INSriTUT.MAX VON LAUE-PAUL [ANGEVIN-GRENOBLE-FRANCE

^

for the use of the ILL facilities

All research proposals have to be submitted to the Scientific Commercially exploitable results Council for approval. The Council meets twice each year and the closing dates for the acceptance of applications are: Visitors and ILL scientists may occasionally be involved in ex­ February 15 and August 31. periments which have possible commercial applications. If any The completed research proposal forms should be sent to: scientist considers that this is the case, he should get in touch Scientific Coordination and Public Relations Office with the Scientific Secretary. (SCAPRO) Institut Max von Laue — Paul Langevin Other publications available 156 X Neutron Research Facilities at the ILL High Flux Reactor, Edi­ 38042 Grenoble Cedex tion June 1986. France Information and Regulations for Reactor Users, Long-Term Tel. 76 48 72 44 B. Maier Visitors and New Scientific Staff, Edition March 1984 76 48 71 79 G. Briggs Brochure "20 years ILL" issued on the occasion of the 20th 76 48 70 41 K. Mayer-Jenkins (Secretary) anniversary of the ILL on 19 January 1987 76 48 70 82 F. Cook (Secretary) all available from SCAPRO Telex: 320621 F Experimental Reports and Theory College Activities 1986 (Appropriate application forms may be obtained on I equest available from the ILL Library. from the above office). Under normal circumstances the ILL makes no charge for the use of its facilities. However, special equipment (other than the existing instruments, counters, standard cryostats and shielding requirements) must be provided by the user. This ap­ plies particularly to the experimental samples which must, in all cases, be provided by the user. Chemistry and Biology laboratory facilities are available for any necessary sample preparation. The ILL makes a limited contribution towards the travel and subsistence expenses for experimentalists coming from approv­ ed laboratories in the four member countries. (Details on request).

Front Cover A decision was made in 1986 to build the European Synchrotron Radiation Facility (ESRF) next to the ILL, following the proposal made by the ILL in Spring 1984. Five countries: France, the Federal Republic of Germany, Italy, Spain and the United Kingdom have already accepted to join the project in its foundation phase. The construction work is expected to start at the end of 1987. The close proximity between the ILL and ESRF will reinforce the com­ plementarity between neutron and X-ray experiments and certainly result in a scientific complex unmatched in the world.

2 Contents

THE INSTITUT LAUE-LANCEVIN p. 5 ORGANISATION OF THE ILL p. 6 VISITS AND EVENTS IN 1986 p. 8 DIRECTOR'S REPORT p. 10

Reactor Operation Colleges Department laCollege 2: Theory p. 19 SaReactor operation 1986 p. 109 College 3: Fundamental and nuclear physics p. 21 Work of the various groups p. 109 College 4: Structural and magnetic excitations p. 33 Other work p. 110 College 5.- Crystal and magnetic structures p. 39 College 6: Liquids, disorders and defects in materials p 49 College 8 and EMBL Grenoble: Biochemistry p. 56 College 9: Chemistry p. 60

Computing Department Instrument iàAutomation and Data Service (SAD) p. 113 Operation Department Central Computer Service p. 115 Special cryogenics 71 uCentral service 71 Maintenance and equipment of buildings and experimental positions 73 Fundamental and nuclear physics 74 ThreB-axis spectrometers 77 Time-of-Right, high resolution and diffuse scattering 80 Diffraction Instruments 87 Administration Special instruments and experiments 91 Special studies of experimental and instrumental techniques p 92 Department New projects p Finance p. 119 Personnel p. 122 Welfare + General Services p. 123

Directorate Services UScientific Coordinatio n and Public Relations Office p. 96 Library p. 98 Safety, Medical and Health Physics p. 99 SÉl^llB Miscellaneous List of seminars p. 126 Workshops, Theses p. 129 Publications p. 130 Author Index for Publications p. 153 Publications "in Press" p. 161 Experiments carried out at the ILL p. 165 ••I^H instruments & ^^^^fl Methods Department Multi-detectors p. 103 Mechanical construction p. 103 Electronics p. 103 Multi-Layer Laboratory p. 104 Monochromators p. 105

3 I I III I I II I I III I II I I III I I III i i mi i ii i .111 I I III I II I I III I « le nsiu 11 tax von -awe - au .angevin

he Institut Max von Laue-Langevin (ILL) at Grenoble was formally founded in January 1967, with the signature of an intergovernmental convention between France and the Federal Republic of Germany. The aim was to provide the scientific community of the affiliated countrieT s with a unique neutron beam facility applicable in fields such as the physics of condensed matter, chemistry, biology, nuclear physics and materials science. The construction of the Institut and its high flux reactor was undertaken as a joint French-German project, with a total capital investment of 335 million FF. The reactor went critical in August 1971 and reached its full power of 57 MW for the first time in December 1971. The year 1972 saw the start-up of the cold and hot sources, the first instruments and the beginning of the experimental programme. On January 1, 1973 the United Kingdom joined the Institut as a third equal partner, contributing its share to the total capital investment. The corresponding intergovernmental convention was formally signed in July 1974 by the pertinent ministers from the three affiliated countries. On December 9, 1981 a protocol was signed by representatives from the three member countries which extended the agreement until 1992 and beyond unless two years"notice of termination has been given. In December 1986, an agreement on 'Scientific Membership' of Spain was signed by the ILL and the Spanish Interministerial Commission on Science and Technology for a period of five years starting on January 1st, 1987.* The ILL is a non-trading company under French civil law. The three countries are represented by the following Associates: - Kernforschungszentrum Karlsruhe GmbH, Germany - Centre National de la Recherche Scientifique, France - Commissariat à l'Energie Atomique, France - Science and Engineering Research Council, United Kingdom. These Associates are represented on a Steering Committee, which establishes the general rules of the management of the ILL. The Institut is headed by a Director and two Assistant Directors, ail with a five year tenure, the former to be nominated alternately by the German and the British Associates, the other two by the remaining Associates. A Scientific Council, nominated by the Associates, advises the Directors on the scientific programme and on practical aspects relating to its operation. The scientific users' community of the ILL is represented in 8 subcommittees of the Scientific Council, which meet twice a year to select those research proposals which are to be carried out at the neutron beam facilities of the ILL. A further subcommittee of the Scientific Council deals with questions of instrumentation, serving as a discussion platform between the ILL and its external users. The purpose of the ILL thus differs from other research institutes in so far as it is a service institute created so that chemistry, solid state physics, fundamental and nuclear physics, biology and metallurgy specialists from laboratories in the partner countries can use the unique power of neutron techniques to broaden the attack on their problems. Designing and operating instruments and helping the visiting users to carry out their experiments is thus the principal task of the Institut's own scientists. The experimental use of the instruments by ILL staff is subject to the same approval system as their use by external teams.

*) Under this agreement Spanish scientists have access to the ILL facilities in the same conditions as the three member countries and have the possibility of sending two thesis students. A seat is reserved for a Spanish scientist in the ILL Scientific Council as well as membership in two of our sub-committees. The participation of Spain to the ILL Budget is limited to 1.5 "to.

5 External Organisation off the Institut Laue-langevin 1986 Associates of fho institut

Science and Engineering Commissariat à l'Energie Kernforschungszentrum Research Council (SERC) Atomique (CEA) Karlsruhe (KFK) Centre National de la Recherche Scientifique (CNRS)

Stooring Commlttoo («I lit larl nMHiii)

Atkinson (SERC) Cribler (CEA) Blncsing (BMFT) Clark (SERC) Horowitz (CEA) Deyda (BMFT) Leadbetter (SERC) Lehmann (CNRS) Klosc (KFK) Coles (Imp. Coll. London) Miquel (CNRS) Peisl (Univ. of Munich).

Audit Commission

Badham Poldermann Noack Middlecote Denby-Wilkes Riess

Scientific Council («I II» last Mtliql

Blanquet — CNRS Palaiseau Haensel — Observer BSRF Rainford — Univ. Southampton Buckingham — Univ. Cambridge Hahn — TH Aachen Rossat-Mignod — CEN Grenoble Comes — Orsay Lambert — Cfc'N Saclay Scherm — PTB Braunschweig Drifford — CEN Saclay Maier — ILL Schmatz — KFK Karlsruhe Dubbers — ILL Marezio — CNRS Grenoble Schult — KFA Jiilich Eitner -ILL Michaudon — ILL Steiner — HM1 Berlin Enderby — ILL Nierhaus — MPI Berlin Stewart — Univ. Reading Finney — Univ. London Ottewill — Univ. Bristol Stirling — ILL Fuller — Univ. Keele Perez y Jorba — Orsay Thomas — Univ. Oxford GeUetly — Univ. Manchester Petroff — LURE Vettier — ILL Gliser — ILL Press '— Univ. Kiel Oyôrffy — Univ. Bristol

SubcommHtoos of tho Scientific Council (at It» last smtlaf )

Fundamental and Structural Crystal and Liquids, Biochemistry Chem stry Instruments Nuclear Physics and Magnetic Magnetic Structures Disorders and Spectroscopy Colloids & Excitations Defects in Surfaces & Polymers Materials Mesophases

•teriovtMxl BMKtar Cnfckikaak Babei Comm Bcytoy BawflU Cabane AleftM *ntl*MW Bow*** Burl* Duptry tUaaquet Howard KoffBMna larjarr OtHttfy HoukM MFtaae> y ChMlwm Durand Bode Huetler Otuwtll Cfcarpak Lk* Hurt.Mi Msaer Dacha Gaakell Chabre Ltwapie» Picot OlfMT Motos LHH—ulMH Jacob» Floaejaet IMbon Finch Scrnrentner Richards Hicfuu FuwéWNify MWMfta Mantis Forgtn Pei»l Oiete Thomas StrobI 3dm** Overfly Sinclair Headanon Msaarat Phonier Stoeb Jacrot fcfHrm VaflaSMaHC* Zim Suck Mutais Taylor PMlipaon WUIaM Saeager

6 General Organigramme

Reactor Department SdeatUk CoortJtaatkii CoUegM Head: F. Franzettl * Pabtk Retatknu OHke Convenors: College Secretaries Reactor Operation Htad: B. Maler 2 Theory Operation of Sub-assemblies Co-ordination of the Experimental 3 Fundamental and Nuclear Physics Site Security Programme 4 Structural and Magnetic Excitations Organisation of Workshops 5 Crystal and Magnetic Structures & Conferences 6 Liquids, Disorder and Defects In Materials Public Relations 8 Biology 9 Chemistry Head: C. Jam* lnmwiet Groups CaatralQroap .-..•• Sample Bnviroaaaaat Oconp Cryoaaaks Service Site Majntraancf Visits and events in 1986

The following personalities visited the ILL in 1986: 12 May 1986 Mr G. Tegart (Secretary General of the Australian Ministry of Science). 18 June 1986 Herr Lothar Spath (Minister President of the Land Baden-Wiirttemberg, FRG). In his company were: — Professor Zwicker (President of the University of Stuttgart). — Professor Kunle (President of the University of Karlsruhe). — Professor Schupp (President of the University Freiburg). — Professor v. Klitzing (Institute Max Planck Stuttgart). 27 June 1986 Sir John Fretwoll (British Ambassador in France). 17 July 1986 Professor H. Staab (President of the Max Planck Society, FRG). 19 August 1986 Mr. J.-P. Capron (General Administrator of the CEA). 3 September 1986 Mr Sun Zuxun (Director of the Institute of Atomic Energy in the Chinese Ministry for Nuclear Energy). 5 November 1986 A delegation of politicians from Berlin (parliament, senate and electrical power company). 13 November 1986 Dr. J. Boright (Scientific Counsellor at the US embassy in Paris and Mr M. Cziesla (representative of the US Na­ tional Science Foundation). 17 November 1986 Professor Johansson (President of the Royal Swedish Academy of Sciences and member of the Physics Nobel Prize com­ mittee). Professor W. Glaser started his four year tenure as Director of I August 1986. In the picture he inspects Ihe new improvements on D7

Sir John Fretwelt fin the middle) fBritish Ambassador in France) visited the ILL on Minister President L. Spath from the Land Baden- Wiirltembcrg, FRG visited oar In­ 27 June 1986. In the picture he is welcomed by Professor Haenset (Director General stitut on IS June 1986. of the ESRF) and Prof. A. Michoudon (ILL French Assistant Director) (on Ihe right) Professor Johansson (Président of the Royal Swpdish Academy of Sciences andM-mber of the Physics Nobel Prize Committee/ visited the ILL on 17 November 1986. In the picture he receives explanations from Professor W. Glàser, ILL Director.

Among others, Mr. Spath was accompanied by Prof v. Kiitzing. Physics Nobel Prize Winner 1985 On the middle). ch schreibe dieses Vorwort zum Jahresbericht 1986, Wegen des grossen Interesses an einem besseren Verständnis meinen ersten 'Bericht des Direktors' ein paar Wochen des Anregungsspektrums von normalflüssigem 3He wurde im vor dem 20-jährigen Jubiläum der Gründung des In­ Laufe des Jahres von einer Kollaboration (Braunschweig, stituts Laue-Langevin. Als 1967 der Vertrag zwischen Studsvik und ILL) am Flugzeitspektrometer IN6 ein umfang­ I Frankreich und der Bundesrepublik Deutschland reiches Experiment an 3He bei T = 120 mK und Drücken bis geschlossen wurde, eine Neutronenquelle hoher Intensität für 20 bar durchgeführt. Streuung an nulltem Schall, an Paramag- die Nutzung in Festkörperphysik, Chemie, Biologie und Kern­ nonen und am Teilchen-Loch- Kontinuum konnten unterschie­ physik zu bauen, war nicht abzusehen, wie gross die Nutzer­ den werden. gemeinde werden würde. Am gleichen Spektrometer wurde von einer Kollaboration Nach der Inbetriebnahme des Reaktors im Jahr 1971 erreich (Darmstadt, München, ILL) bei der Untersuchung das Tun­ te das Institut mit seiner einzigartigen Ausstattung schnell ei­ nelverhalten von Wasserstoff in Niob unterhalb des Supralei­ ne führende Position auf dem Gebiet der Neutronenforschung. tungsübergangs der Einfluss der Leitungselektronen direkt Schon 1973 trat das Vereinigte Königreich als 3. Partner dem nachgewiesen. ILL bei. Schliesslich wurde 1986 Spanien für zunächst 5 Jah­ Mit Hilfe des Rückstreuspektrometers 1N10 konnte zum er­ re mit einem Beitrag von 1,5% des Budgets Mitglied des ILL. sten Mal die Sclbstdiffusion in Titaneinkristallen systematisch Einen Eindruck von der Grösse der Nutzergemeinde vermit­ untersucht werden und aus der Q-Abhängigkeit auf den do­ telt die jährlich eingereichte Zahl von Experimentiervorschlä­ minanten Diffusionsmechanismus geschlossen werden. gen. So wurden in den beiden Sitzungen des Wissenschaftlichen Rates im Jahr 1986 1147 Vorschläge mit einer gewünschten Fortschritte sind im Verständnis der Bewegungen von Mole­ Messzeit von 12780 Tagen beraten. Das Institut konnte nur külgruppen in molekularen Systemen zu verzeichnen. So wurde 5700 Messtage zur Verfügung stellen. z.B. mit dem IN5 und der hochauflösenden Rückstreuspek- trometrie erstmals nachgewiesen, dass sich auch die

Dabei sind die Experimentiermöglichkeiten in den letzten Jah­ NH3-Gruppe wie ein fast freier Rotator verhalten kann. ren insbesondere in dem grossen Modernisierungsprogramm wesentlich erweitert worden. Der Rt tktor kann jetzt mit ei­ Das wachsende Interesse an ungeordneten und teilgeordneten ner verbesserten Kalten Quelle und einer ganzen Reihe neuer Materialien spiegelt sich auch im .'rogramm des ILL wieder. Instrumente effektiver genutzt werden, als das vorher der Fall Erwähnt werden sollen nur die systematischen Untersuchun­ war. Der im Modernisierungsprogramm vorgesehene Einbau gen zur Aufklärung quasikristalliner Strukturen in Al/T- einer zweiten Kalten Quelle wird Ende 1987 abgeschlossen und Legierungen (T = Übergangsmetall). Hier bietet die Isotopen­ für mindestens 5 weitere Instrumente Platz schaffen. substitution einmalige Möglichkeiten. Auch der Reaktor selbst wurde durch Auswechseln der inten­ Auf dem Gebiet der Biochemie wurden Fortschritte in der Pro­ siv bestrahlten zentralen Einbauten und Strahlrohreinrichtun­ teinkristallographie gemacht. Mit dem Diffraktometer D19, gen modernisiert. Seit seiner Wiederinbetriebnahme im August das 1986 routinemässig eingesetzt werden konnte, konnten 1985 konnten 8 Reaktorzyklen zuverlässig gefahren und ef­ komplette Datensätze für Lysozym und Human-Haemoglobin fektiv genutzt werden. Eine 1986 vom Service Central de Sû­ aufgenommen werden. Seit April 1986 steht auch das neue Dif­ reté des Installations Nucléaires veranlasste umfassende fraktometer DB21 an der Kalten Quelle für die biologische Neubewertung der Sicherheit hat bestätigt, dass unsere Anla­ Strukturanalyse zur Verfügung. ge den modernen Sicherheitsanforderungen voll entspricht. Bei den Polymeren verschiebt sich das Interesse auf die syste­ matische Untersuchung von molekularen Prozessen bei der ge­ zielten Deformation der Materialien. In dieser Richtung sind im letzten Jahr mit Hilfe der Kleinwinkelstreuung eine grös­ Wissenschaftliches Programm sere Zahl von Versuchen durchgeführt worden. und Ergebnisse Ein neues Gebiet beginnt sich mit der Untersuchung von Ober­ Herausragende wissenschaftliche Ergebnisse des Jahres 1986 flächen, Oberflächenschichten und Grenzflächen zu ent­ sind in den anschliessenden Berichten der Kollegien zusammen- wickeln. Die Anwendung der r 'cutronentotalreflexion unter gefasst. Bei einem so umfangreichen Forschungsprogramm auf Ausnutzung der Isotopensubsticution kann neuartige Einsich­ ganz verschiedenen Gebieten, wie es am ILI. durchgeführt ten in das Verhalten von Oberflächen und oberflächennahen wird, wird es immer schwierig sein, aile Ergebnisse richtig zu Schichten vermitteln. würdigen. Ich möchte hier nur versuchen, anhand einiger Bei­ Bei den S-Experimenten möchte ich insbesondere den 1986 im spiele neuere Entwicklungen anzudeuten. Bereich der hochaufiösenden -/-Spektroskopie erzielten Fort­ schritt erwähnen. Mit dem Doppelkristallspektrometer Die Inbetriebnahme des thermischen 3-Achsenspektrometers GAMS4 (Kollaboration Washington, ILL) wurde zum ersten IN20 mit der Option der inelastischen Polarisationsanalyse im Mal für -y-Energien im MeV Bereich der Idealfall der dyna­ Laufe des Jahres 1986 hat neue Untersuchungsmöglichkeiten mischen Beugung experimentell verwirklicht (Auflösung eröffnet, die in ersten Experimenten erfolgreich genutzt wer­ 5 den konnten. So konnten z.B. in dem quasi-ld System AX/X, = 10"). Hier zeichnen sich interessante neuartige An­ CsNiFj, das ferromagnetisch ist, mit Hilfe der Polarisations­ wendungen ab. analyse zum ersten Mal Spinenergie-Dichtefluktuationen nach­ Schliesslich konnte 1986 die auf dem Niveau D des Reaktors gewiesen und in dem ebenfalls quasi-ld TMMC installierte neue Quelle für sehr langwellige und ultrakalte Neu­ (antiferromagnetisch) 2 Magnonen-Moden identifiziert wer­ tronen in Betrieb genommen werden (Kollaboration München, den. Verbesserungen der Superspiegelpolarisationstechnik er­ ILL) Mit dieser Quelle konnte die früher am Strahlrohr PN5 möglichen es, den dynamischen Bereich der inelastischen verfügbare Intensität um einen Faktor 50 - 80 erhöht werden. Polarisationsanalyse am Instrument D7 wesentlich zu ver- In erster Linie stellen die sehr langsamen Neutronen geeigne­ grössern. te Objekte zur genaueren Untersuchung der Eigenschaften des

10 Neutrons se'bst dar, eröffnen aber auch neue Möglichkeiten für die Erforschung der kondensierten Materie. Im Laufe des Zum Abschluss obliegt mir die traurige Pflicht, vom Tod Jahres wurden zwei Speicherexperimente mit dem Ziel einer dreier dem ILL verbundenen Personen zu berichten : Das genaueren Bestimmung der Lebensdauer des Neutrons begon­ frühe Ableben unseres wissenschaftlichen Mitarbeiters nen. Weiter konnte das Prinzip eines Neutronenmikroskops Rudolf MEYER wird von uns allen, seinen Kollegen und mit einer Vergrösserung von etwa 100 getestet werden. Freunden betrauert. Prof. Werner SCHMA TZ und Prof. Walter HOPPE, unerwartet bzw. nach langem Leiden verschieden, haben durch ihre jahrelange, engagierte Mitarbeit in unserem Wissenschaftlichen Rat das ILL Personalia mitgeprägt. Wir werden sie deshalb in besonderer Erin­ nerung behalten. Mitte des Jahres fand ein unvorhergesehener Wechsel im Direktorium statt. R. Haensel schied Ende Mai als Direktor des ILL aus, um die Leitung der aufzubauenden Europäischen Synchrotronstrahlungsquelle (ESRF) zu übernehmen. In den W. Gläser Monaten Juni und Juli leitete J.E, Enderby die Geschicke des Instituts. Sein Nachfolger kommt aus München, wo er am Physik-Department der Technischen Universität das Gebiet der Neutronenphysik vertreten hat und von wo aus er seit langem als aktiver Nutzer die Experimentiermöglichkeiten des ILL schätzen gelernt hat. Auch in diesem Jahr sind wieder einige Mitarbeiter ausgezeichnet worden oder haben Berufungen erhalten. P. Ageron hat den Prix 'Foucault' der französischen physikalischen Gesellschaft bekommen und A. Hewat ist mit der Ehrendoktorwürde der Universität Uppsala ausgezeichnet worden. K. Ziebeck hat einen Ruf als ordentlicher Professor an die Universität Loughborough angenommen und R. Pynn ist zum Direktor des Neutronenstreuzentrums am Los Alamos Scientific Laboratory bestellt worden. Diese Anerkennungen sind auch eine Auszeichnung für das ganze Institut. Zu erwähnen ist weiter, dass im Berichtszeitraum eine Reihe von bekannten Politikern und Wissenschaftlern das Institut besucht haben. Hier sind u.a. zu nennen: Herr L. Späth (Ministerpräsident von Baden-Württemberg), Sir J. Fretwell (Botschafter Grossbritanniens in Frankreich), Herr Prof. Dr. H. Staab (Präsident der Max-Planck-Gesellschaft), M. J.P. Capron (Administrateur Général des CEA), Herr Prof. Sun Zuxun (Direktor des Instituts für Atomenergie Pek­ ing), Herr Prof. S. Johansson (Präsident der Schwedischen Akademie derWissenschaften).

Zusammenarbeit mit ESRF 1986 hat die Vorbereitungsphase für die Errichtung der Europ. sehen Synchrotronstrahlungsquelle in Grenoble begon­ nen. Das ILL freut sich, dass der provisorische Rat der ESRF in seiner Sitzung am 24. Oktober den vom ILL ursprünglich vorgeschlagenen Standort für das Synchrotron direkt neben dem ILL zwischen Drac und Isère ausgewählt hat, der die besten Voraussetzungen für die zukünftige Zusammenarbeit beider Institute bietet. Da die ESRF während der Vorbereitungsphase legal noch nicht existiert und nicht eigenständig handeln kann, hilft das ILL zunächst hauptsächlich in administrativen Angelegenheiten aus. Im Laufe des Jahres sind zwei Abkommen zwischen dem ILL und der ESRF-Projektgruppe abgeschlossen worden, die Einzelheiten dieser Hilfe regeln. Es ist weiter zu erwähnen, dass die Direktoren beider Einrichtungen kürzlich ihren Wunsch zum Ausdruck gebracht haben, beide Einrichtungen auf einem gemeinsamen Gelände zu betreiben. Dies wird die Basis für weitere Schritte in Richtung auf eine ökonomische und ef­ fektive Zusammenarbeit zum Vorteil beider Institute sev am writing this introduction to the 1986 Annual Re­ spectrometer IN6 by a collaboration between Brunswick, port, my First Director's report', a few weeks before Studsvik and ILL. It was possible to distinguish between scat­ the 20th anniversary of the foundation of the Institut tering at zero sound, paramagnons and the particle-hole con­ Laue-Langevin. When the Agreement between Fran­ tinuum. I ce and the Federal Republic of Germany was signed On the same spectrometer the effect of conduction electrons in 1967, to build a high intensity neutron source for use in so­ was directly verified in the study of hydrogen tunnelling in Nio­ lid state physics, chemistry, biology and nuclear physics, it bium below the superconducting transition by a collaboration could not be foreseen how large the user community would (Darmstadt, Munich, ILL). become. With the back-scattering spectrometer IN10 it was possible for After the reactor started up in 1971, the Institut with its uni­ the first time to investigate systematically self-diffusion in Ti­ que range of equipment rapidly attained a leading position in tanium single crystals and to draw conclusions on the domi­ neutron research. In IV J the United Kingdom joined the ILL nant diffusion mechanism from the Q-dependence. as third partner. Finally in 1986 Spain joined ILL, initially for Progress has been made in understanding the movements of five years, making a contribution of 1.5 % to the Budget. groups of molecules in molecular systems. For example with The numbe- of experiment proposals submitted each year gi­ IN5 and high resolution back-scattering spectrometry it was ves an impression of the size of the user community. At the shown for the first time that the NHi group can also behave two meetings of the Scientific Council in 1986, a total of 1147 as an almost free rotator. proposals for a requested measuring time of 12780 days were The increasing interest in disordered and partially ordered ma­ discussed. The ILL was able to provide only 5700 measuring terials is also reflected in the ILL programme. Mention should days. only be made of the systematic studies to clarity quasi- This is despite the fact that in recent years the experimental crystalline structures in Al-T alloys (T = transition metal). facilities have been considerably extended, particularly under Here isotopic substitution offers unique opportunities. the large scale Modernisation Programme. With an improved In biochemistry, progress has been made in protein crystallo­ cold source and a range of new instruments the reactor can graphy. With the multi-detector diffractometer D19, which was now be used more effect'vely than before. The installation of scheduled routinely in 1986, complete data sets were recorded a Second Cold Source provided for under the Modernisation for lysozyme and human haemoglobin. Since April 1986 the Programme will be completed at the end of 1987 and provide new diffractometer DB21 on the cold source has also been avai­ space for at least 5 further instruments. lable for biological structural analysis. In polyn. -, interest is shifting to the systematic investigation The reactor itself has also been modernised by the replacement of the central elements and beam tubes which have been sub­ of molecul, nrocesses in deliberate deformation of materials. ject to intensive irradiation. Since the restart in August 1985 A large nun r of experiments have been carried out in the 8 reactor cycles have been operated with a high degree of re­ last year in t sense with the aid of small angle scattering. liability and effective utilisation. A comprehensive re- A new area is starting :o develop with the study of surfaces, evaluation of the safety of the reactor requested by the French surface layers and interlaces. The use of total neutron reflec­ Central Safety authorities in 1986 has confirmed that our in­ tion with isotopic substitution can give a new insight into the stallations are fully in accordance with the latest safety requi­ behaviour of surfaces and layers near the surface. rements. As regards the "S"experiments, particular mention should be made of the progress achieved in 1986 in the field of high re­ solution gamma spectroscopy. With the double crystal spec­ Scientific: programme and results trometer GAMS4 (collaboration Washington, ILL) the ideal case of dynamic diffraction was experimentally realised for Excellent scientific results for 1986 are summarized in the re­ the first time lor gamma energies in the MeV range (resolu­ ports from the colleges which follow. With such a compre­ tion AX/X = 10'}. There are interesting and novel applica­ hensive research programme as is carried out at ILL in very tions in this yrca. varied fields it will always be difficult to make a full appre­ Finally, in 1986 the new source for very long wavelength, ultra- ciation, but a few examples will give an indication of the new cold neutrons installed in level D of the reactor started opera­ developments taking place. tion (collaboration Munich, ILL). With this source it has been The commissioning during 1986 of the 3-Axis spectrometer for possible to increase the intensity previously available on be­ thermal neutrons 1N20 with the option of inelastic polarisa­ am SN5 by a factor 50 to 80. In the first place very slow neu­ tion analysis has opened up new possibilities for research, trons are suitable subjects for the more detailed examination which have been successfully utilised in the initial experiments. of the properties of the neutron itself, but they also open up

For example in the quasi-ld system CsNiF3, which is ferro­ new possibilities for the study of condensed matter. During magnetic, it was possible for the first time with the aid of po­ the year two storage experiments were started with the aim of larisation analysis to verify spin energy-density fluctuations, a more prec;se determination of the neutron lifetime. It was and in TMMC (antiferromagnetic), which is also quasi-ld, to also possible to test the principle of a neutron microscope with identify 2 magnon modes. Improvements in supermirror po­ a magnification of about 100. larisation technology permit a considerable increase in the de­ veloping area of inelastic polarisation analysis on D7. Because of the great interest in a better understanding of the Personnel excitation spectrum of normally fluid 3He, a comprehensive In the middle of the year there was an unforeseen change of experiment was carried out during the year on 3He at Director. R. Haensel gave up his post as Director of the ILL T = 120 mK and pressures up to 20 bar on the time-of-flight at the end of May, to take charge of the European Synchro-

12 tron Radiation Facility (ESRF), which is to be built up. In June and July J.E. Enderby directed the destiny of the Institut. His successor comes from Munich, where he represented the Neutron Physics field in the Physics Department at the Technical University, from where he has long valued the ILL'S experimental facilities in his capacity as an active user. This year too, certain ILL staff members have received honours or prizes. P. Ageron received the"Prix Foucault"of the Société Française de Physique, and A. Hewat was award­ ed an honorary doctorate of the University of Uppsala. K. Ziebeck accepted a post as Professor at the University of Loughborough and R. Pynn has been appointed Director of the Neutron Scattering Center at the Los Alamos Scientific Laboratory. These honours are also a distinction for the en­ tire ILL. It should also be mentioned that a number of well-known political and scientific personalities have visited the Institut. To name but a few : Mr. L. Spath (Prime Minister of Bade- Wurtemberg), Sir J.Fretwell (British Ambassador in France), Professor H, Staab (President of the Max Planck Gesellschaft), Mr. J.P. Capron (Administrateur Général of the CEA), Pro­ fessor Sun Zuxun (Director of the Atomic Energy Institute, Peking), Professor S. Johansson (President of the Swedish Academy of Sciences).

Collaboration with the ESRF In 1986 the preparatory phase for the establishment of the European Synchrotron Radiation Facility in Grenoble began. The ILL is pleased that the provisional Council of the ESRF at its meeting on 24 October chose the site for the Synchrotron directly adjacent to the ILL between the Drac and the Isère, as originally proposed by the ILL, which offers the best con­ ditions for the future collaboration between the two institutes. As the ESRF during its preparatory phase has as yet no legal existence, and cannot negotiate independently, the ILL is assisting it, at first maii.ly in administrative matters. During the year two Agreements have been signed between the ILL and the ESRF Project Group, covering details of this assistance. It should also be mentioned that the Directors of the two organisations recently expressed their wish that both institutes should be operated on a joint site. This will be the basis for further steps in the direction of an economical and efficient collaboration to the advantage of both organisations.

Finally 1 have the sad task of recording the deaths of three scientists associated with the ILL: the untimely death of the young ILL physicist, Rudolf MEYER, is mourned by all his colleagues and friends. Professor Werner SCHMATZ died unexpectedly and Professor Walter HOPPE after a long illness; both helped to mould the ILL by their years of commitment to the work of the Scientific Council. We shall remember them particularly for this.

W. Glaser

13 k i i i i ill l m » ,' w i

'écris cette introduction au Rapport Annuel 1986, de façon significative la gamme dynamique de la diffusion iné­ mon premier "Rapport du Directeur", quelques lastique avec analyse de polarisation sur l'instrument D7. semaines avant le 20e anniversaire de la création de A cause du grand intérêt d'une meilleure compréhension du l'Institut Laue-Langevin. Lorsqu'en 1967 la Conven­ spectre d'excitation de 3He normalement fluide, une expé­ J tion entre la France et la République Fédérale rience très complète sur 3He à T = 120 mK et à des pressions Allemande jusqu'à 20 bars a été effectuée cette année sur le spectromètre a été conclue pour la construction d'une source neutronique à temps de vol IN6 dans le cadre d'une collaboration (Bruns­ de haute intensité pour son utilisation dans les domaines de wick, Studsvik et ILL). La distinction a pu être faite entre les physique de l'état solide, chimie, biologie et physique nucléaire, diffusions du "son zéro", des paramagnons et du continuum il était impossible de prévoir à quel point la communauté des particule-trou. utilisateurs deviendrait importante. Sur le même spectromètre l'influence des électrons de conduc­ Après la mise en marche du réacteur en 1971, l'Institut avec tion a pu être directement vérifiée lors de l'étude de l'effet tun­ son équipement unique a rapidement atteint une situation de nel de l'hydrogène dans le Niobium en phase supraconductrice pointe dans le domaine de la recherche neutronique. En 1973, dans le cadre d'une collaboration (Darmstadt, Munich, ILL). le Royaume Uni adhéra à l'ILL en tant que troisième parte­ Grâce au spectromètre à rétrodif fusion IN 10, il a été possible naire. En 1986 l'Espagne a rejoint l'ILL, dans un premier pour la première fois d'étudier systématiquement l'auto- temps pour une période de cinq ans, avec une contribution au budget de 1,5 <7o. diffusion dans des monocristaux de titane et à partir de la dépendance en Q de tirer des conclusions sur le mécanisme de Le nombre des propositions d'expériences soumises chaque diffusion dominant. année donne une idée de l'importance de la communauté des Des progrès sont à signaler dans la compréhension du mouve­ utilisateurs. Ainsi, lors des deux réunions du Conseil Scienti­ ment des groupements moléculaires dans les systèmes molé­ fique en 1986, au total 1147 propositions, correspondant à une culaires. Ainsi, avec IN5 et la spectrométrie à rétrodiffusion demande de temps de mesure de 12780 jours, ont été discu­ à haute résolution, il a été vérifié pour la première fois que tées. L'Institut n'a pu mettre à disposition que 5700 jours de le groupe NH3 peut également se comporter comme un rota­ mesure. teur presque libre. Ceci malgré l'augmentation considérable des possibilités L'intérêt croissant pour des matériaux désordonnés et partiel­ expérimentales ces dernières années, en particulier dans le cadre lement ordonnés se reflète également dans le programme de de l'important Programme de Modernisation. Le réacteur peut l'Institut. Mentionnons seulement les études systématiques maintenant être utilisé avec davantage d'efficacité, avec une pour clarifier les structures quasi-cristallines dans les alliages source froide améliorée et toute une série de nouveaux Al-T (T = métal de transition). Ici la substitution isotopique instruments. L'installation d'une nouvelle source froide pré­ offre des possibilités uniques. vue dans le Programme de Modernisation sera achevée fin 1987 et créera de la place pour au moins cinq instruments supplé­ Dans le domaine de la biochimie, des progrès ont été faits dans mentaires. la cristallographie des protéines. Avec le diffractomètre D19 qui a pu être exploité de façon routinière en 1986, des séries Le réacteur lui-même a également été modernisé par le rem­ complètes de données ont pu être enregistrées pour la lysozyme placement des éléments centraux et des doigts de gant soumis et l'hémoglobine humaine. Depuis Avril 1986 le nouveau dif­ à une irradiation imense. Depuis son redémarrage en Août fractomètre DB21 sur la source froide est disponible pour 1985 huit cycles de réacteur ont pu avoir lieu et être exploités l'analyse des structures biologiques. de manière efficace. En 1986 une nouvelle étude approfondie Dans les polymères, l'intérêt se déplace vers l'examen systé­ de la sûreté, demandée par le Service Central de Sûreté des matique des processus moléculaires sous l'effet d'une défor­ Installations Nucléaires, a confirmé que nos installations cor­ mation appliquée. Un grand nombre d'expériences a été respondaient tout à fait aux exigences actuelles de la sûreté. effectué dans ce sens pendant l'année grâce à la diffusion aux petits angles. Un nouveau domaine commence à se développer avec l'étude Programme scientifique et résultats des surfaces, des couches superficielles et des interfaces. L'uti­ Des résultats scientifiques excellents de l'année 1986 sont résu­ lisation de la réflexion totale des neutrons avec substitution més dans les rapports des Collèges qui suivent. Avec un pro­ isotopique peut donner des indications nouvelles sur le com­ gramme de recherche aussi vaste et se répartissant sur des portement des surfaces et des couches près de la surface. domaines si différents, il sera toujours difficile d'évaluer tous En ce qui concerne les expériences spéciales dites "S', j'aime­ les résultats correctement. Ici je me contenterai d'illustrer par rais mentionner en particulier les progrès réalisés en 1986 dans quelques exemples des derniers développements. le domaine de la spectroscopic gamma à haute résolution. Avec La mise en service en 1986 du spectromètre à 3 Axes IN20 pour le spectromètre à double cristal GAMS4 (collaboration Was­ la diffusion inélastique des neutrons thermiques avec option hington - ILL) le cas idéal de courbure dynamique a été réa­ lisé pour la première fois pour des énergies gamma dans la d'analyse de polarisation a ouvert de nouvelles possibilités de 5 recherche qui ont été exploitées avec succès lors des premières gamme du MeV (résolution AX/X = 10 ). Des nouvelles expériences. Ainsi par exemple, dans le système ferromagné­ applications intéressantes se dessinent ici. tique quasi-unidimensionnel CsNiF3, il a été possible avec Enfin la nouvelle source de neutrons ultra-froids de très grande l'aide de l'analyse de polarisation de mettre en évidence les longueurs d'onde installée au niveau D du réacteur a pu être fluctuations de densité d'énergie de spin et d'identifier des mise en marche en 1986 (collaboration Munich - ILL). Avec modes à 2-magnons dans le TMMC (antiferromagnétique), cette source il a été possible d'augmenter d'un facteur 50 à également quasi-unidimensionnel. Des améliorations de la tech­ 80 l'intensité disponible sur le faisceau SN5. D'abord les neu­ nique de polarisation par supermiroirs ont permis d'augmenter trons très lents sont bien adaptés à l'étude plus précise des

14 propriétés du neutron lui-même, mais ils ouvrent également des nouvelles possibilités pour la recherche sur la matière con­ Pour conclure, j'ai le triste devoir de faire pan du décès densée. Pendant l'année deux expériences de stockage ont de trois chercheurs étroitement associés à l'Institut : notre démarré en vue de la définition plus précise de la durée de vie jeune collègue scientifique Rudolf MEYER, disparu du neutron. Par ailleurs 1-* principe du microscope à neutrons prématurément et regretté de nous tous, ses collègues et avec un grossissement de 100 environ a pu être testé. amis ; le Professeur Werner SCHMA TZ décédé subitement ainsi que le Professeur Walter HOPPE disparu après une longue maladie qui, en tant que membres du Conseil Scien­ tifique pendant de nombreuses années, ont marqué de façon Questions de Personnel décisive l'activité scientifique de l'ILL. Nous leur en som­ Au milieu de l'année il y a eu un changement imprévu à la mes particulièrement reconnaissants. Direction. A la fin du mois de Mai, R. Haensel a quitté son poste de Directeur de PILL afin de prendre la Direction de la Source Européenne de Radiation Synchrotron (ESRF) à con­ W. Glâser struire. Pendant les mois de Juin et Juillet, J.E. Enderby a dirigé le destin de l'Institut. Son successeur vient de Munich où il a représenté le domaine de la physique neutronique au Départe­ ment de Physique de l'Université Technique et à partir d'où, en tant qu'utilisateur actif, il a pu depuis longtemps apprécier les possibilités expérimentales de TILL. Cette année également quelques collègues ont reçu des prix ou des distinctions. P. Ageron a reçu le Prix Foucault de la Société Française de Physique et A. Hewat a été honoré d'un Doctorat Honoris Causa de l'Université d'Uppsala. K. Ziebeck a accepté un poste de Professeur à l'Université de Loughborough et R. Pynn a été nommé Directeur du Centre de Diffusion Neutronique au Laboratoire National de Los Alamos. Ces distinctions sont également un grand honneur pour tout l'Institut. Il faut d'ailleurs mentionner que pendant l'année plusieurs personnalités du monde politique et scientifique ont visité l'Institut. Citons entre autres : M. L. Spath (Premier Ministre de Bade- Wurtemberg), Sir J. Fretwell (Ambassadeur britannique en France), le Professeur H. Staab (Président de la Max-Planck- Gesellschaft), M. J.P. Capron (Administrateur Général du CEA), le Professeur Sun Zuxun (Directeur de l'Institut de l'Energie Atomique à Pékin) et le Professeur S. Johansson (Président de l'Académie des Sciences Suédoise).

Collaboration avec l'ESKF En 1986 la phase préparatoire de la construction de la Source Européenne de Rayonnement Synchrotron à Grenoble a commencé. L'ILL se réjouit que le Conseil provisoire de l'ESRF lors de sa réunion, le 24 Octobre, ait choisi pour le synchrotron le site proche de l'ILL, entre le Drac et l'Isère, proposé par l'ILL à l'origine, offrant les meilleures conditions pour la collabora­ tion future entre les deux Instituts. Puisque pendant la phase préparatoire l'ESRF n'a pas encore d'existence légale et ne peut agir pour elle-même, l'ILL l'aide au début, surtout pour les questions administratives. Pendant l'année, deux accords ont été signés entre TILL et le groupe de projet ESRF, qui règlent les détails de cette assistance. Il faut également mentionner que les directeurs des deux organismes ont récemment exprimé le souhait d'exploiter les deux installations sur un site commun. Ceci sera la base pour d'autres pas dans le sens d'une collaboration économique et efficace à l'avantage des deux Instituts.

15/' COLLEGES

tj Einleitung Die gesamte wissenschaftliche Tätigkeit des Instituts ist in Kol­ erste dem ILL unterbreitete Vorschläge zu neuen Forschungs­ legien mit spezifischen wissenschaftlichen Interessen aufgeteilt. vorhaben im Hinblick auf ihre technische Realisierbarkeit. Zur Zeit sind folgende Kollegien am Institut tätig : Daraufhin werden sie den Unterausschüssen vorgelegt. Eine Kollegium 2 : Theorie. weitere Aufgabe der Kollegien ist es, zu einem reibungslosen Kollegium 3 : Grundlagen- und Kernphysik. Ablauf der Experimente beizutragen : Sie stellen den Gastfor­ Kollegium 4 : Strukturelle und magnetische Anregungen. schern wissenschaftliche Hilfe vor Ort und beraten den Ver­ Kollegium 5 : Kristallographische und magnetische Strukturen. antwortlichen der Experimentiereinrichtung und den Kollegium 6 : Flüssigkeiten, Unordnungen und Fehlstellen in Wissenschaftlichen Sekretär über die Zeiteinteilung für die Ex­ Substanzen. perimente an den verschiedenen Instrumenten. Die Sekretäre Kollegium 8 : Biochemie. der Kollegien werden normalerweise für 2 Jahre gewählt, und Kollegium 9 : Chemie. halten mit der Direktion und den "Senior Scientists" regel­ Jedes Kollegium entspricht einem Unlerrausschuss des Wis­ mässig Sitzungen ab, um den notwendigen und alle wissen­ senschaftlichen Rates des ILL, der die Direktion in Fragen des schaftlichen Tätigkeiten des ILL betreffenden Informations- wissenschaftlichen Programms berät. Die Kollegien prüfen als fluss zu gewährleisten.

