasma-well interaction in divertor and other areas of Globus-M was presented in [1, 2]. It is well known the interaction between plasma and inner walls leads to the formation of a dust in modern tokamak. This dust can influence on the properties and work of the tokamak. This paper is devoted to the studying of composition of the dust collected in the Globus-M tokamak. The dust samples were collected on place of exit of the separatrix into the divertor plates. The boron and carbon content in the dust was determined by Nuclear Reaction Analysis comparing alpha and proton particle yields in 10B(d, α)8Be and 12C(d, p)13C reactions on the PNPI electrostatic accelerator. Energy of deuterons was 0.9 MeV. The dust samples consisted of graphite, TiC, Fe2O3, amorphous carbon and boron. Atomic relations 1. V.K.Gusev et al. // Nuclear Fusion. 2009. V.49. № 10. P.095022. 2. V.K.Gusev et al. // Journal of Nuclear Materials. 2009. V.386–388. P.708. 258 DECAY SCHEMES COMPLETENESS AND DECAY HEAT CALCULATION PROBLEMS I.N. Izosimov Joint Institute for Nuclear Research, Dubna, Russia E-mail: [email protected] The total absorption γ-ray spectroscopy (TAGS) is based on summation of cascade gamma quantum energies in the 4π geometry [1]. The TAGS may be applied for β-decay strength function Sβ(E) measurement, for total β-decay energy Qβ determination and for decay scheme completeness testing. The combination of the TAGS with high resolution γ-spectroscopy may be applied for Sβ(E) fine structure study and for detailed decay schemes construction [1]. The β and γ decay energies realized through the natural decay of fission products may be up to 13% of the total energy generated during the fission process and becomes dominate component following reactor shutdown [2]. This energy source is commonly called decay heat. There are some discrepancies between calculations of decay heat with using different libraries and the experiments connected with γ and β components of the fission products [2]. To improve agreement between decay heat calculations and experiments it is necessary to have more complete decay schemes of fission products [3]. The principles of the more complete decay schemes construction by using the combination of the TAGS spectroscopy with high resolution gamma spectroscopy are presented. The possibilities of TAGS applications for decay schemes completeness testing and more complete data using for decay heat calculations are discussed. 1. I.N.Izosimov // Phys. Part. Nucl. 2011. V.42. P.963. DOI: 10.1134/S1063779611060049. 2. T.Yoshida et al. // Journal of Nucl. Scince and Technology. 1999. V.36. P.135. 3. I.N.Izosimov et al. // Phys. At. Nucl. 2004. V.67. P.1867. 259 ATOMIC NUCLEI GROUND AND ISOMER STATES PARAMETERS DATABASE FOR SCIENCE RESEARCH AND EDUCATION V.V. Varlamov, S.Yu. Komarov, N.N. Peskov, M.E. Stepanov Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University, Russia; Centre for Photonuclear Experiments Data E-mail: [email protected] Various relational nuclear databases produced at the MSU SINP CDFE [1] are widely used for both scientific research and solving of many educational tasks primarily in coordination with the Chair of General Nuclear Physics of the MSU Physics Faculty. Using those databases powerful and flexible Search Engines students have access to modern accurate and reliable international nuclear data funds. The databases produced at the CDFE contain various data on the nuclei themselves, their shapes and sizes, their levels and transitions between them, various nuclear reactions and radioactive decays features, parameters of giant dipole resonances [2], correspondent bibliography information. Useful information on main nucleus parameters were spread before between many sources and efficiency of their using was not enough. Because of that the new “Nucleus Ground and Isomeric State Parameters” database (http://cdfe.sinp.msu.ru/services/gsp.ru.html) was produced combining important nucleus data from several sources and therefore giving to one convenient and comfortable possibilities for various data combined processing. Those parameters of both ground and isomeric states of all known till now atomic nuclei (Z = 1 – 118) are: – Abundance of stable isotope or half of time of unstable isotope; – Spin and parity of ground or isomeric state; – Energy of isomeric state; – Nucleus atomic mass, mass excess and binding energy [3]; – Nucleus decay modes [4]; – Nucleon (p, n) separation energy; – Nucleus decay (e–, e+, ε, α) energy. The work was partially supported by RBFR Grant 09-02-00368, scientific schools grant 02.120.21.485-SS and contract 02.740.11.0242. 