HIIIOUUCIHHI

All the internal scientific activity of the Institut is grouped in­ tific programme. New research proposals submitted to the ILL to "colleges" with particular scientific interests. will first be examined by the Colleges with respect to their The following is the current list of colleges: technical feasibility and then be presented to the Council Sub­ College 2: Theory. committees. A further task of the College is to contribute to College 3: Fundamental and Nuclear Physics. a smooth carrying-out of the experiments by appointing local College 4: Structural and magnetic excitations. contacts and by advising the instrument responsible as well College 5: Crystal and magnetic structures. as the Scientific Secretary on the time schedules for the various College 6: Liquids, disorders and defects in materials. instruments. The College Secretaries are normally elected for College 8: Biochemistry. a 2 year term and have regular meetings with the Directors College 9: Chemistry. and Senior Scientists to ensure the flow of information on all Each College corresponds to a Subcommittee of the Scientific matters concerning the scientific activity of the Institut. Council of the ILL, which advises the Directors on the scien­

Introduction

L'ensemble de l'activité scientifique de l'Institut est réparti en faisabilité technique des propositions de recherche soumises collèges avec des intérêts scientifiques spécifiques. à TILL. Elles sont ensuite présentées aux sous-comités du Con­ La liste actuelle des collèges est la suivante : seil Scientifique. Les collèges contribuent également au bon Collège 2 : théorie. déroulement des expériences en proposant des collaborateurs Collège 3 : physique fondamentale et nucléaire. locaux aux chercheurs invités, et en conseillant le responsable Collège 4 : excitations structurelles et magnétiques. d'instrument ainsi que le Secrétariat Scientifique de la répar­ Collège 5 : structures cristallographiques et magnétiques. tition du temps d'expérience sur les différents instruments. Les Collège 6 : liquides, désordres et défauts dans les matériaux. Secrétaires de Collège sont normalement élus pour 2 ans et se Collège 8 : biochimie. réunissent régulièrement avec la Direction et les "Senior Scien­ Collège 9 : chimie. tists" dans le but d'assurer une bonne circulation de l'infor­ Chaque collège correspond à un sous-comité du Conseil Scien­ mation dans tous les domaines d'activité scientifique de tifique de l'ILL, qui conseille la Direction en matière de pro­ l'Institut. grammes scientifiques. Les collèges examinent d'abord la

18 has shown that there are large deviations from the predictions COLLEGE 2 of models that ignore these effects, especially when one is not to close to the transition. There is a satisfactory agreement bet­ THEORY ween theory and experiment. D. Wolf and Nozières have studied the thermodynamics of Members Medium term visitors the solid-liquid interface stressing the differences between sur­ face energy and surface stress which is extremely important E. Akkermans S. Aubry (F) should the solid be a crystal. In the past the confusion bet­ H. Capellmann P. Coleman (GB) ween the two concepts has led to paradoxes and false conclu­ D. Edwards B. Gyôrffy (GB) sions. This approach leads to correct equations for the H. Glyde A. Huiler (D) equilibrium conditions and for the solid-liquid transformation D. Grempel J. Janssen (DK) in the presence of an external driving force. J. José R. Marshak (USA) P. Nozières P. Quemerais (F) R. Prange W. Schirmacher (D) J.M. Richard L. Sneddon (USA) 2. Magnetism, valence fluctuations S. Robaszkiewicz J. Timonen (Finland) N. Schopohl F. Zawadowski (H) and heavy fermions J. Solyom Solyom has extended his work on the properties of one- dimensional magnetic chains. He has studied the important problem of the eventual differences between integer and half- integer one-dimensional Heisenberg models, a topic that has been the subject of many theoretical and experimental studies INTRODUCTION concerning the nature of the excitation spectrum (massive or gapless). In collaboration with J. Timonen he has investigated The research activities of the Theory College cover a large the effects of biquadratic exchange terms for the spin one case, range of subjects in Theoretical Physics, including various finding that the spectrum remains gapless over a larger than branches of Solid State Physics and Nuclear and High Energy expected range of couplings. Physics. Motivated by apparent contradiction between experimental The group receives every year a substantial number of medium data and theory, José has studied the effect of correlated ex­ term visitors whose research interests overlap and complement change disorder in the antiferromagnetic Heisenberg quantum those of ILL theorists and experimentatlists, as well as those chain. The susceptibility in this model diverges at low of scientists at neighbouring institutions. temperature with a temperature independent exponent in con­ Besides its internal activities the College contributes to the trast with the results of the uncorrelated disorder model that general scientific life by organising the ILL General Interest predicts a temperature dependent exponent. José's model, sup­ Colloquium, the weekly Theory Seminar, and occasionally, ported by X-ray data, may solve the contradictions between series of lectures. During 1986 R. Marshak delivered a series theory and experiment. of lectures on Qusxks, Leptons and Gauge Interactions that was attended by a large audience. Nozières continues with his Schirmacher and Nozières have worked on weak itinerant lectures at Collège de France, the topics for 1986 being magnetism and almost ferromagnetic metals. They have in­ Superfluidity and Phase Coherence in Quantum Fluids, and cluded the effects of fluctuations in the gradient and fourth Magnetism and Localisation in Fermi liquids. P. Coleman has order terms of the free energy functional. A self-consistent lectured at the CNRS on his approach to the problems of mixed calculation leads to an estimate of the size of the critical region valence and the Kondo effect. (Guinzburg's criterion). They are searching for the possibility of having a metamagnetic transition in the exchange enhanc­ ed Fermi liquid, with applications to 3He that shows some ex­ perimental evidence for "almost meU.magnetism". Capellmann is editing a book on "Metallic Magnetism" and SCIENTIFIC TRENDS studying magnetic fluctuations in a metallic medium with disordered moments. In collaboration with K. Neumann he AND HIGHLIGHTS M 1986 has developed a theory of intermediate valency to explain low energy and low temperature behaviour, in particular magnetic properties He participates also in the experimental work done 1. Surface Physics by Neumann, Ziebeck and Scharpf on the magnetic proper­ ties of heavy fermion superconductors. In close collaboration with experimentalists at the Ecole Nor­ male Supérieure Nozières has solved a number of problems Together with scientists of the CNRS Robaszkiewicz has pro­ posed by the analysis of experimental results on the roughen­ posed a phenomenological theory of heavy fermion systems ing transition of solid-liquid interface of "He. In particular he and 3He on the basis of a lattice gas model of a mixture of has studied the broadening of the transition for a stationary heavy fermions and bosons. The model is able to describe the interface inclined at an angle and the effects of overpressure thermodynamic properties of CeCu2Si2 and UB,3 over several both in the stationary case and for a growing interface. He decades of temperature.

19 3. Low dimensional systems Glyde has investigated the electronic density of states in disordered systems, proposing an explanation of the exponen­ Sneddon developed and solved a model of the elec­ tial tail observed in optical absorption from disordered crystals tromechanical properties of charge-density wave (CDN) con­ and amorphous materials. ductors. This model is succesful in explaining vibrating reed Grempel and Prange have worked on the problem of quan­ measurements of Young's modulus and Q-factors in these tum effects on the stochastic transition from integrable materials. He has investigated the dynamic oscillatory in­ ("smooth") to chaotic ("turbulent") motion in dynamical stabilities of the CDW that are the origin of spontaneous in­ systems. The emphasis was on the scaling behaviour near commensurate CDW oscillations. With Kassman he has stochasticity in the period doubling cascade of bifurcations and worked on the critical depinning transition in the dynamics the breakdown of the last KAM trajectory. In both cases one of incommensurate systems, a subject closely related to the sees a fractal structure of phase space near the transition that problem of the dynamic threshold of CDW conductors. is drastically modified by quantum effects at long time scales. Aubry and Quemerais continued previous work on incommen­ In this same field José has studied some of the quantum surate structures with emphasis in applications to CDW com­ mechanical manifestations of classical chaos, in particular the pounds. They have treated the problem of non-linear statistics of quasi-energy levels in the Fermi acceleration model. conductivity associated with generation of current noise in a The change of the spectrum, from Poissonian to Gaussian as model based on the idea that pinning of the CDW is due not the coupling constant increases is a manifestation of non- to impurities but to the underlying lattice. integrability of the classical system. In this model the non-linear conductivity originated from the nucleation of domain walls and their annihilation at the edges of the sample. 5. Low temperature physics Solyom and Horowitz have studied the problem of the neutral- ionic transition in organic mixed-state compounds. They have Glyde centred much of his activity on developing a first prin­ shown that this transition is always accompanied by dimen- ciples theory of liquid 3He that could predict accurately the zation, and have worked out a detailed phase diagram. dynamic form factor, S(q,w). At high q the form factor can be calculated reasonably well. Interesting behaviour is shown by oscillations in the peak position and width as a function of q. In collaboration with W. Stirling, an experiment on 4He 4. Disordered and non linear systems was planned and executed with the purpose of testing if the single excitation component of S(q,w) disappears about the Akkermans has worked on the problem of backscattering of Lamda transition and whether the decomposition of S(q,w) light waves by a coherently illuminated semi-infinite medium. into normal and superfluid components can be tested. The albedo (or angular dependence of the reflected intensity) shows a peak around the backscattering direction whose origin Robaszkiewics has studied the thermodynamic and elec­ is the interference of time reversed waves. The predictions of tromagnetic properties of the normal and superconducting his theory, an analogue of the theory of weak localisation ef­ phases of a system of bipolarons. The phase diagram and ex­ fects is in remarkable agreement with the experiments of Wolf citation spectrum have been derived. Qualitative di fferences and Maret done at the CNRS. Work is in progress to extend exist between this strong-coupling narrow-band superconduc- this theory to mediums like gels: in principle the albedo tivily and the usual BCS type. Applications are made to A15 lineshape could give useful information about the fractal struc­ compounds and Chevrel phases. ture of these materials. He has also worked on numerical Schopohl has investigated the effects of spin orbit interaction simulations of the primary chemical reactions that occur in and crystal field on the superconducting p-wave pair states and silica aerogels; systems that are known to be fractals. The study their collective mode spectrum. These effects could well be of the modes propagating in such a structure reveals their ther­ responsible for the experimentally observed peaks in acoustic

mal and mechanical properties and can be compared with attenuation just below Tc in heavy fermion compounds. He values obtained experimentally. has developed a theory of the spectrum of quasi particles trap­ ped inside vortex cores in superfluid 3He and has also done José has studied the Stark ladder resonances in disordered and work on the interface between the A and B phases of 3He. ordered chains for arbitrary potentials. These resonances, Excellent agreement has been obtained between measured and equivalent to Landau levels in an electron gas in a magnetic calculated surface tension. field, are subject of intense search by several experimental groups. Grempel has worked on the transport properties of disordered 6. Nuclear and high energy physics systems in the presence of spin-dependent forces (i.e. spin-orbit J.M. Richard has worked on the problem of stability of multi- scattering). He has established the existence of localised states quark systems against dissociation, with applications to QQqq near the band edges and has investigated, numerically, the and QQQqqq. He has also been involved in the calculation metal insulator transition in the strong spin-orbit scattering of masses of baryons as a function of the masses of consti­ case. With H. Kunz he has developed a theory of the effect tuent quarks. He has finished a study of nucleon-antinucleon of disorder on the electron spin resonance line shape which interactions, with application to antiproton-nucleus scatter­ could be applied to current experiments on spin relaxation in ing experiments and to exotic antiprotonic atoms. the Si:P system. He has also developed the theory of precur­ sor effects to localisation at weak disorder in metallic dirty Secretary: films. D.R. Grempel

20 COLLEGE 3 GENERAL SUMMARY NUCLEAR AND As in the past the activities of College 3 have covered a very broad scientific field - nuclear structure physics, neutrino and positron physics, fission, electric charge of the free neutron, FUNDAMENTAL lifetime of the neutron and electric dipole moment of the neutron may be mentioned as the most prominent features. PHYSICS Nuclear structure studies have been performed on the electron spectrometer BILL (PN2), the curved crystal spectrometers Members of the College GAMS 1, 2/3 (PN3), the new flat crystal spectrometer GAMS 4, the pair spectrometer PN4 and on the on-line mass I. Internal Members R. Brissot (Grenoble) separator OST1S (SN6). J.P. Bocquet G. Danilyan (ITEP) H.G. Borner A. D'Eer (SCK/CEN) The thermal neutron induced fission process was studied us­ G. Colvin P. De Saintignon (ISN) ing the parabolic spectrometer LOHENGRIN (PNl) and the J. Copnell T. Ebisawa (Osaka) energy-time-of-flight spectrometer COSI FAN TUTTE (PN8). D. Dubbers W. El-Samman (Grenoble) In fundamental physics, activities have been very widespread: H.R. Faust S. Freedman (AND SN5 and the polarized beam facility SN7 and mainly the new I. Fôrster R. Golub (HMI) ultra cold neutron-very cold neutron (UCN-VCN) facility on P. Geltenbort G. Greene (NBS) level D have been used. F. Hoyler P. Grivot (ISN) B. Krusche E. Kessler (NBS) W. Lippert l.A. Kilvington (RAL) W. Mampe R. Kossakowski (Chambery) ^Au^aY)19^ G. Martinez E. Kriiger (PTB) D. Richardson S. Lamoreaux (Seattle) S. Robinson P. Liaud (Chambery) K. Schreckenbach R. Marshak (Virginia) U. Stôhlker W. Nistler (PTB) H. Weikard W. Paul (Bonn) M. Pendlebury (Sussex) H. Prosper (RAL) II. Long-term visitors V. Rabbel (Giessen) F. Anton (Bonn) A. Steyerl (TUM) F. Baumann (Bayreuth) C. Vivier (Grenoble) T. Bitter (Heidelberg) W. Weirauch (PTB) L. Bondarenko (Kurchatov) S. Yamada (Kyoto) Collaborations of College 3 with Institutes and Universities in 1986 Algiers Imperial College London Argonne Nat. Lab Jiilich KFA Bayreuth Karlsruhe KFK Belgrade Karlsruhe University Berlin HMI Kôln Bonn Leningrad NPI Bordeaux CEN Livermore LL Braunschweig PTB Los Alamos Braunschweig University Mainz Brookhaven Nat. Lab Manchester Bruyère-le-Châtel Mol SCK/CEN Chambery Moscow ITEP Darmstadt GSI Moscow Kurchatov Darmstadt TH Miinchen TU Fribourg Munchen University Geel JRC Osaka ao ai Giessen kutherford Lab. Gôttingen Seattle Energy (MeV) Grenoble CEN Sofia Figure i: A portion ofthe primary gamma-ray spectrum, observed with the pair spec­ Grenoble ISN Surrey trometer PN4, following thermal neutron capture by mAu. The two spec­ tra are the sum of data taken during two successive 20h periods following Grenoble University Sussex the start of irradiation. The burn-in of lines from the double capture reac­ Harvard Tubingen tion '97Au(r., y)mAu can be seen as an approximate doubling of their inten­ sities between the first (upper) and second (lower) spectra. The complex Harwell Washington NBS structure at - 6.1 Me V is an unresolved combination of single and double Heidelberg capture transitions.

21 SCIENTIFIC TRENDS

1381 k* THEORY 1381 keV I EXPERIMENT AND HIGHLIGHTS Si440 Si 440 1

10000 IN 1986 10000 ' • "a M 'S 1 I 7500 Nuclear Structure I 7500 (J ^ — -14ppm —J L—l&ppm The field of nuclear structure physics has provided a full ex­ perimental schedule in 1986 for the curved crystal spec­ J 5000 J 5000 trometers PN3 and the pair spectrometer PN4, together with PN2, and this work has, as usual, constituted the majority of ' experiments petformed by the spectroscopy group. 2500 2600 1 One major sub-topic is to continue the study of the applica­ tion of the IBA (Interacting Boson Approximation) model and Li-10 L1 0 12 its derivatives. In the W-Os-Pt region, for example, recent ex­ Interferencafringes (arburtits) periments on both even-even and odd-A nuclei were perform­ ed to obtain a better understanding of the transition from SU(3) to O (6) limiting symmetries and to look for multi-j Figure 3: Experimental resolution obtained for a 1381 keV y-ray measured in 2nd order supersymmetries in the framework of the IBFA (Interacting of reflection, compared to the predictions calculated with dynamical diffrac­ tion theory. Boson Fermion Approximation). (Collaboration with Man­ chester). Still in the domain of odd-A nuclei, a comprehen­ sive level scheme has been established for ,65Dy following neutron capture (thermal neutrons plus Average Resonance Capture) which is believed to be essentially complete up to about 1.5 MeV in 1/2 and 3/2 levels of both parities. (Col­ 1762 keV laboration with CEN Mol). 350 - Si 440 t (a) Interest is also increasing in the study of odd-odd nuclei. • i—INSTRUMENTAL • 4 Previously, such studies have been avoided due to the com­ RESOLUTION * + plicated spectra produced and the lack of sound theoretical «250 * • background. However, the predictions of supersymmetric c quartets by the IBA have prompted studies of both 76As and g l98Au. In addition the structure and level densities of the O nuclei M2Pr and 170Tm were extensively studied. 150 Still on the topic of odd-odd nuclei, data taken at the ILL have \ played a major part in the establishment of a comprehensive level scheme for 134Cs, which includes 64 levels up iO 50- 1.27 MeV. Its lower part shows fair agreement with calcula­ tions based on two quasiparticles coupled to a vibrational core. -513 -511 -509 -R07 -505 (Collaboration with Boris Kidric Inst., Belgrade). Interference fringes (n iative units)

226 1498 keV (b)

m Si 440 |™Hf "•w HI ™HI "•HI «HI \ *2d -HNSTOUMEN1AL

] m 175 \L u \pt, u\ X RESOLUTION \ n ^ axn^ S7d \ \ "«Vb t»Yb ™Yb ™Yb ™Yb ™»Yb 176 Yb §125 "•• VV \4.2 d ,W *•* «•Tft\ i ^ \ J •V* \12S d I92\ y \ 2Jd \ "\ "\ N N N

\ 170 ~Ec «Er wEr Er 75 ". V \ \ \ \ ^ \93 d *.v _S \ \ \ v \ \ ^ 25 ,."•«"•*? Sft|î ";• »imiH | t.fnfml -927 -925 -923 -921 -919 -917 Interference fringes (relative units)

Figure 2: A section oj the nuclear ihart showing the path traced by the slow neutron capture nucleosynthesis process (s-process). Also shown is the $~-decay Figure 4: Example for Doppler broadened line shapes obtained for some (a + b) tran­ feeding following rapid multiple neutron capture (r-process). It can be seen sitions in **77. The abscissa scales with relative interference fringes from the that mLu is shielded from r-process population by the ^-stable nucleus ,nYb angular interferometer. Onefringe corresponds to 0.04 arc sec. Theinstrumen- thus making it a suitable candidate for studying the characteristics of the tal resolution corresponds to about 0.4 fringes, e.g. more than a factor of s-process (see text). 10 less.

22 The high sensitivity of the PN4 pair spectrometer is illustrated The highest resolution in v-ray spectroscopy has to date been by the observation for the first time of a primary gamma- obtained with the two-axis flat crystal spectrometer GAMS 4 transition feeding the ground-state of 199Au following double which is a cooperative effort of the National Bureau of Stan­ 1,7 neutron capture by Au (E,,= 7584 keV, Iy = 0.03 per 100 dards (Washington) and the ILL. This spectrometer is capable neutron captures in l9SAu). In addition many other new of making precise absolute wavelength measurements. primary transitions have been observed. Recently new Si crystals have been developed at NBS which A close link between nuclear structure and astrophysics is allow to obtain a resolving power extremely close to that revealed by the recent nuclear structure study of 176Lu under­ predicted by dynamical diffraction theory for ideal crystals as taken at GAMS and BILL in collaboration with KFK, demonstrated in figure 3. For more details see blue box con­ Karlsruhe. The present understanding of stellar nucleosynthesis tribution. This feature can be exploited for several very in­ indicates that all nuclei beyond iron are produced by neutron teresting experiments, as outlined in an example below: capture, either at relatively low stellar neutron densities (s- process path, close to the region of stable nuclei) or by an ex­ This resolution which can be in the order of about 10 ppm plosive process within high neutron densities involving multi­ or better, is sufficient to measure Doppler-broadening of ple captures (r-process) producing very neutron rich nuclei secondary y-ray lines: If a short-lived (= 10~12 - 10"'5 sec) which then beta-decay towards the line of stability. Since nuclear level is fed by a high energy (primary) y-ray transi­ l76Lu is shielded from r-process population by the stule tion, the recoiling nuclei may have sufficient velocity to nucleus l76Yb and beta-decays to 176Hf with a ! tlf life of broaden and change the line shape of the second y-ray. The 3.6 x 1010 years it is, at first sight, a candidate for a cos.mo- velocity distribution of the decaying nuclei and the lifetime logical clock by comparing the natural abundance of 176Lu of the level determine the width and shape of the recorded pro­ with s-process calculations. This comparison becomes more files. Currently the experimental limits of such mesurements complex when a burn-out process in the hot environment of are being tested and - as an example - in 49Ti Doppler- the s-process (about 30 keV) is important. In fact an isomeric broadened lines (figures 4a and 4b) with a total width of about state in l76Lu at about 120 keV with a beta half-li'e of 3.7 h 400 eV have been investigated with a resolution of about 20 eV may be populated by thermal excitation and then decay to studying y-rays in the 1.5 MeV region. 176Yb. Apart from the temperature this effect depends on possible excitation routes, which most likely go via in­ Further investigations at BILL have covered present problems termediary nuclear levels, since the spins of the ground and in neutrino and positron physics. isomeric state are very different (7~ and 1 ~). The present in­ M1 vestigation provides a detailed spectroscopy of the ,76Lu level In the field of neutrino physics the Pu fission product beta scheme and may decide whether 176Lu could act as a sensitive spectrum has been measured with the aim of determining the thermometer for the s-process. correlated anti-neutrino spectrum. An absolute precision of 5% in the energy range 1.5 to 5.0 MeV was obtained. This spectrum is of importance for neutrino experiments (such as neutrino oscillations) using power reactors as anti-neutrino sources since the anti-neutrinos from 24lPu are a strongly varying component in the total reactor anti-neutrino spectrum (burn-up of 24lPu). The present work provides the first ex­ perimental data on this spectrum. A further study was a search for possible kinks in the nuclear beta spectrum of l77Lu which could be due to massive neutrino branches. The energy region close to the beta end- point of 500 KeV was scanned many times with an energy resolution of 300eV. For massive neutrinos in the range 7 to 80 keV a limit of 10"3 times the main beta 'jranch was established. In a first measurement e+e~ Bhabba scattering was in­ vestigated to try and detect a possible resonance structure in the scattering cross-section. This is motivated by the observa­ tion of narrow positron lines in heavy-ion collisions which could be interpreted as quantised e+e~ states with energies of about 600 keV. In the present experiment positrons were pro­ duced by a Ti plate at the in-pile target position of the BILL spectrometer, providing a positron beam intensity in the focal plane ofI6 000 e+ per keV at 1500 keV. This beam was scat­ tered in a lead foil which was viewed by two silicon surface- barrier detectors from which both single and coincidence events were recorded. Bhabba scattering was observed at 180° (in the Centre of Mass System [CMS]) but no resonance enhancement was observed in a short run from 1200 to 1900 keV, correspon­ ding to energies of 500 to 700 keV in the CMS lor free e+e" scattering. A further experiment with a multi-detector set-up is planned to improve sensitivity. (Collaboration with GSI, W. Gellelly, Chairman of the Fundamental and Nuclear Physics Subcommittee ofthe Scientific Council has been committed to the ILL for many years Darmstadt)

23 On the on-line mass separator OSTIS (SN6) the systematic Another rather specific problem was the following: recently, Qp-measurements continued on very neutron rich Br isotopes. it has been pointed out by the TRISTAN-group that pairing- Another long-standing research branch is the determination free bands (A = 0) may exist in several odd-odd A = 100 of P-decay half-lives and delayed neutron emission pro­ nuclei, where evidence for low-lying K" = 1+ rotational

babilities of very neutron-rich nuclei. The newly developed bands with moments of inertia of J ^ 0.9.Jrig has been

negative ion source makes beams of mass-separated halogens found. Among these nuclei is'§§Y6, which has been studied available at OSTIS, and supplemented the already extensive extensively at OSTIS. Because of the interesting question studies performed in the past by the Mainz-group on alkaline whether the pairing-free phase may be reached in deformed precursors to isotopes of bromine and iodine. Their delayed- A = 100 nuclei, the possibility of extracting information on neutron emission probabilities are of vital interest for a ther­ the amount of pairing reduction by comparing experimental mal nuclear reactor, where Br and I are the main contributors data on l00Y with RPA (Random Phase Approximation) of beta-delayed neutrons. Preliminary results show an overall shell-model predictions of low-lying J" = 1 * states of two- agreement with published values, but a more refined analysis quasi-particle nature for different assumptions on pairing has is underway. been examined. As can be seen from figure 5, the obtained results on 1+ level energies and log (ft) values indicate that the pairing strength is well reduced by about 60Vo but that the pairing-free phase has not been reached in the low-level-density nucleus l00Y. »TO>il.»l>3iVii uS I i.i 1600- A.1ÎS | e^lt /T~\ I* fcgff I'.I* inn 5.1 : ,' ., 1000 vKn*ll.rlQ1>ll SSI l si 1000 _LZ/' / «00 1. 112 MW \

v[«llVi]xlUl»il 1.2/ 200 500 _• / vUlftl.irlMNl) » it » 70 80 --E_5£ En«sy[M«f] EntrgyfM*/}

A 3 -H'l > figure 7: Kinetic energy distribution of fission products from "Amf2nihJ). The in­ creased variance of the kinetic energy distribution for mass A = 128 amu 1 5.1 vll,*lU2*il is shown, which depends on the ionic charge state q. The given energj is not •^-v corrected for the energy loss in the protective M layer of about 0.25)im. The 3*,, RM SHELL HOKL solid line between the data points is drawn for guiding the eye. {E

Figure 6: Systemalics of proton odd-even effects as a function ofZf/Ap. where ZF and Af means the nuclear charge and mass of the compound nucleus. The in figure 7. This reveals a new mode of fission, which however proton odd-even effect is measured at the mean kinetic energy. does not occur exactly at symmetry.

24 Furthermore a synthesis was made on Qp-values measured on PN1 as well as on the on-line mass separator OSTIS. In the mass region above 100 amu peculiar fluctuations have been found to be uncorrelated with the nucléon number. This is a • Radiochemical sign for an additional correlation effect in the nucleus, which x This work is not yet introduced in nuclear mass formulae based on the liquid drop model and the Strutinsky prescription which ac­ counts for shell and pairing effects only. With the recently installed N-jet system for the rapid transport of short-lived fission fragments to a suited detector the delayed neutron decay in the mass region 100 amu to 110 amu was studied. One assumes that this kind of nuclear disintegration influences significantly the origin and formation rates of par­ ticular stable isotopes of the solar abundance distribution. The measurements of the mass-, energy- and charge MI characteristics of the Pu (nlh, f) fragments at the COS! FAN TUTTE (PN8) spectrometer were finalised. About another 106 fission events have been recorded, which are be­ 90 100 110 120 ing analysed. In one part of the experiment a novel configura­ Light fragment mass (amu) tion of the spectrometer was used which should give access to primary masses and energies of the fission fragments (before i4, Figure 8: Comparison of the pu(nlfl,f) mass distribution obtained on PN8 (*) and prompt neutron emission). A first result is shown in figure 8: by Cunin.\ame et al (o) using a radiochemical method. the mass distribution of the fragments in thermal neutron in­ duced fission of 241Pu is in excellent ag'eem .it with radiochemical work. The data evaluation of experiments in thermal neutron induced fission of 23»Pu and M9Cf, performed in 1986 on PN8 is still underway. -p2000 o

V) Fundamental Physics Ï. Activities in Fundamental Physics have been rather a 1000 widespread, as indicated by the many experimental installa­ c tions, situated in the reactor hail on level C and on level D, in the neutron guide hall and even in the new second guide hall. è 10 The superfluid Helium - UCN (ultra cold neutron) source has J ./v* been reinstalled at the cold beam H17 on level C in the reac­ °() 1000 2000 tor hall. A cryogenic UCN exit system - constructed at RAl. Position ( um) - has been installed, permitting the use of low transmission loss polyethylen windows at low temperature at the UCN side of the source cryostat. But even with this improved system and Figure 9: Image of the entrance muttisllt of the neutron charge experiment. The image 4 is scanned with a 10 nm slit at the detector position in a distance of 10 m. very pure He the measured UCN density was about 10 times The image obtained during the first generation experiment by Cahier et al lower than the expected value. Therefore more detailed studies is shown for comparison. are currently underway, in order to find out whether the discrepancy is due to uncertainties in the incident neutron spec­ trum or whether the UCN production mechanism in superfluid Helium itself is questionable. The second generation of an experiment from Bayreuth, testing the electrical neutrality of the free neutron, started successful operation at another cold neutron beam H18 (neutron wavelengths between 10 and 30 Â). An improved optical system consisting of cylindrical mirrors and high precision multislits (31 slits of 10 //m width and 38 cm height, separated by 10 nm) permits the lowering of the present upper limit of the neutron's charge by about one order of magnitude. Figure 9 shows the image of the multislit installed at the en­ trance of the optical system, scanned with one single slit at the about 10m distant detector position. In the true neutron charge experiment this image is viewed with a multislit iden­ tical to the entrance slit and a possible deflection of the 31 lines, due to the passage of the neutrons through a transverse electric field of 6 kV/mra over a length of I'J meters, can be observed simultaneously. Together with the new Figure 10: Neutron microscope scan.

25 were taken with 50 UCN per measuring cycle (or 300 UCN after installations of the replacement source in 1985), now 12000 UCN were counted on the TGV under the same measur­ ing conditions. The EDM limit observable with the apparatus in a given time t is inversely proportional to VTvf

26 coated with fluorated pump oils. The wall loss contributions 35 m long, and the neutron spin residual field magnetometer of the ultra cold neutrons during storage in the bottle can be are being developped at the ILL (second guide hall) and the eliminated by using bottles with different volume to surface University of Heidelberg. The apparatus is scheduled for data- ratios. For that purpose the volume (maximal 72 1) of the taking for Autumn 1987. storage bottle can be changed periodically in situ. The experi­ ment yielded, even at a test beam position with only one fifth of the final UCN intensity and with a severe monochromatisa- tion, within 24 h a standard deviation (statistical) of only 2%. Possible systematic errors are under investigation. "Coln.a,! In the neu' guide hall n° 1, a whole series of different ' 'in beam" me; for the determination of the neutron lifetime - ''Caln.va.jl were tried oui n the neutron decay drift chamber as well as on the superconducting neutron decay spectrometer PERKEO, •lltn.OI in order to find out which method gives the least systematic 14 errors. "C,>[„.a > . J "Colnya,! 0 In the helium filled drift chamber the lifetime of the free neutron is determined from the ratio of neutron decay elec­ t ¥\j\ 3 tron events to He(n|h, p) events. The energy and spatial A^/i distribution of proton tracks have been measured and com­ pared with a Monte-Carlo simulation. The apparatus will move , . I\ 260 350 to the end position SN7 of the cold neutron beam H14 out­ CHANNEL NUMBER side the guide hall in Spring 1987, where the radiation background is significantly lower than at the present Tl 6 posi­

4, tion inside the hall. Figure 13: Pulse-height spectrum of the Cainth,a) and fnlh,a) reactions taken with a SOitni thick, totally depleted detector. The apparatus PERKEO was also used for a sensitive search for a new type of particle, the "axion", whose existence is necessary in several grand unified theories. The experiment answered a very special and topical question: at the heavy ion Special Beam Experiments facility of the GSI in Darmstadt, evidence was found for a At the end position S34 of the thermal neutron guide H22 ex­ new particle state produced in heavy ion collisions, and there periments on nuclear structure physics and on prompt gam­ has been speculation whether this state might be the axion. + ma activation analysis (PGAA) of geological samples have If it was, then the axion should also be visible as e e~ events been performed. in neutron-proton capture. However, the data taken with PERKEO at SN7 excluded this interpretation, as shown in In the nuclear structure experiments the main emphasis was figure 11. the study of 0(6) limits in nuclei of the A = 130 and A = 195 mass region. In addition angular correlations were measured As already mentioned in the last report, resonance scattering as well as lifetimes using the generalised centroid-shift method. of polarized neutron capture v-rays is a novel method to search + + By establishing lower limits for the B(E2,04 - 2, ) values in for parity non conservation (PNC) in nuclear radiative tran­ l24Te and l96Pt the validity of the corresponding selection sitions. Circularly polarized v-rays are produced by irradiating rules in the 0(6)-limit of the IBA model was tested. a suitable target with cold polarized neutrons on SN7. The helicity dependence of the resonance scattering cross section After encouraging results in studies of trace and rare element at a scatterer has been studied. After investigating suitable scat- concentrations in geological samples obtained at S34, a more terer candidates - Tf, La, Pr, Nd and Pb - a real experiment powerful and moie permanent facility for PGAA has been set has been recently carried out on SN7 with Fe as a target and up in the casemate H22F just in front of S34. To explore the 205T1 as a scaiterer. In a rather preliminary analysis a physical performance of this installation the concentrations of Boron, asymmetry of a = (2.3 ± l.ljlO-5 has been obtained. This Samarium and Gadolinium have been measured for 23 observed asymmetry can either be due to the helicity geological reference materials. Because of the high neutron flux dependence of the resonance scattering cross section of the and the favourable background conditions at this neutron Y-rays on 205T1 or to the PNC effect in the Fe(n, y) reaction. guide far from the reactor core sensitivities three to tenfold better than published sensitivities at other existing PGAA Recently, a new astonishingly simple law was derived from the facilities have been recorded. Schrôdinger equation, concerning a particle's quantum- mechanical phase in complex topologies, the so-called "Berry's A completely different field has been explored at the cold topological phase". These topological phases seem to have far- neutron guide SN7: neutron activation of oil paintings by Rem­ reaching consequences in particle gauge theories, and there was brandt and other artists of his time (Collaboration with the some discussion whether they could be detected experimen­ Painting gallery, Rathgen Laboratory and HMI Berlin). tally. In a very simple neutron spin rotation experiment such After successful tests, the painting "Adoration by the phases were indeed easily detected as proved in figure 12. Shepherds", about 1615, attributed to Cornelisz van '.ijck Last but not least, the neutron-antineutron oscillation project (Delft 1568-1628), was irradiated for only 4 hours on a special was progressing well. The 80 m3 large detector for the an­ scanning device. With this experimental method, a uniform tineutron annihilation products is being assembled at the activation of the whole painting area of 23 cm x 31.5 cm was Universities of Padua and Pavia. The magnetic shielding of obtained using a small neutron beam of only 3 cm x 5 cm. the neutron beam down to 5 nTesIa over a length of 75 m, With an angle of incidence of 6° between the beam and the the divergent neutron guide which is beryllium coated and surface of the painting, a sufficient activation was achieved

27 Photo G. Scliultz. Adoration by the Shepherds (Oak, 23 cm x 31.5 cm), ca 1615 by Cornelisz van Rijck, Delft Gemàïdegaterie SMPK Berlin. with a neutron fluence of only 8.9 x 10" neutrons/cm2 paint surface. Thus the utilisation of the beam is improved by a fac­ A x10"* tor I0-I5 with respect to the previous technique. Add'tional advantages at the SN7 position are the absence of direct Q2 •1.5 Y-radiation and the easy access to the object during activation. The original and first autoradiography exposed over 3 hours 01 w\*\ try .i are shown in the photographs. 1.0 Due to its clean experimental conditions, H22D has again been

1 o a very useful position for systematic studies of the (n,h, p), (n,|„ a) and ternary fission reactions. This is demonstrat­ f-0.1 ed by the fact, that for the first time the occurence of the JI •"Ca (nlh, va,) and Ca (nu„ yo-o) reaction was observed (see J-Q2 figure 13). Moreover, the4,Ca (n,i„ a,) transition appears to 4 •o be about four times stronger than the 'Ca (n,|„ a0) transition, — the preliminary cross-section values being 140 mb and 40 mb •I 2 ISxIOO , respectively. 0) The neutron induced fission of the 26 min isomer 235mij has 1 been studied at the cold neutron beam position SN7 and at the hot neutron beam H3. The targets are prepared by collec­ 1 ,••••*• ting --,5mu recoils produced by a-decay of 239Pu. The max­ 0 •.•••V imum number of collected uranium atoms per target is several -1 109. Great care was taken to keep possible Pu-contamination 0 25 50 under control. The data are being analysed. Flocking angle (") Using the high-resolution Double-Crystal spectometer S21 together with a Dual Polarized Beam Technique based on Zeeman-Splitting established earlier (ILL Report 03-13-47), Coherent Spin-Rotation in a Neutron Beam due to Neutron- .• Transmitted beam polarization ve rsns the rockine an file in. f/VI, ,V I are the dual lyeani components Mill antlparallcl spins. A is lite overall transverse Atom Spin-Orbit (S-O) lnterac;ion was observed for the first polurtzation, 5 is lite l.mritndinnl polarization (spin-orbit rotation effectI. time. The dual polarized beam, produced by the first Quartz

28 Fini autoradiography. {Irradiation time - 4 hours, film exposure lime - 3 hours). crystal in a magnetic field is transmitted by a second Quartz crystal which is protected by magnetic shields. This generates spin rotations due to S-O in opposite senses, corresponding to the senses of deviation from the Bragg condition and thus a new longitudinal polarization component S is created. Figure 14 shows the measured transmitted beam polarizations as a function of the rocking angle co of the second Quartz crystal. NT, Nl are the dual beam components with antiparallel spins, A the overall transverse polarization and S the extra longitudinal polarization due to Spin-Orbit Rotation Effect.

Seminars The College seminar program has been continued and has covered a wide range of topics, mainly topical experimental and theoretical problems in nuclear and fundamental physics. Furthermore, "Eight Lectures on Quarks, Leptons, Gauge In­ teractions and Chirality" have been given by Professor R.E. Marshak of Virginia State University. These lectures were in­ tended to focus attention on some of the key concepts on which our present-day understanding of the elementary constituents of matter and the basic forces of nature is based. The emphasis was more on physical ideas and not on mathematical for­ malism. Secretary: P. Geltenbort

29 High resolution interferometry at ILL At ILL the most widely exploited physical phenomenon is the interference of neutron waves. Among the ILL'S in­ struments there is a class of very high precision machines, the performance of which is due to some kind of in­ terferometry method. At first sight these experiments are very different one from another; therefore it seems to be a useful exercise to work out their common features. The first instrument that comes to our mind is, of course, the by now classical two beam neutron interferometer at ILL. Figure 17: Signal from the double-beam neutron interferometer. However, let us start with the less obvious and first turn to an instrument which is usually not considered to be an in­ terferometer, the neutron EDM-machine which is employed to search for an electric dipole moment of the neutron. This instrument does indeed produce quantum-mechanical in­ 2500- terference (not in space but in time) between events that are separated by as much as several minutes. The method ap­ plied is the Ramsay separate oscillatory field technique: A number of ultracold polarized neutrons are stored in a bot­ tle over a period of T and are exposed both at the beginning .« 2000 and at the end of the storage period to a short pulse of dura­ tion t of a phase-locked rf-magnetic resonance field. The coherent summation of the resultant spin-transition ampli­ tudes gives rise to an interference pattern in the radio- frequency spectrum of the polarization of the emerging 1500 neutrons*.

- 6000

5 5000

4000 <*•

Figure 18: Central part of Laue-case rocking curve (cf Fig. 19) measured at the neutron Interferometer without and with a 5 mm a perlurc. Figure 15: Separate oscillatory field magnetic resonance curve from the neutron elec­ tric dipole experiment (with stored neutrons). The typical features of such an interference pattern can be seen from Fig. 15: The width of the fringes is determined by the time-energy uncertainty relation to Av = 1/2T - 0.01 Hz; the width of the whole structure is determined by the rf-pulse duration to Avtot. = 1 /t - 0.2 Hz. In an electric field, the position of the fringes is sensitive to the neutron's electric dipoie moment, and energy shilis as small as AE — I0-20 eV can be detected. Hopefully this experiment will one day solve the mystery of the violation of time-reversal invariance, and wi: it the question why matter dominates antimatter in the un erse. When for comparison we turn to experiments relying in­ terferometry in space we just have to replace the time and 2 4 6 8 energy variables by space and momentum (or angular) Position scanning slit IlOO^m] variables. Fig. 16 shows the result of a neutron double-slit experiment, which is the exact analogue of the "in beam" Figure 16: Neutron double slit interference pattern. version of the EDM experiment, see also Fig. 20. Here, for

30 a slit separation of 100 urn, the position-momentum uncer­ tainty relation gives an angular resolution of two seconds of Q8 an arc. The experiment was carried out to search for a non­ linear term in the Schrodinger equation, which could be mimicked for instance by the neutron's interaction with vir­ tual black holes. 0.6 As a further example, Fig. 17 shows a typical interference pattern from the two beam neutron interferometer. This in­ strument allows extremely sensitive neutron phase-shift >• measurements, and has produced many results on neutron scattering lengths and checks of quantum mechanics. It is, |o.4 however, not angle-dispersive.

The highest angular resolution in spatial interference ex­ periments has been obtained at ILL from Laue-case rocking : AK curves. For neutrons, this was done on the neutron in­ Q2 terferometer in the single beam mode. For gamma rays this / was achieved with the double crystal gamma ray spectrometer \ GAMS4 and exploited for several very interesting experiments**. The angular resolution obtained in both cases is typically several times 0.001 of an arcsecond, see Fig. 18. Dynamical diffraction theory shows that there is interference 0 between the scattering amplitudes both from the front-layer -1.0 -0.5 0 0.5 1.0 and the back-layer (thickness ~ one extinction length each) Reduced Frequency of the thick transmission crystal. Therefore it may not be sui- prising that the line-shape of the rocking curve, Fig. 19, has Figure 20: Full Ramsay curve using a separate oscillating field and a neutron beam. (Note a striking similarity with the original Ramsay separate the similarity with Fi§ 16 and 19). oscillating field pattern, Fig. 20.

We turn to the next case where the interference signal is due to the coherent excitation of two neutron states which have an accidental energy degeneracy. This sounds unfamiliar because free neutrons have no excited states accessible at ILL energies which might show a level-crossing. However, when free neutrons are exposed to a strong radio-frequency magnetic field, and when this system is treated with second quantization methods, the resulting "dressed neutron" system turns out to have a rich energy-level diagram with an infinite number of level-crossings. Fig. 21 shows the resulting neutron polarization level-crossing signal measured with a very cold "dressed" neutron beam at the SN5 facility. The signal shown appears at the crossing between the two dress-

4000 6000 Hz Frequency Hz

Figure 21: "Dressed neutron " level crossing signal.

ed neutron states: [neutron spin up + number n of rf-quanta] and (neutron spin down + (n + 2)rf-quantaj. The signal shape is similar to that in Fig. 15, and the position of the signal

Intensit y is equally sensitive to the neutron's EDM. Of course, the resolution of this curve is still rather low because the neutron time of flight through the apparatus was short. These level- crossings are worth study for still another reason: Neutron- antineutron oscillations, if they ever occur, are suppressed -1" 0" 1" by the presence of the earth's magnetic field, which lifts the degeneracy between neutron and antineutron. At a dressed angle neutron level-crossing point, however, the degeneracy and partly also the oscillation process can be restored, even in Figure 19: Full Laue-case rocking curve (calculated). the presence of an external static magnetic field.

31 The next example is the neutron spin-echo instrument. Generally, when an inhomogeneous but coherent quantum mechanical system is tickled by a sequence of two (not necessarily coherent) pulses separated by a time interval T the system will respond with an echo pulse a further time T later on. The echo pulse height depends on the history of the system between the pulses. This again is an in­ terference phenomenon, which has been observed in the form of NMR-spin echos, photon echos, phonon echos, and, at ILL, neutron-spin echos. Fig. 22 shows the resulting interference pattern as obtained with the neutron spin-echo machine, which displays the same features as the preceding figures. A last example for neutron interferometry at ILL is the high resolution meander coil velocity selector in the h/m project. Thus, neutron interferometry experiments at ILL observe particle self-interference over distances of several cen­ timeters and over time intervals of several minutes, which allow measurements with extreme accuracies limited only by the corresponding uncertainty relations. D. Dubbers

Figure 22: Neutron spin-echo signal.

* Of course, this and several of the following examples can equally well be described in the usual neutron spin-rotation picture. In fact, the precession equation for the neutron polarization: dP/dt = yBxP, often misnamed "classical", is merely the irreducible representation of the corresponding equation of motion of the density operator: idp/dt = [H,p|. •* The absolute gamma-ray wavelength measurements on GAMS4 even involve a whole series of optical. X-ray and gamma-ray interferometry experiments. COLLEGE 4 SCIENTIFIC TRENDS STRUCTURAL AND HIGHLIGHTS IN 1986 Although the college 4 experimental program in 1986 includ­ ed numerous studies of lattice dynamics and incommensurate AND MAGNETIC phases, the great majority of experiments performed were con­ cerned with the investigation of magnetic phenomena. The im­ EXCITATIONS portance of neutron polarisation analysis in the unambiguous identification of magnetic scattering processes is outlined in the inserted box. The thermal beam 3-axis spectrometer with polarisation analysis, IN20, was commissioned early in 1986. Members of the College Polarisation analysis is an option now used regularly on the I. Internal Members cold source 3-axis spectrometer, IN 12, and will be a standard R. Currat feature of the new cold source spectrometer, IN14. The in­ L. Cussen stallation of IN14 wil! commence in late 1987. B. Dorner Several members of College 4 (Christian Vettier, Bill Stirling B. Farago and Keith McEwen) were involved in the organisation of the V. Frank highly successful Internationa] Conference on Anomalous Rare P. Frings Earths and Actinides. The conference, which was held at P. Gibbons Grenoble University in July, attracted over 350 participants. H. Lauter The papers contributed dealt with the theoretical and ex­ E. Lindley périmentai aspects of the hybridisation between the f- and the A. Magerl conduction band electrons in rare earth and actinide com­ K. McEwen pounds and dilute alloys. A. Murani R. Pynn B. Sarkissian U. Steigenberger G. Steyrer W. Stirling C. Vettier K. Ziebeck C. Zeyen

GENERAL SUMMARY The experiments accepted by the ILL through Subcommittee 4 were performed on the various 3-axis and time-of-flight spec­ trometers, and on the neutron-spin-echo spectrometer, INI 1. These instruments have, in general, operated successfully dur­ ing 1986. The thermal beam 3-axis spectrometer, IN3, is now partially scheduled as a "special beam" instrument giving an Figure 23: Predicted heal transport for infinite free path length for GaAs as a function opportunity for certain user groups to undertake lengthy pro­ of lime. jects often involving the study of excitations in a whole class of materials. Lattice properties A virtually uninterrupted program of weekly College 4 The project on the lattice dynamics of the technologically im­ seminars attracted substantial audiences throughout the year. portant semiconductor GaAs continued. Several eigenvectors The speakers, invited by Roland Currat, included both ILL were determined [1] and the phonon dispersion curves in six and visiting scientists. symmetry directions were measured with high precision. These A number of College 4 members have been involved in the experiments will allow the most appropriate of six proposed technical and scientific planning of the X-ray beam lines to lattice dynamical models to be selected. be installed at the European Synchroton Research Facility. The As part of the same project the effect of low temperature attractive possibility of combining the techniques of inelastic anharmonicity in GaAs has been investigated. The mean free or magnetic X-ray with neutron scattering has led to the paths and lifetimes of "nonequilibrium" acoustic phonons can establishment of fruitful collaborations with the synchrotron be determined from inelastic neutron scattering data in con­ community. junction with heat transport measurements. Dispersion sur­ We were shocked to hear, in November this year, of the death faces and phonon group velocities are obtained from neutron of Professor Werner Schmatz, following a heart attack. Pro­ measurements and heat transport properties may be calculated fessor Schrnatz, who retired as chairman of college 4 after the on that basis alone. These predictions may be used as reference October subcommittee meeting, has been involved in the evolu­ in the limit of infinite free path lengths. In the case of GaAs tion of the ILL for the last 22 years. He will be greatly missed. strong heat transport focussing is observed in a 10° cone

33 around the [100] direction, as seen in figure 23. Comparison with heat transport measurements at 1.4K [2] shows that the "early signal" observed in the experiment is produced by TA phonons with frequencies around 1 THz. Such phonons pro­ T NEODYMIUM pagate ballistically over 2.3 mm. The later signal, due to higher 300 [0,0,3] frequency phonons, is much more diffuse than predicted from • the group velocities because the corresponding mean free paths are much shorter than the sample dimension [3]. H Jj T-2K T PrTk T 200

J V :300 co100 A ¥ B«0 tz- 8 I \ ^^H-1! -200 i ° . = 300 \,,\ Bi2Te«l« -100 Z3 LU IT z 1 ' ~%. INS set-up for low-angle measurements of the excitations In liquids. Note the extended 200 arms of the instruments and the He filled flight chambers to reduce background air- scattering. ° Magnetism ' 1 A YjJ- \l B»4T«3la The properties of the exchange-enhanced paramagnets are 100 often explained by invoking spin-fluctuation correlations (paramagnons). The time-of-flight spectrometer IN5 was us­ ed to investigate high quality samples of the nearly- u ferromagnetic compounds Ni3Ga and TiBe2 [4]. Within the experimental resolution, and over all the accessible (Q,

34 periments, which require considerable preparation and/or long measuring times, include studies of the Une shapes of magnetic Dynamics of Actinide Systems excit, '.cms due to chemical disorder and of thermal fluctua­ The present interest and activity in studying both the phonon tions near to the ordering temperature. The materials in­ and the magnetic response functions in the 5f systems stems vestigated included Cr,.xFe, alloys and the ordered compound from a number of unique reasons. First, the 5f electrons PdMnSb. In addition, part of the time has been used to per­ in the early actinide metals (U, Np and Pu) are, in general, form feasibility studies. In this category the low energy much less localised than the 4f elect/ons in la.ithanide magnetic excitations in the intercalated compound Mn 2STaS2 systems (excepting cerium). This lack of localisation '.eads, were measured and an initial study of the low energy phonon of course, to an increased interaction with the conduction branches of ZrZn2 was carried out. electrons in metallic systems. The effects of this interaction The special beam time allocated to the German group *• on can be seen by studying the evolution of the coherent spin IN3 has been used to study excitations at interfaces, in par­ waves as a function of q, and of temperature. Such studies ticular excitations of helium films on graphite. These investiga­ performed at ILL (and elsewhere) have shown that the spin tions require long counting times due to the small scattering waves in ordered metallic systems are subject to strong dam­ cross section of 4He and due to the small thickness of the con­ ping mechanisms that almost certainly arise from the 5f- densed 'He film: from a monolayer up to a few layers. Some conduction band interaction. In fact in some ordered of the excitations in the film which resemble localised modes systems (eg UAs (1]) spin waves cannot be seen at all. This and which may play a rôle in the problem of the Kapitza strong interaction is also one of the acknowledged features resistance, could already be shown to originate mainly in the of "heavy-fermion" physics. It has been speculated that, second adsorbed layer (the first two layers adjacent to the at low temperatures, a "coherent" state is developed bet­ substrate are solid). The development of excitations (mainly ween the Sf and the conduction electrons and that this gives in plane phonons and out of plane vibrations) as a function rise to the correlations (in time and energy space) that can of film thickness is investigated using different hydrogen be probed by neutron scattering. Experiments, some using isotopes. Hydrogen has a much higher scattering cross section polarisation analysis, to search for these effects are being and is thus easier to study. Hydrogen systems s.*«ow the same attempted at ILL. quantum effects as the helium system except for superfluidi­ The second feature, again a consequence of the spatial ex­ ty. This offers the opportunity to select excitations which are tent of the 5f electrons, is that strong interactions can take purely connected to superfluidity. place with electrons on neighbouring atoms. This gives rise to anisotropic interactions. Although these are often most 'B.D. Rainford (Southampton), R.A. Cowley {Edinburgh). D. McK Paul (Warwick), easily identified in diffuse scattering experiments in the P. W. Mitchell (Manchester). L. Cassen (ILL) critical regime, these interactions are also important in "P. Lelderer (Mainz), V. Frank (ILL), H.J. Lamer (ILL) describing the spin wave spectrum (eg in USb [2]). In a re­ cent study of the dynamics of a single crystal, single do­ Secretary: E. Lindley main ferromagnet, M2PuSb a new mode was discovered that appears to represent a linearly polarised spin wave [3]. This mode can be reproduced from theoretical models on­ ly by introducing an extremely anisotropic interaction. A third feature of 5f systems is that, like their lanthanide analogues, they have an orbital moment which gives rise to both crystal field states and to magnon-phonon interac­ tions (via the lattice-orbital moment interaction). Crystal field states are difficult to see in almost all metallic actinide systems because of the damping effect of the interaction bet­ ween the 5f and the conduction electrons. They can,

however, be observed in such systems as U02 and UC14. In

U02 [4] (Np02 [5]) the crystal field energy levels have been measured using a pulsed neutron source since the energies involved are very high (E> lOOmeV). However, the real in­ terest has been in the unexpected splittings due, it is thought, to quadrupolar (or strong orbit-lattice) interactions. This effect has been studied recently at ILL, using a single crystal of UC1„ [6]. The difficulties involved in producing large single crystals (for dispersion studies), the often high energy transfers re­ quired and the current lack of understanding of the 5f /;/ Strauch and Darner J Phys C 19 2853 (1986) 12) Ulbrich in "Nonequilibrium Phonon Dynamics" ed Bron. NASI Series B Vol 124 systems mean that these studies are truly at the frontier of 101 (I9SS) solid state physics. Neutron scattering experiments have led 13) Strauch and Dorner exp 4-01-294 14) Bernhoe/t and Paul exp 4-03-425 Bernhoefl. Lonzarich, Paul and Mitchell Physica to dramatic increases in our understanding of the fundamen­ 136B 443 (1986) tal interactions in these systems. 15) Lonzarich J Magn Magn Mat 54 612 (1986) (I) Stirling, Lander and Vogl Physica 102B 249 (1980) [6J McEwen, Stirling and Stanley exp 4-03-393 PI Lander and Stirling Phys Rev B21 436 (1980) PI McEwen and Walker Phys Rev B34 1781 (1986) 13) Lander. Stirling, Rossal-Mignod, Spirlel. Rebizant and Vogl Physica 136B 409 18) Ziman and Lindgard Phys Rev B33 1976 (1986) Jensen. McEwen and Stirling in press (1986) (9) Morin, Flouquet and Vettier exp 4-03-416 (4) Kern, Loong and Lander Phys Rev B32 3051 (1985) Hayes, Osborne. Taylor. (10) Loveluck and Balcar Phys Rev Lett 42 1563 (1979) Boland. Bowden, Hackelt and Hulchings Internal Report RAL (1986) III) Steiner, Hirakawa, Reiter and Shirane Solid Stale Commun 40 . (1981) 15) Kern, Under, Loong, Goodman and Con Internal Report IPNS ANL (1986) )12) Kakurai. Pynn, Steiner and Dorner to be published f6) Vettier, Delamoye and Reichardl exp 4-03-402. 113/ Pynn. Regnaull. Boucher and Endoh to be published + z Neutron Inelastic Scattering U = b - pS x + BI2 (1) U-- = b + pSz - BL_(2) with Polarisation Analysis x U-- = - p(S*± + iSvj + B(IX + ily) (3) TJ-- = - p(S* - iS ) + B(I - il ) (4) The pioneering paper on neutron polarisation analysis (PA), x ± X y published by Moon, Riste and Koehler in 1969 [1], still pro­ where b, B and p are, respectively, the nuclear coherent, the vides a complete reference manual for anyone involved in spin-dependent nulear incoherent and the magnetic scatter­ this particular field. ing amplitudes. I is the nuclear spin operator and S x is the The authors describe in detail both the neutron PA techni­ component of the atomic spin operator which is perpen­ que and its applications. The experimental results presented dicular to the scattering vector, (J. The neutron polarisation in this paper indicate the problems involved, at that time, direction is defined to be in the z direction. in obtaining adequate intensities. In the intervening years the intensity problem has been Two very important points can be seen immediately. The first gradually overcome following the discovery and fabrication is that coherent nuclear scattering is always nsf (ie + + and of improved polarising and flipping devices [2]. The thermal — ). Secondly, the magnetic and nuclear-spin scattering is

beam spectrometer, IN20, is the first 3-axis instrument at ILL sf (ie + - and - +) for the components of I and Sx specifically designed to include a PA option. Good quality perpendicular to z and nsf for the components parallel to z.

Cu2MnAl Heusler crystals [3], together with a focussing Therefore, if the applied field (and hence the neutron system, have been used in the construction of the polarising polarisation direction) is parallel to (Jail the magnetic scat­

monochromator and analyser. The neutron spins are flipped tering will be sf, since Sx = 0. In this configuration the by DC flat coil flippers with an efficiency of almost 100%. magnetic and the nuclear scattering can be unambiguously On IN! 2, PA experiments can be performed with a super- separated simply by measuring the signal with and without

mirror "bender" [4] to polarise the incident beam and a the spin-flipper switched on. Specific components of Sx can Heusler analyser. The new cold source 3-axis spectrometer, be determined by selecting the appropriate field direction. IN14, will employ a virtually identical system. For coherent scatterers (for which the scattering is all "non-spin-flip") the signal obtained with IN 12 and IN20 in PA mode is approx­ imately 10-15% of the non-polarised signal (obtained with a PG002 monochromator and analyser). CeAI ; IN8 The "flipping ratio", R, is the ratio of the intensity measured 2 with the flipper off to that with the flipper on (for an instru­ [4,0,0] /i\ ment where the monochromator and analyser polarise in the CO same sense) for a coherent scatterer. For a perfectly efficient H instrument with no background R would be infinite. The flip­ Z ping ratio on IN20 is typically 20 ± 5 (depending on the sam­ 3 (a) / ^ ple environment), although values of over 30 have been o obtained for low incident energies. o On IN12 flipping ratios in excess of 70 have been achieved. A complete description of both instruments can be found in the ILL Yellow Book. In a neutron scattering experiment with PA we require a 10 20 polarised beam where the orientation of the polarisation direction, z, with respect to the scattering vector, Q, is known. We then determine the nature of the scattering, that is the IN20 "spin-flip" (sf) and "non-spin-flip" (nsf) components as a function of the wavevector and energy transfer, Çf and o>. For a paramagnetic or an antiferromagnetic sample the polarisation direction can be easily selected by applying a small magnetic field, in the required sense, at the sample C/3 position. H (b) If the sample is ferromagnetic, the applied field is necessari­ Z ly much stronger since the sample must be saturated to avoid o beam depolarisation. This can lead to technical constraints a on the choice of the polarisation direction. To demonstrate the power of neutron scattering with PA we give, in equations (1) to (4), the expressions defining L™, the scattering amplitude corresponding to a process in which the neutron has an initial spin state s and a final spin state s'. NSF • U" is the scattering amplitude for a single scattering centre, s and s' are denoted as either " + " (or "up", where the 10 20 neutron spin is parallel to the applied field) or "-" ("down'). The quantities appearing in these equations are ENERGY TRANSFER (meV) defined fully in reference [1] where a complete derivation of Figure 25: Inelastic scattering spectrum of CeA t2 at 6K. (a) IN8 data, (b) IN20 data; all the relevant scattering cross sections is also given. H \, Q; o = flipper on ; • = flipper off. The experiments described below illustrate the clarity of the The transverse-spin-density wave (TSDW) phase of pure data obtained using PA. chromium exists between 122K and the Née) temperature (311.5K). The SDW is incommensurate with the Cr lattice The intermetallic compound CeAl2 is expected to have a and has a modulation wavevector along one of the three single inelastic crystal field transition (between the r7 and r8 (100]-type directions. A single-q crystal can be produced by states). However, neutron scattering experiments indicate the cooling the sample through TN in a large applied magnetic presence of two inelastic magnetic lines as well as an unusual field. The "commensurate excitation" in the TSDW phase temperature dependence of the phonon spectrum [5]. of single-q chromium was first observed, at Brookhaven Na­ The separation of the magnetic and the phonon scattering tional Laboratory, at a wavevector of [100] and an energy that is possible using PA is invaluable in the investigation transfer of 4 meV [8]. Further measurements, performed on of these phenomena. Figure 25 shows the inelastic neutron IN8, showed that this excitation does, in fact, have con­ scattering spectrum of Ce Al2 at the [400] reciprocal lattice siderable structure in (($, to) space [9J. Figure 26 shows two point, at 6K. The upper spectrum was measured with un- constant energy scans around [100] measured on IN20 [10] polarised neutrons on IN8, figure (b) shows the spectra with the applied field parallel to Q. The nsf scattering ("flip­ measured on IN20 with the applied field (i.e. the neutron per off) gives only a flat background. The two outer peaks polarisation) parallel to Q [6). in the sf spectrum are spin waves. These data clearly show

Since the nuclear spin incoherence is negligible in CeAl2 the that the commensurate excitation (at 4 meV energy transfer) sf signal ("flipper on") is all due to magnetic scattering, and the "extra structure" (at 6 meV energy transfer), which whilst the nsf data ("flipper off") shows the phonon scat­ lie between these spin waves, are of entirely magnetic origin. tering. The spectra measured on IN20 clearly show two peaks of magnetic origin which are thought to be the result of coupl­ TMMC has been extensively studied as a physical realisation ing between the crystal field excitation and the phonons [7], of a classical ID Heisenberg XY antiferromagnet. It has been The study of the dynamics of CeAl2 on IN20 will be con­ found that, in a magnetic field of 10 Tesla, four well defin­ tinued in early 1987. ed excitations may be observed near to the magnetic zone centre [11]. Two had been designated as the in-plane (IP) and out-of-plane (OP) magnons, the others were thought to be double magnon modes. These four modes have been clearly identified and separated using IN20 with PA [12]. Figure 27 Cr230K sw E = 4meV shows a constant-Çf scan for TMMC at 1.5K in a field of 400 9.7 Tesla. In the coordinate system used (defined in figure SW 27c) the nsf spectrum corresponds to S^Q, to) while the sf h A" A scattering represents [.S5Sw((J, OJ) + .45SK((j, co)]. The con­ fusion which would arise if the same experiment were per­ formed using unpolarised neutrons is obvious. The large .£ /r 1KJ / \X>^ \Q \ E 200 / \SF CM 1 \ X J V 750 pr o a NSF

2 wo a 0.9 1.0 1.1 500

D O E=6meV 250 o oSW _| ~400 >r--

Figure 26: Constant energy scans through {100J for Cr at 230K with H \\ Q. o = flip- Figure 27: Inelastic scattering spectra at Q (0.1.25,1.1) for TMMC at 1.5 and 9.7 Tesla. peron;* =flippero/f. The SDW modulation wave vector was (I + %,0,0). (a) flipper off. (b) flipper on.

37 narrow peaks in figures 27a and b are the IP and OP magnons respectively. The broad feature at 2.4 meV in figure 27a is an "xx" mode, that at 2.9 meV in figure 27b is mainly "yy". These modes have been followed across the zone. The mode at 2.1 meV in figure 27b has not yet been fully explained. Following this experiment the need for fur­ ther theoretical work on this system has become apparent.

Ill Moon, Rim and Koehler Phys Rev 1S1 920 (19691 PI Pynn Physico 136B 75 (1986) PI Freund, Pynn, Stirling and Zeyen Physica 136B 86 (19861 Ml Schaerpf, MP ConfPncS9 ed Fober 182 (I9SI) 151 Loewenhaupt, Rainford and Sleglich Phys Rev Lett 42 1709 (1979) Reichardi and Nuecker J Phys F 14 L13S (19841 16] Loewenhaupl. Rekhardt, Pynn and Lindley in press PI Thalmeier and Fulde Phys Rev 49 1588 (1982) 18/ Fincher Shirane and Werner Phys Rev B24 1312 (1981) 19/ Burke, Stirling, Ziebeck and Booth Phys Rev Lett 51 494 (1983/ [101 Stirling, Lindley, Pynn, McEwen exp 4-O3-410 ill J Heilmann, Kjems, Endoh, Reiter, Shirane and Birgenau Phys Rev B24 3939 (1981) 112/ Pynn. Regnaull, Boucher and Endoh to be publish.

38 loss of polarised diffractometers for hot neutrons will create a grave imbalance in the 1987 scientific programme. Another COLLEGE 5 serious problem will be the loss of several of the most ex­ perienced and productive members of the college, including CRYSTAL Werner Kuhs, Garry Mclntyre, and Kurt Ziebeck. In short, the data collection rate and number of visitors is continuing AND MAGNETIC to increase while scientific staffing of several machines has been reduced to a single person. STRUCTURES SCIENTIFIC HIGHLIGHTS IN 1986 Members of the College 1. ILL Members 2. External Members C'ryNliill<»f>i'U|iliy on non-magnetic systems J. Baruchel A. Murani M. Anne (CNRS) P. Bordet K. Neumann M. Backmann Structural disorder in the ices P.J. Brown J. Pannetier (CNRS) The ice phase diagram is extremely rich. This is partly due to T. Briickel R. Pynn P. Becker (CNRS) the topological versatility of the tetrahedral hydrogen bonding, O. Chaix-Pluehery M. Roth M. Belakhovsky and partly to the possibilities of proton order / disorder within B. Chenevier B. Sarkissian (ESRF) the hydrogen-bonded network. The free energy differences bet­ B. Convert O. Schaerpf E.F. Bertaut (CNRS) ween neighbouring phases are small, and theoretical attempts A. Filhol J. Schweizer J.X. Boucherie (DRF to understand particularly the proton order / disorder transi­ A. Fitch J. Soubeyroux CENG) tions are very sensitive to model assumptions i.e. the water- A. Freund F. Tasset T. Chattopadhyay water interaction potentials. A series of powder and single M. Goldmann P. Timmins (DRF CENG) crystal neutron diffraction experiments have been undertaken B. Hamelin W. Trost D. Fruchart (CNRS) (in collaboration with Birkbeck College, London) to assist in A. Hewat C. Vettier D. Givord (CNRS) improving our understanding of water-water molecular interac­ R. Hock D. Waller D. Gregson (CENG) tions. The phase diagram of heavy ice in the range of 0 - j kbar W. Kuhs S. Wilson J.C. Marmeggi has been explored. Most of the high pressure ices have only P. Lacorre A. Wright (CNRS) been studied as samples quenched to ambient pressure. High M. Lehmann G. Zaccai C. Riekel (ESRF) quality neutron powder diffraction patterns of the ordered D. Londono C. Zeyen G. Rouit (CENG) phase ice II were obtained for the first time in the region of G. Mclntyre K. Ziebeck M. Schlenker (CNRS) stability at different pressures and were used to refine the struc­ S. Mason Tran Qui Due ture of ice II (see fig. 28). The molecular geometry differs con­ (CNRS) siderably from results obtained on quenched samples and is J. Vicat (CNRS) now in excellent agreement with recent in-situ Raman spec­ P. Wolfers (CNRS) troscopic work. In contrast to the generally accepted phase

-400 GENERAL SUMMARY 1986 was a busy year for College 5, with a return to a full pro­ -295 JftJ i ii -LiiftihuUlj JJ^UiiJ/.iA lAtoiikàkià gramme of experiments and the commissioning of several new m diffractometers to replace existing machines. D2B, the new high resolution powder machine, after some mechanical pro­ 1 blems, started intensive operation with two visitor groups per 12 j week. Because of user demand, a full experimental programme |-190 • was also maintained on Dl A, but this machine will be available for longer term experiments in 1987, if only because of lack u of staff to maintain a full programme. D20, the new high flux powder machine completed the first test measurements suc­ cessfully. D9 was completely rebuilt, gaining nearly an order -85- of magnitude in flux, and improved resolution at high Q: be­ ' t it ing on the hot source it is unique for high resolution struc­ UMB-I J.-ljIUi... tural studies of atomic distributions. D19, with its two-dimensional position sensitive detector, started full time -20 11, iTT operation, producing large amounts of data on biological 38 75 113 29° structures, but also on the physics of solid helium! Less hap­ Ice n',195K and 4.7 kbar pily, 1986 was the lasl year of operation for the polarised neutron machine D5. D3, too, will be closed down for much Figure 28: Powder diffraction spectrum recorded an DIA. Bottom curve and poinh jre of 1987 to permit installation of the second cold source. This calculated and observed values, while top curve is the difference.

39 diagram, the formation of ices HI and V could not be observ­ ed: ice I and ice II were found to be the only stable phases in the explored part of the phase diagram. He-gas, which was used as pressurizing medium, obviously inhibits the transfor­ H2 H2 mation into ice HI or V by a not yet fully understood mechanism. New transient phases have been observed. Neutron powder diffraction is the most appropriate tool to map the phase diagram which still seems to be full of surprises. However the slow kinetics at lower temperatures make studies of phase transitions very time-consuming; it is only through the special beam operation of D1A that a systematic survey of this kind has become possible. For the first time an in situ neutron single crystal diffraction study on one of the iiigh pressure ices has been performed. Crystals of heavy ice VI have been grown from ths liquid in­ side the pressure cell at ~ 0.9 GPa/9 (kbar). The new cell (con­ (a) structed at the University of Marburg) allows a largely unrestricted three-dimensional data collection and has been mounted on the D9 offset Eulerian cradle. High resolution data of a quality comparable to ambient pressure data have been D2 D2 obtained. Details of the molecular disorder were studied. The oxygen atoms are found displaced in a direction opposite to the molecular bisectrix as seen in fig. 29. The resulting in­ tramolecular geometry is quite different from the previously established values. This is a further confirmation that (similar to ice Ih; see Annual Report 1985) the geometry of the water molecule is by far more "normal" (i.e. closer to the free water molecule) than indicated by earlier lower-resolution crystallographic work. The small, but highly significant in­ crease of the OH(D) bond-length by some 0.02Â as found in recent high-resolution studies must be ascribed to the cooperativity of the water-water interactions.

Figure 30: Disorder deformation density of the oxygen atoms in H20(a) and DjO(b) ice Ih al I5K. The deformations are due to antisymmetric Ithird order) and symmetric (fourth order! terms and give the deviation from the harmonic

probability densities. Significant differences between H20 and DjO are observed. The data were taken on D9l measured at the neutron itjerferometer without and with a 5mm aperture.

Two further experiments on the ambient pressure phase of ice have been performed. The first was dedicated to study and compare the structures of normal and heavy ice Ih at extreme resolution. Using the two-stage displex cryorefrigerator, recent­ ly installed on the D9 offset Eulerian cradle, data were col­ lected at 15K out to sinOA-values of 1.6Â1. Structural quantum effects have been detected unequivocally for the first time in one of the phases of the solid water. The disorder defor­ mation densities shown in figure 30 show a significant dif­ ference between light and heavy ice Ih. This difference must be due to a wider range of hydrogen bond distances (and angles) manifesting a more pronounced molecular disorder in

H20 ice Ih. Finally in a study of heavy ice Ih two degrees below the melting point, data of excellent quality have been obtained on D9 (pro­ ving the reliability of the sample environment). As expected, the molecular disorder increases non-linearly on approaching the melting point. It i i planned to compare the observed atomic probability densities with results from molecular dynamic simulations in order to test the water-water interaction poten­ tials used in the latter. A first comparison indicates that real ice Ih near the melting point is more "crystalline" (i.e. shows Figure 29: Disorder deformation density of the oxygen atom in ice VI at 9 kbar, show­ ing the disorder déplacement along the molecular bisectrix. The single crystal less orientational disorder) than predicted by recent simula­ data were measured on D9. tions of ice melting.

40 Engineering Applications of translation, to measure the residual stress distribution in a Neutron Diffraction double-V weld in a thick aluminium alloy plate. Figure 31 shows the (311) Bragg reflection profiles obtained when a Neutron diffraction has been used extensively as a unique traverse is made through the weld, passing through heat- penetrating, investigative technique by scientists, particularly affected and fusion zones. Analysis of the profile shapes and in physics, chemistry, biology and materials science. Its use positions yields information regarding macro- and micro- in engineering by research engineers is rare. Recently, however, residual stresses, plastic strain and preferred orientation. a collaborative research investigation has been started at the Subsequent, destructive, traditional measurements show good ILL involving both engineers and scientists from the Civil agreement with the neutron results. Engineering department at Salford University, the Mechanical It is intended that, when the prototype equipment and techni­ Engineering department at Imperial College and the Fracture ques have been developed, neutron scattering will become Division of the Welding Institute, Cambridge. established as a routine investigative tool, for research and The research programme is principally concerned with the development engineers, with widespread industrial ap­ measurement of residual stresses in the interiors of important plications. engineering components. Although the number of shapes and sizes of engine.ring components is essentially infinite there is a much smaller number of generic shapes, such as plates and cylinders; standard casting, rolling, punching, drilling and working techniques; and standard welding and h-.at-treatmcnt procedures. The investigation involves the use of Dl A to make a detailed study of the stress distributions in engineering components, with principal generic shapes, that have been subjected to standard and experimental working and heat- treatment procedures with a view to obtaining a fundamental understanding of the physical processes involved. The results will enable the effects of traditional and new techniques to be determined and compared, and will permit assessment of the fatigue life, inherent safety, practicality and economic viability of generic components to be made. Traditional engineering stress measuring techniques such as hole drilling, Sachs boring, layering and X-ray diffraction tend to be destructive, or limited to near surface measurement and often give an averaged result, but they are mostly portable and may be used on site on large components. The high resolu­ tion neutron diffraction technique is essentially complemen­ tary giving specific detailed information regarding the strain at a point in a sample; but components must be transported to a high flux neutron sou. ce. In recent years the demand for welded structures, manufac­ tured from much thicker plates, has increased considerably and this has led to an intensification of efforts in search of new and improved welding techniques which could meet all the re­ quirements of heavy wall fabrication. D1A has been used, in Figure 32: (a) The B-configuratiott of the ET molecule in P-f£7Vi/.,«A al 20F from conjunction with a prototype engineering adaptation package neutron diffraction data. The a-configuration is also found in the $-(ET>2X< which provides fine beam collimation and automatic sample X - Aul, and /fir. . salts. fit} Tlte disordered FT molécule in Q-IETlJ, under ambient pressure. One ethylene group has two configurations IH atoms not shown), fcj The ET molecule in fi"- iFTt.Jial 4.5 A' and l. S kltar front neutron dij- fraction data. Tlte FT molecule is ordered and has the A-configuration, whereas all the other [W£7>_„V .V17//.V have the H-configuralitin.

Organic Superconductors Since the discovery in 1980 of superconductivity in the organic

salt (TMTSF)2.PF6(TC = 0.9K, P>12 kbar) there has been substantial progress in the understanding of the phenomenon and properties of organic superconductors. Of particular in­ terest are synthetic metals based on b: (ethylenedithio) tetrathiafulvalene (BEDT-TTF, or abbreviated ET). A "high-

Tc" state has been reported for P-ET,I3 (TC = 8K, P = 1.2-1.3 kbar) which may be stabilised at ambient pressure if a special cooling/compression procedure (the Orsay route) is followed. Furthermore this latter compound displays an in­ teresting set of phases: - a disordered phase above 200K - disorder of one ethylene Figure 31: (3111 Bragg peak profiles obtained by scanning an Aluminium weld on DIA. group at one end of the ET molecule

41 - a modulated phase below 200K leading to superconductivity Reflections [1,1,0], [2,0,0] and even [2,1,1] were successfully

below TC=1.2K (satellite /eflections in diffraction patterns collected at three wavelengths [0.86, 1.09, 1.71Â] in order to have been analysed in terms of rigid-body sinusoidal displacive measure the anomalously high Debye-Waller factor and to modulations of the ET molecules and the I3- anions about estimate the extinction in this quantum solid. their average positions ••:•. the unit cell) - if pressure is applied at high enough temperature and then the temperature is lowered, the satelites do not appear. This phase leads to the high-Tc superconducting state but its struc­ ture (ordered or randomly disordered?) was unknown until now. Neutron diffraction data were thus collected on D15 from a single crystal of P-ET2I3 at 4.5K and 1.5 kbar (collaboration with Argonne National Laboratory). The corresponding struc­ ture (R = 0.068 for 681 reflections) is probably the first for an organic conductor in its superconducting phase. This is a new ordered structural phase, called P*-ET2I3, which is not isostructural with other known p-ET2X materials (figure 32). In addition there appears to be a correlation between the degree of structural order and Tc in these compounds.

(b)

Figure 34: {a} Magnetic structure of antifcrrttmagneticatly frustrated tfajMjOo Figure 33: Diffraction patterns obtained on D2B from 5-fold symmetry quasicrystals fb) The sign of the supcrexchange integrals J(Ni-F~Nil. J = weak fer­ of Al Mn. 4 romagnetic; Ji,J;' and J,' - strong anlifcrromagnetic.

3 Helium single-crystal diffraction High-pressure single-crystal studies During a previous experiment at the Melusine reactor of the on Squaric Acid CENG the [1,1,0] and [2,0,0] reflections of a bcc 3He crystal were observed employing very long counting times. As in KDP, the phase transition in squaric acid is associated with the ordering of H atoms that are disordered over two sites

Further measurements have been performed at ILL on D19 in O - H ....H - O bonds above Tc. Structural data were deter­ (collaboration with CNRS, Grenoble) to take advantage of the mined for squaric acid at room temperature and 12.3 kbar (in very high incident neutron fluxan d of the possibility of chang­ collaboration with Edinburgh University). Comparison with ing wavelength. Several bcc 3He crystals were grown suc­ atmospheric pressure results at 394°K shows that the dimen­ cessfully at about lOmK in a special cryostat installed on D19 sion of the C4O4 "squa' ;s" do not change significantly and and easily oriented from peaks visible on the graphic display. their orientation changes by only 0.5°. Instead, almost all of

42 the compression in the structure is taken up in a substantial a Alg5 Si (Mn Fe)14 alloy with a zero scattering (Mn, Fe) mix­ resduction of the O O bondlength. The pressure dependence ture (figure 45b). It was found thai the stability of the of the H-site separation is observed to be about three times icosahedral phase related to surface energy effects and the longer than in KDP corresponding to the greater dTc/dP crystallization is controlled by the diffusion at the interface found in squaric acid. This suggests that there is a common with fee aluminium. The incoherent background observed with structural basis to the loss of the ordered phase in the two AI85Si Mnl4 decreased significantly during the crystallization materials. whereas such a background was not observed with the other sample. Furthermore, it is clear from figure 45 that most of the relevant diffraction lines vanish with crystallization, as op­ posed to the lines due to the Al network (figure 34b) which

smoothly transformed into lines of the orthorhombic - AI6Mn compound. Both types of results suggest that manganese forms a disordered quasi-lattice which acts as the skeleton of the icosahedral phase. Ternary Graphite Intercalation Cor. pound Study Thermodiffractometry is still an important activity and an ex­

ample of this was the study of CsCM(THF), 7 performed bet­ ween 4 and 300°K on DIB (THF = tetrahydrofuran). Two phase transitions were observed: (i) between 300 and 247°K, the intercalated layers are in a li­ quid state and then, only the 001 peaks from the intercalate and hkl from the graphite host are observed. The c-axis parameter is 7.055 Aat 27S°K and decreases continuously to 7.02 Â at 247°K, (ii) below this temperature, one observes weak and rather broad new peaks. They are associated with an in-plane liquid- solid transition (in agreement with quasiei- ''C studies on IN6). Simultaneously, the 001 peaks split. This splitting is interpreted as coming from two positions of the THF molecule in the solid Figure 35: Neutron scattering intensity along the I 0 t reciprocal lattice line of phase. No other particular features are observed down to 4 CsMn ^FefiojBr, as a function of temperature. 0 K for those two kinds of peaks. Below 150°K, the Ohl (1 = 1,2, etc) peaks from the graphite host decrease, while the corresponding OhO broaden. Finally Quasi-crystals an asymmetric Warren profile of the OhO peaks was obtained around 80°K. This indicates an unusual decorrelation or in­ The electron diffraction pattern of icosahedral Al4Mn shows a 5-fold rotational symmetry if oriented in the appropriate crease of stacking faults when the temperature decreases. There direction (see e.g. Annual Report 1985). This contradiction are two possible explanations for this: with the rule of classical crystallography has produced con­ 1) At low temperature, the structure of the intercalate plane siderable theoretical effort, including the construction of may become incommensurate with the graphite structure; then, atomic models. In order to te; t such models with accurate dif­ no correlation would exist between the first neighbour plane fraction data, a series of neutron diffraction experiments was (as this compound is a first stage) and consequently, between devoted to the quasi-periodic phase in Al-Mn and related graphite planes. However, this seems inconsistent with the fact alloys. that correlations between graphite planes do exist when the intercalated layer is in the liquid state. Manganese is a negative neutron seatterer (bM„ = — 0373 10" '2 cm). It may be isomorphically substituted by positive 2) From other experiments (IN6), the existence of an excess scatterers such as iron or chromium (bFc = +0.954 of THF in this saturated compound appears possible. The ideal |2 l2 10- cm, bc, = 0.363 10 cm). This contrast variation "composition" would be CsC24(THF),. When the excess of technique was thus applied to several Al-T icosahedral samples THF solidifies, it would increase the stacking faults between with nearly identical aluminium content but varying scatter­ planes. ing contrast of the 3d metal mixture (T = Mn, Fe, Cr). An example of diffraction spectra recorded with the newly design­ Ab initio structure solution from powders ed D2B high resolution diffractometer is shown in figure33 . The development of methods for ab initio structure solution The respective contributions of the aluminium and transition from high resolution powder data employing both neutrons metal T sublattices were calculated from the diffraction data and X-rays was continued during 1986. Data recorded at the after normalisation of the spectra. Both the positions and in­ end of 1985 were used to solve the structures of I 0 and tensities were found to be consistent with the cut and projec­ 2 4 A12Y409 using profile decomposiiton into individual structure tion model (Cahn, Schechtman and Gratias). amplitudes, followed by application of standard Patterson and A thermodiffractometric study on DIB (d = 2.52 Â) has direct methods. An interesting case was ihe solution of the shown that a quasi-crystalline Al Si Mn, alloy transforms 8s 4 structure of I 0 , which was a collaboration with Oslo, in a two-step mechanism to orthorhcmbic AI Mn and then to 2 4 6 Aarhus Universities and Risp National Laboratories. The com­ small amounts of a - Al Mn Si (figure 45a). The transforma­ pound crystallizes in a monoclinic spacegroup and previous tion of the aluminium quasi-îattice was followed by studying attempts to solve the structure from neutron data had not been

43 successful. Taking advantage of the dominating scattering below TN. It is clear that the asymmetry observed in, e.g. the power of I in the X-ray case (96%) it was however easy to find 1/3 1/3 1 peak, in the high resolution scans of figure 35 is due the iodine atom positions from high resolution X-ray syn- to the magnetic intensity peaking at 1/3 1/3 1 and decreasing chroton data, and it was even possible to get a first estimate gradually towards 1/21/21, 1/2 0 1 and 0 1/2 1. This may of the oxygen positions from difference Fourier maps based be modelled by a continuous variation through the lattice in on the same data. Following this, final atomic coordinates were the angle between the spins of nearest-neighbour magnetic then obtained using Rietveld profile refinement techniques on atoms from 120° to 180°. neutron powder data, where the oxygen atoms contribute 71 % of the scattering power. This approach might be generally useful, relying on heavy atom methods and X-rays for struc­ ture solution, followed by neutron powder analysis for peak location of the lighter atoms.

Sludii's In\ol\ inti YI;i»iu'!ir hid'niciions Ordered magnetic frustration inside even cycles of Ni2+ in I^NijF,,,

The magnetic structure of the antiferromagnet Ba2NijFKi

(TN = 50K) was refined from low temperature patterns col­ lected on DIB. In this compound, the magnetic frustration occurs in distorted square platelets of edge and corner shar­ ing NiFg octahedra. In these platelets, the 3 strong AF (180° superexchange) and the weak F (90° superexchange) interac­ tions imply strong magnetic constraint on the weakest one (F), which results in antiparallel spins in bioctahedra units

(NirNi|) (figure 34). As a direct comparison, in the same compound, unfrustrated rutile-type chains (90° path) exhibit a ferromagnetic alignment. Spin-glass behaviour and magnetic frustration in insulating magnetic materials Recent diffraction studies on cation-doped antiferromagnets eg. CsLjRbjFeClj and RbFe,.., Mg,CI3 have shown that dop­ Figure 36: Scattering intensity distribution within the f = 1 layer o/CsMn^yiFeocjBr^ ing concentrations as low as !% destroy the long-range at ai 7\ * 0.5 and hf Ty 0.5. The contours are on the same /arbitrary) magnetic order of the pure compounds (collaboration with Ox­ scale in both plots; lite 65 uppermost contours are omitted from b) ford University). The sharp magnetic Bragg peak of the pure compounds become Lorentzian-shaped. This phenomenon is 12.1 postulated to be due to relief of the frustration found in the 'log (I) triangular antiferromagnetic structure of the pure compounds. Replacement of one magnetic atom in this array by an atom with a different magnetic moment leads to imbalance in the '02M .^ 102M superexchange forces acting on the nearest neighbour atoms 1 N \ and their moments relate to new directions. Thus a single im­ purity can introduce relatively long-range disorder. 8.9 These early studies were limited by the low Néel temperatures T=20K of the pure compounds. Later more extensive experiments on Mg or Fe doped CsMnBr have shown that a similar 3 I 1 phenomena occurs in these compounds. Furthermore the dop­ 1 ing does not necessarily simply destroy the 3-D long-range • } order (as reflected by a lowering of T ). Below T a broad ) N N 5.7 V diffuse peak is also observed below the intense Bragg magnetic peak. This feature is present even for very low concentrations and cannot be due simply to the lack of 3-D periodicity aris­ V \] ing from the nonstoichiometry. ]i! 11/ \i i/ Figure 35 shows the temperature dependence of the magnetic 2.5 l scattering in CsMno95Fe0osBr, along the hhf direction. It can W\ also be seen in figure 35 especially above TN, that the diffuse 1.5 2.0 2.5 magnetic peaks are asymmetric about 1/31/31 and 2/3 2/3 1. To map out the scattering within the f = 1 plane the scans C*(rlu) were repeated on the multidetector diffractometer DI6. Fifiti 37: Magnetic xatefliivs in hotmiwtt near 20k' as predicted by ihe square-wave Figure 36 shows the distributions observed just above and just soliton model of Bruce & Cowley.

44 New Measurements on Single Crystals of Holmium New low temperatures ultrasonic and diffraction measure­ ments on a very pure single crystal of holmium (collaboration with Hull and Edinburgh University) have indicated that the transition from the spinal to conical magnetic structure near 20K is not as simple as thought from earlier studies. High resolution neutron scans have revealed a further series of magnetic satellites, centred on each of the fundamental magnetic peaks, which do not fall at the positions expected from the spin bunching model (figure 37). These peaks can be predicted by the square-wave soliton model derived by Bruce and Cowley, using elements of the spin-slip model that was used by Moncton to explain the X-ray magnetic scattering from holium. The anomalies observed in the ultrasonic data at 18K and 20K are also confirmed by discontinuities in the temperature dependence of the satellite positions and inten­ sities (figure 38).

Metamagnetic transition in TiBe2 Figure 38: Neutron scattering intensity along the 101 reciprocal lattice tine of Ho ver­ sus temperature. TiBe2 is a prime example of a highly exchange enhanced paramagnet which apparently undergoes a metamagnetic tran­ sition in a magnetic field of 5.4 Tesla. A similar transition has been predicted for pure palladium but at 200 Tesla. A study of the magnetisation density (by Warwick Universi­ ty) at 2 and 4.6 Tesla and 4.2K have shown that the magnetisa­ tion is ,>redominently but not entirely situated around the T2 site (figure 39) and a future extension of these experiments to higher magnetic fields will probe the rearrangement of the magnetisation after the metamagnetic transition.

Magnetic Structures of Eu(AsxP,.x)3 Compounds

The incommensurate intermediate magnetic phase of EuAs3 first discovered on D15 some years ago, has stimulated con­ siderable interest. It provides the first example of a structure whose propagation vector follows the temperature dependence of the ideal sine-Gordon theory. An explanation of the stability of the incommensurate phase in terms of highly anisotropic magnetic exchange interactions has been given by Thalmeier. This explanation is still somewhat speculative and the Figure 39: Magnetisation density and the Ti-sites in rlie rrteta/nagnel TtBe; al 4.2K. microscopic origin of the anisotropy of the exchange is still not clear. To investigate this problem further the magnetic phase diagrams of Eu(As0 6P0.4)3 and Eu(As02P98)3, both 0.3 isomorphous with EuAs3, have been studied. An incommen­ surate phase very similar to that found in EuAs3 is also found in Eu(As0 6P04)3 in the temperature range 9.0 to 10.3K. Figure 40 shows the temperature dependence of the propaga­ Q2 tion vector in this phase compared with that in pure EuAs3.

Substitution of As by P in EuAs3 destroys the logarithmic behaviour of the temperature dependence of the propagation vector and reduces it to a straight line. The lock-in transition 0.1 temperature changes from 10.3K for EuAs3 to 9.0K for

Eu(AS(, 6P0.4)3. The first order transition is more pronounced in Eu(As06P04)3 and the propagation vector variation smaller. Several other incommensurate phases are found in »»» » J» >• these phases but in none of them does the thermal behaviour °8.5 of the propagation vector resemble that of pure EuAs3 in zero field, suggesting that this special behaviour is the result of a very delicate balance of forces. Figure 40: Temperature dependence of the propagation vectors of EuAs, Eu(As0(lP0J}.