1. Centre for Photonuclear Experiments Data Web-site http://cdfe.sinp.msu.ru. 2. V.V.Varlamov et al. // Book of Abstracts of Conference ”Nucleus-2011”. Sarov. P.266. 3. G.Audi et al. // Nucl.Phys. A. 2003. V.729. P.337. 4. Current version of “Nuclear Wallet Cards”, USA NNDC. http://www.nndc.bnl.gov/wallet/wccurrent.html. 260 "NUCLEAR PHYSICS IN INTERNET" - THE EXPERIENCE OF USING INTERNET TECHNOLOGIES IN EDUCATION E. Käbin1,2 1 Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Russia; 2 Faculty of Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] Department of General Nuclear Physics, Moscow State University in conjunction with the Institute of Nuclear Physics, Moscow State University have created web site "Nuclear Physics in the Internet" [1]. The site provides open access to educational and reference materials for nuclear and particle physics and related disciplines. There are especially materials for the general training course of nuclear and particle physics and in addition, for special courses and applied aspects of nuclear physics. This project will allow us to solve the following tasks: 1. Promptly supplement the instructional information that is especially important in this rapidly changing field of science as a nuclear physics; 2. Alleviate the shortage of modern textbooks; 3. Help other universities, often have no resources for the production of laboratory work; 4. Assist lecturers in preparing their lectures, providing materials in digital form (e.g. visual); 5. Provide materials for self-education. Published materials include: • Materials of the policies of nuclear physics and particle (lecture materials, problems and their solutions, methodical, and so on); • Materials of special courses; • Popular scientific articles; • Materials on applied aspects of nuclear physics; • Materials on radiation ecology; • Reference materials (link-lists of scientific centers sites, scientific journals, references to nuclear databases, etc.); • Photographs and biographies of physicists; • Links to educational materials, published on other sites, • Virtual laboratory practice, etc. 1. http://nuclphys.sinp.msu.ru. 261 THE EDUCATIONAL ABILITIES OF MSU NUCLEAR PHYSICS INSTITUTE AND NUCLEAR PHYSICS DEPARTMENT OF PHYSICS FACULTY M.I. Panasyuk, V.V. Radchenko, E.V. Shirokov Lomonosov Moscow State University, Skobeltsyn Nuclear Physics Institute, Russia E-mail: [email protected] MSU Nuclear Physics Institute and Nuclear Physics Department have more than fifty years experience of education for the students of different specialties in experimental basis at the atomic, nuclear and cosmic physics. The Nuclear Physics Department consists of 9 chairs with more than 250 students and 80 PhD students. The experimental training for Faculty of Physics students in general atomic and nuclear physics courses, and in special courses of Nuclear Physics Department takes part in the laboratories of general and special practicum of Nuclear Physics Institute. At the present time the laboratories have more than one hundred facilities. Each facility consists of radioactive (or X-ray) source, detector, additional electronic devices and PC. At the last years the Nuclear Physics Institute upgrades the facilities by changing the different parts. Moreover, the new educational tasks for the students are created in this period [1]. Nowadays, when a lot of universities in Russia don’t afford to have special laboratories for the students training, Nuclear Physics Institute and Department of Nuclear Physics have possibilities not only to offer own laboratories for another students, but also to organize on-line remote trainings on their facilities. By the information from the MSU space satellite “Universitetsky-Tatyana” and the information from another space devices, which are adopted to use in education, the special “space practicum” course was developed in the Nuclear Physics Institute [2]. Some tasks from this course already are performed in the local universities. The special devices for the imitations of real experimental facilities, without radioactive sources, based on PC for real data simulation were developed in the Nuclear Physics Institute, too. They also are very useful for many local universities. 