45 Spin Localisation in NbeI„

The insulating transition metal cluster compound Nb6In has some intriguing properties. The structure and some physical properties of Nb6In were investigated more than a decade ago, but only fairly recently have developments in technique made it possible to deal with its behaviour quantitatively (col­ laboration with MPI Stuttgart). The structure of Nb6In is characterised by units of 6 Nb atoms arranged in an octahedron surrounded by 8 iodine atoms in a distorted cube, one over each face of the octahedron. The units are connected by 6 ad­ ditional bridging iodine atoms, one opposite each apex and shared between two clusters according to the formula

Nb6I8I6/2. The occurrence of an Nb6I8 arrangement is rather surprising .because each cluster has only 19 electrons available for 12 metal-metal bonding d-orbitals. Due to the odd number of electrons in the cluster the compound Nb6ln is paramagnetic. Thus experimental determination of the spin density in a high field should enable the distribution of elec­ trons in the Nb-Nb bonding states to be determined. To this end polarised neutron diffraction measurements have been car­ ried out at 285K and at 40K in an applied field of 4.6 Tesla.

At 285K each Nb6I8 cluster in Nb6IM carries three unpaired spins whereas at 40K, below the spin-crossover transition, the cluster carries only one unpaired spin. The measurements show that at 40K the spin density is not delocalised in the cluster, but can be associated with the bonds formed with just one of the Nb atoms. In the higher temperature phase in which there are three unpaired spins the spin density is found to be more evenly distributed over the cluster, although the moment on one of the three pairs of equivalent Nb atoms is significantly higher than that on the other two. Some idea of the spin den­ sity distribution in the two phases can be obtained from the density maps of figure 41 which have been calculated from the models giving the best fit to the observed data. These results can be understood in terms of earlier molecular orbital calcula­ tions which associate the electronic levels with different Nb-

Nb bonds in the Nb6 octahedron.

Figure 42: Ferro-helimagneric phase coexistence in MnP at 47K. fa) Neutron topography: the ferromagnetic phase occupies the upper part oflhesample. whereas the helimagnelic one •slocaledin thelowerarea. The boundary displays a finely meshed zig-zag structure around an average direc­ tion corresponding to a stale of minimal elastic energy. fb) Synchrotron topograph of the sample, where the zig-zag structure is the main contrast.

a - Fe2 03 (flux grown) 1 lint (m) J arb. units 1^

"| ft $ ' « Figure 41: The spin density distribution in M>„/,;. Solid contours at equal intervals are 150 200 250 300 drawn in the plane ofNbl. Nb2 and NblA, and dashed contours at the same intervals in the parallel plane through Nb2A. The skeleton of the Nb/, oc­ Figure 43: Integrated intensity of the III magnetic reflections and corresponding tahedron and the positions ofthe Nb a fonts are indicated, topographs of a flux grown crystal ofa-Fe/Dj. The Morin transition occurs fa/ 40K: Contour intervals 5 x 10 *u.BA >. through abrupt transitions if different regions of the sample. fb) 2SSK: Contour intervals 2.5 x 10 4v>BA '

46 Topography: magnetic phase coexistence A phase transition between magnetically ordered states can be studied in at least two ways. A first line of research involves investigating the microscopic origin of the transition and/or exploring the critical behaviour of the phase charge. A second, more macroscopic approach is to investigate the morphology of the phase transition by studying the orientation and the kinetic behaviour of the boundary separating the phases. The competition between different energy terms leads to a rich and unexplored variety of situations. The shape of the phase boun­ dary results from the minimisation of the sum of these terms, and its observation could thus indicate some of the terms which determine the critical behaviour. Figure 42 shows results obtained for the heli-ferromagnetic transition in Mn P (T< 47K, B0 ~0.1T). The phase transi­ tion was approached by varying either the temperature or the magnetic field. In the first case the boundary between the two phases occurs on average in directions which correspond to a minimum of the elastic energy remitting from the variations of the lattice parameters between the phases (figure 42a) but also displays a finely resolved zig-zag structure arranged on both sides of these average directions, with the "needles" be­ ing directed along the easy axis of magnetisation (figure 42b). Neutron diffraction topography indicates in a direct way but with low resolution through magnetic diffraction the main magnetic features (figure 42a), whereas synchrotron topography only indicates their lattice counterpart through the distortion associated with the variation of magnetostriction between phases, but permits the kinetics of the phase transi­ tion to be followed in real time with enhanced resolution. These two techniques are thus very complementary tools when per­ forming this kind of investigation. The observed morphology results from the competition bet­ ween the elastic and magnetostatic terms of the total energy. When the transition is field driven this last term predominates and the boundary no longer displays an elasticity controlled average direction. The helimagnetic region is, in this case, ex­ pelled to the edges of the sample and forms a kind of closure domain pattern, the boundary retaining its finely structured zig-zag shape. A different kind of co-existence between ordered magnetic- phases was observed by neutron topography on flux grown high crystalline quality samples of hematite (a-Fe203), which nevertheless display a widely spread-out main transition (as indicated by the curve of the integrated intensity of the 111 purely magnetic reflection as a function of temperature (figure 43). Topographs performed at different temperatures (inserts of figure 43) clearly indicate that the transition takes place, in this crystal, through a succession of abrupt transi­ tions in different regions of the sample. These regions appear to be related to the way the crystal grew. Indeed it is generally accepted that the reorientational Morin transitions result from the competition between the two main terms of the anistropy (dipolar and single ion) which only differ by a few percent in magnitude and are opposite in sign. The temperature of the transition is therefore very sensitive to small variations of these energies, and its variation probably "amplifies" in our case the presence of a small chemical inhomogeneity associated with the different amount of impurities incorporated during t he dif­ ferent periods of the growth process.

Secretaries: A.W. Hewat M.S. Lehmann Magnetic frustration is much greater than the Néel temperature TN. Indeed the ratio 8„/TN is often used as a measure of frustration. As in­ The concept of frustration in magnetic systems was introduc­ dicated above, frustration may lead to non-collinear magnetic ed by Toulouse [I J; it describes the inability of a system to structures it may also give rise to incommensurate phases or satisfy simultaneously all the constraints to which it is sub­ only partly ordered ground states. In disordered systems ject. Frustration occurs very frequently in magnetic systems frustration may result in spin glass phases. which adopt frozen arrangements of moments at low In recent years much theoretical interest has focussed on temperatures. Such frustration may arise in ordered systems frustrated systems and at the present time several neutron when the geometrical constraints imposed by the crystal struc­ diffraction studies described elsewhere in this report are in ture do not permit all of the energetically most favourable progress. A systematic study of fluorides containing transi­ magnetic couplings to be satisfied throughout the crystal. tion metals is being carried out to determine the influence Alternatively frustration may occur in disordered systems, of cationic ordering and other crystal chemical considerations such as random solid solutions, when the two end members on the degree of frustration. Considerable interest is also be­ have very different magnetic interactions. ing shown in partly frustrated solid solutions such as the mix­ A very simple example of frustration is provided by atoms ed garnets (FexCr,.}l)2Ca3(Ge04)3, the mixed arsenides with antiferromagnetic interactions between them arranged Eu,Sr,. As and europium arsenide phosphide Eu As,P| )]. on a hexagonal lattice. As can be seen from figure 44a only x 3 4 four out of the six possible antiferromagnetic interactions can be satisfied with a collinear arrangement of spins. If the ex­ J. Brown

change interaction is of the form J(S.|jL2) this gives an ex­ change energy per atom of - JS_2(2-1)= -JS2. In this case the non-collinear arrangement of figure 44b is energetically more favourable with an exchange energy of -1.5JS2 per atom. The result of frustration is to lower the Néel temperature, at which antiferromagnetic order sets in below that correspon­ ding to the strength of the interatomic exchange interactions in the paramagnetic phase. Thus the negative intercept 8P of the inverse susceptibility vs temperature plot V^

V-* G> O

«e-

&> &>

Figure 44: Magnetic f-ustralion. (a} Only four out of the six possible antiferromagnetic interactions can be satisfied with a collinear arrangement of spins. (bl non-collinear arrangement, which is energetically more favourable with an exchange energy of -1.5JS1 per atom. //; G. Toulouse; Commun. Phys. 2_ (1977} 115. been studied over a wide concentration range. A direct coupl­ ing of a tunnel state to conduction electrons has been establish­ COLLEGE 6 ed. The unique power of quasielastic neutron scattering (|QNS|) to measure jump frequencies and jump vectors has LIQUID, been used to directly determine the diffusion mechanism in the high temperature phase of the refractory metal P-Titanium. Also this experiment was characterised by a large technical ef­ fort, a special furnace has been developed which allows for DEFECT MATERIALS the in situ growth of these crystals in the backscattering spec­ trometer IN 10. The first available one domain V2H single crystal made it possible to determine, by means of high resolu­ tion QNS, details of the hydrogen diffusion path in a hydrite. Several groups focussed on the dynamics of the giass transi­ Members of the College tion. As a common feature of almost a dozen glasses quasielastic scattering over a large energy region has been 1.Internal Members detected at temperatures close to the glass transition J.P. Beaufils M. Liss temperature. J. Bouillot A. Magerl O. Chaix-Pluchery M. Maret P. Chieux R. Meyer D. Degenhardt R. Oberthiir A.J. Dianoux W. Petry J.E. Enderby C. Poinsignon B. Frick R. Pynn SCIENTIFIC TRENDS T. Flottmann A. Rennie V. Frank D. Richter AND HIGHLIGHTS IN 1986 W. Glàser C. Ritter A. Heidemann M. Roth Quasicrystalline Structures A. Heiming O. Schârpf C. Janot H.P. Schildberg Three years after the first observations of 5-fold rotational W. Just W.G. Stirling symmetry in the diffraction pattern of rapidly solidified Al- G. Kearley W. Trost Mn alloys the existence of a class of crystals producing sharp M. Kim A.F. Wright Bragg peaks but having no long range translational invariance H.J. Lauter - the so-called quasicrystals - is well established. Some insight into the actual atomic arrangement of these icosahedral quasiperiodic phase has been obtained using X-ray and neutron 2. External members diffraction. Several models, all filling non periodically the P. Becker ( CNRS, Grenoble) space with more than one primitive cell, have been proposed. F. Cyrot (CNRS; Grenoble) However, at present we are still facing two basic questions: P. Desre (ENS Electrochimie, St. Martin d'Hères) i) Where are the atoms? and ii) why is the density of state of J. Dupuy (Dept. Physique Matériaux, Université Claude Ber­ all models too small in comparison to the experimental value? nard, Lyon) J.F. Jal (Université Lyon I, Villeurbanne) F. Volino (CENG - RFS PHS C5)

SUMMARY The scientific activities of College 6 members during 1986 were influenced by a fully operational reactor, which enabled a large number of experiments to be carried out. Some of the most exciting experiments were: the partial structure factors of quasicrystals which have been determined by means of the con­ trast variation method. Diffraction pattern of quasicrystals ex­ hibit an up to now forbidden five-fold symmetry and the crystal structure has no long range translational invariance. The best inelastic neutron data obtained hitherto on liquid 3He at various pressures were recorded with the TOF instru­ ment IN6. The experiment being technically very difficult was only feasible because of the low background of IN6 (for 512 3 Figure 45: Thermo-diffraclometry patterns of the i-Al^SiiM^ fat and time channels from - 4 Hz to ~7 Hz, for 337 He detectors i-AlKSi,(Mn7!Fe2sii4 (oj phases. of 90 cm2 active surface). Tunnelling of a single H atom trap­ Six-index notation for the i-phases and the conventional three-index ones for the crystals are labelling the measured diffraction peaks findicales traces of ped at an immobile interstitial like O or N in a Nb matrix has the O-phase in the as-quenched sample).

49 Fractons 10° There has been considerable interest recently in the dynamical ILL-IN5 Data properties of random systems. Alexander and Orbach first showed that for a fractal network, the thermal excitation spec­ trum is influenced by the fractal character of the system. They

predicted a new dynamical exponent ds to describe the densi­ ty of state G(a>)~cùds-1 of the so-called fracton spectrum. Furthermore at the cross-over from the fracton to the phonon regime an anomalous enhancement of the density of states, the so-called fracton edge, was postulated. Last year we reported about the first neutron scattering experiments on vitrous silica and epoxy resins which were interpreted in terms of such a fracton edge. To give more experimental evidence these inelastic neutron- scattering measurements (IN6) have been continued with samples of the monomer DGEBA (diglycidyl ether of bisphenol A) which is the basis of most types of epoxy resins. The physical and chemical properties of these samples are bet­ ter defined and samples in both the crystalline and amorphous state, are available. For the crystalline material it was found that G(co) is proportional to to2 at low energies. At high energies (> 3.5 meV) (as in most crystals) it shows some struc­ ture. For the amorphous material the results confirm the earlier work of Rosenberg in which G((o), whilst initially proportional to to2, varies as a higher power of co above about 1.2 meV. This behaviour coincides with what phonon-fracton theory predicts for the transition from phonon (propagating) to frac­ ton (localised) excitations. In an alternative approach the vibrational density of states of Titi) = E(meV) an agglomeration cluster formed from silica smoke particle aggregrates was investigated by means of inelastic neutron Figure 46: Density oj stales ZfbiJ/ta2 from extrapolating Ihe measured scattering curves spectroscopy using 1N5. In advance the fractal nature of its to Q = Ofor T = 265 K and T = 136K. In the insert are shown two typical geomerical structure was established by small angle neutron extrapolations leading to the two points with error bars on the 26SK data. scattering. It is characterised by a Haussdorff dimension The slopes are 1.2 and -0.9 Jor the T = 136K and T = 265 K dala. respec­ tively. dr = 2.6 ± 0.1. In order to visualise the cluster vibrations in the scattering experiment, the cluster surface was saturated To find an answer to these questions an extensive neutron dif­ with hydroxy! groups. At low frequencies the incoherently scat­ fraction study of quasicrystalline alloys of the Al-T system tering H-atoms follow the motion of the surface and thus mir­ ror the density of states. Figure 46 presents the resulting density (with T = 3d transition metal or alloy), the icosahedral struc­ 2 ture and its thermal transformation into the crystalline phase, of states G(d))/ta which was obtained from the difference has been started. By using neutrons and contrast variation by spectra between hydroxylated and hydrogen free Si02 isotopic and isomorphous substitution the diffracted intensities clusters. According to standard procedures, thereby, the measured intensities were extrapolated to Q = O due to different species of the material can be separated. Fur­ 2 2 thermore the penetration depth of neutrons guarantees the (ln(I(Q,co)/Q ) vs Q ). See also the insert in figure 46. Below measurements of bulk properties which are of particular im­ a cut-off frequency given by the internal vibrations of the small portance for the thermal transformation experiments. At the Si02-spheres around 1.5 meV (see in particular the i36 K present stage, the partial structure factors (amplitudes and data) the density of stales of the cluster excitation is observ­ ed. Other than a Debye spectrum which scales as G(û))~œ2 phases) related to Al and the transition metal atoms, respec­ 0J tively, have been obtained for about 30 diffraction peaks. Their a much weaker power law of G(co) ~co° * - is observed at position and intensities are in good agreement with what is ex­ I36K. The power changes to 1.1 at 265K, yielding spectral pected from a model using projection from a 6-dimensional dimensions ds = 1.8...2.1. These values are larger than space to a 3-dimensional real space. In an annealing experi­ theoretical expectations which are of the order of 1.5. A com­ ment, diffraction patterns have been recorded every 1.2K in parison of spectra taken at different temperatures reveals im­ a temperature range between 520 and 750K. The results (see portant anharmonicity of the present fracton modes. figure 45) clearly show the transformation from the icosahedral Comparing these two experiments one observes that the epoxy into the conventional crystalline phase in two steps. First the results are concerned with the cross over from the phonon (at low frequencies) to the fracton regime at higher frequency. orthorombic Al6Mn phase is formed and at the last instants of the transformation small amounts of a-AIMn is formed. In particular they show the "bump" effect at the cross over. The stability of the icosahedral phase is related to surface The smoked silica data on the other hand are aimed for the energy effects, and crystallization is controlled by the diffu­ fracton regime itself and directly show the weakly increasing sion of AI at the (i-phase-fcc-Al) interface. It seems evident density. Since homogeneity in these clusters is only reached that the Mn subnetwork forms the skeleton of the icosahedral for distances in the order of several hundred  the fracton quasiperiodic structure with "AI cement" filling up the voids phonon cross over is expected only at inaccessibly low fre­ to reach a proper metal packing fraction. quencies.

50 HoSk Q-CMïm3

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-0.S o as 10 u uo -as o at IJO u IO ENERGY (m«V) ENERGY (m.VI 0.4 0.8 1.2 _ 1 Figure 47: Energy spectra of liquid 'He at 120 mK (IN6, \ = S. 16À,. The pressure Wavevector Q (À" ) dependence of the inelastic scattering is shown at two waveveclors (0.5 and 0.8 À 'I

Quantum Liquids 3 Liquid He figure Jit: Contour map of the inelastic intensity of'He tSv'P/ at 120 mK; the three Some years ago, the excitation spectrum of (highly-absorbing) main components of the scattering are clearly defined: 3 (a/ the steeply rising collective "zero-sound" mode normal liquid He at saturated vapour pressure was examin­ (0/ the low energy "paratnagnon" mode ed, at first at ILL by Scherm, Stirling and collaborators, and tel the "qtwsi-particle tptasi-holc continuum" tit larger wavevectors. then at Argonne National Laboratory by Skôld et al. A new study of the pressure-dependence of the excitations has recently 4 been performed on 1N6; this experiment involved close col­ Liquid He laboration between teams of scientists and technicians from The cold-neutron triple-axis spectrometer IN 12 continued to P.T.B. (Braunschweig), ILL and Studsvik (Sweden). be used for detailed investigations of the elementary excita­ The experiment has been very carefully prepared over two years tion spectrum of superfluid 4He. by a series of background measurements resulting in signifi­ Previous high-resolution measurements of phonon frequen­ cant improvements of the IN6 shielding, and by test: tg of the cies at saturated vapour pressure were extended to applied re-entrant pressure cell and dilution refrigerator. pressures of up to 20 bars. As expected theoretically and from During the experiment both the cryogenic system and the spec­ phonon propagation experiments the anomalous (positive) trometer were operating well and data was obtained for dispersion observed at saturated vapour pressure decreases in pressures of 0, 5, 10 and 20 bars, all at a temperature of magnitude and disappears rapidly with increasing pressure. 120 mK. The spectra obtained were certainly the best ever ob­ Taken in conjunction with the earlier saturated vapour pressure tained for this extremely challenging sample. As shown in results, these data represent the most precise information figure 47, at small wavevectors, the zero-sound (collective- available on excitation frequencies in the phonon regime. mode) peak is very clearly observed at low pressures; the in­ Despite considerable experimental and theoretical effort, there crease in frequency and width with applied pressure has been is as yet no firmly established connection between superfluidity clearly observed for the first time. At larger wavevectors there and the excitation spectrum of 4He. One attempt to make this were significant changes with pressure in both the low frequen­ connection was the proposed decomposition of the 4He scat­ cy spin-dependent (paramagnon) scattering and the particle- tering function into two parts arising separately from the hole continuum scattering. The three principal components of superfluid and the normal fluid - the Woods - Svensson the excitations spectrum are prominent in a contour represen­ hypothesis. However, other interpretations of the temperature tation, e.g. figure 48. Detailed analysis of these results and dependent S(Q,co) measurements cannot be ruled out. By mak­ comparison with theory are presently underway. ing measurements of S(Q,co) at an applied pressure of 20 bars,

51 the ratio of the superfluid to normal fluid density - an impor­ orientations at 420K. While for Q parallel to the plane one tant parameter of the model - is significantly altered, and thus broad line is observed, in perpendicular direction the spectrum the relative weights of the different components change. In is much narrower and composed of an elastic plus a quasielastic this way, an independent check on the hypothesis of Woods contribution. For the parallel orientation only 50% of the in­ and Svensson can be made. The 1N12 data for the "maxon" tensity observed at 200K lies within the energy window of the (Q = 1.13 Â"') and "roton" (Q = 2.03 Â1) are at present instrument indicating the existence of much broader lines not being analysed in terms of the above mentioned model. For visible on [N10. On the other hand for the perpendicular direc­ the roton wavevector, it is evident from the "raw" data that tion only a slight decrease of intensity which can be attributed the Iineshape changes significantly at, or near, Tx; quan­ to the Debye Waller factor is found. titative conclusions must await completion of the model-fitting procedure. The experimental results can be understood in terms of a highly anisotropic two state diffusion process. For a time i„ the H diffuses slowly in the occupied planes, then it escapes into the .i unoccupied layer, where it diffuses rapidly. After a time t| it finds an empty site in one of the adjacent sheets. According : : ' .... * to this model two-component spectra are expected for V2H. For the case of Q perpendicular and , Q | = 1.4, Q is close 6000 to the (001) superlattice reflection and a spectrum composed of a S-function and a quasielastic line is expected. Us width • corresponds to T - 1/T- 1/T,. In the parallel direction the ! QH IOJ .«*-'• t width within the IN 10 window is determined by the diffusion Qi IQI-1AÂ"1» 14000 within the occupied plane (F - l/tB f(Q) + l/t„) where • 1/TB is the jump rate and f(Q) the Chadley Elliot factor. * Qualitatively the experimental results reflect this theoretical prediction. A quantitative analysis is still to be done. 2000 2(X ) 300 T [K] 400

Figure 49: Temperature scan with a constant energy window of lueV. The intensity slope • at low Tresults mainly from the Debye-rValler factor. The high temperature intensity drop indicates the onset of diffusive motion.

Hydrogen Diffusion in a one domain 1 • V2H Single Crystal Among the binary Vb metal hydrogen systems V-H is a par­ ticular case, since the H occupies both octahedral and • tetrahedral sites. The occupancy, thereby, depends on

temperature and H-concentration. In the p-phase which is INTENSIT Y stable around a H concentration of 50% the H-atoms occupy ;ets of octahedral sites which form sheets normal to a (11 in­ direction. These sheets are separated by layers of non-occupied O-sites. From the disappearence of the X-ray superlattice ht K V reflection at the phase transition from the P to the e-phase at jk& \PVÏ 170°C it was concluded that this transition occurs by ran­ > ^ domisation of the H atoms on the two sets of octahedral in- 0 terstitials. This transition is beiieved to be of second order and -10 -5 0 5 10 precursor effects are already seen at room temperature. •hw(peV) Up to now a detailed study of H-diffusion in ordered metal Figure SO: Quasi-elastic spectra for V H at ,Q = 1.4A at 420k'. (o) = Q parallel to hydrides was not possible, since only multi-domain crystals 2 the H planes; (•) = Q perpendicular to the planes. The solid fines are results were available. Recently, however, in Julich the production of fitting routines assuming une Lorentzian for Q\ and u Lorcntzian plus 3 an elastic contribution fat Q. of a 3cm large one domain V2H single crystal was achieved. It offered the unique possibility to study the expected aniostropic H-diffusion in an ordered metal hydride in detail. Figure 49 presents the outcome of a so-called elastic Diffusion in crystalline and temperature scan on IN10. Thereby the scattered intensity within the resolution window ( — 1 ueV) is measured as a func­amorphous solid state ionics tion of temperature. Broadening of the quasielastic line is seen by a reduction of the intensity within the resolution window. Apart from the famous exception of hydrogen with its huge In this experiment Q was oriented parallel and perpendicular incoherent cross section of 80 barns there exists a couple of to the H-planes for | Q | = 1.4 Â1. Obviously the H mobili­ very interesting (metal) isotopes having a moderate incoherent ty sets in earlier and is much higher in the direction of the cross section between 5 - 0.5 barn. Among those are: V, Ni, planes than perpendicular to them. Finally figure 50 displays Cl, Co, Se, Ti, W, Cr, Na, 7Li, Ag All these elements quasielastic spectra obtained on IN10 for the same sample are potential candidates for long range diffusion studies by

52 means of quasielastic incoherent neutron scattering (QNS), The mechanism of conductivity has been looked for in the ionic provided the coherent elastic scattering plays a minor rôle. glasses 0.85 AgP03 - 0.15 Pbl2 and 0.65 AgP03 - 0.35 AgBr.

+ By small angle scattering it has been shown that small Agl2 The diffusion of Na ions has been studied in a powder of clusters of an average size of 20 Â are heterogeniously dispersed non-stoichiometric 3-alumina (Al O Na with n ntV! ] + !k in the AgP0 network. A similar behaviour can be assumed x = 0.25) at temperatures between 77K to 673K using the TOF 3 for the glass AgP03 - AgBr. Small amounts of quasielastic instrument 1N6. Quasielastic scattering is clearly evidenced scattering in the energy window of IN6 were observed. The above RT. From the lineshape two kinds of motions were iden­ 12 large value of the EISF (0.95 for AgP03 - Agi) and a too tified : localized jumps (T - 10" S, activation energy + s 2 large diffusivity of Ag (as deduced from the line broaden­ -0.050 eV) and long range diffusion D - 0.75 x I0 cm s', ing) in comparison with tracer measurements suggests for both activation energy -0.25 eV). cases i. model where the Ag+ ions diffuse fast within the Taking oriented single crystals for this kind of study has the dispersed clusters. These hypothesis assumes that ionic con­ advantage that both jump frequencies and jump vectors can duction in these glasses is almost entirely within the cluster be evaluated from the measured S(Q,

Figure 52: Longitudinal phonons measured in bec-titanium single crystals. Remark the "soft" 2/3 phonon.

Diffusion in refractory metals Self-diffusion in the group IVb metals, Zr, Ti and Hf, exhibits several anomalous properties with respect to normal diffusion: scaled with the melting temperature self diffusion is much faster and the diffusivities plotted on an Arrhenius scale show pronounced curvatures. Common to these metals is a marten- sitic phase transition from hep (low temperature phase) to bec above 800°C. Classical methods like tracer measurements have so far failed to explain the mentioned anomalies. An extensive quasielastic (IN 10) and inelastic (IN3) neutron scattering study helped to clarify some of the basic questions (see Fig. 51). Quasielastic neutron scattering on oriented (and in situ grown) bcc-Ti single crystals clearly revealed the underlying diffusion lattice: most of the Ti atoms jump in < i 11 > direction into the nearest neighbour vacancies. However, a fraction of roughly 25% jump events goes direct­ ly (and/or via an encounter) to next nearest neighbour sites. Although knowing the dominating diffusion mechanism an answer has still to be found to the question why its diffusivity is so much larger than in other refractory metals. Phonon spec­ troscopy on the same bcc-Ti single crystals showed now that the longitudinal < 111 > phonon at temperatures close and far away to the phase transition) "softens" at q*= 2/3 to hco< 0 (see Fig. 52). This is an exciting result because it principally implies that the lattice is no longer stable. Obviously Figure 51: Self-diffusion ofb-Ti. Dependence of the quasi-elastic line broadening YtQ) on momentum transfer for various rotations a around the single crystal axis that is not true - the measurements were carried out at two < I00> perpendicular to the scattering plane. Also shown is a comparison temperatures above the phase transition. This puzzle can be with the theory which matches best with the measured data: 75 So nearest neighbour jumps into direction and 25% next nearest neighbour solved assuming a strong tendency of forming co-phase em­ jumps into < IOO> direction. bryos. This co-phase is not stable (there is no super lattice

53 reflex). It exists only as fluctuations of the Ti atoms towards co embryos. Simple geometrical considerations show that defor­ ming the bcc cell into an co-embryo pushes the Ti atoms into POLYBUTADffiNE the < 111 > nearest neighbour direction. So we return to the initial question. The principle diffusion jump in bc>^ Titanium is a nearest neighbour jump which is enhanced by fluctuations of the bcc lattice into co-phase embryos. The crucial problem to be solved when carrying out the ex­ periments was, how to obtain bcc single crystals which are only stable in the high temperature phase. This has been overcome by the construction of a furnace in which the single crystals are grown, kept at high temperatures whilst carrying out the neutron scattering measurements.

100 200 Temperature [K]

POLYBUTADIENE

Figure 54: Elastic energy scan of polybutatiene glass measured at IN 13 with a resolu­ Figure S3: Quasi-elastic scattering contribution of tri-naphyl-benzene measured on IN6. tion of9\ieV. Top: normalized intensity as a function of temperature for Shown is the difference of spectra measured at 27 K above T^ = 342 K and different Q. Bottom: normalized intensity as a function of Qfor different temperatures. TF marks lite glass transition temperatures. 42 K below Tg, respectively, clearly revealing the quasi- elastic contribution. The full line represents a fit with a single Lorentzian.

1.0 1 Dynamics of the glass transition ' 'J I "«I . 'o ii'o'WI,^ ' 'I 'HI

In spite of its obviously universal nature, the solidification of a liquid can only be described by phenomenological «0 06 parametrizations. Recently, however, several theories were published which provide a microscopic description of the glass S 0.4 transition using free volume, mode coupling arguments etc. U) In the framework of these theories the vitrification is accom­ Q2 panied by a quasielastic scattering with a non-trivial line shape (non-Lorentzian). This theoretical progress prompted in the 0 last 18 months a series of quasielastic neutron scattering ex­ 10" t(s) 10"" periments on a large number of glasses with quite different physical and chemical properties. Substances investigated by Figure 55: Measured rJSE spectra al q = 1.7Â' in a {CalNO^JoJKrJOJçn ionic glass QNS in the last year are summarised in the following table. system at various temperatures above the glass transition. The solid lines repre­ sent the stretched exponential A.exp{r'/^l. With the exception of Zn CU and glycerol all glasses indicate the onset of quasielastic scattering close to Tg, either this has been directly measured by S(Q, co) (figure 53) or indicated by co-range (i.e. with different instruments) deviations frr-n a a so-called elastic window scan (see figure 54). In such a scan single Lorentzian line shape have been found. Thi is best the intensity falling into an energy window given by the in­ shown by the measurements on the spin echo instrument INI Î strumental resolution is recorded as a function of Q and sam­ which measures directly in the time space (see figu. .: ;. Here ple temperature. In all cases in the table the intensity drops a scattering law of a stretched exponential S(Q, t; = 0.84 exp at T ^Tg (glass transition temperature) beyond which is ex­ (-(t/T)0SS; has been found. Summarising one should state pected from a "normal" Debye-Waller factor. This decrease that, in spite of the large class of different glasses, a general of intensity indicates the onset of quasielastic scattering within similarity of the different samples has been found and that a time scale equal or shorter than that given by the instrument. a qualitative agreement with the theories exist. Quantitive com In those cases where S(Q,co) has been measured over a large parison is still missing and will be the subject of further studies.

54 Glass Instrument Elastic window scan Quasielastic intensity performed anomalous intensity Close to Tg decrease poly-butadiene IN6, INIO, IN13 yes yes yes poly-ethylene IN4, IN6 no - yes poly-styrene IN13 yes yes no

Zn Cl2 INIO yes no no [Ca (NO ) ] . [KNO ] . INI 1 yes 3 2 0 4 3 0 6 no - Se IN6, IN 13 yes yes yes tri-naphtylbenzene IN5, IN6, IN13 yes yes yes poly-carbonate (meta IM, IN13 yes yes yes bridged biphenyl) ortho-terphcnyl IN13 yes yes 7 polymethylphenylsiloxane 1N13 yes yes ? (isotaclic) poly siloxanc IN13 yes yes 7 (hetereotactic) benzene in ortho-terphenyl 1N13 yes yes yes glycerol 1N13 yes no no

Ttihle: Summary itf quasivlmlif ncutnm scan'riii^ axpcriimmls on uttisscs

To conclude the College report on a sad and personal note, we pay tribute to our friend and colleague Rudi Meyer whose untimely death after a long illness has affected us all. Secretary: W. Petry

55 COLLEGE 8 Structure-solvent interactions Small-angle scattering studies of malate dehydrogenase from Halobacterium maris mortuii/solvent interactions have con­ ANDEMBL tinued (ILL, Weizmann) and been extended to collaborations with other reactor centres (Oak Ridge, Saclay). Solvent- GRENOBLE structure interactions are greatly amplified in this system and may provide a model for salt effects in molecular biology. Re­ cent measurements show that the enzyme structure and sol­ BIOCHEMISTRY vent interactions are identical in NaCl and KC1. Kinetic measurements on the denaturation of the enzyme at low salt (1 M NaCl) have also been done. The results indicate that the protein dimer loses its exceptional salt and water-binding pro­ Members of the College perties and dissociates into monomers which show more "nor­ mal" solvent interactions. Thus the exceptional salt and I. At ILL II. At EMBL water-binding of the native enzyme is associated with the struc­ L.F. Braganza M. Adrian ture of the dimcr. A.J. Dianoux C. Berthet K. Ibel J. Chroboczck M.S. Lehmann M. Cuillel S. Mason S. Cusack R. May C. Devaux G. Mclmyre A. Gabriel R. Oberthur F. Guinet A. Rennie M. Hârtlein M. Roth B. Jacrot P. Timmins J. C. Jesior J. Torbet J. Langowski S. Wilson R. Leberman G. Zaccai D. Wild

INTRODUCTION After the reactor shut-down in 1984-85, experiments recom­ menced in September 1985 with renewed vigour and en­ thusiasm. Several diffractometers which were modified or built during the shut-down are now in routine operation. The small- angle diffractometer DU with its continously-variable sample- to-detector distance functions well and is a modification to the instrument that has resulted in a more efficient use of Figure 36: A schematic représentation o/lhc probable C-2 assignment in the Bit struc­ neutron beam-time. The single-crystal diffractometer D19 on ture. A protein trimer is shown with the boundary of one of the BR molecules the thermal neutron beam H11 has worked routinely since indicated. Shading densities reflect the probability for each position to be occupied by one of the two C-2 helices. The most probable assignments are April 1986. DB21, the single crystal diffractometer for low 1*7 or 6+7. resolution protein structural studies, has also been operational since April 1986. The instrument characteristics are similar to those of Dl 7 which was the machint previously used for these studies. DB21 is dedicated exclusi\sly to measurements on single-crystal macromolecular assemblies and several studies Membranes have been started (see Protein Crystallography). Bacteriorhodopsin (BR) is a transmembrane protein which functions as a light-driven proton pump and occurs in naturally crystalline purple membranes. The low-resolution structure of BR shows features which are likely to be seven helices spann­ ing the membrane. The problem of identifying these structural SCIENTIFIC TRENDS features with seven a-helical regions observed in the amino- acid sequence of BR has been tackled by neutron diffraction. AND HIGHUOHTS IN 1986 Diffraction measurements have been done on reconstituted BR where the first two predicted transmembrane segments (frag­ A meeting funded by the CNRS on "Molecular Biology and ment C-2) were deuterated (Yale, ILL). The diffraction Crystallography" was organised by the I LL/EMBL and took changes when the natural C-2 fragment is substituted by a place in March 1986 at Biviers near Grenoble. The major topics deuterated one have been analysed in terms of a seven-helix covered were neutron, X-ray and electron diffraction. model (see fig.56).

56 The structure of BR under different conditions of hydration, temperature and hydrostatic pressure have also been in­ vestigated (ILL).

Filamentous DNA-protein complexes Recombination in E. coli depends on two DNA-binding pro­ teins, the single strand-binding protein (SSB) and the recA gene product (RecA) which function in an interdependent way. Both the SSB and RecA protein complexes with DNA are currently being investigated by small-angle neutron scattering. Apart from its role in recombination, SSB plays essential roles in a number of other cellular processes such as DNA replica­ tion and repair. When visualised in the electron microscope (EM) and SSB-SS DNA (single-stranded DNA) complexes are filamentous and may have a regular beaded substructure (Fig 57). Small-angle neutron scattering has been used to

measure the cross-sectional radius of gyration (Rc) and mass per unit length of this complex in solution at different contrasts (EMBL, Hannover, ILL). The Stuhrmann plot 2 (i.e. 1 /p vs Rc ) has almost no slope indicating that there is lit­ tle asymmetry in scattering density across the filament and sug­ gests that the DNA is distributed uniformly in cross section.

The Rc at 1/p = 0 is about 53 Â which is larger than seen in EM images and may mean that the complex in solution con­ tains a solvent pocket. The mass per unit length in solution indicates that there is one protein about every 10 Â along the filament. The purified recA protein (MW 38000) is able in vitro to ef­ fectuate strand exchange between two homologous DNA molecules, which accounts for its activity in recombination. As well as forming well defined filamentous complexes with both SS and dS-DNA (double-stranded DNA), recA self- polymerizes into filaments as observed by electron microscopy. Small angle neutron scattering is being used to characterize each of these filaments in terms of mass per unit length and cross-sectional radius of gyration (Zurich, IBMC Strasbourg, ILL). The initial results show that the diameter of dS-DNA filaments is less than that of self-filaments although the mass per unit length is almost unchanged. Experiments with deuteratd DNA are planned and will enable the DNA within the complexes to be located.

Other Nucleic acid-protein complexes Small-angle scattering has been used for the study of the solu­ tion structure of in vitro transcription complexes formed bet­ ween DNA-dependent RNA polymerase of E. coli and a short DNA fragment of 130 base pairs carrying the strong promoter Al of bacteriophage T7 (ILL, MPI Martinsried). The experiments carried out so far show that RNA polymerase (RNAP) specifically bound to DNA at 37°C in the so-called FiRure 57: Sehematw representation of the filamentous SSB-singte stranded DNA transcription active "open complex" has a conformation dif­ etttnplcx. ferent to that of isolated RNAP. Measurements on complexes with labelled (deulfrated) RNAP RNAP is an extended molecule (with a ratio of about 2 bet­ subunit sigma and DNA and contrast matched RNAP core ween long axis and cross sectional dimension) and the cross enzyme show that the sigma subunit touches the DNA and sectional radius of gyration has been measured. From cross hence may mediate its specificity via DNA contact. linking experiments it is known that the long axis of RNAP and DNA axis are roughly aligned. The comparison of the Another nucleic acid-protein complex, the 7S RNP particle is cross sectional radii of gyration of complexes with both DNA also under study (EMBL Heidelberg, ILL). 5S ribosomal genes and RNAP labelled (RC = 37.8Â) and RNAP alone labelled of Xenspus are transcribed by RNA polymerase III in the

(Rc = 35 Â) leads to a mean distance of 50Â between the DNA presence of 3 protein factors one of which is TFIIla. After and long RNAP axis. transcription a large part of the SS RNA is associated with

57 TF Ilia in the form of 7S RNP particles. Small-angle scatter­ E. coli large ribosomal 50S subunit ing has been used to show that this particle is a 1:1 complex of molecular weight 80000. Contrast variation studies show Assembly of new proteins takes place on the surface of that both the 5SRNA and TFIIIa are extremely elongated in ribosomes which are particles composed of several large RNA the complex and that the protein covers a large part of the molecules and more than 50 proteins. The complex is com­ 150 Â long stacked double helical domains of the RNA. Model posed of two subunits which for prokaryotes are the 50S and building studies incorporating results from enzymatic and 30S particles with a mass ratio of 2:1 (see figure 58a). For a chemical protection experiments are underway. number of years, small-angle scattering measurements (Max Planck Berlin, ILL) have been devoted to the study of the ar­ rangement of proteins within the 50S subunit. By using a new program for peak fitting in real space to treat the data, an im­ proved model for the locations of eleven proteins within the subunit has been obtained (figure 58b). This model includes five proteins (LI, L4, L9, L20 and L23) which are present in the surface location map determined by means of immuno- electrrm microscopy, the two methods give excellent agree­ ment lor the location of these surface proteins. Further measurements arc planned which arc aimed nt resolv­ • ing uncertainties concerning a few protein locations. Depen­ ding on the results, a model containing - 15 of the 32 proteins CO *>S in the 50S subunil should be available soon.

23S+SS 32 profitas jf 16S 21 prottins RNA I" "*>' RNA IS1-S21)

Figure 59; View down the three-fold axis of the protein frimer showing the pores form­ ed by the interfaces of protein subunits.

Figure 60: Neutron scattering length density maps of TBSV in 0. 38, 70 and 100% D20.

0%D20 shows a distribution of density similar to that revealed by X-rays, making it impossible to distinguish between protein and RNA. 38% D,0 reveals mainly the RNA but also contains significatif contributions due to fluctuations of scattering within the protein. The 70% map shows mainly Figure 58: 'a} Schematic protein and nucleic acid composition of the E.coli ribosome. protein and in particular reveals the existence of globular domains at low (b) Locations of eleven proteins in the large (50S} rihosomal subunit. particle radius.

58 Protein crystallography and low resolution crystallography of macromolecular assemblies The structural studies on the crystalline membrane protein, matrix porin have been continued and the model refine-1 to 16 Â resolution at four different contrasts using the non- crystallographic 32 symmetry of the pair of porin trimers (figure 59). The elucidation of the detergent structure is prov­ ing more problematic and further experiments will be carried out using deuterated detergent (Biozentrum, Basel, EMBL, ILL). Three complete protein data sets have been measured on D19 to a resolution of 2Â for lysozyme and to better than 3.5Â on a low salt crystal form of the much larger protein human haemoglobin (unit cell 614.000Â3). H/D exchange in haemoglobin will be modelled in a full joint least-squares refinement using as observations both the limited neutron data set and very high-quality X-ray data (to 1.6Â resolution) measured at the Daresbury synchrotron. This combination of high resolution X-ray and medium resolution neutron data is most easily obtained for large proteins and a successful refine­ ment would be a major step forward for H/D exchange studies of larger proteins which are not easily accessible to solution technqiues such as n.m.r. The neutron scattering length density maps of TBSV have been refined to 16 Â using the non-crystallographic five-fold sym­ metry and solvent flattening (EMBL, ILL). The refinement yielded R factors of between 10 and 7% for the four contrasts

(0, 40, 70 and 100% D20).

The 70% D20 map shows clearly the bilobal distribution of protein with a region of density connecting the centre and in­ ner shells. At 40% D20 the density clearly shows the presence of localized regions of RNA although some of the density may be ascribed to proteins (see figure 60). Full data sets up to 16 Â resolution have been collected on DB21 for several systems. These include a contrast variation study on the expanded form of satellite Necrosis Virus (Biomedicum, Uppsala, Institut Pasteur, LURE, ILL) with the aim of producing a low-resolution density map of the RNA in this virus. Measurements have also been done to elucidate the detergent distribution in crystals of the photosynthetic reac­ tion centre from Rhodopseudomonas Viridis (MPI Martins- ried, LURE, ILL). Some test measurements have been carried out on 50S ribosomal subunit crystals (Weizmann, MPI Berlin, LURE, ILL) and data collection has started on the expanded form of Tomato Bushy Stunt Virus (IBMC Strasbourg, EMBL, ILL).

Secretary: L.F. Braganza Head of EMBL Outstation: B. Jacrot COLLEGE 9 i i I

0.7%Sn(CH3)4. CHEMISTRY in Ar Members of the College 1 ? v. J P. Chenevas M. Lehmann R. Ghosh P. Pautrot \ 50K- ! 9a: Molecular Spectroscopy, Surfaces and Mesophases J.P. Beaufils A. Magerl lo M. Bée S. Mahling-Ennaoui * V*" VA H. Blank J. Pannetier A.J. Dianoux W. Petry y • \45K V. Frank O. Chaix-Pluchery A. Heidemann C. Poinsignon v A • G. Kearley C. Ritter Inte n V V32K H. Godfrin B. Saubat-Marcus / V W. Langel M. Liss H.J. Lauter M. Kim V* '- 9b: Colloids and Polymers •" \ 5K P. Chieux J. Kugler < 1 i

B. Farago R. Oberthiir o P.J. Feeney A.R. Rennie -100 0 100 B. Frick D. Richter K. Ibel A.F. Wright Energy transfer[ueV]

Figure 61: Tunnelling spectra of 0.7% SnfCHilj isolated in Ar as measured al a sam­ ple temperature T - 5K after annealing for about lit at the indicated temperatures. The neutron TOF spectrometer 1IV5 of the ILL was used with

an incoming wavelength \„= lOA an energy resolution oE0 = 14 \ieV. INTRODUCTION The temperature dependence of the tunnelling spectrum of methyl groups in lithium acetate dihydrate has been studied In 1986, two conferences took place in which many of the Col­ in the temperature range between 1.2 and 8.0 K by inelastic lege members participated: the 41st International Meeting on neutron scattering (Nottingham, ILL). The results unam­ Dynamics of Molecular Crystals organized by the French biguously prove that it is to a first order approximation cor­ Chemical Society at the University of Grenoble and the rect to describe the tunnelling motion by a model of coupled workshop on "Quantum Aspects of Molecular Motions in CH3 pairs which are isolated from each other. However, from Solids" at the ILL. Interesting scientific work was also car­ the fact that the tunnelling frequencies shift to higher values ried out in other fields, as described in the following. with decreasing spin temperature, we conclude that coupling effects are important not only between nearest neighbour

CH3 groups. Quantitatively we can describe the observations by a model of coupled pairs with a fixed value for the interac­

tion potential W, and a variable single particle potential V3 SCIENTIFIC HIGHLIGHTS IN 1986 which depends linearly on the concentration of the spin sym­ metry species. Quantum and Rotational Motions Rotational tunnelling transitions of the methyl groups of The workshop about tunnelling (in cooperation with KFA Sn(CH3)4 isolated in an Ar matrix have been observed at Julich) demonstrated that this field continues to be very ac­ energies Ito,! = 83 neV and hwl2 = 68 ueV (Julich, ILL). tive. A selected review of subjects will be presented in the Beside of the corresponding well-defined matrix sites there is following. a broad distribution of surroundings with strong rotational potentials leading to inelastic intensity at smaller energy

We may now add NH3 to the rather short list of molecular transfers. The tunnel splittings are large compared to the bulk groups for which free rotation has been observed. Inelastic because of the reduction of the intermolecular interaction and neutron scattering (INS) spectra (ILL) of the ionic solid the resulting removemenl of the molecular distortion found

Co(NH3)6(PF6)2 show transitions between rotational levels for in the bulk. They change significantly by annealing as a con­ the NH3-groups. The hindrance potential can be interpreted sequence of the rearrangement of the Ar atoms at temperatures as being of sixfold symmetry. A high resolution study of the s 32 K and diffusion of the guest molecules at higher temperature dependence of the spectra reveals satellite peaks temperatures (see Fig. 61). The strange shift of the tunnelling around the 0 -» I transition feature, which originate from a line with temperature due to coupling to phonons is explain­ coupling between NH3-rotors. ed on the basis of two inequivalent matrix sites.

60 Quasielastic Scattering The dynamics of water were studied in silica and ceria gels (Harwell, ILL) having well defined pore sizes, and different Quasielastic neutron scattering (QNS) is applied in a wide varie­ water contents. The diffusional constant is more affected by ty of different fields. Examples of investigations carried out the solid than is the rotational diffusion constant. For the lat­ at the ILL are reported below. ter, a slight increase in activation energy is determined in the

case of a well hydrated gel (30% H20 by weight). Similar The solid-liquid phase transition of ethylene (C2H4) layers on graphite was the subject of investigation (Brookhaven, ILL). measurements were performed on pure water and water in gels The data obtained show an increase of the translational dif­ between 310 and 500 K (but not yet fitted). fusion constant with increasing temperature at all coverages In many cases the elastic incoherent structure factor (EISF) (0.5, 0.6, 0.7 and 0.8) studied so far. Finite non-zero values allows a distinction between different types of local motion of the translational diffusion constant occur even in the solid only for large momentum transfer (above the normal cold phase, End the translation motion increases continuously neutron Q-range). An INI3 model experiment on through the solid-liquid phase transition. Furthermore, at a polycrystalline benzene demonstrates the possibility of analys­ given temperature the diffusion constant increases with ing the EISF up to 5Â1, showing clearly the sixfold molecular decreasing coverage. jumps about the benzene out of the plane axis (see Fig. 62).

1.0 •12 ElSf of potycrytttMn» twinnt X", /,<^ (7 (XV^V-VJ "*\ MIIN 5 (273 K) 1*\ A.IN 10(210 tO o.IN 13(246Kr 2Q5 \ <• A, * pOpQ dj^*. ^^i

Figure 62: EISF of polycrystalline benzene as measured on instruments INS and JN10 using cold neutrons and the backscattering spectrometer IN 13 using thermal neutrons. The measured EISF compares with the theory (A(Q)) for sixfold molecular jumps.

NEUTRON COUNT RATE (a) 1] ^m X(deg) 1+12

0 -12;L—• "x7d«Bl

À IT' ; NEUTRON COUNT RATE ll 1 - •12-. ^aiB8g«B^^BB^^6BH m

Y \ """o -12J- "" ~Xdeg 24 -12 Figure 63: The 2-D scattering distributions in the smectic $-phase for fa) the pure perdeuterated liquid crystal SO. 7 and 24 X(deg) (b) the same compound doped to 5% with hydrogenenous molecules. The X and Y axes are the detector angles in and out of the equatorial plane, e 64: The 2-D scattering distribution in respectively. The 7. axis is the neutron count rate. Each plot is a composite (a) the smectic B phase and of 9 frames of data Jrom the DI9 multidetector. The beam stop obscures fb) the isotropic phase of the liquid %ivstal 50.7. The X and Y axes are as the low angle region. in fig. 63.

61 + f solution planar H502 ion can be fitted to the observed spectrum, ex­ 1- f solvent cept that in the spectral region of the terminal HOH defor­ 1 0.4 mations, there is disagreement between the observed a.*d calculated profiles; this is taken as evidence of disorder of the o o o o o o ° 3 o oxygen atoms about the planar positions. Besides Raman and infrared spectroscopy INS has been used Q3 • to study the density of vibrational states in cis- and trans- polyacetylenes and iodine-doped cis-polyacetylene in the fre­ quency region 400 - 3500 cm"1. Trans and cis-polyacetylene ~T: -1 Q2 * f give characteristic spectra in the 400 - 1600 cm region which 1 are very different from each other. It was found that cis- ! Tf 1 polyacetylene is converted into trans with increasing dopent 0.1 quantity. • | 1 A ! -«> 4<>. * ! i 1 '' — N. 4 1 t Figure 65: The ••< uttering pattern of the drag reducing colloidal additive (900 ppm) in a punijh-il fluid (heavy water) is monitored as a function of lime. The initial­ ly rod like and POM- oriented micelles are destroyed, although a level of about 3 .i5"'n drag reduction is maintained. \

^2

é—« C J1 \t , 0 I \ ft -1 \ , 1/ 5 -4.5 -3.5 -5 Ln(Q)

Figure 67: Small angle scattering from a 11.5 cm path length sample of tobacco smoke. The straight line in this logarithmic plot of intensity vs scattering vector has a gradient of 4 showing good agreement with Porod's law.

Q[À-1P

Figure 66: Relaxation lime V/q3 against scattering vector q for a microemulsion of deuteraied decane Dfi and 2-di-ethylhexylsuiphosuecinate (AOT). The con­ centration of AOT and water was adjusted to give droplets of radius 3SÂ <•) and 25 A ( + ). The tatter sample was also measured with II 00 ppm

Vibrational Spectroscopy The INS spectrum of dod<"catungstophosphoric acid hex- ahydrate shows the presence of at least one type of + H502 ion, and most of the normal coordinates of a near-

62 The Orientational Distribution Function Some selected themes of research are mentioned briefly below: in Liquid Crystals Reflection from Surfaces There have been a number of different theories for the An area that has attracted increased interest in the past year nematic liquid crystal phase, but none of them model all was that of critical reflection from surfaces. This technique experimental observations simultaneously (e.g. both the is very sensitive to surface layers; the possibility of using order parameter and the nematic to isotropic transition isotopic substitution allows measurements on organic layers temperature). One of the best quantities for comparison bet­ such as surfactants and polymers. Several groups are now pur­ ween experiment and theory would be the distribution func­ suing research in this area - in particular there have been some tion for the orientation of the long molecular axes. very exciting results on polyethylene oxide solutions in water Unfortunately it has not yet been possible to measure this which show an excess of polymer at the air-liquid interface function directly, although certain averages over it can be (Oxford, ILL). Other experiments in this area have included measured by, for example, NMR, optical scattering and further measurements on soap films (Oxford) and Langmuir- conventional X-ray diffraction. Blodgett layers (Bristol). The quantity required to be measured is the molecular form 2 factor |Fm(Q.;P)| averaged over the singlet orientational Diffusion of Polymers distribution function f(P): |F (OJ|2= if(P)|F (g_;p)|2 m m The diffusion of macromolecules as previously has been of d cosft. much interest. Although much useful work is still done with 2 Conventional diffraction measures |Fm(OJ| , modified quasi-elastic scattering - for example of ionomers (London, strongly by a highly oscillatory intermolecular interference Exxon) and alkanes in polyethylene (Freiburg, ILL), there is function. The proposal has been made that the effects of increasing interest in time resolved.small angle scattering. The the interference function could be avoided by measuring the change in structure factor with time of latex particles has per­ diffraction from a random solution of hydrogeneous mitted determination of diffusion coefficients down to molecules in a solvent of perdeuterated molecules of the 10""cm2s'' (BASF, ILL). Much progress has also been made same compound. For a random solution the interference in the study of chain scission and diffusion using precise ther­ 2 function is a constant and |Fm(0_)| for the hydrogenous mal degradation of polymers (Mainz, Darmstadt, ILL). molecules can be obtained from the difference between a Kinetics of segregation in mixtures and copolymers have been pure solvent of perdeuterated molecules and the same sol­ studied by groups from London and Strathclyde. vent doped with some hydrogeneous molecules. One of the first experiments of this type was performed on Stretched and Deformed Polymers the multidetector difftactometer D19 on the liquid crystal As in previous years there have been several experiments to 50.7 CsHMOPhCHNPhC7H]5) which exhibits a number of determine molecular conformation in solid polymers. Recently smectic (S) phases as well as a nematic (N) phase: interest has turned to the molecular processes that occur dur­ 15°C 36°C 51°C 54°C 65°C 78°C ing deformation and in the past year a wide variety of materials crystal S S S S N isotropic. have been studied. These include polypropylene fibres (Lud- G B c A wigshafen, ILL), silicone elastomers (Strasbourg, Mainz, ILL), Two-dimensional scattering distributions were obtained for polycarbonate glasses (Mainz, Darmstadt), polyethylene each of the six higher-temperature phases on pure perdeu­ (Bristol) and polystyrenes (both linear and "star-shaped") terated 50.7 and on a doped sample. Fig. 63 shows the (Strasbourg). This last experiment in which molecular elonga­ distributions observed in the SB phase. In addition to a tion was measured as a function of strain and strain rate pro­ higher incoherent background, the small angle scattering mises to provide very useful data about the diffusional from the solution of hydrogeneous molecules in the mixed relaxation of star and branched polymers. sample U clearly evident. For this phase f(p) - S(P) and we observe the anisotropy of the molecular form factor directly in the small angle scattering. Fig. 64 shows the con­ Drag Reduction tour plot of Fig. 63b and the contour plot of the scattering The molecular changes occurring under shear in systems used distribution for the same sample in the isotropic phase. for drag reduction have been studied in a new experiment car­ In the isotropic phase f(p) = constant and we observe the ried out on Dll (Dortmund, ILL). Some results are shown spherically averaged molecular form factor. Analysis in Figure 65. A detailed interpretation of this data offers the is underway to obtain f(p) in the other phases, with prospect of large energy savings in pumping systems such as 2 |Fm(0_;3)| established by the .B distribution. those used in district heating schemes.

Microemulsions Colloids and Polymers Once again the properties of microemulsions have attracted As in previous years there have been many different materials attention - these dispersions of, for example, small amounts investigated. The vast majority of experiments use the small of water in oil are stabilized by smail amounts of surfactant. angle scattering instruments Dl 1 and D17. The remaining ex­ There has been considerable interest in the structure and periments concern mostly difftactometer s or quasi-elastic scat­ dynamic properties of such systems. An example of this work tering spectrometers. Nearly all the experiments have been is shown in Figure 66 which presents spin-echo spectroscopy conducted with visitors from outside the ILL; unfortunately data from INI 1. The effective diffusion coefficient is seen to the shortage of manpower in this area prevents the provision vary strongly as a function of scattering vector. The peak in of more than rudimentary support to experiments in this field this plot can be interpreted in terms of shape fluctuations of of science. the droplets. A simple model of an elastic sphere predicts

63 that the peak position should vary as one over the radius of the drop. This is indeed seen in the data as are changes that following way: structural investigations on deuterated single occur on adding salt to the water (Exxon, ILL). crystals defined the atomic surrounding and revealed a ther­ mal cloud consistent with a 5 meV harmonic CD3 - libra- In the same area there has been considerable work on the struc­ tion. Quasielastic neutron scattering at elevated temperatures tural properties of similar systems particularly at concentra­ (50K < T < 150K) yielded a 120° reorientational jump pro­ tions in which there are ordered or liquid crystalline phases cess with a barrier of 10.2 meV. Tunneling spectroscopy of (Saclay, ILL). The structural changes close to room the groundstate splitting on deuterated and protonated species temperature can provide useful variation in physical proper­ yielded splittings of 1.7 and 35 ueV, respectively. The spec­ troscopy of librational states resulted in CH -excitations at ties. This possibility of application has clearly been important 3 in the increase in number of experiments in this field. 6.7 and 17.5 meV while in the deuterated case 5.3 and 10.6 meV were observed. Finally, experiments on the pressure dependence yielded an unusual decrease of the librational Smokes levels and an increase of the tunnelsplitting with pressure. In the past many colloidal systems have been discussed in this This large variety of experimental data could be explained report - they have nearly all concerned liquid dispersion media. in terms of a superposition of 3- and 6-fold componenents There are clearly as many interesting phenomena in samples in the potential. Fig. 68 presents the best fit to the experimen­ containing liquids or solids dispersed in gases; such aerosols tal data at 1 bar pressure. This phenomcnological potential are commonly known as fogs and smokes. First steps have now was reproduced from Lennard Jones potentials between the been made to use small angle neutron scattering on such different atoms. Thereby it became evident that the 6-fold systems. Figure 67 shows data from D17 on tobacco smoke. term originated from O-H repulsive forces while the 3-fold From the scattering in this angular region it is possible to deter­ parts are traced back to H-H interactions. The asymmetric mine the surface area per unit volume of the smoke. It is hoped position of the 6-fold term relates to the asymmetric distribu­ to extend this wjrk to smaller angles and determine size tion of oxygens with respect to the CH group. distributions as well as characterize smokes obtained under dif­ 3 ferent conditions.

Secretaries: H. Blank (9a) A. Rennie (9b)

Quantum motion of light particles in condensed matter Tunneling phenomena in molecular crystals were first observ­ ed with macroscopic methods like specific heat experiments and later also with NMR. Finally the development of high resolution neutron scattering techniques like neutron backscattering led to a direct spectroscopic observation of the tunnel spiit groundstate. This breakthrough was achiev­ ed in 1975 at Julich. Since then the large variety of high resolution techniques in combination with high neutron flux made the ILL the leading laboratory in the field of tunnel­ ing spectroscopy. Since 1980 regular meetings of scientists involved in this topic were organized every two years (Jûlich, Braunschweig, Nottingham) and led to an intense exchange of ideas and experimental results. In September 1986 in col­ laboration with the Institut fur Festkôrperforschung of the KFA Julich the ILL organised a workshop on "Quantum Aspects of Molecular Motions in Solids" which presented the state of the art in this field. Here I take the opportunity Figure 68: The rotational potential as a function of methyl group rotation with to have a "second harvest" and to present some of the parameters corresponding to 1 bar. Also presented are the torsional levels highlights. for CHJNOJ (solid lines) and CD,NO] (dashed lines). The level splittings are only schematic for the lower levels. The first session of the workshop dealt with rota­ tional tunneling in relation to the molecular potential and interactions with phonons. Important progress has been The transition from quantum rotation at low temperatures achieved in the precise determination of rotational potentials to thermally activated classical jump reorientation at high by combining spectroscopic measurements of librational temperatures provides one of the most fundamental and thus levels and tunnel splitting of deuterated and protonated most interesting features in rotational tunneling. Experimen­ molecules of the same species. Varying external parameters tal data are available since a decade but the theoretical like the pressure adds further information. As an example description is still a matter of controversy. A very general I quote the case of nitromethane /1 / (CI^NOJ, where the treatment of the coupling of a quantum rotor to the phonons methyl-rotational potential has been investigated in the by second order perturbation theory provides a consistent

64 description of the general observations 111. Often more in­ sight is obtained by using simplified models with coupling Hamiltonians of special symmetry. Another access to the pro­ I I blem consists in solving numerically the time dependent Schrodinger equation /2/. cn In the session on coupled systems the new feature c 1,0 — — of rotor-rotor coupling was established by many experimen­ £i tal results. In the simplest case a coupling of just two rotors was found while in the most complex case a three-dimensional 3.0.5 L network of coupled rotors has been considered. As an ex­ a 11A ample I consider the case of Lithium acetate (LIAC) crystals CO /*!. »i \ where two CH groups occur in pairs at a distance of 2.5 Â 3 —F A;^\v—>?,-.»— * * F.A :^ . _^ with a common axis of rotation. Under these circumstances -250 0 25t 0 the rotational Hamiltonian can be written as: ENERGY TRANSFER (ueV)

Figure 70: INS spectrum of L1AC at a temperature of 2.6 K. The dashed lines indicate the result of the model calculation with the Hamiltonlan. = -B(-TT + JL-rr) - V3(cos 3*, + cos 302) \bfi

- W3 COS 3 (0, - 02> (1) peak around 250 ueV. Good agreement with the theory and the experiment is achieved if one uses the parameter pair

V3 = 2.96 B; W3 = -6.58 B. Thus, the interaction term is where B is the rotational constant and \ and 02 are thedominating , leading to a staggered orientation of the rotational coordinates of the two groups. A diagonalisation CH groups. of the Hamiltonian leads to a level scheme for the ground- 3 state splitting as shown in Fig. 69 /3/. The ground state In the third session on rotational tunneling the use multiplet contains four levels. The possible neutron induced of tunneling molecules as a probe to study its environment transitions are indicated by arrows (they have to fulfill the was emphasized. Site symmetries in solid phases and on sur­ selection rule Am = ± 0, 1). It is clear that in low barrier faces, phase transitions, the structure of rare gas matrices systems the influence of rotational coupling should be more used for matrix isolation spectroscopy, the chemical environ­ pronounced but also in high barrier systems due to the ex­ ment, intra- and intermolecular interactions were in­ treme sensitivity of the tunnelsplitting to changes in the poten­ vestigated. The sensitivity of the tunnel splitting to small tial coupling is observable /4/. LIAC is a low barrier system. changes of the rotational potential makes this probe especially Spectroscopic results taken on INS are shown in Fig. 70. Ob­ useful. viously the 4 predicted transitions appear in the spectrum.

The low frequency h

perimental results obtained for Nb(OH)x in the normal and Figure 69: The energy levels of two coupled methyl groups in the librational ground- state. The numbers next to the arrows are indicating the weights of the cor­ superconducting state at T = 0. IK (applied magnetic field responding neutron induced transitions. 0.7 T). In addition to the elastic scattering there is a well

65 defined inelastic peak from the H tunnel state. On the energy gain side the excitation cannot be seen at this low temperature. Two important phenomena are observed: (i) The peak position is shifted from 0.226 meV in the super­ conducting state to 0.206 meV in normal conducting Nb. (ii) In normal conducting Nb the peak exhibits a dynamical width of 45ueV. These differences immediately show the impor­ tant rôle of the interaction between the tunnelstate and the conduction electrons. From the ratio of the tunneling matrix elements in both conduction states the interaction strength K can be extracted /'8/.

JN fn Kiln s + 1.1 (1 (2) Q J + 2A(0) 2A(0)7 there A(T) is the electronic gap energy with A(0) = l.53meV. Equation (2) yields K = 0.053 ± 0.008 and shows that the coupling to the electrons is only weak. Then the low T linewidth can be estimated from a Korringa formalism. In the superconducting state it reads:

kT 47tK- (3a) 1 + exp (A(T)/kT)

while in normal conducting Nb

T = 7tKJN coth (3b) -0.2 0 0.2 0.4 l2kTf—) i ENERGY [ meV] holds. Without adjustable parameters, equations (3a) and Figure 71: Neutron spectra measured at 0.1 K in the superconducting (part a) and in (3b) predict T = 0 for superconducting and T = 35 ueV for the normal conducting state (part b). The dashed line gives the elastic energy normal conducting Nb. The agreement with the experimen­ resolution of the spectrometer and the thin solid Une shows the Jilted in­ elastic scattering. The thick solid line is the sum of both scattering con­ tal data is remarkable. tributions. The data were taken with the itime focusing time of flight spectrometer IN6 at the ILL. The regime of quantum hopping (T > T*) is realised by the motion of positive muons in Al and Cu /9/. Fig. 72 presents muon jump rates as observed in Cu. From a low temperature plateau, which most likely, is related to site disorder as a con­ sequence of the Cu isotope mixture and/or of strain fields 10 o Welter et ol. due to impurities, the jump rate decreases with increasing •1 Brewer et al. temperature following a power law * / 2 2K o Clawson et QI. / 1/T - J T " (4)

1.0 with K = 0.2 - here the strong coupling case is realised. A minimum value of the diffusion coefficient is reached around 50K. Thereafter, as a consequence of phonon interaction, the jump rate first increases linearly (1 phonon) and then ex­ ponentially with temperature. The muon motion in AI 10" behaves qualitatively similar, though the time scale is ac­ celerated by 4 orders o lagnitude. In the framework of Ron­ dos theory, the observed jump rates can be described using reasonable parameters. Some problems exist at high temperatures, most likely because a combination of advanced small polaron theories with the electronic interaction theory 0.1 1.0 10 100 of Kondo has not yet been worked out. T(K) Finally in the session on disordered systems the low temperature anomalies of amorphous substances were Figure 72: Muon jump rales in Cu. discussed and the two state tunneling model was presented. Solid tine: Result of Equ. (JJ Dashed line: High T behaviour However a microscopic understanding of the tunneling en­ Dashed dolled line: linear T dependence. tities has still to be achieved.

66 I hope that the survey on quantum motion in molecular crystals, metals and glasses which was given at the workshop may stimulate further interest in this field. In particular, organic chemistry could establish the tunneling entities as a new highly sensitive probe to investigate local en­ vironments. Further perspectives are also linked to new developments in instrumentation. Very high resolution spec­ troscopy at large energy transfers employing e.g. the neutron spin echo technique or advanced time of flight methods at spallation sources, may allow study of the tunneling split­ ting of excited states in more detail. In addition, a variety of new spectroscopic NMR methods have been developed which greatly extend the range of detectable tunneling fre­ quencies and which provide information complementary to those obtained from inelastic neutron scattering.

D. Richter

References fl/S.F. Trevino, Proceedings of the workshop on "Quantum Aspects of Molecular Motions in Solids", Grenoble 1986 to be published in Springer Proceedings in Physics 12/ A. Haller in réf. HI P/S. Clough, A. Heldemann, A.H. Horse* % M.N.J. Paley Z. Physik B55. 1 (1984) 14] M. Prager, A. Heidemann. W. Hausle.. Z. Physik B64, 447(1986) 15/ J. Kondo. Physica 126B, 477 (1984) 16/ H. Craberl in réf. (1/ 171H. Wipf, D. Steinbinder, K. Neumaier, P. Gutsmiedl, A. Magerl, A.J. Dianoux in réf. Il] 181 H. Tetchier in ref 11) 191 D. Richter in ref. [1] 110] J.M. Welter. D. Richter. R. Hempelmann, O. Hartmann. E. Karlsson, L.O. Narlin, T.O. Nirnikoski, D. Lenz. Z. Physik B52, 303 (1983) 111] C. W. Clawson; K.M. Crowe, S.E. Kohrt, S.R. Rosenblum, C. Y. Huang. J.L. Smith, J.H. Brewer Physica 109 + 110 B. 2164 (1982) 112] J.H. Brewer, M. Celio, D.R. Harshman. R. Keilel, S.R. Kreilunann, G.M. Luke, D.R. Noukes. R.F. Turner, E.J. Ansaldo. C. W. Clawson. K.M. Crowe, S. Kohn, S.R. Rosenblum, J. Smith, C.Y. Huang Proceedings ofthe 4th conference on muon spin rotation 23 - 27 June 1986 Uppsala, Hyperfine interactions in press. INSTRUMENT OPERATION DEPARTMENT problem has been effectively brought under control ; although INTRODUCTION the liquid helium consumption continues to increase, as was L'activité du Département Exploitation s'est distribuée cette expected with the increase in low or very low temperature ex­ année suivant l'habituelle proportion de tâches quotidiennes periments, the dramatic reduction in losses on recuperation imposées par la lourde planification des expériences et de tra­ made it possible to live with a budget of the same order as vaux plus spécifiques liés à de nécessaires enveloppements in previous years. A quick reaction was also necessary to adapt ou/et transformations de l'Institut. Dans cei deux catégories the experimental equipment for non-typical experiments, as d'activité, le rôle du Département Exploitation a été le plus for example the modification by the vacuum and cryogenics souvent de "répondre (positivement !) à la demande" et groups of a standard cryostat for use with hazardous samples d'essayer de concilier des exigences pas toujours compatibles. (plutonium compounds). Le Service d'Entretien et d'Aménagement des bâtiments a été, For the Advanced Cr>ogenics Service, 1986 was the year of une fois de plus, très fortement mis à contribution avec, notam­ provision of 'comfort' for the experimentalists, with the in­ ment : les aménagements de locaux liés aux multiples dépla­ troduction (still in progress) of a large number of temperature cements de personnes (dans un sens et dans l'autre !) à controllers. l'occasion de la venue des premiers "éléments" de l'ESRF dans Budgetary and manpower problems were particularly felt in nos murs ; l'aide à la mise on place de locaux provisoirespour the sample environment area. This is a sector which must have ce même ÉSRF ; l'installation de la future expérience nn ; les absolute priority at the ILL if we are to cope with the increas­ constructions ou modifications de protections sur un grand ing scientific demand. nombre d'instruments, etc. Le Service Central d'Assistance aux Expériences, ce "Bon-à- toul-faire", de l'Institut, a mis en évidence son efficacité dans plusieurs secteurs sensibles. 11 faut citer la très nette reprise EINLEITUNO de contrôle sur "l'affaire Hélium liquide" ; si la consomma­ In diesem Jahr verliefen die Tatigkeiten der Abteilung Instru- tion d'hélium liquide a continué à croître, comme il était pré­ rn"itenbetrieb im Rhythmus der umfangreichen Experimen- visible avec le développement des expériences à basses ou très tenplanung mit seinem (iblichcn Anteil der vielen, tâglich zu basses températures, la spectaculaire réduction des pertes en lôsenden Aufgaben und spezieller Arbeiten im Zusammenhang récupération -x permis de "vivre" sur un budget du même ordre mit notwendigen Entwicklungen und/odci 'Jmwandlungen im que celui des années passées. Il a fallu aussi "réagir vite" pour Institut. In beiden Tàtigkeitsbereichen war die Abteilung In- adapter le matériel d'expérience à l'occasion de mesures non strumen'.enbetrieb bemiiht, so oft wie môglich positiv auf An- typiques, comme par exemple la modification, par les Grou­ fragen zu antworten und zu versuchen, nicht immer pes Vide et Cryogénie, d'un cryostat standard pour son utili­ miteinander zu vereinbarende Anforderungen in Einklang zu sation avec des échantillons dangereux (composés du bringen. plutonium). Die Dienste der Gruppe "Einrichtung und Instandhaltung der Pour le Service Cryogénie Avancée, 1986 aura été l'année de Gebàude" wurden wieder sehr stark in Anspruch genommen. la "fourniture de confort" aux expérimentateurs, avec la mise Insbesondere bei der Einrichtung von Biiros aufgrund von en service (encore actuellement en cours) d'un grand nombre mannigfachen Verschiebungen (in die eine oder andere Rich- "DU" contrôleur de température. tung) von Personen anlâsslich der Ankunft der ersten ESRF- "Elemente" auf unserem Gelânde. Unsere Hilfe wurde auch La pression, tant budgétaire qu'au niveau de la main d'oeu­ bei der Einrichtung des provisorischen ESRF-Gebaudes, der vre nécessaire, a été particulièrement sensible dans les problè­ Installierung des zukiinftigen nn sowie beim Bau oder bei Àn- mes d'environnement d'échantillon. C'est un secteur qui doit derungen der Abschirmungen einer grossen Anzahl von Instru- absolument devenir prioritaire à l'Institut si l'on veut suivre menten beansprucht. Die Zentralgruppe fur die Unterstutzung la progression de la demande scientifique. bei Experimenten, diese vielseitige Einrichtung des Instituts hat seine Leistungsfàhigkeit in mehreren Schliisselbereichen un- ter Beweis gestellt. Dabei muss das Problem des fliissigen He­ liums genannt werden. Auch wenn der Verbrauch an fliissigem INTRODUCTION Helium weiterhin gestiegen ist, wie es aufgrund der Entwick- The work of the Instrument Operation Department was divid­ lung der Expérimente mit Tief- oder Tiefsttemperaturen zu er- ed this year in the usual proportion of daily tasks necessitated warten war, so erlauble doch eine spektakulàre Verminderung by the heavy burden of experiment planning and more specific der Helium-Verluste in den Riickleitung mit dem gleichen Bud­ tasks associated with necessary developments and/or changes get auszukommen wie in den letzten Jahren. Ebenso gait es at the ILL. In these two categories of work, the role of the schnell zu handeln, um Experimentiereinrichtungen fur nicht- Instrument Operation Department was most often to respond typische Messungen anzupassen. Zum Beispiel wurde von der (positively) to requests, and to attempt to reconcile re­ Grupj. fur Vakuum und Tieftemperaturen ein Standard- quirements which are not always compatible. Kryostat zur Verwendung mit gefàhrlichen Proben The Maintenance and Equipment of Buildings group has again (Plutonium-Verbindungcn) abgeandert. been in great demand, in particular for equipment for rooms Fur die Gruppe "Tiefsttemperaturen" war 1986 das Jahr der associated with the many changes of office (in one direction "Bereitstellung von Komfort" fiir die Experimentatoren mit or another) on the arriva! of the first ESRF staff on our der Installierung einer grossen Anzahl von sehr leistungsfàhi- premises ; assistance with the provision of temporary offices gen Temperaturreglern. Besonders im Bereich der Probenum- for the same ESRF ; installation of the future nn"experiment; gebung war sowohl im Hinblick auf das Budget als auch construction or modification of shielding on a large number arbeitskràftemâssig eine starke Belastung fuhlbar. Dieser Sek- of instruments, etc. tor muss up.bedingt eine Vorrangstellung im Institut erhalten, wenn mit den wissenschaftlichen Anforderungen Schritt ge- The Central Service for Assistance on Experiments, has shown halten werden soil. its efficiency in a nun;' :r of sensitive areas. The liquid helium

70 ADVANCED SUPERCONDUCTING MAGNETS The coils of the 6T cryomagnet (for the triple-axis group) were CRYOGENIC SERVICE replaced in July by new coils operating at the 6T field as plann­ ed (instead of the lower 4.3 T field previously obtained). It has been possible to increase considerably the number of experiments in a magnetic field with the aid of this equipment. In addition to the D3 cryomagnet, which is in use practically THERMOMETRY all the time, there were 17 experiments with a cryomagnet, totalling 157 measuring days. There is also a renewal of in­ AW INSTRUMENTATION terest in measurements with a horizontal magnetic field. Eleven ILL model temperature controllers have started opera­ tion, which brings to 29 the current number of controllers in operation. Their great adaptability to all types of equipment (^:yostat or furnace) resulted in the progiammingof 91 pairs VERY LOW of EPROMS, associated with 45 different instruments with their sample holders. TEMPERATURES At the request of the users, the programming has been improv­ The cryostats developed in previous years are in intensive use. ed in a number of ways. The lumber of effective neutron measurement days at very At present the controllers are mainly used on cryostats. The low temperature was 263, spread over 29 instruments and 49 control of furnaces is being gradually implemented, as a func­ samples. tion of requirements and the availability of staff. These figures give only a very approximate idea of the work The introduction of a computerised system to supervise the of the group, as every experiment requires special preparation. controllers and EPROMS avoids duplication. Certain experiments hav» necessitated three or four months The prototype automatic cold valve for cryostats started last of preparation, in collaboration with the experimentalists. year has been improved, particularly as regards the electronics. Considerable use has been made of the fast sample changes A preliminary series of five will be evaluated under actual permitted by the cryostats which we have developed. In some operating conditions. cases three different samples were measured on the same in­ strument, with the same cryostat in a single week. Despite these The current maintenance load for all the measuring in­ struments associated with the sample environment continues strict constraints, the failure rate has been remarkably low. to be very high. This covers essentially : Finally it should be noted that, as for the cryomagnets, a non- - the supply of calibrated thermometers negligible proportion (approximately 20 %) of the experiments - the repair of helium level meters for cryostats carried out at very low temperatures had been accepted by the - the repair of old temperature controllers still in operation Scientific Council on the basis of proposals not specifying this assistance as required on specific problems with experiments as a requirement.

Assistance was given in the relocation of the instruments S21 CENTRAL SERVICE and the second cana! technique position. The Group dealt witn the handling of the experimental pro­ CENERAl INTERVENTIONS CROUP tection, the distribution of the special shielding materials, and As well as the routine surveillance of the experimental zones the distribution of cryogenic fluids and gases. and instruments, and regular testing of the safety interlocks The lorry and its crane continued to provide invaluable ser­ and gas detectors, special efforts were required for the prepara­ vice for special transport and handling and for maintaining tion and supervision of the PuSb experiment on 1N20 and the site roads free of snow during the winter. PuTe on D3. Technical assistance was given to S experiments, particularly Attention has been given to reducing the noise level in Level C. those installed on SN7, and to rin". Measurements of The problem has been exacerbated by the increase in the background radiation were made around the zone HI 1, per­ number of vacuum pumps in the hall and by the large number mitting the necessary modification to be made for D19 and of ventilators needed to cool the electronics, the long reverbera­ D20. Shielding modifications were made to PN8, IN20, tion time of the hall accentuating the problem. Sound proof­ GAMS 2 and 3, D1A and B, and to the zone around the ing studies are in hand to identify all sources with the hope V.T.E's to facilitate rapid intervention. of alleviating at least some of the inconvenience in 1987.

71 TEMPERATURE, PRESSURE AND VACUUM GROUP

Standard Cryostats An average of eight interventions p^r month have been car­ ried out on the cryostats including repairs, modifications and testing. Five new cryostats have been assembled and commissioned, one of which has been specially adapted for hazardous ex­ periments involving transuranic elements (see photo). A cryofurnace has been developed and tested for use on D2B in the range 1.5 to 600 K and a cryorefrigerator for small angle experiments is under construction. In collaboration with other ILL staff, a cryorefrigerator has been adapted to operate in the range 10 K to 650 K, and a fibre optic liquid nitrogen level sensor developed. All liquid helium dewars in service have now been fitted with digital read-out gauges, which have been modified to improve reliability. During the year 73308 litres of liquid helium were used representing the equivalent of nearly 300 litres/reactor operating day. Of the liquid used, 84 % was recovered in the form of gas, 9 % was then reused on the instruments and 75 % returned to CENG for a credit worth more than 1,3 MF. Argon gas is now supplied to instruments for flight paths in­ stead of helium gas resulting in economies of more than 70 KF/year.

Vacuum The vacuum section has continued to carry out maintenance and repairs to the primary and secondary pumps, and is cur­ rently assembling the pumping system for the Horizontal Cold Source (see photo). A computerized inventory of all vacuum equipment has been established, which will assist in maintaining a reliable and ef­ ficient service.

High Temperature The High Temperature Group has continued its programme of furnace modernisation with the introduction of four new general and two special furnaces in response to the increased demand on the group for high temperature experiments. The general purpose units comprise two top loading furnaces operating up to 1000°C with vanadium and niobium elements respectively, and two 1600°C niobium furnaces for large samples (0 :40 mm, h: 60 mm). These are direct developments of the 3-axis design first introduced in 1984 as the "blue" series, offering a particularly low temperature gradient and ease of use and maintenance. They can be fitted with a mobile support for measurements on two samples without dismoun­ ting. The two special furnaces are a non-magnc-iic furnace for INI 1, and an orientable tube furnace in a light-weight cloche for small angle scattering. To simplify installation a:.d operation, a fleet of mobile con­ trol and power consoles has been designed and built for the

72 "blue" series furnaces. These carry all the equipment necessary ed in CuBe vessels up to 10 kbar and cooled down to 70 mK. for a high temperature neutron measurement, including the Pressure is determined by measuring the lattice constant of furnace itself, in a compact and ergonomie system. They NaCl, mounted with the sample. The cryostat is a CRTBT- replace two units used previously for the same purpose. ILL type dilution cryostat. New CuBe cells are being built to provide 20-25 kbar under applied magnetic fields. They have been designed to fit the D3 High Pressure magnet; on the high pressure side, more handy and compact

Recently developed pressure cells for neutron scattering can A1203 pressure cells will be tested soon before operation in now be used at very low temperature: samples can be pressuris- the 30-35 kbar range.

BUILDING TECHNICAL ASSISTANCE MAINTENANCE AND TO OTHER GROUPS Workshop Services MODIFICATIONS The self service mechanical workshop and the main sheet metal workshop allowed modification or production of items which SERVICE were difficult to subcontract or were needed at short notice.

The Group comprises 26 persons and its main responsibilities are the maintenance and improvement of the Institute site and buildings, and the preparation and adaptation of the ex­ Services for external perimental positions to the requirements of the users. The organisations Group has 3 essential activities. The group carried out maintenance of the building and the technical installations of European Molecular Biology Laboratory outstation and was involved in studies for the lay­ out of the European Synchrotron Facility, and the installa­ MAINTENANCE, REPAIR tion of the temporary Project Group accommodation. AND RENOVATION The main purpose is to keep in an operational state all the General Services buildings and technical installations (electricity, water, drainage, gas, heating, air conditioning, ventilation, handling) The group was involved in provision of logistical support for excepting those of the reactor. The group carries out these in­ special visits and events in the ILL life, it also carried out the terventions with its workshops and by the placing of external majority of office and laboratory removals and furniture pur­ contracts ; it also supervises the general cleaning of buildings chases. and the supply of electrical and heating power.

CONSTRUCTION AND EQWPMENT WORK In collaboration with the Central Service, Reactor Department and Instruments and Methods Department, the Group defines and organises the construction and assembly of the biological shielding and infrastructure required in the experimental halls; it designs and follows up construction or modification of buildings and technical installations. The principal work in 1986 has included infrastructure for the rin" experiment, con­ struction of a building for radio protection storage and ex­ tension of ILL6 for the new Horizontal Cold Source compressor. Studies are well advanced for the installation of the shielding associated with the new Horizontal Cold Source, the guides and the planned new instruments.

73 tion chamber. To fully use the capacity of the chamber a disc INSTRUMENT GROUP with 164 Megabytes was connected and the necessary software for data evaluation of the multi-parametric listmode data was FUNDAMENTAL AND installed. An N2-jet system was developed and implemented at the exit slit to improve the sensitivity for gamma-spectroscopic work, NUCLEAR PHYSICS Qp measurements and delayed neutron decay. The jet covers 70 cm of the parabola in the focal plane and uses KC1 clusters PNl : Fission product separator (LOHENGRIN) on beam to which the fission products attach. The transport time to the tube H8 (H.R. Faust, J.P. Bocquet, G. Martinez, 150 cm distant detector is below 800 msec. This allows for the I. Gartshore). investigation of neutron rich nuclei down to the shortest known PN2 : Beta spectrometer (BILL) on the vertical beam tube P-halflife. The efficiency of the jet is about 80% for most of B3 (K. Schreckenbach, G. Colvin, B. Krusche, the isotopes produced by the fission process. G. Blanc) PN3 : Three curved crystal spectrometers (Gams 1,2,3) and PN8 : one flat crystal spectrometer (Gams 4) on the The coincidence fission fragment spectrometer COSI FAN throughgoing beam tube H6 - H7 (H. Borner, TUTTE was running smoothly in 1986. During the summer F. Hoyler, S. Robinson, R. Oliver) shut-down the biological shielding of the central part of the PN4 : Ge(Li) pair spectrometer on beam tube H7 (F. Hoyler, set-up has been improved (against y-rays and fast fission R. Oliver) neutrons). SN5 : Ultra-cold (UCN) and very cold (VCN) neutron source with 3 beam positions on the inclined beam tube IH3 SN6 : (P. Ageron, W. Mampe, A. Beynet) The negative surface-ionization source is used on OSTIS since SN6 : On-line mass separator for thermally ionized fission spring 1986. The lifetime of the source is now 2-3 weeks com­ products (OST1S) on neutron guide H23L pared to 2-3 days for the earlier version. The source has a high (U. Stôhlker, W. Lippert, T. Manning) selectivity for halogens. Pure beams of fission produced Br SN7 : Cold polarized neutron beam at end position of guide and I isotopes are available for nuclear spectroscopic investiga­ H14 (K. Schreckenbach, D. Dubbers) tions. Fig. 73 shows the dependence of the delay halflifes for PN8 : Fission product coincidence spectrometer (COSI FAN the Br and I isotopes on the source temperature. TUTTE), (P. Geltenbort, T. Manning) The construction of a magnetic electron separator for Qp H17 : Cold neutron guide with liquid helium UCN source spectroscopy will be completed in spring 1987. (P. Ageron, LA. Kilvington) H18 : Cold neutron guide (W. Mampe) H22 : Thermal neutron guide : neutron induced particle emis­ sion (H22D), (J.P. Bocquet) ; prompt gamma activa­ tion analysis (H22E), (F. Hoyler, D. Oliver); y-y angular correlations (H22F), (F. Hoyler, J. Copnell) TGV : Vertical VCN guide in cold source connected to Steyerl turbine (Niveau D), (P. Ageron, W. Drexel, W. Mampe, A. Beynet, A. Steyerl).

INSTRUMENT IMPROVEMENTS AND DEVELOPMENTS Fission Research Fission experiments are performed on three machines : PN1, PN8 and SN6.

PNl : The trend of research proposals at the mass spectrometer LOHENGRIN is directed towards the investigation of fine structures in the fission process. In these studies the spec­ trometer is operated close to its limits in resolution and sen­ sitivity : Cold fragmentation proceeds at a level of 10-\ symmetric fission at a yield of 10 ' and tripartition with light particles around mass 20 with a probability of 10"' per fis­ sion. To ensure the quality of the data of those measurements a considerable effort went into the optimisation of the beam optics and into the reduction of background, which can be easi­ figure 73: The dependence of the delay halftives Jor the Br and I isotopes on the source ly discriminated by E - A measurements with the big ionisa­ temperature a/ .W6

74 Figure 74: The figure demonstrates the influence of surface coils on the low energy resolution, fb) corresponds to a scan without surface coils, (a) and le) to a surface coil current of ± 400mA. The resolution is given by FWHM = 20,25 and 27.5 eV for a,b,c, respectively. Spectroscopy PN2 : 3000 The high resolution electron spectrometer BILL was running smoothly throughout 1986. A new PDP 11 computer was in­ stalled and a TSX system incorporated. An important improvement in the resolution at low energies was obtained by introducing surface coils at the entrance and exit of the second magnet. Without current in these correc­ tion coils a K conversion line in 56Mn at 20 keV was record­ Intensities measured within 12 mm of the ed with a resolution of 24 eV. At an optimum setting of the focal plane corresponding to dp/pi9x10~4 current the resolution was improved to a value of 16 eV FWHM (full solid angle, 7 ug/cm2 target). In particular studies of the conversion of outer shell electrons in dependence of the chemical bound can now be carried out with better preci­ 100 200 sion (see Fig. 74). Channel Figure 75; e+ spectrum for a momentum window of Ap/p = 9.10 4 al PN2. The Several test measurements were carried out to produce an in­ target was a 2 mm thick plate of titanium ; the detector was a muiti- wire pro­ tense positron beam at the BILL spectrometer, in particular portional counter ('- 100% efficiency). in the energy range 1-2 MeV. The internal e+e~ pair produc­ tion with a "3Cd target was compared with the external (and some internal) pair production in a 2 mm thick plate of tita":_.... At 1.5 MeV positron fluxes of 4 . 104 positrons per sec and cm2 in the focal plane were measured with an energy spread of 5 keV. Thus experiments searching for resonances in e*e~ scattering can be performed under favourable con­ ditions (see scientific part college 3). (see Fig. 75). PN3 and PN4 : A high purity Ge-detector has been installed at GAMS 2/3 enabling a modernisation of the data acquisition system. As at GAMS1 the data are now taken via two ADCs and win­ dows are set on the different reflection orders in an on-line software fit. This allows for the simultaneous recording of up to 10 orders of reflection. On GAMS2 a new Si crystal with a variable radius of curvature is currently under test. New perfect Si and Ge crystals have been tested on the double Ll'&te&m flat crystal spectrometer GAMS4 with a view to optimising This is a unique picture, as it shows all the six responsibles of BILL (from its construc­ the sensitivity at high energies ("5 MeV). Fig. 76 shows an tion to present day}; B. Maier (builder of BILL 1969 - 1972) on the right; W. Mampe (1972 -1978/ . third from right; H. Faust (1978 • 1981), second from right; K. Schrecken- example of the high resolution obtained with one pair of these bach (1975 -1985} third from left; O. Colvin (1982 • 1986), second left; B. Krusche (from crystals. 19861. left.