1. http://nuclphys.sinp.msu.ru/p/index.html. 2. http://www.sinp.msu.ru/structinc/lib/books/space/space.pdf. 262 MAXIMAL FUEL DEPLETION DEPTH EVALUATION FOR PWR A. Aleinikov, M. Grigoriev Voronezh State University, Voronezh, Russia E-mail: [email protected] Fuel Assembles (FA) for Pressurized Water Reactors consist of uranium dioxide. This fuel is enriched up to 3-5% by U-235 isotope. Matrixes made of this granulated dioxide are allocated in zirconium alloy claddings. An efficiency of fuel usage depends on the maximal depletion depth of both fissile isotopes – initial U-235 and secondary Pu-239, which is reproduced in a reactor core during its operation. An increasing of the fuel depletion depth is one of the most important problems of the modern reactor physics because it determines the efficiency of the power unit operation. But strength properties of fuel claddings make a limitation of infinite increasing of this value because of fuel swelling due to nuclear decay products (moreover, some of them are gaseous). Authors estimated the excessive pressure created by mentioned reasons. Computer program was developed for this purpose. It was shown that partial pressure of decay gaseous products is quite insignificant and does not exceed 100 –300 kPa. The main reason of maximal depletion depth limitation concerns the solid decay products accumulation inside the fuel matrix. Its ultimate value should not exceed 85 MW∙day/kg for average fuel density 10.5∙103 kg/m3 and for 40 000 hours of fuel lifetime. The porous fuel becomes the solid one within this period (the chemically pure uranium dioxide density is 10.96∙103 kg/m3). Calculations were carried out with taking into account the absence of central opening in fuel matrixes. In spite of the fact that the fuel burn up process can reach depletion depth values beyond 50-55 MW∙day/kg, this limitation should be taken into account while designing pressurized water reactor cores. 263 NON-DESTRUCTIVE HYDROGEN ANALYSIS BY NUCLEAR PROTON METHOD BACKSCATTERING SPECTROMETRY O.V. Bespalova, A.M. Borisov, V.G. Vostrikov, E.A. Romanovsky, N.V. Tkachenko Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Russia E-mail: [email protected] Hydrides of metals are used in devices applied in modern Nuclear and Hydrogen Energetics. It is important to know H concentration in hydrogenated structures to investigate the process of hydrides formation and decomposition. Usually H concentration is determined by various physical and chemical methods which destroy a sample. In [1], it was studied how presence of H in surface layers of materials effects on the energy spectrum of protons with Ep = 7.6 MeV and α-particles with Eα = 2.5 MeV scattered at back angles on hydrocarbon materials and AlH3 targets. We have used the observed regularities to elaborate nondestructive method of hydrogen analysis in hydrogenated layers. In the present work, we measured spectra of protons with Ep = 7.5 MeV scattered at θlab = 160° on Al, Mg, Ti targets and AlHx, MgHx, TiHx targets with the various values of stoichiometric index x in order to determine H concentration. The spectrum amplitudes for Al and AlHx; Mg and MgHx; Ti and TiHx targets differ respectively. Namely, the larger index x the smaller spectrum amplitude is. It allows constructing a calibration curve and then to determine H concentration in surface layers of hydrogenated Al, Mg and Ti materials without destroy of the sample. The accuracy of the method with the use of calibration curve is about 2% if H concentration in surface layer is more than 30%. 1. A.M.Borisov, V.G.Vostrikov, V.S.Kulikauscas, et al. // Izv. RAN. Ser. Fiz. 2006. V.70. No.8. P.1210. 