75 as studied earlier, was now applied for the storage volume in situ and improved the neutron storage as well as the behaviour with respect to the applied electric field. An active closed loop compensation of external magnetic fields reduces the effect of perturbation inside the u-metal shields by a further factor of 10. c) A fluid wall neutron storage experiment has been set up. During the learning phase it became possible to study the stability, the important parameters for a neutron lifetime measurement using a liquid walled bottle of variable volume, and possible systematic errors. The experiment now gives a reproducible result at room temperature and a pressure of 10-' torr. d) The neuron storage ring NESTOR has been connected to the very cold neutron beam via a double curved n-guide in the turbine housing and a following 2 m long divergent guide. Both guides were manufactured at Garching using the new replica technique. The experiment was started successfully. Cold neutron work was continued at several beams: H18: The neutron charge experiment, after having improved its sen­ sitivity, encountered (similar to the EDM experiment at the new VCN source) a new limitation in stability : thermal drifts generated by air currents from the air conditioning system ( ± I °C) in the reactor hall. A large tent made of polyethylen foil helped to solve this problem in both cases for the moment. A microprocessor from Bayreuth had been installed for data acquisition and handling of the large amount of information (I measurement point every 10 seconds).

Figure 76: Dynamical diffraction theory shows that there is interference between the scattering amplitudes from the front-layer and the back-layer of a (thick) transmission crystal, the quality of the experimental data (Fig 76b) obtain­ ed at GAMS4 with "ideal" Si-crystals can be judged by a comparison with the theoreticaf predictions (G. Greene et al, Fig 76a). The abscissa is scaled in relative units of interference fringes (from the angular interferometer). One fringe corresponds to 0.04 arc sec.

Fundamental physics Long term experiments on ultracold, very cold, cold and ther­ mal beams have been performed throughout 1986. The activity in research with ultra cold neutrons was deter­ mined mainly by the installation of the new source (neutron turbine) on level D. After the necessary infra-structure had been made available 4 important experiments had been set up and started operation: a) the neutron microscope (Garching, ILL), b) EDM experi­ ment (Sussex, RAL, ILL, Harward, Seattle, Garching), c) neutron lifetime experiment (ILL, Risley), d) neutron storage iiag (Bonn, ILL). The main technical improvements performed by the listed groups were : a) modification on the neutron microscope enabling increase of the magnification to 80, a new neutron guide and a new platform. b) Replacement of the computer controlling the EDM experi­ ment by a VAX 11/730. Modification of the vacuum system for easier interventions in case of dismantling or transport of the experiment. Improvement of the sensitivity of the 3 in­ tegrated Rb-magnetometers. An Ar and D2 glow discharge, Testing of the Mu-metal shielding for the n-h experiment

76 SN7 : At the SN7 polarized neutron beam a copper coated neutron INSTRUMENT CROUP guide system was installed to improve the flux at the distant measurement position. A magnetic guide field was accomplish­ ed by a solenoid, wound directly around the neutron guide. THREE-AXIS This way the polarized neutron flux in a distance of 3 m from the polarizer was improved by about a factor of 3 compared to the previous installation without guide. This modification SPECTROMETERS did not affect the degree of polarization. The measured polariz­ ed neutron capture flux at the guide exit was 4 x 10s n s~ ' INI :3-axis and beryllium-filter spectrometer on the hot cm"2 in 3 x 5 cm2. The experimental site will be equipped beam-tube H8 (U. Steigenberger, B. Dorner, H.J. with thermal insulation and air conditioning at the beginning Lauter, J.P. Varini). of 1987. 1N3 :3-axis spectrometer on the thermal guide-tube H24 (H.J. Lauter, L. Cussen, V. Frank, R. Arthaud). IN8 :3-axis spectrometer on the thermal beam-tube H10 SSO: Determination of h/m„. (R. Currat, P. Frings, C. Vettier, A. Brochier). The final instrument is under construction. Using a preliminary IN12 :3-axis spectrometer on the cold guide-tube H142 apparatus, the most important components were further tested (W.G. Stirling, K.A. McEwen, D. Puschner). and improved. IN 14 :3-axis spectrometer on cold guide-tube H53 on the second cold source (W.G. Stirling, W. Kaiser, mT experiment: A. Brochier). The preparation of the experiment programmed for the 2nd IN20 :3-axis spectrometer with polarized neutron option on cold source has progressed at different locations : the in­ the thermal beam-tube H13 (R. Pynn, E.J. Lindley, frastructure including a new building and a 60 m long dam W. Kaiser, P. Flores). is in preparation -- ILL, the vacuum system and the magnetic shielding is handled by a group from Heidelberg at the ILL and the large detector with its electronics is being completed in Italy GENERAL In late 1986, the Three-Axis Group suffered tue almost Coordinator: W. Mampe simultaneous departure of four members of the scientific staff, U. Steigenberger to R.A.L.1, U.K., K.A. McEwen to the University of London, U.K., R. Pynn to L.A.N.L.2, U.S.A. and E. Lindley to the Paterson Institute for Cancer Research, U.K. This serious loss of extremely experienced staff was somewhat compensated by the arrival of L. Cussen and V. Frank, although their principal responsibility will be for the "special-beam" operation of IN3. With such an obvious shortage of personnel it is not certain that in 1987 the group can continue to provide the usual high standard of scientific support to external users, along with instrument operation, modification and construction.

1. Rutherford Appleton Laboratory 2. Los Alamos Nuclc. 1 aboralory

INSTRUMENT IMPROVEMENTS Software development (Frings, Lindley, Messoumian, Pynn) Most of the spectrometers in the three-axis group (INI, IN3, IN8, IN20) have now been equipped with a PDP11 computer running under TSX (a multi-user version of the RT11 operating system). Simultaneously with this change of the hardware, a new general spectrometer control program was developed (call­ ed TAS). This program, rigorously identical on all the in­ struments, has many new features such as automatic alignment, temperature control, temperature scanning, scan simulation, ASCII scan files, etc. In addition, the instruments can be monitored from virtually any terminal. Together with this new standard program, powerful and flex­ ible data-handling (FILING) and data-analysis (modified PKFIT) programs were developed to run on the instrument computers:

77 FILING allows one to add scans together, to correct for IN8: 3-axis spectrometer on thermal beam background, to process polarisation-analysis data - with cor­ rect (statistical) error calculations during these operations. (H10) The instrument IN8 has been running in the scheduled opera­ PKFIT can read the new scan-files and fit them to simple func­ tion mode throughout the year. The implementation of the new tions in a faster and more interactive fashion. The user is con­ primary and monochromatic beam geometry, initiated during stantly informed about the fitting parameters and can easily the long 84-85 shut-down, was pursued with the installation of stop a fit which is not converging without having to restart a 15x15 cm2 Cu(220) monochromator assembly with variable the program. Other programs available on each instrument in­ vertical curvature. As a result of the increased vertical diver­ clude a simple graphical version of the resolution calculation gence and improved focussing geometry, a two-fold flux in­ program (RESCAL), programs to survey the cryostat and the crease was obtained at the sample position (4± 1 x 107n/cm2/s spectrometer, and programs to list and sort scan files. in the incident energy range 35 meV

IN3: 3-axis spectrometer on the thermal IN20: 3-axis spectrometer with polarisation guide (H24) analysis on thermal beam (H13) The control computer of the instrument has been replaced by The commissioning of the 1N20 spectrometer, which began in r a PDP 11/73 and this is running well with the new control December 1985, was completed in February 1986. Most of the program. This has been the first step to further improvements, spectrometer components worked at design specification im­ in particular closed-loop control of D.C. Tanzboden motors, mediately so that debugging time was minimal. Some reliability to be installed in February 1987 together with the new (already problems were experienced with the RS232 interface between constructed) double-faced monochromator (P.G.(002) and the PDP 11/23 computer and the motor-drive modules. Cu(lll)). Both m.nochromators have variable vertical cur­ However, these problems proved to be solvable. The remain­ vature. The horizontally curved analyser is often used on IN3. ing electronic components functioned as anticipated and have A change in position to the end of the H25 guide would pro­ proved reliable. Measurements of instrument performance vide many advantages. showed that the unpolarised flux (with graphite or Copper

78 (Ill) monochromators) on IN20 is essentially the same as that IN14: 3-axis spectrometer on the on IN8. At 14 meV incident-neutron energy the polarised flux using the Heusler (111) monochromator at the sample posi­ horizontal cold source (H53) tion is - 9xI06 neutrons/cmVsec when 40' collimation is in­ Considerable progress has been made in the definition and stalled between monochromator and sample. design of this instrument. The monochromator shielding is be­ For neutron energies in all graphite-filter windows the large- ing constructed, the design of the monochromator curving beam flip-ratio of the instrument is — 20. This flip-ratio can device has been completed and details of the secondary spec­ trometer are under consideration. Electronic modules and com­ be maintained when the sample is contained in a vertical-field ponents are being ordered at present. A final decision on the cryomagnet generating 10 Tesla or when the triple-Helmholt? type of control computer for IN14 (and for 1N12) will be made coils are used to give a small ( 20 Oe) field in any direction in early 1987. at the sample position. A more complete description of the instrument is to be found in the revised ILL brochure It is intended to make the first tests of monochromator per­ "Neutron Research Facilities at the ILL high flux reactor" formance as soon as possible after the installation of the and a general view of the instrument is shown in the horizontal cold source late in 1987. photograph. Coordinator : W.C. Stirling

A general view of the polarized neutron-triple-axis spectrometer IN2Q; the Helmholtz coil assembly, which can produce a magnetic field it any direction, is mounted on the sample table. Guide fields and flippers are mounted as necessary on the optical benches before and after the sample position.

79 elaborate method of operation which usually achieves adequate INSTRUMENT GROUP phase-stability for more than 90% of the time, whilst main­ taining the temperature of the gadolinium/epoxy disk-coating below 60°. An air-conditioning system will be installed within TIME-OF-FUCHT, the concrete shielding of the primary spectrometer, since this has been found to be an effective method for reducing the chopper-disk temperature without causing differential expan­ sion problems. The software has had to be extended such that the user is oblivious of the complex chopper manipulations AND DIFFUSE which have to occur in response to simple commands to change the resolution, energy-range, wavelength, etc. Furthermore, SCATTERING the instrument computer now surveys the temperatures of the chopper motors and disks (via remote IR thermometers), phase stabilities and dilation of the chopper housing. IN4 : Time-of-flight spectrometer on thermal tube H12 (A. Murani, W. Langel, A. Key). The programable time-of-flight unit has been commissioned 1N5 : Multi-chopper spectrometer on cold guide H16 and works wcl!, allowing the long cherished dream of fully (G. Kearlcy, H. Blank, S. Jenkins). automatic instrument operation to become a reality. It is even IN6 : Focussing TOF spectrometer on cold guide H15 possible to schedule a series of runs with different resolutions, (A.J. Dianoux, M. Bée, Y. Blanc). energy-ranges, etc. as desired! A further enhancement is INIO : Backscattering spectrometer on cold guide H15 automatic data-checking after two minutes data-collection, (A. Magerl, H. Godfrin, P. Joubert). various spectral characteristics being compared with those INIOC : (project) New backscattering spectrometer calculated from the instrument parameters. We look forward (A. Magerl, J.L. Coquin). to being able to include software control of the sample environ­ IN11 : Spin-echo spectrometer on cold guide H142 ment when an ILL temperature controller becomes available. (B. Sarkissian, B. Farago, J. Bauchat). IN11B : (project) - Multidetector spin-echo spectrometer on cold guide H142 (B. Sarkissian, J. Bauchat). IN6: TOF spectrometer on cold guide H15 IN13 : Backscattering spectrometer for short wavelengths Besides its high neutron intensity, the main characteristics of on thermal guide H24 (W. Pétry, A. Heidemann, IN6 is its extremely low background. It has led to a successful J.F. Barthélémy). experiment on the temperature and pressure dependence in ex­ IN15 : (project) Spin-echo spectrometer for long citations in liquid 3He : this is detailed in the College 6 report. wavelengths (F. Mezei, D. Richter, C. Lartigue, A further reduction of the background has been obtained by F. Douchin). painting the stator of the choppers with Gd02 paint and by D7 : Diffuse scattering instrument with polarization installing a Cd tunnel between the two choppers. analysis on cold guide H15 (O. Schârpf, \V. Just, R. It is now possible to open or close the beam before the monitor Rebesco). II without breaking the vacuum in the sample vessel : this Dl 1 : Small angle scattering diffractometer on cold guide facilitates quick transmission measurements, whilst removing H15 (P. Timmins, A. Wright, R. May, R. Baker). the parasitic scattering of the exit window which occurs when D17 : Low Q, high resolution diffractometer on cold guide the beam is left on. H16 (R. May, J. Torbet, P. Timmins, M. Cruz). Another cryostat, shared with IN5, is now available as a stand­ by. The reliability of the heating and cooling loop (temperature variation from 77°K to 673°K) has been increased by a new IN4: TOF spectrometer on thermal beam design and its versatility will be enhanced by monitoring the H12 flow of cold N2 gas using a flow control device. IN4 continues to operate in the double monochromator con­ IN6 has worked very efficiently during the year with very few figuration principally with graphite monochromators (002) and computer or electronic breakdown. The storage capabilities (004). Recently a Winchester disc with a memory of 134 mega­ have been increased by the installation of a third disk drive. bytes has been added to the PDP 11/40 computer system im­ The instrument has been connected to the MICOM network: proving data storage capabilities significantly. The new ILL this permits remote control of the operation. precision temperature controller has also been installed dur­ ing this year and works satisfactorily with the IN4 horizontal- tail cryostat. No decisions regarding the proposed modifica­ IN10: cold neutron backscattering tions incorporating the Fermi choppers on magnetic bearings spectrometer in the single monochromator configuration have yet been taken. It may be noted that if the proposed modifications are The low neutron flux at the sample is one of the main limita­ adopted the single take off angle will initially limit the available tions of this instrument. Of course, this is intrinsically due to incident energies to 17, 68 and 115 meV with graphite (002), the concept of this spectrometer but there are also significant (004) and Cu(220) monochromators respectively. losses e.g. in the neutron guide between the graphite deflector and the sample. This guide (30x30 mm2 cross-section, 4200 mm long) has been replaced by a new one with a super- mirror coating which accepts a higher beam divergence. The IN5: TOF spectrometer on cold guide H16 guide was made by NTK while the coating was done at the The in-service development of the new chopper driving and ILL. On average, the flux increased by a factor of 1.3. The phasing system supplied by KFA-Julich, has resulted in an monitor spectrum shows that the flux increase is particularly

80 'Sa"'-*,

View of the INI IB test layout, showing the multidelector bank, the wide angle Larmor precession field magnet and the collimator important at high energy transfers. This stems from the in­ Subsequently, the beam will be monochrom ed by Si-crystals creased horizontal divergence of the new guide. A new 70 ram mounted on a Doppler drive. The large m nochromator (up cryostat, but with a 120 mm outside diameter, was commis­ *o 25x70 cm2) will have a spherical shape io focus the beam sioned this year so that the usual sample cells from IN3/IN6 onto the sample. can be used without modifications. In addition a long-tail At present, detailed studies of individual components are under cryofurnace with 50 mm inner diameter is now available on way. They include for example, the mounting of three layers IN10. The maximum sample temperature is 550K. of graphite on the disk to obtain an anisotropic mosaic spread A new software routine called TSCAN has been developed and the optimisation of the shape of the monochromator sup­ which enables "fixed window scans" to be carried out port. It will be fabricated from carbi .i fibre reinforced resin automatically. The ouiput file is written in a format such that to reduce its weight, and computer 1 ased calculations are be­ the usual display programs on the instrument can be easily ing performed to study the deformations of the adapted. As a pilot project for the new VME standard at the monochromator for the maximui. acceleration of the Dop­ ILL an acquisition system based exclusively on VME module pler drive. has been developed for IN10. Early in the year 1987 this system Technical drawings for the primary spectrometer and in par­ will be installed at the instrument and run initially in parallel ticular for the shielding and the nechanics of the first deflec­ with the CAM AC system. tor, have started and first order e.g. for graphite material have been placed. IN10C: new backscattering spectrometer at the 2nd cold source IN11: Spin-echo spectrometer on the cold The basic layout of the instrument has been defined. The guide H142 primary spectrometer will be very different from the present The old RT-11 compute has been replaced by a new TSX- IN10. First, the large beam available from the guide will be PLUS extended memor computer to support simultaneously deflected and concentrated into a beam with a small cross- a wide variety of jobs a' J programs for the INI IB multidetec- section and high divergence by a double deflector system with tor neutron spin-echo spectrometer. The old KEPKO power a conical guide in between. The second deflector will also serve supplies have been replaced by new DRUSCH power supplies. as a chopper with a duty cycle of 50%. This is achieved by Some parts of the electronics have also been changed. The ex­ mounting graphite in two 90° sections on a chopper disk. isting programs remain effectively unchanged.

81 IN11B: The Multidetector Neutron cover the angles 28 = ± 12°. The associated correction coil for the field integral inhomogeneities is now being made and Spin-Echo Spectrometer tested (photograph 1). It is found to be highly efficient and (NSE) test results show that better th • .>"/o of the instrumental in­ Further successful tests were carried out on the INI IB using homogeneities were corrected oil INi IB. simultaneously a multi-detector bank which spans different The spectrometer will be used to study simultaneously the scattering angles (28 = 0.2° ± 5°) in the time domain up to dynamics of polymers and critical dynamics in magnetic an 10-° sec (at X ~ 4.8 Â) and 12x10"° sec (at X ~ 8.8 A) with non-magnetic systems at different Q-values, up to 0.29 Â- ' a neutron beam cross-section at each detector of 20x50 mm2. (for X ~ 5 Â) and up to 0.15 Â- ' (for X ~ 8 A), with an ac- The tests were carried out with the lay-out version of the spec­ cessiole time domain extended from 1.5x10" '2 sec (at trometer shown in photograph 1. Examples (a set of six) of X - 4 Â) to 10x10"° sec (at X - 8 Â). The effective Lorent- the multi-;i/2 neutron spin flippers with their correction coils zian spectral resolution of the final version of the spectrometer and the analysers (Co-Ti supermirrors, D7 type) are shown for all Q's will be better than 50 neV. The data collection rate in photograph 2. The number of n/2-spin flippers and will be increased by about x50 as compared with the existing analysers will be increased to about 50 in the near future to INI 1 spectrometer.

View showing the arrangement of some of the multi-n/2 spin flippers, associated cor­ Correction coil for the wide angle field integral inhomogenities rection coils and the analysers

82 TN13: Backscattering spectrometer Q-resolutiun. In principle, both contributions can be measured separately by polarisation analysis. In a test experiment super- for short wavelengths mirrors have been installed on IN13 as polarisers and analysers. on thermal guide H24 A flipping ratio cf 34 was easily achieved. Of course, polarisa­ IN 13 operates with a new monochromator cryo-furnace allow­ tion analysis is only achieved at the detriment of intensity which ing for a continuous change of the monochromator decreased to 7% compared with IN13 operating under nor­ temperature between 77 and 730°K. This corresponds to a mal conditions. neutron energy transfer range from -125 ueV to 350 ueV at In 1986 a large number of INl3-typical experiments were car­ a resolution of 9 ueV. A mechanically more reliable moun­ ried out. The jump vectors of hydrogen motions in single ting of the curved graphite deflector combined with a precise crystalline molecular crystals such as adamjntane, pivalic and adjustment of the individual crystals resulted in a substantial benzoic acids were determined from the Q-cicpendence of tl •; flux increase of about a factor of 2. EISF. The diffusion mechanism in super-ionic conductors LiAI and Li N (Jjoth single crystals) have been studied by measur­ Separation of coherent and incoherent scattering is an inherent 3 problem of a spectrometer devoted to the study of quasi-elastic ing the Q-dependence of the line broadening. The Q- scattering at high momentum transfers with modest dependence of the tunneling peaks of the two-dimensional rotor H2 in a tungsten-complex yielded the inelastic in­ coherent structure factor. The dynamics of the glass transi­ tion has been studied in a series of glasses. Relaxation phenomena and exchange interactions have been investigated (G: Neutron Guide) in magnetic systems.

1st Chopper Group IN15: Neutron spin-echo spectrometer for Velocity Selector long wavelengths at the second cold source Diaphragm (progress report) IN 15 will be locatea at the polarizing neutron guide H511 on Evacuated Conic Tube- the new horizontal cold source. The project of the instrument includes two modes of operation: a conventional NSE mode and a time-of-flight NSE mode. A schematic lay-out is shown in the figure 77. Compared to IN 11 the energy resolution should be improved by a factor of 20 due to the use of long wavelength neutrons (up to 25 Â) and by improving the homogeneity of the field 2nd Chopper Group- integral along the neutron path (larger precession coils, op­ timized field design). Simultaneously a much better Optical Focussing System- Q-resolution can be achieved by focussing the neutrons onto the detector using either a superconducting magnetic hexapole lens or an elliptic assembly of 8 mirrors with supermirror coating (both also act as a polarizer). Up to now, preference is given to the latter device: it is focussing for neutrons with X > 12 Â while the hexapole is usable only for X > 16 Â; n/2 Ffipper- for shorter wavelengths the mirror can still be used as a non- focussing but polarizing device while the hexapole has to be replaced by a polarizer ; furthermore the hexapole is much more expensive. A decision can only be taken after an in­ Pracession Field [Hoi-—i vestigation of the mirror performances: small angle scatter­ ing from the mirror surface would make it unusable (test in December 1986). The focussing device together with a n Flipper - multidetectoi • ' substantially improve intensity at high Q- resolution. Sample- For the T.O.F. mode an arrangement of 5 choppers is pro­ Precession Field (Hil ^ posed: the velocity selector is replaced by a set of 3 choppers defining the width and the frequency repetition of the pulses. A filter (set of 2 choppers) is located before the focussing n/2 Flipper device.

Polarisation Analyser

Multidetector D7: Diffuse scattering instrument with polarization analysis

Figure 77- Schematic view of the ultra high resolution spin-echo spectrometer at the 2nd The modifications carried out during 1986 were directed cold source. towards facilitating the use of the instrument:

83 1) Most users prefer polarization analysis at >. = 3.1Âinview of the larger Q-range accessible and the unambiguous inter­ pretation of the results. Along these lines 20 analysers were installed providing improved transmission at higher energies (up to 120 meV). They are composed of 200 supermirrors re­ quiring a total evaporation time of one year. The final aim is to completely equip D7 with this kind of analyser. 2) A necessary prerequisite to reliable measurements is the repetition of each run by a setting without polarization analysis, i.e. by removing the analysers from the beam. Previously this had required delicate manual handling of heavy weights (20 kg/analyser) in a reproducible way. This function has now been automated by pneumatic jacks which permit precise lifting of the whole assembly of magnets and aligned analysers of one bank out of the beam and back in.' o the beam. This cheap and efficient device will be applied also to the re­ maining banks. 3) To meet certain sample requirements a Eulerian cradle is now available which can be adjusted inside a cryostat by means of step motors on the top of the cryostat. Additionally, it is constructed so that it provides the possibility of a comnr -r controlled rotation in equal steps, oi "ie aligned sample in the cryostat. Polarization analysis set-up on D7. Pneumatic jacks permit precise lifting of the whole 4) A future modification aims at an intensity gain in the short assembly of magnets and aligned analysers out of and back into the beam. wavelength range of 3.1 Â (for polarization analysis). For that purpose a polarized proton filter as polarizer will be developed. 1986 has been the first full year of operation of Dl 1 since its The intensity gain expected *ill be of the order of 10. The re­ major reconstruction. The facility of positioning the detector quired techniques as well ai .: ..ipetent staff is available in at any distance between 1.2 and 37 meters from the sample order to achieve a cheap realisation of this project. has been widely used, fully justifying the implemente I changes. For many experiments it is now possible to fully cover the 5) Another improvement required, an'i apparently easy to available Q range from 5xl0"4 to 0.5 Â-1 in one 24 hour realise, is the change from the seeing with polarization analysis measuring period. to that for normal diffuse scattering. The modification describ­ ed under 2) could provide this possibility '"-y simply sliding a A new sample changer operating in air has been constructed. collimator box undei the analysers. This setting would thus It has a horizontal motion, is fully computer controlled and be operational each time when the analysers are in the upper can take up to 20 of the standard narrow rectangular cells. (out of beam) position. Adaptor plates for other types of sample cells including all those used with the previous changer or that of H17, are also 6) The possibility of carrying out mass-spectroscopic available. The vertical sample changer remains in use and measurements is another new feature of the machine. A thanks to a collaboration with Kostorz (ETH Zurich) may now micromass Q9 quadrupole spectrometer for masses 1 -400 link­ also be adapted to measure samples in vacuo. ed to an oscilloscope or a pen recorder allows measurements of isotopic abundance, qualitative analysis of a gas mixture, A new furnace operating up to 1000°C has been constructed. obtaining spectra of small organic molecules, identification of It may be installed ir a new light-weight "cloche" that can unknown organic compounds of gas samples and liquids, etc. also serve other installations. ILL standard temperature con­ trollers have been purchased for Dll and D17 and are cur­ rently being installed, and a program for auto-natic Dll: Small-angle scattering diffractometer terrperature control is under test. A review has been made of cryogenic equipment of both instruments, and a new cryostat on cold guide H15 is being prepared for D17 as well as a closed cycle cryo-furnace. D17: Low Q, high resolution A prototype module for surveillance of a range of instrumen­ diffractometer on cold guide H16 tal and security parameters has been constructed by the Cen­ tral Group and has been installed on Dll and D17 for test. 1986 has seen a major progress in our efforts to increase the It will eventually permit the security status of the instruments compatibility between the two existing low-Q scattering in­ struments, DU and D17. The purchase of a Vax-11/730, also to be conveyed to the control room at any time, as well as to for D17, replacing the ageing PDP-11/40 has pemi'ted us to group together a whole range of instrument parameters for use modern software identical to the.: of the other instrument. instrument scientists and local contacts. In particular the data acquisition software, developed by close On D17, the CAMAC memory has been extended to the max- collaboration of the software group a::i t'-ie instrument respon- in~ apacity of 256K to permit rapid time-resolved and cyclic sibles, is now essentially the same on both instruments, very m .. --ments on the instrument. In the area of sample en­ flexible and ea*'' to use. The users are now benefitting from vironment, an absolute encoder is now used to control the rota­ a more reliable computer and software that is easier to main­ tion of the standard sample table. tain and offers easy means of instrument control by advanc­ As in previous years, the instrument has proved extremely ver­ ed screen display: the instrument state is now permanently satile; in addition to the standard use for small-angle scatter­ displayed or five lines of the control terminal. ing it has also been used for crystallographic and reflection

84 experiments. These latter experiments have included studies of surface acoustic waves on a crystal as well as horizontal INSTRUMENT GROUP liquid surfaces. The instrument has operated relatively trouble- free without any major interruptions to the schedule. There is now a superconducting magnet available which pro­ DIFFRACTION vides a maximum field of 7 tesla (70 kGauss) in a vertical at­ mospheric bore of 50mm diameter. Once cold the helium boi!-off rate in the persistance mode is rather low so it can be kept running for long periods. This magnet belongs to D1A : High resolution powder diffractometer on thermal EMBL and was brought to ILL mainly to use as a means to guide H22 (A. Hewat) orient liquid crystals, polymers and gels which is consequent DIB : Two-axis diffractometer with multidetector on ther­ on magnetic (usually diamagnetic) anisotropy and cooperative mal guide H22 (C. Ritter, J.L. Soubeyroux, K. Ben behaviour. As there is no radial access the magnet cannot be Saidane) usefully used directly in a beam, but orientation is often stable D2B : Very high resolution powder diffractometer on ther­ enough so that samples can be taken to instruments without mal beam Hll (A. Hewat, J. Davies) loss. D3 : Two-axis polarized neutron diffractometer with lif­ ting counter on thermal beam H5 (F. Tasset, J. Baruchel, A. Dorn) D22: Low Q small angle scattering D4 : Liquids diffractometer sharing the hot beam H8 facility (project) at the second with IN IB (P. Chieux, R. Meyer/A. Barnes, A. Hawes) cold source D5 : Three-axis polarization analysis spectrometer on hot The initial phase for the definition of the new low-Q instru­ beam H4 (K. Ziebeck, J. Schweizer, P. Agnes) ment D22 at the horizontal cold source has been completed D9 : Four-circle diffractometer on hot beam H3 with the presentation of a paper (ILL Technical Report (W. Kuhs, M. Lehmann, J. Archer) 86MA07T) describing the scientific case and the technical over­ D10 : Four-circle triple-axis spectrometer on thermal all outline. The cost of the instrument in a basic version is guide H24 (neutron spin echo option) (C. Zeyen, estimated to be 8.1 MF, and 11.5 MF in the final version, in­ G. Mclntyre, R. Chagnon) cluding a second detector for simultaneous wide-angle scat­ T12 : Neutron camera on thermal guide H23 (A. Wright) tering measurements as well as neutron polarizers and D15 : Four-circle MK6 diffractometer on the inclined analysers. thermal beam IH4 (J. Brown, G. Schmid) Detailed planning has started with studies of the chopper D16 : Four-circle MK6 diffractometer on cold guide -116 systems for the time-of-flight mode of operation of the new (G. Zaccaï, L. Bragaiu.a, J.-R. Reynal) instrument, including its implications for the location and D19B : Multidetector diffractometer for protein width of cuts in the neutron guides, and of the drums con- crystallography (S.A. Mason, M. Thomas, t-inip» the collimating and polarizing systems, the design of M. Berneron) the detector tube and sample zone has been started. D20 : High flux multidetector (J. Pannetier, P. Convert, J. Torregrossa) Co-ordinators: A. Dianoux DB21 : Four-circle diffractometer with PSD for biological R. May macromolecules (M. Roth, P. Metcalf (EMBL), P. Agnes S18 : Neutron interferometer on the thermal neutron guide H25 (A. Rumpf, G. Schmid) 520 : Neutron topography diffractometer (J. Baruchel) 521 : Double crystal diffractometer (C. Zeyen, R. Chagnon) S42 : Laue Diffractometer (J. Marmeggi, W. Drexel) S42B : Laue Diffractometer (J. Baruchel, A. Filhol)

MAJOR MSTRUMENT MODIFICATIONS D1A: High Resolution Neutron Powder Diffractometer on the H22 Guide D1A has been used intensively to reduce the backlog of ex­ periments due to commissioning delays on the new machine D2B. With D2B now working routinely, more time will be available tr -atisfy the demand for longer term experiments. For exam[ British, German and French groups are using

85 DIA for the study of stress in engineering materials. Other is also slower, but this will be cured with a more powerful elec­ longer term projects include zeolites as catalysts, water struc­ trical supply. Large amounts of data are produced in just one tures in high pressure ice phase, 'frustrated' magnetic struc­ full reactor cycle, but fortunately the new VAX-8650 computer tures, systematic studies of magnetic and structural ph<»se is so fast as to make data analysis as rapid as on DIA. VAX transitions etc. Several of these experiments were highly graded programs have been developed to calibrate the detectors, plot by the Science Council subcommittees. Following the replace­ the data, index die pattern, perform Rietveld or Pawley refine­ ment of the electronics and computer systems, the casemate ment, plot the structure, Fourier maps etc. The European and incident beam geometry have been rebuilt to avoid in­ EARN computer network permits data transfer directly to the terference with DIB, and to allow for more space to mount home laboratory. engineering samples such as railway lines, welded pipes, tur­ bine blades etc. No official ILL support is available for these One of the main scientific applications of D2B, the structure special experiments, and there is only one scientific and of zeolite catalysts, will be the subject of a forthcoming ILL technical responsible for both DIA and D2B. DIA users are workshop. therefore now expected to provide technical and financial sup­ port to the ILL in return for beam-time. DIB: Two-axis diffractometer on thermal D2B: Very High Resolution Neutron guide H22 Powder Diffractometer on Beam Hll Following the complete reconstruction, in heavy concrete, of D2B has now started normal operation, with an average of the casemate the provisional lead shielding of the two user groups per week. One group even managed to run monochromators on D1A/D1B has been removed. This allows 26 samples in 3 days by working shifts ! Removing the primary the wavelength to be changed between 2.52Â and 1.28Â collimation gives resolution comparable to DIA with 7 times routinely. The ILL precision temperature controller has been the intensity, but the normal high resolution mode requires equipped with PROMS for the furnaces allowing the measuring times of 12 to 24 hours. The initial problems of temperature dependent programmable data acquisition now detector positioning have now been reso'ved by fitting a new also in the elevated temperature range. In addition to the incoder concentric with the detector axis. The remaining already existing options of omega, chi, omega in chi and chi mechanical problems will be resolved in February with a new in omega scans, the Eulerian cradle can now be programmed detector support. Although the machine is conceptually sim­ for phi, chi in phi and phi in chi scans. This is particularly ple, the problem of repositioning every few seconds to better useful in the study of textures. The DIB cryostat can be op­ than 0.005 degrees a detector weighing more than 1 ton, is not timized for surface studies at low temperatures by exchang­ trivial. Improvements are also being made to the incident beam ing the vanadium tail for a specially designed aluminium tail. geometry and beam stoo to reduce low angle scattering. The Above 60K the extra time needed for changing and stabilizing 300mm focussing monochromator produces a clean beam with temperature counteracts the improved signal to noise ratio ob­ a 40mm focal spot, but profile refinement reveals that tfce line tained with the new set-up. The layout for the use of polariz­ shape should be described by two Gaussians at low angles. This ed neutrons (supermirror and pi-coil flipper) has been is a little inconvenient, but at least the line shape and its varia­ optimized yielding a 90% polarized beam at 10% of the in­ tion with angle are well understood (Fig. 78). itial flux for 2.52A. The exchange of the Solar computer for a PDP 11 accompanied by the standardisation of the elec­ tronics for the instrument control and data acquisition, is planned for the shut-down Feb./March 87. ?! D3: Two-axis polarized neutron diffractometer on thermal beam H5 The instrument has operated without major break-downs for the last 10 years, but will be shut down in early 87. It was devoted to the precise measurement of atomic magnetic den­ sities and combined several aspects of advanced technology. In addition detailed neutron measurements which formally ex­ -JW tend over a long period require high reliability and stability. 130 140 2ehdtQmu 150 Each of these features was gradually improved and automated AI2O3 stlndtrdon D2B.total tkrn-100min. during the past years. Consequently, despite its inherent com­ plexity, D3 had become an efficient instrument with an easy Figure 78: A portion of the diffraction pattern of the standard AljOj sample on D2B access and a large and versatile scientific output. Its main al I.S95A compared with the same portion on DIA a: I.384A. Note that the two small DIA lines marked with an aslerix are revealed as three lines features were as follows: a high polarized (98%) beam of both onD2B. The total counting time on D2B was 100 minutes for the 15 x IS mm spin states with perfect stability, variable wavelength with 0 sample. reproducible characteristics, mechanical hardware and associated software for accommodating single crystals, a super­ The new cryofurnace, operating from 1.5K to 650K is routinely conducting magnet (4.6T) and low temperature insert (variable used. The only inconvenience is that the more massive vacuum temperatures 1.4-300K). The data acquisition and reduction seals mean that 2 hours is required to cool from 300K to 1.5K, system was so convenient th it it has become a standard for compared to less than one hour with the DIA cryostat. Heating this type of instrument.

86 D3B: Improved version of D3 considerably upgraded. With a Cu 220 monochromator in transmission the gain in flux is more than a factor of 3. At D3B, the reconstruction of D3 is underway. It will be transfer­ the same time the resolution at high scattering angles has been red to the hot beam H4 (previously occupied by D5), where improved. The new instrument is equipped with a 2-stage it can be used in a much shorter wavelength region than before. displex cryorefrigerator operating down to temperatures below This has to be considered as an important step towards im­ 15K under full computer control. A pressure cell has been proving the direct space resolution of the instrument. It had tested successfully and will become available for general use already been reported in the Annual Report 8.' (D5 section) in 1987. Data collection rates are quite high : more than 1000 that the modular monochromator system was successfully reflections/day have been measured with statistical R-factors rebuilt during the long reactor shut-down. Other modifications < 3% on crystals with a volume of - 10 mm3. A further im­ will be a Tanzboden floor, a new filter system (Maltese provement is expected from a 32x32 pixel gas detector, which Caroussel) and new antimagnetic motorized BjC slits. The was tested successfully and will become operational on D9 early completion and installation of the instrument is expected by in 1987. The installation of the multidetector will not only im­ the end of 87. prove the quality of the integrated intensity data (or speed up the data colUvtion), it will also facilitate the investigation of materials v, ith satellite or split peaks. A first test of a horizon­ D4: liquids diffractometer on the hot tally focussing Be-monochromator is scheduled for November 1986. The horizontal focussing should facilitate the variation beam H8 of the reciprocal space resolution in order to match the Although the instrument has been working with only one demands of a given experiment; an additional intensity gain multidetector for most of the year, more than half of the ex­ factor of > 2 is expected. periments were performed at a statistical accuracy between 0.3 and 0.1%, i.e. at the limit of the present machine, with the instrument set in its highest flux configuration (detector at 75cm from the sample). A new monitoring system as well as various software facilities (plots of monitor/time ratio, systematic numerical or graphical comparison of repetitive scans...) have been implemented in order to ensure and con­ trol the quality of the data acquisition in the most accurate cases. Many users have indeed used the repetitive scan techni­ que (3 to 5 scans per run). Of course at high accuracy the overall stability of the instrument becomes a problem, and 0.1 % is achieved only with difficulty. Not only the monitor­ ing but other elements of the instrument might fail too, e.g. during the year, difficulties were encountered with the beam opener, the high-voltage supply to the detectors, the sample environment or the containers... A systematic effort is being undertaken to improve this stability and progress is expected. For the experiments involving a variation of temperature, con­ centration or pressure, the MAD program for powder diffrac- Tht new fully completed diffroclomeler D9 on the Hoi source tometers has proven very efficient and versatile. The full computer control of the D4 furnace and vacuum level in the bell-jar has been tested. The severe outgassing of the B4C plates in the vacuum vessel should be solved soon and thus D10: Four-circle triple-axis spectrometer on reduce the time spent for heating. Finally all data handling programs necessary for creating regrouped files are also now the thermal guide H24 available on the central computer, which permits the reprocess­ DIO operates very smoothly with its new "Bounolleau" coder ing of old data. multiplexei and motor drive system. The D10 4-circle helium flow cryostat is increasingly used at 4K and below for solving involved magnetic structures. Operated routinely since 1978, a copy will have to be built this year to avoid increasing beam D5: Three axis polarization analysis time losses due to aging of some of its components. spectrometer on hot beam H4 In February 1987. D5 was definitively dismantled and discard­ ed in order that even more exciting experiments could be car­ D15: Four-circle MK6 diffractometer on ried out using the Horizontal Cold Source. the inclined thermal beam IH4 ... Farewell, long and faithful servant. Anon. D15 has been used steadily during the year for study of atomic and magnetic structures at low temperatures, under pressure D9: Four-circle diffractometer on hot and in applied fields of up to 4.6 T. As an example of results beam H3 obtained with the 4.6 T vertical field superconducting magnet (figure 79) shows the magnetic phase diagrams of EuAs3, an< The completely reconstructed four-circle diffractometer D9 has Eu(As060Po.4)3 3 Eu(As0.o2Po.9s) established jointly by been operational on a fully scheduled basis since December magnetisation and by diffraction measurements. The magnetic 1985. Compared to the old D9 the new instrument has been structures found for the different phases are given in table 1.

87 Eu|As0.6oPo.40)3 Hllb Eu|Asa02PQ98)3 Hllb

o MH(TJ ~"^Xti

• MT(T] I-2 SFP2 . P \ 9 . SFP1 -oooS^\

ICP1 ICP2 \ 0 4 8 12 4 8 12 4 8 12 Temperature (K) Temperature (K) Temperature (K)

Figure 79; Magnetic phase diagrams establish d jointly by magnetization and diffraction measurements (on DIS},

TABLE 1

Magnetic structures of the magnetic field induced phases uf EuAS,, Eu(As0/J)P0.40)3 and Eu(As0n2P0 ,,8)3. The magnetic moments of all these phases lie in (010) plane. Compound Phase T(K) H(T) Wavevector Type of modulation a + (deg) Axial ratio* * Hu R(%)

EuAs3 SF4 6.0 4.0 [-0.90,0,-0.21] Linear modulation 91(1) — 15

Eu(ASo.6oPo.4o).1 SFM1 2.5 1.15 [-0.89,0,0.32] Elliptic modulation 100(2) 0.45(5) 5.6 8

Eu(As060P040)3 SFM2 2.5 2.07 [- 1 0,1/2] Linear modulation 96.7(6) — 4.7 15

Eu(AsowP0.j0)a SFM3 2.5 3.22 [-0.91,0,0.32] Elliptic modulation 99(1) 0.68 3.4 8

Eu(As0.02P0.,8)3 SFP1 2.5 1.15 [-0.68,0,0.34] Elliptic modulation 124(2) 0.53(3) 24 SFP2 2.5 1.61 [-0.71,0,0.21] EU(AS0 02P0.98)3 — — — — - * a is the angle between a-dircction and the major axis of the ellipse. * * ratio between the lengths of the major to the minor axis of the ellipse. Tests of a small (32x32) crossed wire multidetector have been Y carried out. Whilst the uniformity of response of the detector was not perfect, it was possible to measure reflections in an incommensurate phase of RbMnBr, such as that shown in figure 80. This study demonstrated the potential of the detec­ tor and it is hoped to install it for further tests with improved detection electronics early in 1987.

D16: Four-circle MK6 diffractometer 1 on cold guide H16 There have been no major instrumental modification on D16 in the past year. The diffractometer operated smoothly for data collection in the very diverse fields that require good q resolu­ tion at low q values. Because of the increase in single crystal proposals on D16, an effort will be made to implement full software compatibility with the other instrument in the group. This will add to the existing compatibility between D16 and z — the small angle instruments Dl 1 and D17 for data treatment. More elaborate improvements under study are at the monochromator level, and in the development of an approach in the study of cyclic kinetics in biological and chemical Figure 80: A demonstration of the potential of a t •• small I32xi2l crossed » muttidelector on DI5. systems. D19: Multidetector diffractometer for S18: Neutron interferometer on the protein crystallography on Hll thermal guide H25 D19 shares the thermal beam HI 1 with the powder instruments A new calculator (PDP 11/73) and an additional terminal have D20 and D2B. It has run scheduled experiments routinely since been connected to the overhauled microprocessor system. The spring 1986 and has been tested in a number of configurations new PDP facilitates experimental work as well as data analysis and on a variety of samples from 3He single crystals at lOmK and data transfer. The power supply was improved by the con­ to human haemoglobin. nection of a filter device. A 2-stage Displex cryorefrigerator for temperatures down to An additional possibility to use the X-ray equipment has been 20K is now available. placed at the left-hand side of the neutron optical bench. This is used for the development of an interferometer which com­ Much effort has been expended to simplify and automate dif­ prises two separated crystals. In this way, we hope to increase fractometer control, read-out of the 8K pixel 4°x64° area free sample space and the measurement sensitivity by an order detector and transfer of the data from the instrument of magnitude. PDP11/34 to the dedicated VAX 11/750 computer. We have manufactured and successfully operated a new single Experience has shown that accurate on-line integration of crystal interferometer with an interference contras/ of 82% at Bragg peaks from the range of samples encountered on D19 2.5 A and a wavelength range of 2.5 Â s X s 5 À. This new cannot always be guaranteed, i.e. re-processing will often be crystal is actually used for multiwavelength intci feromctry and necessary, so that data must be archived for seme experiments. harmonic suppression and is available to external users. All data reduction is done on the instrument 'AX, which is Measurements have been performed on neutron phase changes by gravity, non-dispersive b measurements, Pendellosungs now close to saturation if data are collected at faster than c 15.000 frames per day. As the final aim is to run at up to 50.000 effect with optical interferometer components, influence of frames/day (2 sees/step), brute force archiving would mean sample environments on fringe contrast and phase shift, a dou­ up to 24 magnetic tapes (1600 bpi, 2400') per day. Research ble coil expi iient on quantum beat effect with an energy sen­ into data compression has begun, but it is clear that when the sitivity of •-.

89 ponents can also be separated from the fundamental wavelength. Figure 82 shows a Zeeman splitted spectrum with clearly separated and polarized components of X = 4.83 Â and 2.42 Â neutrons (C. Zeyen, to be published). For more details on the possibilities of this instrument con­ sult the new (1986) brochure "Neutron Beam Facilities at the ILL". The photograph shows the general layout of the instru­ ment with the gamma-diffractometer disconnected.

Co-ordinator: J. Pannetier

Figure 8!: Results obtained with the position sensitive detector on S20. (a) picture obtained by using a position sensitive multiplier ib) corresponding topograph, n-corded photographically

S21: Double crystal diffractometer S21 has been rebuilt at the end of i!>e H25 thermal guide tube and is operational. The flux has increased by more than an order of magnitude with respect to the old situation. The flex­ ibility of this high resolution double crystal spectrometer has also improved and an on-line gamma-diffractomcter is now available on request. Recently spin rotations due to spin-orbit coupling could be observed on quarU crystals (exp. report 3.13.83 and FORTE, ZEYEN, to be published). Furthermore the excellent energy resolution of S21 has been Figure 82: Splitting 0/4.83Â neutrons by a 7 Testa magnetic field on S2I. The beam used to produce perfectly polarized beams by separation of contained a significant amount of 2nd order which is also separated and the Zeeman doublet. Using the same principle, high-order polarized.

S2I has been rebuilt at the end of the H2S thermal g*iide tube. The flux has increase J by more than an order of magnitude with respect to the old situation. The flexibility of this high resolution double crystal spectrometer has also improved and an on-line garnir n diffractometer is now available on request. For more details consult the brochure "Neutron Research Facilities at the ILL High Flux Reactor". The picture shows the general layout of the instrument with the gamma-diffractometei disconnected.

90 A stand-by computer for S-activities has been acquired. SPECIAL During 1986 much effort has been put into S-experiments aim­ ing at measuring the neutron lifetime to better than I %: S52 INSTRUMENTS AND detecting the neutron beta decay particles, PERKEO the neutron decay spectro-spectrometer, NESTOR the supercon­ ducting magnetic neutron storage ring and another bottle ex­ periment using a neutron bottle with variable volume and walls (W. Drexel) covered by a H-free oil (see College 3 report for results). The preparation of the neutron-antineutron oscillation experi­ The table gives an overview of S-activities in 1986 at the ILL. ment has progressed, construction work has been started so Most of them were in routine operation; progress was achiev­ that the experiment itself can start when the neutrons from ed as follows: the 2nd cold source become available. S18 received a new computer and is now running satisfactori­ Important progress has been made in the use of the new source ly; a multiwavelcngth interferometer is in development as well of very cold (VCN) and ultracold (UCN) neutrons on level D. as a 2-separate-crystal interferometer (for the use of big In 1985 the vertical neutron guide and the neutron turbine had samples). been installed (Garching). In early 1986 flux and spectrum S21 has been installed at the H25C position with a 10 times measurements have been performed and published (A. Steyerl higher flux. A gamma-ray facility tranverse to the neutron et al. Phys.Lett. A 116 (1986) 347). All the necessary technical beam for simultaneous use with the neutron beam has been infrastructure was installed in late 1985/1986: platforms, elec­ incorporated. tric power (normal and ARC), cooling water, compressed air, S42 can work now in 3 modes: Laue diffraction with helium recuperation line and computer links The photographic detection or with a Boron counter and white photograph shows the status around the turbine in November beam diffuse scattering with photographic detection. 1986: The neutron turbine is housed in the bine vessel to the right. The black vessel in the centre near the top contains the SN6: New computer installed. set-up for the UCN-microscope (all VCN/UCN experiments Software for the neutron microscope has been developed. have to be performed under vacuum). In front of it, 'o the A computer was boughi for NESSIE and software develop­ right, one can see a metallic vessel containing the neutron ment was started. lifetime experiment. Just in front of the microscope vessel is

Special experiments on level D using the new source of very cold and ultracold neutrons

91 the vessel of NESTOR the superconducting magnetic neutron storage ring where VCN's are stored in a toroidal magnetic SPECIAL STUDIES field configuration avoiding perturbations by interactions with material walls. At the left, the EDM-experiment (open) is in­ stalled. All these experiments have extended their experimen­ Or EXPERIMENTAL tal limits due to the intensity gain of between 50 and 80 compared to the UCN source on level C (SN5) depending on AND INSTRUMENTAL the neutron velocity used (see College 3 report for results). Projects for this source for 1987 are: the transfer from Gar- TECHNIQUES ching of their gravity diffractometer and their gravity spec­ trometer (NESSIE). External proposals have been accepted by (P. Ageron) the Scientific Council: (i) a set-up for optical experiments with VCN's (Wien, Garching, ILL) and (ii) an experiment using a VCN diffractometer for a study of the coexistence of fer- PRODUCTION AND USE romagnetism and superconductivity (CENG). OF VERY COLD NEUTRONS It has to be stressed that this source is open for external pro­ posals (its main features being described in the brochure "Neutron Beam Facilities at the ILL High Flux Reactor). Different methods have been tested in order to obtain steady state, collimated, monochromatic beams of VCN: - a velocity selector with helical plexiglass blades. With the pre­ Table: Special Instruments/Experiments sent geometry, the band width A\/X is too large (18 - 36%) and the total possible reflections on the blades at large angles Condensed matter for VCN deteriorate the collimation. S18 neuiron inter feromeier Dortmund/Wien - a reflection on nickel followed by a transmission through a S20 neutron topography CNRS thin silicon substrate covered with nickel, at a slightly different S21 high resolution double crystal ILL spectrometer using neutron and angle. Such a system has been abandonned because it cannot gamma simultaneously HMJ Berlin ensure, at the same time, a narrow AX and a good overall S30 concentration profiles by (n,p); (n.alpha) transmission. S42 Laue diffraction CNRS S44 channeling/blocking HMI Berlin - Bragg reflection on multibilayers (from 40 to 400 bilayers) made of Al-Ti, Ni-Al or Ni-Ti, with a "d" spacing of between Nuclear physics 2 x 50 to 2 x 100 Â. Such artificial crystals are attractive wcause S10 (n,alp ha) reactions Gent/Mol they yield good monochromation for VCN (AX/A. = 5-10%) S34 gamma-gamma correlations ILL/Sussex and strong deviation. Further developments are underway in SSI fission studies, neuiion activation analysis Darmstadt/ order to improve the reflectivity and to avoid the parasitic total Grenoble SNo Ostis mass separator Giessen/Mainz reflections on the substrate. Braunschweig Such VCN monochromators have been used on SN5, for the OAMS4 double flat gamma crystal spectrometer NBS/1LL following purposes: Fundamental physics - technical tests of various mirrors (glass or solid nickel) S50 h/m-determination Braunschweig covered with natural Ni or 58Ni, for the guides of the second S52 neutron lifetime experiment LAPP/ISN/ILL n-charge search for an electric charge of the neutron Bayreuth/ cold source. Multiple (up to 10) reflections between a pair of Garching sample mirrors (500 mm long, 6 mm apart) permit measur­ n-nbar neutron antineutron oscillations Heidelberg/ ing at a fixed wavelength (60 Â) both the critical angle and Padova/ILL the loss per (total) reflection. S-UCN superthermal liquid He-source Rutherford SN5 UCN-source on level C ILL - measurements, in cooperation with the Laboratoire Léon (for developments) Brillouin, of the reflectivity profile on horizontal liquid sur­ SN7 beam of polarized neutrons ILL faces (solutions of polymers) with a fixed beam of variable on SN7: PERKEO neutron decay spectrometer; parity Heidelberg wavelength (between 20 and 60 Â) obtained by rotation of a violations in gamma resonance scattering Kurchatov double monochromator. VCN have the main advantage of working with relatively large incident angles (3 - 4°) hence pro­ Level D experiments viding easy experimental conditions. In this first attempt the TGV+ VCN/UCN source Garching/ILL statistics were insufficient to draw quantitative information turbine: Bonn on the concentration at the interface. The counting rate will Nestor magnetic ncuiron bottle for neutron lifetime be improved by better monochromaters and the use of the EDM search for the neutron electric dipole Sussex et al. more intense VCN beam on the HFR top (level D). momtm n-bottle: neutron lifetime experiment in a material ILL The figure 83 compares the TOF measured brightness, as func­ neutron bottle (varying volume, H-free tion of the wavelength, at SN5 and at VCN beam of level D. walls) The present VCN guide, inside the turbine, is at the moment n-micro- development of a neutron microscope Garching/ILL too curved (R = 3.2 m instead of 13 m for the incident beam). scope: This will be corrected by using a new guide of SOLLEF type, Externally Supported Instruments: IN3, DIA. presently under construction at Garching. CALCULATIONS NEW PROJECTS (A. Robert) A program simulating the neutron trajectories was used lo study: OPTIMAL SPIN ICHO - specific points of the guides for the second cold source: ef­ fect of polygonal approximation, gaps, the reflected and MAGNET DESIGN transmitted spectra by a deviator made of supermirror coated wafers and optimization of the geometry. (C.M.E. Zeyen) - a focussing guide associated with focussing monochromators The feasibility of optimised precession magnets, which are for different experiments. homogeneous enough to reach the fundamental resolution An option, in development, will extend the possibilities of this limits inherent to the NSE method itself and given by the program to trajectories inside magnetic fields, for the optimisa­ nonlinearitics in the spin precession/energy tiansfer relation, tion of a hexapole focussing and polarising device. is now well established. Such magnet systems comprise com­ posite solenoids reproducing the analytical optimal field shape Possible improvements of the cold neutron flux from the se­ (OFS is the analytical solution of the variational line integral cond cold source, by addition of different amounts of homogeneity problem) to better than 106, in-beam correction hydrogen to the liquid deuterium, are being investigated with lenses and gradient coils for generalised (local matching of the thermalisation program DOT. slope and curvature of dispersion relation) focussing of elemen­ tary excitations. Composite (superconducting) solenoids guarantee the best possible homogeneity for a given magnet length. They are made of a number of superposed solenoids, the lengths of which are calculated to reproduce OFS to the desired degree

6 of accuracy. The diameter of the solenoids can be kept very T,10 A/\ \ \ small (such as to contain the chosen beam diameter) as OFS 3 / I \ does not depend on it. Therefore OFS magnets also have the 2 a/ h \b lowest fringe field levels. « / /\ \ T / 1 \ \ >'< / \ \ Correction coils remove line-integral differences resulting both *- from remaining field inhorr jgeneities and from palhlength dif­ » / 1 \\ \\ ferences of divergent be^ms. The proposed shape of these cor­ f / / \ \ rection lenses in fact also results from an analytical - i-o- " / \ \ optimisation, which starting from the optimal field shape, cs \ I looks for the best longitudinal and radial in-beam current • t> TJ / \ I distribution function minimizing at the same time field in- r«o / \ \ homogeneity and pathlength effects. Because the correcting currents will be distributed both axially and radially the \ necessary current density can be kept very low so that very / v \ thin conductors with negligible neutron absorption can be us­ 10+ ed. The actual current shapes are calculated as discretizations 10 100 1000 of the continuous analytical solutions of the variational op­ NEUTRON WAVELENGTH. (Â) timization. Such corrections improve the homogeneity by more than two Figure S3: Measured VCN brightness of (a} SNS and orders of magnitude while simple spiral coils only yield about fb) VCN beam at level D (temporary guide) a factor of 10. In practice this means that delicate (or impossible in the in­ elastic case!) resolution corrections using measured reference polarizations are not required anymore. Gradient coils dissymmetrize the field distribution so that in the scattering plane, neutron momentum dependent line in­ tegrals are achieved allowing focussing onto dispersive ex­ citations. Because they do not need to respect the cylinder symmetry of the main coils, they need not be produced by in-beam current distributions. Hence they are not limited in magnitude by the

strong-field approximation. (Bcorr < < B) which the other, smaller corrections have to fulfill. A simulation programme solving the spin-equation-of-motion across ai. entire spectrometer (including realistic flippers, field- shaping and correction coils) exactly, is now operational on the ILL VAX. The computing time for the integration of the

93 spin equation of motion across the logarithmic field singularities introduced by the in-beam coils is at present ex­ cessive. This is due to the fact that in order to achieve the high accuracy required, the integration routine chooses very small steps in the vicinity of the singularities. To reduce CPU time, a recently proposed method of integration across strong singularities shall be applied. For similar problems this pro­ cedure has proven to reduce CPU times by as much as a fac­ tor of hundred. The above results do not apply to superconducting magnets alone, but could improve the quality and cost (both length and diameter of OFS magnets are significantly smaller) of classical magnets too. For example, magnets of the length of the INI I solenoids, optimized with the method I propose, would be nearly three times more homogeneous. Correction coils could be used to reach 10"6 homogeneities as well as for supercon­ ducting magnets. Conclusions: the present method of design for neutron spin- echo magnets is expected to lead to successful applications mainly in two fields. Firstly, very homogeneous superconduc­ ting magnets can easily generate line integrals of a few TESLA METER, sufficient to obtain excellent resolutions with ther­ mal and even hot neutrons. Classical magnets would have to be extremely long to yieid such field integrals because of the limited maximum field. Secondly, the possibilities of producing rather short but very homogeneous magnets with very low fringe field and offering the possibility to focus on dispersive excitations definitely open the domain of three-axis spectroscopy with spin-echo (TASSE). Detailed accounts on the above calculations and results will be published soon. This is a collaboration project with the University of Twente, Enschede, the Netherlands.

94 DIRECTORATE SERVICES has been thought to be absr jtely necessary; either due to com­ SCIENTIFIC missioning exigencies or after major modifications. During this report period, September 1985 - December 1986, COORDINATION AND a total of 1136 experiments approved by the Scientific Coun­ cil, were planned and carried out on schedule; a tribute both to the reactor reliability and the level of "productivity" that PUBLIC RELATIONS has been achieved by ILL. scientists and technical st* 7. Beam allocations by the Scientific Council are becoming noticably shortc reflecting not only the high level of competition for oversuiscribed ILL research facilities, but also flux increases at the specimen due to focussing turret mounted SCIENTIFIC PROGRAMME monochromators and an advanced level of computer control for sample environments, sample changers and instrument IN 1986 functions. One must also remember that we are now in a period where full advantage is being taken of the cold neutron flux 1986 has seen the first full year of reactor operation follow­ increases emanating and by virtue of, the advanced design of ing the long shut-down for the renewal programme. Reference the new vertical cold source. to the operational statistics in the Reactor Department section of this report will underline the exceptional reliability of this These "improvements" often translate into extremely arduous neutron source. There was only one slight perturbation of a experimental periods for the guest scientists and local contacts few hours, necessitating a power reduction to 45 MW and this with frequent interventions - despite the automation - necessary was due to a transient fault in equipment extraneous to the both day and night in order to optimise the efficient use of reactor proper. the beam allocation. The time is not too far distant when it will become imperative to have rest facilities (a hostel?) close Due to the very short operational period in 1985 (cf. Annual to the experimental installations. Report 1985) no statistics relevant to the scientific programme of that year were given. This backlog has, therefore, been in­ However, despite the large number of visiting scientists and cluded in the present survey giving a slightly more comprehen­ experimentalists participating in an intense programme impos­ sive overview and covering an allocation period of 7.5 reactor ed by the Institut, the atmosphere remains friendly and, it is cycles, modified in certain cases, by instrument tests where this hoped, conducive to the advanced research being carried out.

Schematic Arrangement of Beam-tubes and Instruments at the HFR (status Sept. 19 86)

Reactor Hall Floor C

HS Hoi source Hoi neutrons VCS Vertical cold source • HCS Horizontal cold source Experiments Reactor Hall Floor D Cold neutrons D DiffractomBler • IN Speciiornetpr Thermal neutrons PN Nuclear physics instrument • 5.5B Special instrument Reactor core T Test instrument • H.m Seam-tube number o Heavy water TGV Vertical neutron guide

Up-dated version of the schematic arrangement of beam tubes and instruments at the HFR (Sept. 1986).

96 Instrument Statistics September 1985 - December 1986 Please note : Included in the following statistics are the beam-time allocations for the latter part of 1985 i.c. during the period September-December 1985; when the reactor restarted after the long shut-down. It will be recalled that certain instruments were, at that time, subject to prolonged test periods for re-commissioning after major modifications and non usage during the reactor shut-down. Instrument calibration following an increase in cold neutron flux was also carried out. Not included : In the statistics are the beam-times attributed to the so-called "Special Beam" experiments which are generally fundamental in their concept and endowed with comparatively long beam-time allocations. They are fully described elsewhere in this report. Due to the inexactitude of the aforementioned test periods at the end of 1985, the specific instrument allocations refer to an equivalent full-power reactor availability of approximately 300 days.

Instrument Instrument Beam Beam Fundamental Structural Crystallo­ Liquids, Biology Chemislry, Comments Group -Time - Time & Nuclear & Magnetic graphy Disordered Small Request. Available Physics Excitations & Magnetic Materials & & Large (days) (days) Structures Metal Physics Molecules Colloids, Polymers Three- INI (3-axis) 369 70 69 1 Time sharing on H8 with D4 and INI (BeF) Axis INI (BeF) 160 50 13 37 Time sharing on H8 with D4 and INI (3-axis) IN3 230 130 90 40 507B availability CF. special beam allocations IN8 419 232 190 33 9 1N12 585 234 140 87 7 1N20 574 165 90 75 New instrument. Period includes commissioning tests Timc- IN4 479 226 126 41 59 of- 1N5 454 237 55 58 124 k flight IN6 753 247 67 95 21 64 Back- IN10 630 249 4 !15 10 120 scattering IN11 777 227 92 21 34 80 Test period for IN11B commissioning & spin-echo IN13 317 259 19 62 6 172 Powder DIB 515 253 125 37 2 89 diffraction D2B 591 208 2 193 10 3 Commissioning. Certain of these experiments have been carried out on D1A D20 164 80 38 33 9 Preliminary allocations. Instrument not yet operational Single D9 419 175 175 Re-built instrument. Period includes commissioning crystal D10 325 236 16 184 35 diffraction D15 538 265 265 D>6 364 273 28 5 142 98 D19 343 151 86 55 10 Limited feasibility programme in progress DB21 281 110 110 Feasibility of low resolution crystallography of biological macromolecules in progress Polarized D3 857 270 270 neutrons D5 1281 232 22 210 Liquids, D4 459 146 II 133 2 Time sharing on H8 with INI (3-axis) and INI (BeF) diffuse D7 398 234 122 73 13 26 scattering Small angle Dll 655 248 24 34 71 119 scattering D17 419 272 1 43 37 45 146 Nuclear PN1 537 304 304 physics PN2 422 249 249 PN3/4 520 240 240 Curved crystal spectrometers Gams 1, 2/3 (PN3) and pair spectrometer PN4 PN8 901 299 299 WORKSHOPS ORGANISED LIBRARY BY THE ILL IN 1986 Colloque National Biologie Moléculaire et Cristallographie : The Library has now 9200 books, 8100 reports and handles CNRS/ILL 19-21/3/86 300 subscriptions to journals (of which 120 are dispatched to Biviers near Grenoble Departments). In 1986 : (M. Lehmann) • 460 books (monographs, serials, conference proceedings...) Workshop on "Structure and Dynamics of Interfaces and Col­ were registered of which 130 were deposited with departments. loids. Can neutrons help applied science ?" • 450 volumes were bound. ILL Grenoble 7-8/4/86 • 400 reports from other laboratories were registered. J.P. Beaufils B. Maier • 350 publications with I.L.L. authors were regi ?red. R.C. Oberthûr 1986 was marked by a significant increase in the i aiber of R. Ottewill on-line bibliographic searches (50 sessions) while purchasing D. Richter of reprints was kept as previously at a very low level. Workshop on "Quantum Aspects of Molecular Motions in In addition to the edition of the yearly volume "19. . ILL Solids" EXPERIMENTAL REPORTS AND THEORY COLLEGE ILL Grenoble/KFA Jûlich ACTIVITIES"*, the Library, thanks to 'stagiaire' help, was 24-26/9/86 able to produce a new report "1985. ABSTRACTS OF D. Richter PUBLICATIONS"» (Collection of abstracts of publications A. Heidemann by ILL staff or related to experimental work performed at the M. Prager ILL, arranged by College). This volume which represented wo T. Springer months of additional work, was welcomed by scientists

PUBLIC RELATIONS • available from ILL Library on request. In 1986 the compilation of two main documents have characterized this field. The new edition of the brochure "Neutron Research Facilities at the ILL-HFR (June 1986)" and a special brochure issued on the occasion of the 20th an­ niversary of the ILL on 19 January 1987. Both brochures are available on request from SCAPRO.

98 SAFETY, GENERA! SAFETY, MEDICAL AND SAFETY ENGINEERING Specific duties have been continued in the following areas: HEALTH PHYSICS • Periodical checks; • Definition of conditions for carrying out experiments or GROUP (SPS) work involving particular risks; • Organisation of meetings for the start of construction work, During 1986 an adviser to the Director of the ILL in the safe­ the secretariat of the Internal Safety Commission, attendance ty, medical and health physics field was appointed, who is at the Committee on Health, Safety and Working Conditions. responsible for coordinating the work in the sectors radiation Safety studies have also been carried out in connection with protection, general safety, safety engineer and works medical new projects: service. The work of the different sectors is complementary, as they carry out service functions for the whole of the Institut. • rin"experiment , for which the gas flow counter uses isobutane • Radiological shielding for neutron guides for the new horizontal cold source • Start of production of graphite monochromators requiring RADIATION PROTECTION the use of a high temperature furnace and a large radioactive source. A regular programme of work was carried out, particularly as regards: • Monitoring radiation levels around the installations and car­ rying out laboratory measurements • Dosimetry for staff and guest scientists MEDICAL SERVICE • Dealing with sources, radioactive samples, gaseous and other The works medical service operates autonomously within the waste safety, medical and health physics group. • Processing forms for samples involving radiological risks Regular medical supervision covers the 500 permanent staff In addition, to maintain or improve the level of safety of the and certain guest scientists. installations, the following work was carried out: There are several aspects of this, of which the most important • In collaboration with the reactor department, installation of are medical examinations and clinical, biological, dosimetry new monitoring instruments for activity in the atmosphere and toxicological tests. Some of these can be carried out in (personnel protection circuit - reactor). the ILL medical service with the aid of the equipment available. • In collabo' ation with the building maintenance and construc­ The service acts as medical adviser to the Director and the tion group, the modification of the health physics measuring departments and participates in various tasks in connection laboratory and the establishment of areas suitable for tem­ with working conditions, study and monitoring of nuisances porary storage of radioactive equipment. and preventive and protective measures. • Formalisation of the procedures used for work subject to It also deals with requests for minor treatment, information Quality assurance. and advice from persons working at the ILL.

99 MICRO-STRIP PLA TE* By means of photolithography, commonly used to fabricate masks for integrated circuits, a precise thin strip structure of conductors is engraved on a plate. This micro- strip plate, installed as an anode in a gas detector, replaces the wires in a so-called multi-wire proportional counter. Due to the high precisian of its structure and the very small distance between the strips, this new type of position sen­ sitive detector only operates at low voltage with a high and uniform amplification on its total surface and accepts counting rates up to 2.5 X 106 c/sec/cm2. In addition, a position resolution comparable to the spacing of the strips can be expected. The micro-strip plate shown in the figure was designed as a proto-type for the new diffractometer D20. The *mall strips, 8 urn in width, are located between two broader strips in a distance of 150 /*m. Four such structures are connected together to form one cell of 2 mm in width, in order to meet the specified position resolution of the in­ strument.

* Brevet: 86 10810 France

100 INSTRUMENTS AND METHODS DEPARTMENT • After design studies at the beginning of the year, work started on INTRODUCTION construction of the new spin-echo spectrometer INI5 in collabora­ Outre les interventions de maintenance des instruments en exploita­ tion with the Berlin and Julich laboratories tion, l'activité de TILL en 1986 dans le domaine des intruments peut • Guides to supply these instruments have been designed and orders être présentée comme répondant à 3 types de problèmes : placed 1) La mise au point d'instruments récemment démarrés (fin 1985), 3) Major work has been carried out on the development of methods : soit à la suite d'une grosse refonte (DU, IN11B, paliers magnétiques • The development of a hot press for producing graphite mosaic sur IN5), soit comme nouveaux instruments (DI9, D20, D2B). crystals in collaboration with Le Carbone Lorraine and with the Il convient de noter aussi le démarrage de nouvelles expériences assistance of the Louis Néel Laboratory at the CNRS spéciales utilisant les neutrons ultra-froids extraits de la nouvelle source verticale et les travaux préparatoires à la nouvelle expérience • The development of new position sensitive detector structures by neutrons-antineutrons. using integrated circuit techniques. It is intended to use the structures for the new D20 1600-cell banana detector, for which a very large 2) Les études et travaux liés aux instruments sur la source froide housing (overall length 4.5 m) has been designed and the manufac­ horizontale. turing contract placed • L'essentiel du nouveau 3 axes 1N14 a été lancé et construit en 1986. En parallèle, la refonte de l'électronique de 1N12 et le remplacement • Continuation of development work in collaboration with external du calculateur SOLAR ont été étudiés et lancés. organisations on : • Les études d'avant-projet de D22 ont démarré au printemps 1986 Beryllium crystals ; the first of these crystals has recently been tested et ont conduit à la définition d'une option T.O.F. performante. En successfully on D9 ; also development of Gc-Si crystals. outre la construction d'un multidétcctcur pour HMI a élé entreprise, qui doit servir de prototype pour D22. • Des tests technologiques sont en cours pour définir le nouvel in­ strument de rétrodiffusion INIOC. EINLEITUNG • Après des études de principe en tout début d'année, la construc­ tion du nouveau spectromètie Spin Echo 1N15 a commencé en col­ Die Tàtigkeitsbereiche der Abtcilung Instrumente und Methoden um- laboration avec les laboratoires de BERLIN et de JULICH. fassen, zusatzlich zu Wartungsarbeiten an den im Betrieb befindli- chen Instrumenter 3 weiterc Bereiche : 8 Les guides destinés à alimenter ces instruments ont été étudiés et lancés en fabrication. l)Justierung der kiirzlich in Betrieb genommenen Instrument im An­ 3) Des travaux importants ont été réalisés pour développer les schluss an eiuen grundsatzlichen Umbau (DU, INI IB und Magnet- méthodes : lager fur IN5) oder neuer Instrumente (D19, D20 und D2B). • La construction d'un four de pressage en vue de la fabrication de Es sei besonders auf die neuen Sonderinstrumente mit ultrakalten Neu- cristaux mosaïques de graphite en collaboration avec le Carbone Lor­ tronen der neuen Vertikalen Kalten Quelle und auf die vorbereiten- raine et avec l'aide du Laboratoire Louis NEEL du CNRS. den Arbeiten fiir das neue Neutron-Antineutron-Experiment • Le développement de nouvelles structures de détecteurs sensibles hingewiesen. à la position par utilisation des techniques de réalisation des circuits 2)Studien und Arbeiten im Zusammenhang mit den Instrumenten der intégrés. Il est envisagé d'utiliser ces structures pour la nouvelle banane Horizontalen Kalten Quelle. de 1600 cellules de D20 pour laquelle une enceinte de très grande dimension (longueur développée 4,5 m) a été étudiée et lancée en • Die Haupiarbeiten fur das neue Dreiachsen-Instrument, IN14, wur- fabrication. den 1986 durchgeftihrt. Parallel dazu wurde die Elektronik von IN 12 erneuert und mit déni Ersatz des SOLAR-Rechners begonnen. • Poursuite du développement en collaboration avec l'extérieur de : Cristaux de Béryllium. Le premier de ces cristaux vient d'être testé • Die Vorstudien fiir das D22-Projekt sind im Fruhjahr 1986 ange- avec succès sur D9, cristaux de Ge-St laufen und haben e'> erlaubt, eine leistungsstarke Flugzeit-Option fest- zulegen. Oberdies wurde ein Multidetektor fur das Hahn-Meitner-lnstitut in Berlin gebaut, der als Prototyp fur D22 die- nen wird. • Es laufen Tests zur Definition des neuen Ruckstreu-Instruments, INTRODUCTION IN10C. Apart from maintenance work on operational instruments, the work • Nach Beendigung der Grundsatzstudien zu Beginn dieses Jahres of the ILL in 1986 in the field of instruments may be summarized wurde in Zusammenarbeit mit den Instituten in Berlin und Jùlich mit as dealing with three types of problems : dem Bau des neuen Spin-Echo-Spektrometers begonnen. 1) The refinement of instruments recently commissioned (end 1985), either following a major rebuild (DI1, INI 1B, magnetic bearings on • Die Leiter, die dièse Instrumente versorgen werden, wurden kon- IN5), or as new instruments (D19, D20, D2B). struiert und ihre Herstellung ist angelaufen. The start of new special experiments using ultra cold neutrons from 3)Zur Methodenentwicklung wurde bedeutende Arbeiten unter- the new vertical source and the preparatory work for the new neutron- nommen: antineutron experiment should also be noted. • Der Bau eines Pressofens im Hinblick auf die Herstellung von mo- 2) Design studies and work associated with instruments on the saikfôrmigen Graphitkristallen, in Zusammenarbeit mit Carbone Lor­ horizontal cold source raine und mit Hilfe des Laboratoriums Louis Néel des CNRS. • The essential part of the new triple axis instrument 1N14 was in­ • Die Entwicklung neuer Strukturen fiir einen ortsempfindlichen De- itiated and built in 1986. In parallel, the new electronics for IN12 tektor durch Verwendung von integrierten Schaltungen. Diese Struk­ and the replacement of the SOLAR computer were designed and turen sollen fiir den neuen aus 1600 Zellen bestehenden started Bananendetektor, D20, benutzt werden, fur den ein sehr grosses Ge- • The preliminary project studies for D22 started in spring 1986 and hàuse (Lange der Abwicklung 4,5 m) konstruiert und bestellt wurde. resulted in the definition of an effective TOF option. In addition the • Weiterentwicklungen in Zusammenarbeit mit anderen Laborato- construction of a multidetector for HMI was undertaken, to serve rien auf folgenden Gebieten : as a prototype for D22 • Technological tests are in progress to define the new back-scattering Beryllium-Kristalle; der erste Kristall wurde mit Erfolg auf D9 getestet. instrument IN10C Ge-Si-Kristalle.

102 On experimental instruments, the Mechanical Construction MULTIDETECTOR Group has contributed - to the completion of the small angle spectrometer D11 CROUP - to the conversion of the spin echo instrument IN11 - to the commissioning of the choppers for IN4 and IN5, us­ 1) Work on gas detectors in 1986 was concentrated on : ing the new technology of magnetic bearings • Commissioning of the new instruments D2B and INI IB in­ The Group has worked on the design and placing of contracts corporating a large number of single detectors arranged in a for multidetector housings for D20, IN 15 and DB21, and on single dimension; the design study and assembly of a high temperature hot press • Installation and operation of multidetectors on : for producing graphite mosaic crystals D4 for hot neutrons D19 512x16 cells for thermal neutrons It has started design studies on projects for future instruments D20 128-wire prototype in the form of a cross, while awaiting to use the neutrons from the new cold source. These new the completion of the final 1600-ceII banana detector studies cover the triple axis spectrometer IN14, the spin-echo instrument IN15, the small angle scattering spectrometer D22 • Development and testing of small 32 x 32 cell multidetec­ and the back-scattering spectrometer IN10C. tors for D9 (hot neutrons) and D15 (thermal neutrons) and a 128 x 128 cell detector with 1.5 mm spacing for the biology Studies have also been carried out on the transfer of the diffractometer DB21 polarised neutron diffractometer D3 to a hot neutron beam (H4) • Modification of the previous D11 detector to make it suitable for use as a replacement for the existing Dl 1 instrument (opera­ The Group has completed the mechanical construction under tion in a vacuum tube) quality assurance conditions of the beam shutter drum associated with the new cold source, and at the end of 1986 • Initiation of the design study and start of manufacture of is refining the electro-mechanical controls and is assembling — the 1600 cell banana for D20 the neutron guides. Design studies have been carried out for — the32x32cell detector for the spin echo spectrometer IN 15 the guides associated with the new horizontal cold source and the choice of subcontractor was made during the year. — a large dimension detector (1 m X 1 m) intended for HMI Berlin and used as a prototype for the future small angle scat­ With industry, the Group has contributed to : tering instrument D22 - the implementation of new non-magnetic mechanical 2) Electronics : modules with incremental or absolute direct angular coding giving these instruments an accuracy of 0.0025°, particularly • Development of new cards for charge preamplitiers and intended for IN14 and IN15. amplifier discriminators (applicable to the Dl 1 replacement detector) - the use of air films produced by porous materials. A first assembly designed for D7 permits operation at 10O0O rpm on • Development of position sensitive electronics by delay lire graphite bearings (collaboration with the University of for small multidetectors in accordance with the EUROP Karlsruhe). standard - the use of composite materials (carbon) or aramides (Kevlar) • Continuation of tests of a time logic for non-metallic chopper discs with real slits for neutrons to • Continuation of work on ILL standard electronics at the re­ pass through at the circumference. These discs permit quest of external laboratories peripheral speeds above 600 m/sec. 3) Laboratory equipment and developments For discs designed for speeds above 300 m/sec it is now cur­ rent to use composite materials reinforced with glass fibre or • A second "canal technique", on the thermal guide H24, to gadolinium oxide. These materials will be used in the IN15, provide the space necessary for tests on future large detectors D22 and IN10C projects. • The purchase of a new binocular microscope with a high precision X-Y translation table permits the study of and if Within the Department this group contributes to contacts and necessary work on microstructures technological exchanges with other research centres. • Developments with a view to replacing multiplication wires in certain cases by structures deposited on glass have continued and the first tests with neutrons are expected at the end of the year. ELECTRONICS CROUP l)In 1986 the Electronics Group continued the development of the new VME standard to replace CAMAC for the new re­ quirements as regards instrumentation electronics. MECHANICAL VME electronics necessitate retraining of technicians in pro­ gramming, and the use of development tools in the form of powerful and flexible computers. The PDP 11/24 system has CONSTRUCTION been replaced by a MICROVAX 2 providing compatibility By its three sectors of work, design studies, production and with the CROSS-SOFTWARE-UTILE from CERN. The new assembly, the Mechanical Construction Group has made a con­ computer should be confirmed as the 'HOST' for the future siderable contribution to improving and maintaining in­ for the instruments equipped with the VME (IN 15, D22, struments in operation. IN10C, etc.).

103 Within a joint VME group, there has been a considerable in­ crease in collaboration between the Electronics Group in the MULTILAYER Department for Instruments and Methods and the Automa­ tion and Data Group in the Computer Department, to try to resolve the problem of communications between HOST and LABORATORY VME, which involves a number of questions including the following: (O. Schàrpf, W. Kaiser, W. Just, W. Graf) 1) The choice of the operation system for VME environment The RIBER and ELECTROTECH evaporators were used for 2) Protocol between the mastd and the peripheral modules the fabrication of supermirror polarisers both for focussing in VME and non-focussing neutron guides and for the development of multilayer monochromators for uitra-cold neutrons. The 3) Testing system (software) and manual control for a VME polarising supermirrors use the technique of an antireflecting system instrument (use of the MACINTOSH !) GdTi-alloy layer between the glass substrate and the polaris­ ing supermirror to avoid the total reflection of neutrons with 4) Problems of links between a VME system and its HOST the wrong spin by the glass substrate. The polarising super­ computer (ETHERNET ?) mirror consists of a sequence of 80 layers of cobalt and titanium with continuously increasing thicknesses in the range A first practical implementation will start operation at begin­ of 70 Â to 400 Â. This extends the range of total reflection ning of 1987 on the instrument IN 10 permitting comparison for the neutrons with the desired spin by a factor of two in with the current system used with CAMAC. comparison to nickel, which is normally the material with the highest critical angle of total reflection. The instrument IN10 will also necessitate a 'Doppler" time- of-flight unit, for which the laboratory tests are in progress at the end of 1986. The polarisers of a cross section of 5 cm x 10 cm use many This time-of-flight unit will be used as a basis for the units such mirrors on a thin glass substrate in a curved soller col­ based on choppers (IN15, D22, IN4, IN5, IN6, etc.) limator set-up with no direct view from the entrance to the exit, thereby ensuring that the neutrons are reflected at least Another development concerns the phase control between 2 once during polarisation. The polarisers have undergone many mechanical choppers, for which ILL is currently dependent improvements since the project began, resulting in a signifi­ on outside laboratories (Julich or Karlsruhe). cant increase in evaporation time.

This type of control will be important in future because of the (i) The first polarisers used supermirrors which were coated development of systems for which the window opening can only on one side of the glass plates. For polarisation of the be varied by adjustment of the phase between 2 coupled whole transmitted beam this is sufficient and the transmission choppers. of a well collimated beam (for example behind a Ni guide) is not influenced by this. Such polarisers on D7 need 50 mirrors. Among the major work carried out may be mentioned : On IN 11B for a test set-up for neutron-spin echo muitidetec- 1) Start up of D2B, D9, D11C tor small angle scattering, we produced 10 analysers with a distance of 1.5 mm between the "one side coated" mirrors. 2) D10 : control of shielding blocks by microprocessor They showed good results for this application of a very well collimated beam. 3) D13C : control of a CAMAC châssis by MACINTOSH and MACAMAC (ii) The application and use of such analysers in front of 5 X 10 cm detectors at a distance of 1.3 m from a sample of 4) D20 : installation and first measurements 1.5 cm diameter on the diffuse scattering instrument D7, re­ 5) Development of the phase control of choppers rotating on quires an increased solid angle as seen by the analysers. This magnetic bearings for IN4 and IN5. necessitated an increase in the angle of acceptance by using plates coated on both sides, still with 1 mm distance between 6) IN12, IN 14 : simultaneous start of reconstruction work the soller plates. This sort of polariser with two sides coated (IN12) and construction work on INI4 to ensure a better is also necessary for an S-curved polariser behind a Ni58 guide homogeneity between the two instruments. for the small angle scattering machine in Julich. In an S-curved guide, the different paths of the neutrons are mixed, and one 7) IN15 : initiation of design studies for the preliminary project gains intensity in a beam which is subsequently collimated by increasing the solid angle of the incident beam in the polariser 8) S18 : a thorough general overhaul enabled this instrument until the full range of acceptance of the supermirror polariser to be re-started, despite the maintenance of the old electronics is used, double coating increases the number of mirrors re­ and a technology too sensitive to excess voltage quired by a factor of two. 9) Neutron turbine experiment installed on the new vertical cold source (level D). CAMAC equipment plus PDP 11. Pro­ (iii) This step was dictated by the wish to also use the analysers gramming using SBASIC. for 3.1 Â neutrons and to have a transmission of inelastically scattered neutrons of as high an energy as possible. This was 10) Supply of a test bench to the Mechanical Construction accomplished by diminishing the distance between the mirror Group for evaluation and calibration of the different angular plates to 0.5 mm thus increasing the number of mirrors again sensors. by a factor of two i.e. to 200 mirrors. The transmission where

104 one can still get reliable results was thus extended to an energy Status of the Instruments range of 120 meV. At the end of 1986 D7 was equipped with 20 such polarisers, the remaining 12 still being of the older D13A has been moved from its position behind D10, S20 and version. It is easy to see from the above that one is still not S21 to a new position on H22 where much more flux and a at the limit of possibility for supermirrors because one can not big beam cross-section are available. This means that the only increase the number of mirrors but also increase the possibilities for test experiments which are usually carried out number of layers. This next step has already been investigated on this intrument are much increased. Simultaneously, hard in some examples of mirrors, so that we already know what and software were improved. is required if we want to go further in this direction. From D13C spent its time mainly on monochromator testing and the above it can also be seen that there is no standard super- assembly. However, some "parasitic" use for short test and mirror polariser as many potential users seem to believe. There feasibility experiments, be it prior or not to regularly schedul­ are supermirror polarisers for small angle scattering without ed experiments on other instruments, was also accepted when a change of direction (S-curved), those with a low angle of "rapid access" was needed urgently. Its flexibility and the ease acceptance, with a high angular acceptance and those with of ation of D13C were substantially improved by the transmission of high energies or alternatively for low energies rea installed control by a Macintosh microcomputer only. Additionally, there are also s/m polarisers for large cross- thanks .o the kind and efficient help of the Computer Depart­ sections (5x10 cm) and also for small cross-sections ment which is greatly acknowledged. (3 x 4.5 cm). Finally they must be suitable for the intended use simply because a multi-purpose polariser requires a tremen­ dous production effort necessitating the daily use of two evaporators during a whole year. D7 requires a further 12 such analysers before production begins on the deposition of more layers to shift the energy limit even higher.

Non polarising supermirrors for focussing and non focussing neutron guides also use 80 layers of nickel and titanium with increasing thicknesses and were produced on glasses prepared by NTK (Munchen) and by BBT (Samuel Paris) for IN 10, Rutherford and Julich. To withstand these heavy demands we have had to improve the RIBER evaporator by changing the main valve. We reconstructed the whole RIBER valve moun­ ting so that the valve is now more efficient and the O-ring can be replaced more easily. This avoids the loss of pumping time and will eliminate repairs and failures in future years. The RIBER machine has been working continuously since 1979, a fact that even the manufacturers find astonishing. The ELECTROTECH machine still had some major problems this year which were resolved by technicians from England. The tist facility S3B is essential for the quality control of the mir­ rors and polarisers and the multilayer monochromators, not only directly after mounting, but also if there are doubts dur­ ing use, for example on D7, IN12 or INI IB. Comparative measurements of some samples of multilayer monochromators gave reflectivities between 38% and 95%. A double monochromator (to retain the same direction of the nionochromated beam as the incident beam and to obtain bet­ ter monochromatization) is mounted on SN5. It is desirable also to include there monochromators with antireflecting layers to avoid total reflection by the glass substrate of the unwanted wavelengths. The hot-pressing facility (SOt al 30G0°C) for producing high quality pyrolylic graphite

Li2A and Li2B were neither modified nor reconstructed; they just satisfied their users. MONOCHROMATORS Li3A to F worked routinely too, using their two y-ray sources of 0.0301 and 0.0187 Â wavelength for studying crystals dur­ (A. Freund, B. Hamelin) ing and after growth, and during and after plastic deforma­ D13A : Neutron double-crystal diffractometer on thermal tion which produces the mosaic spread needed for efficient guide H22 neutron monochromators. Mention should be made of the in­ D13C : Neutron double-crystal instrument on thermal guide creasing use of Li3F for experiments in solid state physics to H23 look at phase transformations, commensurate or incommen­ Li2A : X-ray double-crystal diffractometer surate, at the intrinsic difference between synthetic ice crystals Li2B : X-ray orientation unit and samples from the Antarctic and at crystal perfection in Li3A-F : Gamma-ray diffractometers general as in Np02 and in Ni superalloys. Crystal growth dur­ Laboratory for crystal preparation ing zone melting was observed in situ on Ti.