264 ABOUT THE SLOW WAVE BURNING REACTOR A. Aleinikov, E. Rubashkina Voronezh State University, Russia E-mail: [email protected] Slow burning wave reactor is studied. L. Feoktistov [1] has developed this idea in 1988, and further TerraPower firm evaluated it [2]. The basic idea is as follows. If we have a space filled with U-238 and external source of neutrons placed nearby this space, these neutrons will produce Pu-239 from initial material. Concentration of P-239 will grow and soon or later this system will become critical. Under certain conditions the core moves, and Plutonium is collected in subsequent area. As follows we get a stationary wave spreading in U-238 medium. However, it was proved, that the fuel burn up should be no less, then 20% or higher, but this value on fast breeding reactors now is less than 6%. One more problem was detected – the reactor core should be very long, and hydraulic resistance is very high. Many contradictions of this model do not consider this rector core as real reactor, so further investigations are required. 1. L.P.Feoktistov // Doklady AS USSR. 1989. V.309. P.864. 2. http://www.terrapower.com. 265 CERMET FUEL REACTOR CORE INVESTIGATION A. Aleinikov, S. Sementsov Voronezh State University, Russia E-mail: [email protected] One of the ways of PWR is to develop the usage of cermet fuel. This type of fuel has the matrix structure and it is an alternative fuel to traditional one. The development of fuel elements based on the microstructure of fuel allows improving the reactor set safety as well as operational characteristics of the reactor. The main design peculiarities of the cermet fuel are: fuel core of the cermet fuel element has a matrix structure? The base of it is the zirconium alloy, a space between fuel particles is filled with silumin alloy. Fig. 1. Basic attributes of ceramic and cermet fuel Fig.2. Fuel assembly element: 1 – cladding (zirconium alloy); 2 – 100 mm structure with depleting gap; 3 – uranium dioxide fuel; 4 – water coolant; 5 – depth 110 MW∙day/kg 100 μm aluminum alloy; 6 – zirconium matrix; 7 – micro (higher compactness). fuel (micro particles UO2 of 500 μm size) [1]. It was found that using the cermet fuel allows to increase the depleting depth of the fuel up to 140 MW∙day/kg. Change of fuel particle diameter will be no more then 0.5%. Total radioactivity of the spent fuel element is less than traditional one. 1. I.Fedik, S.Gavrilin // Atomic Energy. 2004. V.96. No.4. 266 SEARCH FOR FUKUSHIMA FALLOUT IN PETERHOF V.A. Sergienko, A.I. Zippa, A.O. Myorzlaya, S.V. Tchenmaryov Saint Petersburg State University, Russia E-mail: [email protected] March 11, 2011 in Japan was the strongest earthquake in the history of the country, followed by a tsunami, resulting in the three reactors of nuclear power plant “Fukushima-1” were damaged. The activity of radionuclides released into the atmosphere, including 134Cs (T=2.06 y) and 137Cs (T=30 y), is estimated to be 1–10 PBq. After the accident, cesium radionuclides were detected in air and soils in North America and some other regions [1]. In 2011 we have carried out a search for cesium isotopes in soils of Old Pe- terhof (near St. Petersburg). Presence of 137Cs was determined from the peak 661.7 keV, and 134Cs – from the peak 604.7 keV. Cumulative yield of 137Cs in the fission 235U by thermal neutrons is equal to 6.22%. 134Cs is also produced during the fission of nuclear fuel, but its yield is small – about 10–5 % [2]. A main channel of 134Cs formation is activation of sta- ble fission product 133Cs. Because of this, activity ratio 137Cs/134Cs depends on a nuclear reactor type. For Fukushima accident the ratio 137Cs/134Cs = 1 (for com- parison, the same ratio for the Chernobyl fallout in 1986 was equal to 1.89) [3]. We have collected the soil samples under drain from the roof of Faculty of Physics (drainage area about 25 m2) and on meadow near the building. The spectra of gamma rays were measured using HPGe detector “Can- berra” with relative efficien- cy 20% and resolution 1.8 keV at the peak of 60Co 1333 keV. In all samples the peak of 604.7 keV 134Cs does Fig. 1. Gamma-spectrum of the soil sample collected under the roof drain of Faculty of Physics. not exceed the background level. Hence, the minimum detectable activity of 134Cs in the samples did not exceed 1.7(3) Bq/kg. In the soil samples collected under the roof drain of Faculty of Physics the peak of 137Cs is clearly visible, which probably has the Chernobyl origin (Fig. 1). 1. E.Norman et al. // arXiv:1103.5954 (2011). 2. IAEA Handbook of Nuclear Data for Safeguards: http://www-nds.iaea.org/sgnucdat/. 3. M.Manolopoulou et al. // J. Environ. Radioact. 2011. V.102. P.796. 267 ANTICOINCIDENCE SPECTROMETER FOR CONTROL OF FUEL RODS IN NUCLEAR REACTOR M.N. Baev1, Yu.G. Polyakov2, S.A. Belov3, V.A. Sergienko3 1 Alexandrov Institute of Technology, Sosnovyj Bor, Russia; 2 Research center «RADEK», Saint Petersburg, Russia; 3 Saint Petersburg State University, Russia E-mail: [email protected] At 235U and 238U fission under the influence of neutrons in a nuclear reactor a large number of nuclides with various half-life periods, from seconds to tens years is formed. For an assessment of a condition of an active zone rather long and unsafe method of sampling now is used. It is offered to register gamma radiation from the radionuclides released in the coolant from failed fuel rods in case of their depressurization. For efficiency of control it is necessary to use the radionuclides which intensity of radiation quickly changes at change of the processes that are taking place in an active zone. It caused a choice of gamma radiation of short-lived isotopes as reference nuclides for control of a condition of fuel rods in an active zone of the reactor. However, changes of level of activity of reference radionuclides becomes complicated of presence at the coolant of a significant amount of the "secondary" radionuclides letting out high-energy gamma radiation and creating a high background at the expense of Compton scattering in a registering crystal. Constructed on a principle of anti-coincidence the gamma spectrometer having in the combined block of detecting, including main and protective detectors, allows to reduce essentially level of Compton background and by that to increase sensitivity of detection of reference nuclides in a spectrum. Along with the detecting block the structure of a spectrometer includes the power unit and the spectrometer block that is turning on modules: – processor module; – module of high-voltage bias; – module of coincidence; – module of amplifiers; – ADC module. The main technical characteristics of the developed spectrometer are presented in the table. Range of registered energy 0.04÷3.0 MeV Integral nonlinearity of spectrometric tract 0.05 % Energy resolution on the 1.33 MeV gamma-line 2.5 keV Temporal instability of energy calibration 0.5 % Maximum count rate (on the 1.33 MeV) 50000 counts/s Peak/Compton ratio 300 Time of setting of work regime < 10 min. 268 THE DEVELOPMENT OF PWR REACTORS CONTAINMENT LEAKS DETECTING METHODS A. Aleinikov1, N. Skrinnik2 1 Voronezh State University, Russia; 2 Novovoronezh Nuclear Power Plant, Russia E-mail: [email protected] Safety and reliability are most important problems of modern nuclear power plants operation. Ecological compatibility main criterion is the reducing of radioactive decay products release into environment both under normal operation conditions and in the case of an accident. One of the main barriers at the way of radioactivity spread is containment – a sealed volume containing all the facilities of the primary circuit. Different methods were developed to define a impermeability of the containment. Basic ones are absolute, compensative and relative. The absolute method of leak detecting is the most widespread. The gist of this method is to create some excessive air pressure inside the containment and then to measure the pressure, temperature and humidity change in time. Further, the total leak value can be defined using gas law. They use modern equipment and computer programs to estimate this value that can improve the measurement accuracy and reduce measuring time. The main idea of the compensative method is to feed excessive air into containment from external source. Leak value is defined by pumped air flow rate. Relative method uses an additional sealed vessel installed inside the containment. Knowing containment and vessel volumes one can define the leakage rate. In the frames of absolute detecting method there was developed computer program which allowed to shorten the power unit stoppage and to decrease the relative error by two times According to IAEA rules, it should be no less than combination of two methods to detect containment leak. Being in usage jointly with other ones, this method can determine the real leak of the containment. 269 AUTHOR INDEX A Barkov L.M. 122, 135 Barns D. 48 Abdullaeva G.A. 96, 218 Batkin I.S. 213, 214, 215, 216 Abdulmagead I. 57 Baurov A.Yu. 70 Abramov B.M. 117 Baurov A.Yu. (junior) 70 Abramovich S.N. 126 Baurov Yu.A. 70 Abu Kassim H. 167, 168 Beard M. 145 Achakovskiy O.I. 53 Belasarov K. 218 Adam J. 35 Beliuskina O.O. 109 Adamian G.G. 154, 187 Belousov A.V. 59, 217 Adel A. 192 Belov S.A. 268 Afanasjev A.V. 145 Belyaeva T.L. 33, 49, 50, 51, 111, 180 Aktaev N.E. 191 Belyshev S.S. 95, 125, 246 Aleinikov A. 263, 265, 266, 269 Berdnikov A.Ya. 120 Aleksa P. 73 Berdnikov Ya.A. 118, 119, 185, 243 Alekseev A.A. 239 Berlev A. 35 Alekseev P.A. 239 Bespalova O.V. 80, 81, 264 Alexandrov A.A. 128 Bezbakh A.A. 68, 230 Alexandrova I.A. 128 Bigan Z.M. 88, 89 Alexeev P.N. 117 Binderbauer M. 48 Almaliev A.N. 215, 216 Blokhintsev L.D. 200 Anderson M. 48 Bondarenko I.P. 104, 105, 106 Andrianov V.A. 245 Bordanovskii A.Yu. 103 Angeli I. 69 Borisov A.M. 264 Anokhin M.V. 244 Borodin Yu.A. 117 Antonenko N.V. 154, 187 Borowicz D. 235 Arsenyev N.N. 139 Botvina A.S. 30, 102 Artemov S.V. 108, 110, 184 Briancon Ch. 233 Artyushenko M. 35 Brudanin V.B. 40, 220, 233, 234, 235 Artyushin A.P. 239 Budzynski M. 250 Asadov M.M. 254 Bulkin A.P. 239 Avdeyev S.P. 30, 102 Bulychjov S.A. 117 Axenov S.N. 239 Bunakov V.E. 42, 43, 190, 193, 195 Burjan V. 114 Ä Burkert V.D. 123 Burmistrov Yu.M. 237 Äystö J. 93 Burtebaev N. 50, 110, 111 Bychkova E.A. 75 Bystritskii V. 48 B Babaikin A.N. 232 C Baev M.N. 268 Bakay D.S. 225 Čermák J. 234 Baktybayev K. 146, 147 Čermák P. 233, 234 Baldin A. 35 Chechenin N.G. 221 Barabanov M.Yu. 56 Chernyaev A.P. 59, 217 Baraeva S.A. 230 Chernyshev B.A. 67, 121 270 Chesnokov V.V. 123, 124 F Chilap V. 35 Chinenov A. 35 Fadeev S.N. 209 Chudoba V. 68, 230 Fedchenko V.A. 239 Chugunov A.I. 145 Fedorets I.D. 225 Chuluunbaatar O. 155 Fedorov A.V. 250 Churakova T.A. 215, 216 Feshenko A.V. 239 Chuvilskaya T.V. 116, 221 Filosofov D.V. 220, 235 Clementyev E.S. 239 Fomichev A.S. 68, 115, 230 Fomicheva L.N. 250 Fomina M.V. 212 D Fonarev B. 35 D’yachenko A.T. 196 Furman W. 35 Danilenko V.A. 257 Danilov А.N. 50, 111 G Demchuk N.A. 70 Demekhina N.A. 115, 116 Galanin M. 35 Demyanova A.S. 33, 49, 50, 51, 111, 112, Galanina L.I. 107, 108, 181 180 Galkin V.I. 244 Denikin A.S. 192 Garate E. 48 Derechkey P.S. 88, 89 Gauzshtein V.V. 122, 127, 135 Dikiy N.P. 225, 226 Giamanco F. 48 Dmitriev S.V. 50, 111 Gin D.B. 34 Dmitriev V.F. 122, 135 Gindin G.M. 193 Dolgopolov M.A. 213, 214, 215, 216 Gitlin V.R. 222, 256 Dolzhek M.A. 226 Gloukhov Yu.A. 112 Dominik W. 230 Glushkov A.V. 156, 170 Dovbnya A.N. 225, 226 Goldberg V.Z. 37 Drapey S.S. 74 Golovkov M.S. 68, 230 Dubinkin B. 35 Goncharov S.A. 49, 50, 51, 111, 112, 180 Dubov А.Е. 244 Goncharova N.G. 144 Dubrovskaya Yu.V. 176 Gontchar I.I. 191 Duisebayev A. 101 Gorbunov V.K. 239 Duisebayev B.A. 101 Gorelik M.L. 148 Dukhovskoy I.A. 117 Gorelov D.A. 93 Dunin V.B. 70 Gorkov V.P. 245 Dusaev R.R. 122, 127, 135 Gorozhankin V.M. 73 Dzhilavyan L.Z. 99, 246 Gorpinich О. 61 Dzhioev A.A. 32 Gorshkov A.V. 68, 230 Gorshkov V.A. 68 E Grachev M.I. 239 Grafutin V.I. 228 Efimov A.D. 150 Grantsev V.I. 109 Efremov V.P. 103 Greiner W. 140, 141, 142 Egorov V.G. 40, 136 Gridnev D.K. 140, 141 Egorova I.A. 68 Gridnev K.A. 140, 141, 178, 196, 208, 209 El Lithi Ali 57 Grigorenko L.V. 68, 230 Elouadrhiri L. 123 Grigoriev M. 263 Elumahov D.K. 103 Grimes S.M. 98 Ermakov A.N. 95, 125, 246, 247 Grishin V.K. 224 Ermakova T.A. 81 Gundorin N. 35 Eronen T. 93 Guo H. 48 271 Gurevich G.M. 29 Kaminski G. 68, 230 Gurov Yu.B. 50, 67, 111, 121, 235 Kankainen A. 93 Gus’kov B. 35 Kannykin S.V. 252 Guseinov D.T. 254 Karaivanov D.V. 250 Gusev A.A. 155 Karamian S.A. 90, 91, 92 Gusev K.N. 160 Karcz W. 30, 102 Karnaukhov V.A. 30, 102 H Karpeshin F.F. 157 Karpov A. 142 Hakala J. 93 Karpov A.V. 192 Havrilec T.V. 132, 133, 134 Kartashov V.M. 169 Heikkinen P. 50, 111 Karvonen P. 93 Hons Z. 72, 73, 114 Kayumov M.A. 184 Hussain I.A. 161, 162 Khankin V.V. 95, 246 Khanov A.I. 117 Kharin A.N. 252 I Khazov Yu.L. 82 Khetselius O.Yu. 164, 171 Ibraeva E.T. 177, 183, 201, 203 Khilmanovich A. 35 Igashov S.Yu. 39, 63 Khlapova N.P. 225 Ilyukhina O.V. 228 Khlebnikov S.V. 50, 111 Imambekov O. 177, 183 Khoviv A.M. 252 Ishkhanov B.S. 65, 95, 123, 124, 246 Khryachkov V.A. 104, 105, 106 Ismailov K.M. 101 Kim V.T. 185 Ivanin I.A. 232 Kinchakov V.S. 172 Ivanishchev D.A. 118, 120 Kirakosyan V.V. 30, 102 Ivanov A.E. 185 Kislitsin S. 35 Ivanova T.A. 104, 105, 106 Kisurin K.K. 109 Izosimov I.N. 259 Klimochkina A.A. 81 Koblik Yu.N. 96, 218 J Kobzev A.P. 46 Kochetov O.I. 233 Janas Z. 230 Koilyk N. 146 Jokinen A. 93 Kolesnikov N.N. 76, 77, 78 Jose J.M. 234 Kolesnikov V. 35 Julin R. 50, 111 Kolhinen V. 93 Juraev O. 130 Komarov S.Yu. 260 Kondratjev N.A. 128 K Konobeevski E.S. 64, 236, 237 Kononyhin A.S. 239 Kabatayeva R.S. 202, 203 Konyuhova I.A. 107, 108 Käbin E. 261 Kopatch Yu. 35 Kadmenskii A.G. 55, 221, 227 Koptelov E.A. 239 Kadmensky S.G. 36, 43, 188, 189, 190, 194, Kopytin I.V. 47, 161, 162, 213, 214, 215, 195 216 Kadmensky S.S. 195 Korablev A.V. 103 Kadykov M. 35 Korneev S. 35 Kajumov M. 130 Kornev A.S. 47 Kalinin A.Yu. 103 Korotkova L.Yu. 67, 121 Kalinnikov V.G. 71, 72, 73 Korovitskaya T.V. 178 Kamanin D.V. 128 Koslovsky A.L. 183, 201 Kamerdzhiev S.P. 53 Kostyuhov E. 35 272 Kotov D.O. 118, 120 Lukyanov S.M. 115 Kovalchuk V.I. 204 Lukyanov V.K. 57, 58 Král V. 234 Lutostansky Yu.S. 198, 242 Krassovitskiy P.M. 155, 183 Lyashko Yu.V. 225, 226 Kravchuk L.V. 239 Lyashuk V.I. 198, 242 Krinitsyn A.N. 103 Kroha V. 114, 115 M Krupko S.A. 68, 230 Krutenkova A.P. 117 Makan’kin A. 35 Krylovetskaya T.A. 161, 162 Maltsev N.A. 208, 209 Kryshkin V.I. 103 Mamedov F. 233, 234 Kucheryavii M. 35 Mar’in I. 35 Kudriashov V.I. 205, 207 Marcynkevich B. 35 Kugler A. 115 Marinova K.P. 69 Kukulin V.I. 31, 179, 202 Maris P. 38, 137 Kulabdullaev G.A. 218 Markov D.Yu. 67 Kulagin N.V. 103 Martemianov M.A. 117 Kulikov V.A. 38, 137 Maslov V.A. 115 Kulikov V.V. 117 Maslovskiy V.M. 255 Kulko A.A. 114, 115 Maslyuk V.T. 132, 133, 134 Kurilik A.S. 95, 125, 246, 247 Matsyuk M.A. 117 Kurteva A.A. 159 Mazur A.I. 38, 137 Kutuzov V.A. 239 Mazur V.M. 88, 89 Kuzmin E.A. 68 Mazzochi C. 230 Kuzmina A.N. 154 Medvedev D.V. 225, 226 Kuzminov B.D. 104, 105, 106 Medvedeva E.P. 225, 226 Kuznetsov A.A. 95, 125, 224, 246 Meshkov I.V. 239 Kuznetsov S.P. 239 Mianowski S. 230 Kuznetsova E.A. 128 Mikhajlov V.M. 150, 166 Kuzyakin R.A. 187 Mishnev S.I. 122, 135 Kvasil J. 73 Mokeev V.I. 123, 124 Moore I. 93 L Mordovskoy M.V. 64, 129, 236, 237 Morozov A.P. 96 Lapik A.M. 238 Morozov V.A. 85, 248 Lapushkin S.V. 67, 121 Morozova N.V. 85, 248 Lapushkin Yu.A. 239 Mrázek J. 114, 115 Lashko A.P. 83, 84 Murzin V.A. 185 Lashko T.N. 83, 84 Mustafaeva S.N. 254 Lebedev V.M. 107, 108, 229, 258 Myorzlaya A.O. 267 Lebedev V.T. 229 Lendyel A.I. 132, 133, 134 N Leshakova N.V. 208 Levin M.N. 255, 256 Nebesniy A.F. 96 Lin E.E. 199 Nedorezov V.G. 41, 99 Litvin V.S. 239 Nguyen VanGiai 139, 143 Loaïza P. 233 Nie G.K. 149, 184 Loginov A.Yu. 122, 127, 135 Nigmatkulov G.A. 97 Lubashevskiy A.V. 219, 220 Nikitin V.A. 70 Lubashevsky D.E. 36 Nikitina L.I. 175 Lukin P.V. 215, 216 Nikolenko D.M. 122, 127, 135 Lukyanov K.V. 57, 58 Nikolsky E.Yu. 66, 68 273 Norbeck E. 30, 102 Pyatkov Yu.V. 128 Novatsky B.G. 66 Novikov L.S. 223 R Nurmukhamedov A.M. 173, 174 Rabotkin V.A. 46, 252 O Rachek I.A. 122, 127, 135 Rachkov V.A. 192 Oeschler H. 30, 102 Radchenko V.V. 262 Oganessian Yu.Ts. 6, 68 Ramankulov K. 146 Ogloblin A.A. 33, 49, 50, 51, 111, 112, 180 Ratis Yu.L. 62, 182 Okhunov A.A. 167, 168 Rebyakova V.A. 119 Omelchuk S.E. 109 Reponen M. 93 Onegin M.S. 205, 207 Riabov V.G. 118, 120 Orlin V.N. 65 Riabov Yu.G. 118, 120 Orlov S.P. 229 Rinta-Antila S. 93 Orlov Yu.V. 175 Rissanen J. 93 Orlova N.V. 107, 108 Rodionov A.A. 82 Osipov A.S. 59, 217 Rogov A. 35 Romanov Yu.I. 165 P Romanovsky E.A. 80, 81, 264 Rosnovskiy S.V. 252 Pafomov V.E. 197 Rostoker N. 48 Palenzuela Y.Martinez 142 Roznyuk Yu.S. 109 Palkin G.P. 109 Rozov S.V. 220, 234, 235 Palvanov S.R. 130, 131 Rubashkina E. 265 Palvanova G.S. 130, 131 Rubchenya V. 93 Panasyuk M.I. 262 Rubtsova O.A. 138, 202 Panov I.V. 198 Rudenko B.A. 109 Parfenova Yu.L. 68 Ruiz L.Felipe 142 Parlag O.A. 132, 133, 134 Rukhadze E.N. 233, 234 Pasternak A.A. 34 Rukhadze N.I. 233, 234 Penionzhkevich Yu.E. 28, 114, 115, 116 Rukoyatkin P.A. 30, 102 Penttilä H. 93 Rumyantseva N.S. 136 Peskov N.N. 65, 75, 87, 260 Rusakov A.V. 238 Pfützner M. 230 Ruskov E. 48 Pietralla N. 139 Ryabov Y.V. 239 Pikul V.P. 96 Ryasny G.K. 250 Piquemal F. 233 Piskoř Š. 114 S Platonova M.N. 31, 179 Plavko A.V. 205, 207 Saastamoinen A. 93 Pohjalainen I. 93 Sadikov R.Sh. 122, 127, 135 Polyakov Yu.G. 268 Sadykov B.M. 101 Pomorski M. 230 Sadykov R.A. 239 Ponomareva E.V. 239 Safin M.Ya. 163 Potapenko A. 35 Safonov I.V. 39 Potashev S.I. 64, 236, 237 Safronova A. 35 Povoroznyk О. 61 Sagawa H. 143 Pritula R.V. 121 Sakhiyev S.K. 203 Prmantaeva B.А. 201 Sakuta S.B. 66, 110 Prokopev E.P. 228, 249 Salamatin A.V. 234, 250 Putvinski S. 48 Salamatin D.A. 250 274 Salihbaev U.S. 151, 153 Solnyshkin A. 35, 153 Samarin K.V. 211 Solodchenkova S. 35 Samarin V.V. 44, 210 Sorokin Yu.I. 158 Samsonov V.M. 118, 120 Sotnikov V. 35 Sandukovskiy V.G. 235 Spasskaya T.I. 80, 81 Saperstein E.E. 187 Spassky A.V. 107, 108 Sargsyan V.V. 187 Spirin D.O. 243 Savin D.A. 200 Stegailov V.I. 35, 71, 72, 73 Savrasov А.M. 74, 94, 100 Štekl I. 233, 234 Saytjanov Sh. 218 Stepanov D.N. 66 Schegolev V. 35 Stepanov M.E. 65, 75, 87, 123, 124, 260 Schramm S. 140, 141 Stepantsov S.V. 68 Schurenkova T.D. 67, 121 Stibunov V.N. 122, 127, 135 Semenov V.S. 109 Stopani K.A. 95, 125, 224, 246, 247 Semenova N.N. 104, 105, 106 Strekalovski O.V. 30 Sementsov S. 266 Struzhko B.G. 109 Semikh S.S. 220, 235 Sukharev D.E. 176 Serbin O.V. 252 Surkova I.V. 129 Serga I.N. 176 Sushko A.A. 231, 232 Sergachev A.I. 104, 105, 106 Sushkov A.V. 71, 72, 73 Sergeev C.V. 70 Svoboda O. 35 Sergeev V.A. 197 Symochko D.M. 88, 89 Sergienko V.A. 257, 267, 268 Serov V.L. 239 T Severyukhin A.P. 139, 143 Sharapov I.M. 64, 236, 237 Talov V.V. 103 Sharov P.G. 68 Taova S.M. 126 Shestakov Yu.V. 122, 127, 135 Tarasov D.V. 140, 141 Shirikova N.Yu. 71, 72, 73 Tarasov V.N. 140, 141 Shirokov A.M. 38, 137 Tatarintsev A.V. 256 Shirokov E.V. 262 Tatarintsev А.S. 255 Shirokova A.A. 116, 221 Tchenmaryov S.V. 267 Shitov Yu.A. 212, 234 Tchuvil’sky Yu.M. 63 Shumeiko M.V. 79 Ter-Akopian G.M. 68, 230 Shvedunov V.I. 95, 246 Tikhomirov V.V. 70 Sidorchuk S.I. 68, 230 Titarenko N.N. 113 Sidorkin S.F. 239 Titova L.V. 43, 188, 189, 190, 194 Sidorov A.A. 122, 127, 135 Tkachenko N.V. 264 Šimečkova E. 114 Tleulessova I. 177 Sinev G.V. 97 Tokarevsky V.V. 52 Skobelev N.K. 114, 115, 116 Tolokonnikov S.V. 187 Skorodumina Iu.A. 144 Toporkov D.K. 122, 127, 135 Skrinnik N. 269 Torilov S.Yu. 178 Skvortsov V.A. 86, 240, 241, 251 Trofimov V.N. 250 Skvortsov V.V. 103 Trunov D.N. 239 Slepnev R.S. 68, 230 Trunov V.A. 239 Slowinski B. 57 Trykova V.I. 113 Slusarenko L.I. 109 Trzaska W. 50, 111 Smolin V.A. 258 Trzhaskovskaya M.B. 157 Smolnikov A.A. 54 Tselebrovsky A.N. 238 Sobolev J.G. 115 Tsupko-Sitnikov V. 35 Sobolev Yu.G. 50, 111 Tsvyashchenko A.V. 250 275 Tulupov B.A. 186 W Turchanovich L.K. 103 Turdakina E.N. 117 Wagner V. 35 Tuszewski M. 48 Warot G. 233 Tyurin G.P. 50, 111 Westmeier W. 35 Tyutyunnikov S. 35 Wiescher M. 145 Wolski R. 68, 230 U Y Ulianov V.A. 239 Urin M.H. 39, 148, 186 Yakovlev D.G. 145 Urinov A. 151 Yakushev E.A. 220, 233, 234, 235 Usmanov P.N. 151, 153, 167, 168 Yanovsky V.N. 232 Utyonkov V.K. 79 Yarmukhamedov R. 110 Uvarov V.L. 225 Yushkevich Yu.V. 71 V Z Vaganov Yu.A. 71, 72 Zagrebaev V.I. 142, 192 Vakhtel V.M. 46, 252 Zaikin D.D. 129 Valiev F.F. 253 Zampaolo M. 233 Van Drie A. 48 Zaparov E.A. 184 Varlamov V.V. 65, 75, 87, 123, 124, 260 Zarubin P.I. 60 Vary J.P. 38, 137 Zavarzina V.P. 197 Varzar S.M. 59 Zelenskaya N.S. 5, 107, 108, 181 Vdovin A.I. 32, 151, 153 Zemlyanaya E.V. 57, 58 Velichkov A.I. 250 Zevakov S.A. 122, 127, 135 Verbitsky S.S. 238 Zhabitskaya E.I. 58 Viñas X. 140, 141 Zhabitsky M.V. 58 Vinitsky S.I. 155 Zhdanov S. 35 Vishnevsky A. 35 Zheltonozhsky V.А. 74, 94, 100 Vladimirova N. 35 Zhigalova А.М. 201 Vlasnikov A.K. 166 Zhitnikov I.V. 212 Vodopyanov A.S. 56 Zholdybayev T.K. 101 Vogel N.I. 86, 240, 241 Zhuchko V.E. 128 Voinov A.V. 98 Zhuk I. 35 Voitenkov D.A. 53 Zhuravlev B.V. 113 Volkov A.A. 103 Zhusupov M.A. 201, 203 Voronina E.N. 223 Zippa A.I. 257, 267 Voronko V. 35 Zon B.A. 45 Voronov V.V. 139, 143 Zuyev S.V. 64, 236, 237 Voskoboynik E.I. 114, 115 Vostrikov V.G. 264 Vyshnevsky I.N. 74, 100 276 LXII INTERNATIONAL CONFERENCE «NUCLEUS 2012» FUNDAMENTAL PROBLEMS OF NUCLEAR PHYSICS, ATOMIC POWER AND NUCLEAR TECHNOLOGIES (LXII MEETING ON NUCLEAR SPECTROSCOPY AND NUCLEAR STRUCTURE) BOOK OF ABSTRACTS June 25 – 30, 2012 Voronezh Russia Editor A.K. Vlasnikov Computer make-up by A.K. Vlasnikov Отпечатано копировально-множительным участком отдела обслуживания учебного процесса физического факультета СПбГУ. Приказ №571/1 от 14.05.03. Подписано в печать 13.06.12 с оригинал-макета заказчика. Ф-т 30х42/4, Усл. печ. л. 16. Тираж 186 экз., Заказ № 1601. 198504, СПб, Ст. Петергоф, ул. Ульяновская, д. 3, тел. 929-43-00.