105 Monochromator production and The development of high quality pyrolytic graphite in conjunc­ tion with the firm Le Carbone Lorraine which started about development a year ago progressed as planned. The hot-pressing facility (50 The following table shows the monochromators which have tons at 3000°C) was constructed at the ILL and transferred been produced in 1986 and which are being prepared signify­ to the Laboratoire Louis Neel of the CNRS-Grenoble, where ing that the crystal material is already available: it is connected to the high frequency generator and first tests are expected at the beginning of 1987. Instrument Material Reflection Dimensions (mm) Observations This year again, the ILL facilities for monochromator pro­ duction were made available to external laboratories. Crystals D9B Be (002) (60 x 130 x 4) Prototype were prepared for the Reactor Institute Wurenlingen (Ge), for D19B Ge (113-115) (lOOx 120 x 10) an Italian instrument at IRIS (Ge), for the Petten Reactor In­ stitute, (Cu) and for Brookhaven National Laboratory DB2I PG (002) 7 pieces Filter (Cu, Si). D20 Cu (200) (80 x 300 x 10) D20 PG (002) (100 x 300 x 2) IN4 Cu (311) (120 x 160 x 10) INI? PG (002) (60 x 120 x 4) Reorientation

In prépara ion: D20 Gc (511) (120 x 300 x 8) IN8 Ge (111) (160 x 160 x 10) IN2G Cu (220) (120 x 150 x 10)

The vertically focussing Cu monochromator in transmission geometry for D20 is the first of its kind in history. Wedge shaped pieces were soldered together to approximate a fixed vertical curvature. The Be prototype monochromator for D9B was also a new development. Undeformed crystal plates with a mosaic spread of less than 0.1° were mounted on a support permitting variable focussing in the horizontal plane. The test results ob­ tained at D9B showed the expected gain in flux by a factor two and a simultaneous gain in resolution. These crystals will be further processed in order to increase the mosaic spread for their use in the framework of the Beryllium Project. The Be single crystal production at the Max-Planck-lnstitut Stuttgart suffered from failures in the existing facilities for purification and growth and from delayed commissioning of the new facilities which will take place only by the end of this year. The production rate was therefore very low and the time schedule established to finalize the planned six mono­ chromators cannot be met. This means that the project has to be extended for two to three years more and it is hoped that the participants will agree to further support this unique cooperation. The recent participation of the Technische Hochschule Aachen as a seventh partner permitted the solu­ tion of staff problems and the choice of a third purification facility which will speed up the production even though addi­ tional crystals will have to be prepared. The results of plastic deformation under tensile stress showed no significant dif­ ference compared to the compression experiments. In- homogeneities in the mosaic spread distribution could not be avoided and problems occurred al the interfaces between the crystals and the pieces fitting the deformation facility. Very detailed characterisations of deformed and undeformed crystals with Synchrotron radiation at the National Light Source at Brookhaven revealed that spark machining may be very efficient to produce a uniform and quite adequate defect structure and studies are under way to use this alternative possibility for preparing crystals with well defined mosaic spreads. On the other hand, it turned out that Be would be a very efficient X-ray monochromator.

106 REACTOR OPERATION DEPARTMENT INTRODUCTION Le Réacteur a repris son rythme habituel de fonctionnement à l'issue des travaux de rénovation qui ont été exécutés durant le grand arrêt de 1985. Ces rénovations ont donné toute satis­ faction et la disponibilité de fonctionnement des installations en 1986 a été remarquable. Six cycles complets ont été effectués en 1986. En dehors des arrêts normaux "inter-cycle'' deux arrêts plus importants, l'un de trois semaines en juin, l'autre de cinq semaines en août et septembre, ont permis de procéder aux travaux d'amélioration de l'étanchéité en partie haute de l'enceinte béton du bâtiment REACTEUR et aux travaux annuels de maintenance.

INTRODUCTION

The reactor resumed its normai operating rhythm following the renewal work carried out during the long shut-down in 1985. The renewal work proved entirely satisfactory and the reliability of operation in 1986 was extremely good. There were six complete cycles in 1986. In addition to the normal short shut-downs between cycles, two longer shutdowns, for three weeks in June and five weeks in August/September, allowed time for work on improving the leak-proofing of the upper part of the concrete shell of the reactor building and for annual maintenance work.

EMLEITUNG

Der Reaktor hat seinen iibiichen Betriebsrhythmus wieder auf- genommen, nachdem die Erneuerungsarbeiten wâhrend des langen Reaktorhalts 1985 beendet waren. Diese Erneuerung­ sarbeiten verliefen zur vollsten Zufriedenheit und die Beiriebs- verfùgbarkeit des Reaktors war 1986 bemerkenswert. Im Jahre 1986 wurden sechs komplette Zyklen erreicht. Neben den uormalen Reaktorabschal'nausen zwischen den Zy­ klen, waren zwei langere Reaktorabschaltpausen (3 Wochen im Juni und 5 Wochen im August/September) vorgesehen. Da- durch konnten ausser den jâhrlichen Wartungsarbeiten, Ar- beiten in Angriff genommen werden, die zum Ziel hatten, die Dichtigkeit im oberen Teil des Betongebàudes zu verbessern. actual operating time in relation to time scheduled 100 % REACTOR No. of fuel elements used 6 No. of fuel elements despatched for reprocessing 2 OPERATION 1986 No. of new fuel elements received 5 Cycle 3/85 No. of unscheduled ?hut-downs 7 This cycle was interrupted for work on the control rod and Including : for the Christmas holiday period, and then continued from brief shut-downs 6 2 January to 12 February with no further incident. shut-downs with Xenon poisoning 1

Cycle 1/86 Operation from 25 February to 10 April. WORK OF The scheduled dates were respected and the cycle was com­ pleted without any notable incident. THE VARIOUS Cycle 2/86 GROUPS Operation from 22 April to 5 June. In addition to the usual maintenance work on all the installa­ tions, certain exceptional operations should be mentioned, in The scheduled dates were respected. During the first day of particular: the cycle the repeated release of safety rods caused brief reac­ tor shut-downs followed each time by an immediate re-start. The remainder of the cycle was completed without further in­ cident. A) IMPROVEMENT OF THE AIRTKHTNESS OF Cycle 3/86 THE CONCRETE SHELL OF Operation from 24 June to 9 August. No incident until 4 August when a mains power failure caus­ THE REACTOR BISILMNG ed a shut-down prolonged by a Xenon poison-out. It was necessary to operate the reactor at reduced power for the last Regular checks on leaks from the shell of the reactor building three days as one of the cold source turbines was not available. had indicated a deterioration of its airtightness, confirmed by The original date for the end of the cycle was postponed by hair-line cracks in the upper part of the concrete wall. two days to make good the shut-down due to the power failure. To remedy this three layers of polyurethane resin were applied to the upper part of the cylindrical wall and the base of the reactor dome. Cycle 4/86 This coating was applied during the two scheduled reactor shut­ downs, one in June and the other in August/September (see Operation from 16 September to 30 October. fig. 84) The scheduled dates were respected and the cycle was com­ pleted without any notable incident, apart from two reduc­ tions in power for work on the cold source compressors.

Cycle 5/86 Operation from 10 November to 24 December. The scheduled dates were respected, and the cycle was com­ pleted without any notable incident.

Data for 1986 No. of days originally scheduled 260 ?.ctual No. of days of operation 259.9 No. cf equivalent days of full power 250 Figure 84; The section through the reactor hall and (he insert on the left of the drawing actual operating time as proportion of year 71 % show the work on the concrete shell carried out to reestablish its tightness. 109 The installation of the equipment in room B42 of the reactor B) AC/DC CONVERTERS FOR basement has started. THE 48 V DC SYSTEM The final design of the control system is in progress and in­ vitations to tender for this contract are being issued at the end The technology of the existing AC/DC converter dated from of 1986. a period before the construction of the High Flux Reactor, and its maintenance in a good operating state was becoming Finally the helium compressor to supplement the two existing difficult. Two new assemblies using new technology were in­ compressors has been ordered and should be operational when stalled. the horizontal cold source starts up (see fig. 85).

C) PROGRESS OF CONSTRUCTION OTHER POINTS OF NOTE Major studies on the safety of the reactor were carried out in WORK ON THE HORIZONTAL 1986, particularly as regards the behaviour of the reactor building under various influences (including earthquake). COLD SOURCE (BEAM TUBE H5) The French safety authorities also requested an overall re- The main sub-assemblies constituting the in-pile part (beam evaluation of the safety of the nuclear installation, to be car­ tube thimble, cell, metal guides, plug) have not yet been ried out in 1986. This resulted in considerable work on the delivered. preparation and up-dating of documents such as: The problems encountered in the construction of these items - the Internal Emergency Plan, are due essentially to the fact that they are prototypes ; - the Safety Report, including a new chapter on risks associated delive: ;es should be spread over the coming months. with the environment to be taken into account and the The other items (main beam shutter, condenser, cold lines, operating experience since operation of the High Flux reactor thermosiphon, etc.) are nearing completion and do not raise began, any particular problems ; some have already been delivered - the General Operating Rules, (deuterium reservoir and cold lines). - the Quality Organisation Manual. The pump set and its containment, which are to be built at This led to an overall examination of the safety oi uie HFR the ILL, are making good progress. by the Permanent Expert Group on nuclear reactors, which The detailed definition for the primary 'casemate', to be in­ met at ILL on 5 June 1986. stalled during the shut-down programmed for February 1987, As a result of the conclusions of this study, authorisation to has been completed. continue operating the reactor was given.

Figure 85: The geometry of the Second Cold Source to be installed in 1987.

110 COMPUTING DEPARTMENT INTRODUCTION EINLEITUNG Seen from inside the Department the year was dominated by Intern geschen wurde das Jahr 1986 in der Informatikabtei- the problems of accommodating the reduction in staff com­ lung von der Frage beherrscht, wie dem Stellenabbau ange- plement to the steadily increasing workload. The latter arises sichts der stândig steigenden Arbeitslast am besten Rechnung principally from the automation of secretarial and ad­ getragen werden kann. Sie ist vor allem auf die Automatisie- ministrative functions and the growing popularity of networks, rung von Sekretariatsarbeiten und Arbeiten verwaltungstech- both within the Institut and externally for remote access to nischer Art sowie auf die steigende Beliebtheit von computers, file transfer and electronic mail. Verbundnetzen sowohl innerhalb des Instituts als auch aus- serhalb fur Computerfernanschlùsse, Dokumemenùbertragun- As far as possible the users of the Department's services have gen und elektronische Post zurûckzufiihren. been shielded from these problems. They have seen the in­ troduction of the VAX 8600 central computer (complemen­ Die Nutzer dieser Dienstleistungen wurden soweit wie môg- ting the DEC-10), which was rapidly converted to a model 8650 lich von diesen Problemen abgeschirmt. Sie haben die Einfuh- to handle the ESRF work-load. Two new standard computer rung des VAX 8600-Zentralrechners (ergànzend zum DEC 10) lines have been established. The MicroVAX II is expected to erlebt, der rasch in ein 8650-Modell umgewandelt wurde, um gradually replace the older PDP-11's on some instruments, and mit der ESRF-Arbeitslast fertig zu werden. Es wurden zwei will p.iso serve in the office automation area. One such will neue Computer-Standard-Linien eingerichtet. Es ist damit zu run the finance package which was installed for the Ad­ rechnen, dass der MicroVAX II nach und nach die àlteren ministration Department towards the end of the year. For PDP-11 gewisscr Instrumente ersetzen und im Bereich der Bù- simpler needs the Apple Macintosh personal computer is be­ roautomatisierung eingesetzt werden wird. Einer der ing widely used. PDP-11-Rechner wird das Programm-Paket fur das Finanzwe- sen der Verwaltungsabteilung betreiben, das gegen Ende des Links to the outside world arc in great demand, being based Jahres eingefiihrt wurde. Fur einfachere Zwecke wird haufig on the Transpac X.25 network for remote access, and EARN der Apple Macintosh Personal Computer benutzt. (European Academic and Research Network) for file transfer. Verbindungen mit der Aussenwelt mit Hilfe des Transpac Services are provided to the ESRF project team in the areas X.25-Verbundnetzes fur Fernanschliisse und des EARN (Eu­ of scientific computing, word processing and the telephone. ropean Academic and Research Network = Europaisches Akademisches und Wissenschaftliches Verbundnetz) fur Dokumenten-Ubertragung haben eine starke Nachfrage ver- zeichnet. Die ESRF-Projektgruppe wird in den Bereichen wissenschaft­ liches Rechnen, Textverarbeitung und Teiefon von der ILL- INTRODUCTION Informatikabteilung unterstutzt. Vu de l'intérieur du Département, l'année 1986 a été caracté­ risée par le problème de concilier la réduction des effectifs et la croissance permanente de la charge de travail. Cette der­ nière résulte principalement de l'automatisation des fonctions de secrétariat et d'administration et de la popularité croissante des réseaux pour, aussi bien à l'intérieur qu'à l'extérieur de l'ILL, l'accès à distance aux ordinateurs, la transmission de fichiers et le courrier électronique. Autant que possible les utilisateurs des. prestations du Dépar­ tement ont été à l'abri de ces problèmes. Ils ont vu la mise en place du VAX 8600 comme ordinateur central en complé­ ment du DEC-10 qui a ensuite été transformé en modèle 8650 pour les besoins de l'ESRF. Deux nouvelles lignes standard d'ordinateur ont été établies. Le MicroVAX II devrait rem­ placer de façon progressive les PDP-11 les plus anciens sur cer­ tains instruments et servira également dans le domaine de la bureautique. Un tel ordinateur fera tourner le progiciel finan­ cier mis en place pour le Département Administration vers la fin de l'année. Le calculateur Apple Macintosh a été intro­ duit pour satisfaire les petits travaux personnels des utilisa­ teurs et commence à être largement utilisé. Les communications vers l'extérieur sont très demandées ; elles s'effectuent au travers du réseau Transpac X25 pour les accès à distance et au travers du réseau EARN (European Acade­ mic and Research network) pour la transmission des fichiers. Des prestations de services sont fournies à l'équipe projet ESRF dans les domaines du calcul scientifique, du traitement de texte et du téléphone.

112 DU, D17) Groups, tailoring operating systems, and design­ AUTOMATION ing and maintaining libraries and basic acquisition software. A considerable fraction of current activities is spent on up­ dating hardware, reducing the efforts required to recover from AND DATA SERVICE computer and electronic breakdowns on the elderly systems which are being phased out. (SAD) In the THREE-AXIS group the SOLAR 16/40 computers on INI and IN3 were replaced by PDP 11/73 systems using soft­ ware similar to that developed for IN8 and IN20. Only IN12 As part of the on-going efforts to rationalise and improve ef­" is still controlled by a SOLAR computer ; though some ficiency, the telephone system was transferred to SAD at the development was still being performed on the latter, its replace- beginning of the year, being merged with the Group responsi­" ment has been proposed for 1987. The changeover of the com­ ble for cabling, terminals and hardware aspects of computer puters, and subsequent common improvements have been networks, to form a new Telecommunications Group. performed with a significant contribution from the scientists, The highest priority continues to be given to standardisationn enabling the operations to be performed with little impact on of software and hardware. This is a matter needing continuous the scheduled programme. Although not fully integrated into revision, because of the rate of appearance of new productss the DECnet system, file-transfer facilities have been developed and the disappearance of existing products from thee for the TSX system which are fully adequate for most catalogues. purposes. For the VERCORS group the performance of some of the older PDP-11 computers has been enhanced with implemen­ SOFTWARE A tation of fast large disks. IN4 and INS have both benefitted and the control programs offer enhanced features including (CRYSTALLOCRAPHK sample temperature control. The complex interrelations of the chopper parameters for IN5 have been mastered, and INSTRUMENTS) simplified for automatic wavelength changes. For the Backscattering instruments sample temperature scans (A. Barthélémy) are now possible on both instruments. On IN13 the use of li­ quid nitrogen to cool the monochromator to extend the scan This Group is responsible for software for the instruments' range required modifications to both control and analysis pro- D1A, DIB, D2B, D3, D4, D5, D9, D10, D15, D16, D19, D20,• grams since the extensions showed up noticeable non-linear DB21, LIS, LI8, SIS. Instrument systems are based on two| effects. principal measuring programs, LSD for single detectors and MAD for multi-detectors. The near completion of the INI 1 multidetector array and the impending flood of data provided impetus to update the com- Work continues on the new instrument D20. A major project1 puter system using a configuration and system similar to that is the first installation of a MicroVAX II on an instrument,1 on the three-axis spectrometers. namely D9. This could well establish a new line of instrument systems. S18 has been equipped with a PDP 11/73 in orderr The small angle scattering instrument D17 was equipped with that it can better follow the Group's standards. an identical computer to that used on DM. There has been continued activity on developing the control systems, which In addition to work directly related to instruments, the Group1 now have reached a high level of functionality. There are very supplies general support for DEC-licenced software (VMS,• few differences now between the two instruments since all pro- RSX11, etc) and for network protocols. The prototype' grams are common, with extensive parametrisation of the dif- Ethernet network is now in full operation, linking the VAX• fercr.ces in easily accessible data file;. and PDP-11 on D19, a SAD development VAX, and the Cen­ tral VAX 8650. On all the multi-channel instruments there is now some con­ tinuous surveillance of count rates and monitor flux during A MicroVAX II has been acquired jointly with the Electronics' acquisition, giving greater confidence in the validity of the data Service, for studies and development of the new electronics' from complex detector arrays. Some analysis programs bus standard, VME. developed on IN6 assisted the experiment on 3He where monitoring the low level signal was crucial. To counter the problems of the complex real-time activities using the VAX computer the Group has modified the handler and supervised programming for an interface to the BASIC SOFTWARE B language to simplify electronic tests. The greater capacity of this system has permitted extensive error logging to be im­ (OTHER NEUTRON plemented on Dll and D17 which has simplified problem SCATTERING INSTRUMENTS) tracing. In addition to the instrument control-related activities members (R. Ghosh) of the Group have undertaken support of projects within the Computing Department, varying from managing the introduc­ Software B supports the experimental activities of the in­ tion of MACINTOSH personal computers to graphics and fur­ struments in the Three-Axis (INI, INFB, IN3, IN8, IN 12, ther development of data treatment programs on the Central IN20) and Vercors (IN4, IN5, IN6, IN10, INI I, IN13, D7, Computers. 113 system is required to be functioning for the start of 1987. This SOFTWARE C has thus been a major activity for the Group in the second half of the year, working in close collaboration with the (NUCLEAR PHYSKS Finance Service and the suppliers DEAL. At the time of writing AND SPECIAL INSTRUMENTS) the system was coming into use. The large number of terminals now installed in offices of the (Ph. Ledebt) Administration Department has necessitated a re-examination of the way they are connected to the computers, which are nor­ In the Nuclear Physics area the Group supports the instruments mally some distance away. A solution based on Ethernet, with PN2(BILL), PN3(GAMS 1,2,3,4), PN4, PN6(OSTIS). terminals grouped around servers is being implemented. For Although the number of instruments may seem small, each certain requirements autonomous personal computers offer a is different and needs its own control system. low cost solution. The Group has implemented some facilities A PDP 11/73 has been installed on GAMS 2/3, to complete using the packages JAZZ and EXCEL on an Apple the modernisation of the BILL/GAMS spectrometers. All Macintosh. these systems are linked to a local data treatment centre, with The Translation Service (Administration Department) is in­ good graph-plotting facilities. Also available to nuclear vestigating automated and computer-aided translations, and physicists via the computer network is a VAX 11 /7S0 oriented has been trying out the package SYSTRAN which is available towards their needs. This reduces the load on the Central Com­ at KFK, Karlsruhe, using the EARN network to transfer the puters. texts. The Group has worked on implementing this. The principal special instruments given support are S3, S20, Some of the facilities supported by the Group are being used S21, S34, S53, SN7, NESSIE, TGV. The old question of the by the ESRF, notably the salaries package PACHA and the level of support to be provided to these remains unresolved. text-handling service OS11, and this has involved a certain It is evident that this area includes some of the most exci'ing amount of extra work. experiments being undertaken at ILL, but the Department's budget contains no provision for them. Fortunately most of the external teams building these instruments are now prepared to adopt ILL standards so that basic maintenance support can COMPUTER MAINTENANCE be provided at little cost. (J.J. Tschofen) The S instruments have been able to fund their own local data The two members of this Group can only hope to carry out inspection facility, offering the possibility of transferring data a fraction of the maintenance themselves. In addition, the from ILL either by magnetic tape or via the EARN network. miniaturisation of modern electronics and the reluctance of The Group has also been responsible for installing a Macin­ manufacturers to supply logic diagrams, makes it impractical tosh system on the instrument D13 A/B/C, providing a con­ in many cases to carry out repairs in-house. nection to the Macamac control systtm and the computer Most equipment is maintained under contract. Manufacturers network for data transfer. and other organisations now offer a range of services from resident technicians, through on-call intervention, to exchange of faulty components returned to them. The most cost-effective MANAGEMENT INFORMATION solution for each type of equipment is kept under constant review. SYSTEMS AND OFFICE The Group has computerised its records of the constituent components of each of the 73 computer systems it has under AUTOMATION its responsibility. (M. Grevaz) This Group has seen a continuing growth in demand for its TELECOMMUNICATIONS services, which has been difficult to respond to fully, giving the overall staffing situation in the Department. (R. Pouget) The centralised word processing facility OS 11 has been extend­ The creation of this Group is a recognition of the coming ed by the addition of 20 workstations and a Micro VAX II in together of computing and communications technologies. At order to reduce the load on the VAX 11/750 which is the prin­ the present time this is most apparent in our links to the ex­ cipal machine supporting this service. It is intended to offer terior, when access to the various data networks is handled this facility to users of the VAX 8650 in the near future. by P.T.T. public or leased lines. Internally the telephone Whilst OS 11 can handle scientific and mathematical texts it system is still distinct from the computer network. is a general putpose secretarial system. Some more recent pro­ The Group's activities cover cabling, mainly in support of the ducts are bettei suited to those secretaries whose work is limited rapidly growing requests for terminals in offices (for scien­ to typing scientific papers. A second autonomous work-station tists, as well as in the office automation area), and the to run the MATHOR package has been acquired, as has a maintenance of terminals and local printers, which for con­ licence for the TEX type-setting package, and the new DEC venience are handled by this Group. product WPS +. Considerable assistance has been given to the ESRF, whose A decision was taken early in the year to modernise the pur­ telephone service is currently provided by a sub-exchange, chasing and finance area, acquiring a standard commercially- dependent on that of ILL, and who use ILL computers ac­ available package to run on an in-house computer. The new cessed from terminals in their own building.

114 CENTRAL SYSTEM AND COMMUNICATIONS COMPUTING (O. Tillier) With the arrival of the «X, devHopn:™;;: c. the DEC !0 SERVICE were stopped, and the effort was mainly concentrated on the The main feature of the year 1986 was the installation and com­ commissioning of the VAX and the creation of an environ­ missioning of a VAX 8600. This machine was purchased to ment to enable the scientists to have rapid access to the facilities resolve the saturation problems on the DEC-10; the VAX was of this machine. selected to augment the resources of the Computing Centre because of the decision by DEC to stop producing the In the system field the work consisted of : DEC-10/DEC-20 series. - organising the work space of users on the VAX A simplified configui Uion of this VAX was installed in March: - setting up a number of procedures for safeguards and 12 Megabytes memory, 3 RA81 disks and 2 1600/6250 transfers of files between the 2 machines, particularly for the magnetic tapes. We linked it with the DEC-10 so as to incor­ use of the DEC-10 output peripherals porate it in joint operation, in particular to share the output - establishing integration tools for conversion of files between peripherals. The two systems have operated on a 24 hour basis the 2 types of machines and for use on the VAX of the DEC-10 partly under operator control (4 persons), and the remainder archives. of the time in self-service operation. The operator cover was For work on experiment data on the VAX : provided on a partial shift basis with the usual hours of 5.30 - transfer of ASCII data from the instruments was operational to 21.30 on Mondays and 6.15 to 20.45 from Tuesdays to from September ; this covered INI, IN11, IN20, IN3,1N8, D3 Fridays. - a study is in progress with a view to setting up a data base for the other instruments to provide information in binary. This study also takes account of the possible integration in this OPERATION OF THE DEC-10 data base of the ASCII files previously referred to. As far as external communications are concerned, we have pur­ AND VAX 8600 chased and installed the software permitting us to connect to (C. Rey) - the Transpac network - the JANET network in the United Kingdom via the Transpac The DEC-10 operated at a very high degree of reliability, i.e. network with a rate of availability close to 100%. The load on this com­ - the EARN network linking university and research centres puter was very high during the first six months, and particularly in Europe and the USA (BITNET) during the second half of the year, when the saturation level was equivalent to that encountered in 1984 before the long A considerable part of the work also consisted of assisting the reactor shutdown. From August the activity started to diminish users in the utilisation of these new facilities and more generally with the transfer of certain applications to the VAX. At pre­ to help them to share their applications between the 2 sent the acquisition of experiment data from the instrument machines. computers is still carried out on the DEC-10; from the begin­ ning of 1987 this data base should also be available on the VAX. The VAX 8600 was installed at the end of March and there GRAPHICS were some operating problems during the first six-month period ; these resulted in often random breakdowns which (Y. Lefebvre) sometimes necessitated relatively long periods of intervention work. Three graphic libraries have been made available to users : - GKS : an international standard The scientists very quickly learned to take advantage of this - NAG graphics : package of subroutines for the scientific area machine by running on it new software written for the VAX using the GKS level in other research centres and transferring a number of applica­ - GREG : an interactive program of data display with the cor­ tions from the DEC-10, in particular those requiring a great responding library. deal of computing power. The arrival on the ILL site of the first ESRF team led to a As regards the colour raster terminal, software is also available contract for the use of our VAX 8600 for a first period of eight in addition to the basic library of this machine: months. This team estimated its computing requirements for - to display experiment data in 3 dimensions 1987 and the beginning of 1988 at approximately half of the - to display coloured spheres (possibility of stereo) showing power of a VAX 8600. The solution adopted to provide the for example protein arrangements: SCHAKAL program capacity necessary to meet this requirement was to increase - to represent sections of molecules in colour for biology ap­ the power of the ILL VAX 8600 system. The ESRF accordingly plications. financed the extension of the VAX 8600 to a VAX 8650 with In addition a stereo view system has been installed on the Evans an increase in power of the order of 45%. This operation was & Sutherland graphics system, and we have purchased a small implemented at the end of November. The statistics on the laser printer with graphics kit for output of Tektronix type VAX 8600 for the last three months show that the average tracings under the GKS system. The 8 colour Tektronix trac­ utilisation was 270 hours per month. ing table is also available under the GKS environment.

115 MATHEMATICS TRAMMG, (C. de Polignac) DOCUMENTATION All the mathematical libraries which we had on the DEC-10 The arrival of the VAX 8600 necessitated a training programme have been converted to the VAX : EISPAC, MATLAB, for the computing staff and scientists. Information sessions SLATEC and the documentation SLADOC and SLASDOC, have been organised at ILL by DEC or by visitors. Several SSP, single and double precision NAG with the corresponding members of the service have also attended VMS courses by documentation. DEC. For the conversion of scientific applications we have also As far as information is concerned, a particular effort was adapted to the VAX a number of sub-routines generally used made this year to update documentation (DEC-10 users guide) at ILL for the treatment of arithmetical errors, sorting and and to disseminate notes on the new functions available as non-linear least squares. regards networks and graphics. ADMINISTRATION DEPARTMENT la réalisation de l'expérience nn (avec les groupes INFN de EINLEITUNG Padoue et Pavie ainsi que l'Université de Heidelberg qui finan­ Es ist nicht leicht, aus der Vielzahl der Ereignisse diejenigen cent en commun environ 90% de l'expérience, soit environ 24 herauszugreifen, die dem Jahr 1986 in der Verwaltung ihren Millions F), la construction de IN 15 avec le HMI et le KFA Stempel aufgedrückt haben. Jedoch an folgende Punkte soll qui se sont déclarés prêts à participer à presque 50% des frais. hier kurz erinnert werden: Par ailleurs, le contrat cadre concernant les prestations de ser­ -Drei Direktoren (Haensel bis Mai, Enderby bis Juli, Gläser vices fournies par le CENG à l'ILL a été renégocié pour une seit August 1986) haben die Planungen im Finanz- und Per­ nouvelle période de 3 ans (1987-1989). sonalbereich für die Zeit nach Abschluss des Modernisierung- -Les domaines Sécurité, Radioprotection et Medicine du Tra­ sprogrammes vorangetrieben. vail ont été ré-organisés et placés sous la responsabilité d'un nouveau collaborateur de l'ILL, M. Bureau du Colombier, -Die Projektgruppe ESRF begann in den Räumen des ILL ih­ ayant rang de Chef de Département. M. Jacquemain a pris re Arbeit. Bei ihrem Aufbau leistete das ILL nach besten Kräf­ sa retraite, mais reste à la disposition de la Direction à titre ten Verwaltungshilfe im finanziellen und personellen Bereich de conseiller bénévole. (gegen Kosten-Erstattung). 5 ILL-Mitarbeiter wurden zur ESRF abgeordnet. Zwei Vereinbarungen mit der ESRF regeln -Conformément à l'obligation faite à l'ILL d'absorber les 17,5 Einzelheiten des "Mandats" des ILL und der Berechnung der cases du Programme de Modernisation d'ici la fin de 1987, Kosten für "Infrastruktur-Dienste". la suppression de postes s'est poursuivie en 1986 (12 au total -Weitere wichtige Verträge betrafen die Wissenschaftliche Mit­ à la fin de 1986). gliedschaft Spaniens am ILL ab 1987 (mit spanischer Beteili­ -Le Comité de Direction s'est réuni au mois de mai 1986 à gung an den Ausgaben des ILL- Budgets in Höhe von 1,5% Cadarache et en novembre à Karlsruhe où il a fixé pour le Bud­ jährlich), die Durchführung des nn-Experiments (mit den get 1987 de l'ILL un montant brut de dépenses de 274,6 Mil­ INFN-Sektionen Padua und Pavia sowie mit der Universität lions F (valeur monétaire 1987, H,T.) - ce qui assure à l'Institut Heidelberg, die zusammen rund 90% des Experiments finan­ un fonctionnement complet de 6 cycles du Réacteur en 1987. zieren, nämlich rund 24 MF) und die geplante Konstruktion von IN 15 gemeinsam mit dem HMI und der KFA, die sich an den Kosten mit fast 50% beteiligen wollen. Ferner wurde INTRODUCTION der Rahmen-Vertrag betreffend die Dienstleistungen des It is not easy to select from the many events in 1986 those which CENG für das ILL für eine neue 3-jährige Laufzeit (1987-1989) left their impression in the Administration, but the following verhandelt. points should be briefly mentioned here: -Der Bereich Sicherheit, Strahlenschutz und Werksarzt wur­ -Three Directors (Haensel until May, Enderby until July, de personell und organisatorisch verändert und unter einem Glaeser since August 1986) have pressed forward with the plan­ neuen Mitarbeiter (M. Bureau du Colombier) im Range eines ning in the financial und personnel areas for the period after Abteilungsleiters zusammengefasst. M. Jacquemain ging in den conclusion of the Modernisation Programme. Ruhestand, steht der Direktion des ILL aber noch als (unbe­ -The ESRF Project Group began its work on ILL premises. zahlter) Berater zur Verfügung. The ILL made every effort to provide administrative assistance -Entsprechend der dem ILL auferlegten Verpflichtungen zum in the finance and personnel areas (against reimbursement of Abbau der 17,5 Stellen des Modernisierungsprogramms bis En­ costs) as it grew. Five ILL staff were detached to the ESRF. de 1987 wurden 1986 weitere Stellen abgebaut (insgesamt 12 Two agreements with the ESRF covered details of the ILL Stellen bis Ende 1986). "mandate" and the charging of costs for "infrastructure -Der Lenkungsausschuss tagte im Mai 1986 in Cadarache und services". im November in Karlsruhe, wo er für das ILL-Budget 1987 -Other important contracts concerned the Spanish scientific Brutto-Ausgaben von 274,6 MF (Geldwert 1987, ohne TVA) membership of ILL fiom 1987 (with a Spanish contribution festlegte, die 1987 einen vollen Betrieb des Instituts mit 6 to the_ILL budget of 1.5 % per year), the implementation of Reaktor-Zyklen ermöglichen. the nn experiment (with the INFN sections Padua and Pavia and with the University of Heidelberg, which together finance approximately 90% of the cost of the experiment, or approx­ imately 24 MF) and the planned construction of IN 15 jointly INTRODUCTION with HMI and KFA, who intend to make a contribution of Il n'est pas aisé de choisir, parmi la multitude des faits, ceux almost 50 % to the costs. In addition the outline contract qui ont plus particulièrement marqué l'année 1986 dans le covering CENG services to ILL was renegotiated for a fur­ domaine administratif. Les quelques points suivants méritent ther 3 year period (1987-89). toutefois d'etre rappelés : -There was an organisational change in the area of safety, -Trois directeurs (M. Haensel jusqu'en mai, M. Enderby health physics and the works doctor, these services being com­ jusqu'en juillet, M. Gläser depuis le mois d'août) ont fait pro­ bined under a new staff member (Mr. Bureau du Colombier) gresser les plannings des domaines financiers et du personnel with the rank of a department head. Mr. Jacquemain retired, pour la période consécutive au Programme de Modernisation. but is still available to the ILL Management as (unpaid) con­ -Le Groupe Projet de l'ESRF a commencé son travail dans sultant. les locaux de l'ILL. L'ILL lui a, dans toute la mesure du pos­ -In accordance with the ILL'S obligation to reduce the staff sible, apporté son assistance à ses débuts dans les domaines complement by the 17.5 posts from the Modernisation Pro­ financiers et du personnel (contre paiement). Cinq agents ILL gramme by the end of 1987, further posts were eliminated in ont été détachés à l'ESRF. Deux accords avec l'ESRF règlent 1986 (a total of 12 posts by the end of 1986). les détails du "mandat" confié par l'ESRF à l'ILL et du cal­ -The Steering Committee met in May 1986 in Cadarache and cul des coûts pour les "services d'infrastructure". in November in Karlsruhe, where it adopted the ILL budget -D'autres contrats importants ont concerné la participation for 1987 with gross expenditure of 274.6 MF (1987 prices, ex­ scientifique de l'Espagne à l'ILL à partir de 1987 (avec une cluding VAT), permitting full operation of the Institut in 1987 participation au Budget de dépenses de l'ILL de 1,5% par an), with 6 reactor cycles.

118 The year 1986 was characterized by the resumption of the nor­ mal operating rhythm of 6 reactor cycles per year. As a result the operation expenditure increased to 228.6 MF (1985: 204 MF). IMPLEMENTATION OF THE 1986 The investments at 33.9 MF remained at approximately the BUDGET (NORMAL BUDGET) same level as in 1985 (33.3 MF). The fact that there were no general salary increases in 1986 The following budget was authorised for 1986 (excluding resulted in savings on the staff costs as budgeted. taxes): The fuel element budget was affected by the fall in the Dollar Expenditure 262.5 MF exchange rate. Income 8.3 MF The total savings (4.6 MF) will be used in the financing of the Associates' Grants 254.2 MF 1987 budget.

Comparison between Normal Budget 1985 and 1986 (excluding VAT)

1985 1986

(1000F) »/o of total (1 000 F) % of total

a) Operation

Consumable materials 21 809 9.2 28 523 10.9 Fuel elements IS 925 7.1 21 477 8.2 Staff costs 137 785 58.1 150 862 57.5 Other expenditures on personnel 1 323 0.5 Taxes 1 260 0.5 1 303 0.5 Long term service & supply contracts 8 912 3.8 7 701 2.9 Other work, supplies & services 11 091 4.7 9 535 3.6 Transport, removal & travel expenses 1 810 0.8 1 680 0.6 Miscellaneous administration costs 4 399 1.8 6 216 2.4

Total operation 203 991 86.0 228 620 87.1

b) Investments

Buildings 976 0.4 1 310 0.5 Equipment 8 891 3.7 6 397 2.4 Experimental instruments 12 713 5.4 15 272 5.8 Other investments 10 675 4.5 10 934 4.2

Total investments 33 255 14.0 33 913 12.9

Total expenditure 237 246 100.0 262 533 100.0

c) Income

ILL'S own income 7 795 3.3 8 308 3.2 Grants from Associates 229 451 96.7 254 225 96.8

Total income 237 246 100.0 262 533 100.0

119 Modernisation Programme 1979-1986 - IN10C backscattering spectrometer with an increase in neutron flux by a factor 6-8 in comparison with the existing The total expenditure for the Modernisation Programme, IN10 which is now completed with the exception of Horizontal Cold - D22 small angle scattering instrument Source was: These instruments necessitate ILL investment funds of approx­ imately 25 MF in 1986 to 1989; contributions from other research organisations are also needed. Project Cumulated expenditure 1979 - 1986 (1000 F)

1. Buildings PURCHASING 1.1. Computing and Biology Building 9 135 1.2. Guide Hall for Horizontal Cold Source 4 701 The major in-pile and external components of the Horizontal Cold Source were ordered in 1985 and 1986 and deliveries of these parts are expected in the first half of 1987. The new com­ pressor which will supply helium to the refrigerator for the 2. Computing cold sources has been ordered from AIR LIQUIDE. The 2.1. DEC 1091 Central Computer 11 611 Deuterium Reservoir has been delivered by SDMS. 2.2. "CAR1NE" replacement 5 501 Neutron guides will distribute the cold neutrons to the new instruments in the experimental hall; the contract for construc­ tion of the 110 metres of guides was awarded to CILAS ALCATEL. This company will also construct the guides in 3. Instruments 3.1. Instruments 30 702 the Shutter. The internal faces of the guides are to be coated 3.2. Sample Environment 9 618 with a thin layer of S8Ni which greatly increases the neutron reflectivity. Four new instruments are planned for use on the Horizontal Cold Source, and the most advanced project is the triple axis spectrometer IN 14. The monochromator shielding for this in­ 4. Replacement VCS, beam tubes, dam on strument is being built by ADP VOREPPE; most of the Drac 4.1. Vertical Cold Source 4 375 mechanics and electronics have been ordered. The graphite 4.2. Beam tubes 6 054 monochromators for IN 14 and IN IOC have now been ordered 4.3. Dam on the river Drac 454 from UNION CARBIDE. Reactor operation as usual involved large expenses. The In­ stitut purchased 5 fuel elements; and offers have been receiv­ ed from CERCA and NUKEM for the manufacture of 12 fuel elements to be delivered 1987 - 1989. 31 kg of uranium 235 5. Horizontal Cold Source 18 699 '' has been ordered from NUKEM. 6.1. Temporary scientific assistance 19 677 After fifteen years of operation the neutron flux monitoring equipment has to be replaced and the supplier of the original Total investments monitors, MERLIN GERIN, was awarded the contract. In the computing area, 4 Microvax computers have been pur­ 6.2. Operation costs chased from DIGITAL as well as several word-processors, ter­ minals and printers for office automation. The discount Total Budget Modernisation Programme 147 876 applicable to purchases from DIGITAL was extended to in­ clude our purchases from DEC DIRECT. Several Macintosh's I) Including money carried forward to 1987 for final payments were purchased and negotiations with APPLE resulted in a discount from the supplier. Some construction work was carried out in 1986: a new building for the storage of radioactive waste (ILL 21 B) and the extension of the Detritiation building to house the new compressor fo' the Cold Source (ILL 6). FORWARD LOOK Competitive tendering for project work continues to bring con­ siderable savings. Négociations with suppliers also resulted in The main items to be financed under investments in the in­ significant economies. Invitations to tender were organised for strument area are the neutron guide HS and four instruments the above mentioned contracts as well as many others and often on the horizontal cold source. The total length of the neutron there was a very large difference between the highest and lowest guides will be 113 m. bids. The ILL ensured that firms in the three member coun­ tries were invited to tender for all major purchases. The instruments planned for the horizontal cold source are: - IN 14 triple axis instrument The distribution of ILL'S "free" purchases ') in 1986 is - IN 15 neV resolution spin-echo spectrometer shown in the following table: 120 Suppliers from MF % France 19.7 70 UK 2.0 7 Germany 2.4 9 Other countries 4.0 14

') Free purchases meats that a free choice of suppliers In lite member countries and elsewhere waspossible, excluding therefore the fuel cycle, electricity and small purchases of less than FF 50 000.

In line with the ILL-ESRF collaboration agreement the ILL purchasing group has been handling orders for ESRF. About Figure 86: Diagram of the free purchases 80 Orders have been placed on behalf of the ESRF including a building from TRANSLOKO, a telephone exchange from THOMSON and the upgrade of the VAX 8600 to 8650 from DIGITAL.

STORES

The stores provide an important service to technicians, scien­ tists, engineers, secretaries and other staff at ILL. Approx­ imately 60 stores requisitions are made out each day so that the annual turnover of stocked items is about 2.5 MF. Careful stock control allows us to maintain the value of stock around 1.8 MF. All deliveries of purchased equipment and materials are receiv­ ed and checked by the storemen who at the same time execute the despatch of samples, returned equipment, etc. In 1986 the raw materials section was completely reorganis­ ed, in collaboration with EDEX, so that the stockage and pro­ vision of ferrous and non-ferrous metals, plastics, etc. has been greatly improved. As regards advancements, the ILL is aligned on the present rates at the CEA, which represents 1.5 % of the total payroll. As regards seniority, the figu e for 1986 is 0.35 %. STAFF The authorized staff complement was reduced from 506 posts GUEST SCIENTISTS in 1985 to 498 in 1986. The aim of an autorized staff comple­ ment of 491 should be achieved by the end of 1987. To this With the reactor restart at the end of 1985 after a shutdown must be added two posts for Spanish thesis students. of more than 9 months, the number of visits by guest scien­ tists to ILL has returned to a normal figure. Staff movements in 1986 were less than in 1985 (see table). The number of scientists visits' in 1986 was of the order of As regards breakdown by nationalities (see table) there were 1 950 including 570 from France, 540 from the United slight reductions in 1986 in comparison with the previous year Kingdom, Ci00 from Germany and 240 from other countries. in the proportion of of French staff (62.2 % instead of 64 %) and British (14 "to instead of 15.6 %), and an increase in the Germans (17.3 % instead of 15.3 <7o) and other nationalities (6.5 % instead of 5.1 %). ILL/ESRF COLLABORATION The average age of the staff increased to 40.3 years in 1986 Finally as regardscollaboratio n between ILL and ESRF in the (40.9 years for men and 39.7 years for women). personnel field, the ILL pcrr-crincl group p : ' support for The breakdown by sex was unchanged in 1986 (17 % women, the ESRF project group on offers of employment, contracts, 83 % men). pension schemes and assurance, and on the payment of travel costs and salaries, the latter with the aid of the "PACHA" software introduced in 1985, which continues to operate very CHANGES IN THE TOTAL satisfactorily. PAYROLL In 1986, in view of the directives adopted by the Government, no general salary increases were implemented at the CEA and this is also true for the ILL. These guidelines were on the basis of ar average price inflation of 2.4 %. As all the salary items (including advancements and the seniority allowance) are cur­ rently to be taken into account and as the anticipated increase in the total payroll is of the order of 2.4 % (carry forward effect 1985:0.4 %, advancements : 1.6 <7o; seniority : 0.4 %), there was no general increase in 1986. These developments resulted in a revision of the staff costs budget for 1986, which should provide for a saving of the order of 3 000 KF in comparison with the initial budget. Figure 87: Staff breakdown by t.ationalities in 1986

Staff Movements (on posts) in 1986

CATEGORIES POSITION RECRUITMENT DEPARTURES DIFFERENCE POSITION CHANGE % ON ON COL. 4 31/12/85 31/12/86 COMPARED WITH COL.2

(I) (2) (3) (4) (5) (6) (7)

SCIENTISTS 70 19 17 + 2 72 24.3 ENGINEERS 56 --- 56 - OTHER "CADRES" 11 2 2 - 11 18.2 THESIS STUDENTS 25 8 6 + 2 27 24 TECHNICIANS 171 - 3 - 3 168 1.8 OTHERS 161 2 3 - 1 160 1.9 SN^ËSHI

122 Secondary education WELFARE The local education authority and the City of Grenoble are making detailed preparations for the introduction in September AND GENERAL 1987 of "sections internationales" in the CES and Lycée Sten­ dhal in the centre of Grenoble. The ILL and ESRF note that this project is an advance on the present situation. However SERVICES the two institutes are continuing their long term efforts for the establishment of a "European School" operating within Honswr the framework of the "Conseil Supérieur des Ecoles Européen­ nes" in Brussels. We consider that a European school is more appropriate for the needs of non-French parents and children, Employers' >ntribution to housing particularly those resident in Grenoble for a limited period. Employers in France are required to make a contribution to housing (0.8 % of the total payroll) which may be in the form of loans for purchase of housing or for the reservation of flats in a development. Over the last fifteen years, from 1972 to 1986 there have been: TRAINING : 1) For purchase of property: 244 loans granted to ILL staff AN INVESTMENT for a total of 6.7 MF. representing an average loan of 27 500 Francs at 1% interest. Employers in France are required to contribute a proportion 2) For reservation of new housing: 14 flats in Grenoble and of the total payroll (1.1 <7o) to the annual training plan. suburbs 8 houses in a radius of 20 km around Grenoble S flats In 1986 there were approximately 13 000 hours of training, in the "Maison des Universités" at Grenoble for a total sub­ 80 % of which were for work-related courses and 20 % sidy of 1.0 MF, i.e. an average of 37 170 Francs. language courses (French, German, English). Specific courses are organised in collaboration with the heads of departments and groups, the potential trainees and the train­ New families ing subcommittee of the Works Committee. For example in 1986: In 1986 we assisted about 50 persons (new ILL and ESRF recruits and long term visitors) in looking for flats or houses • Structured programming of microprocessor systems followed to rent, by contacting house agents, telephoning in answer to by a Pascal language course. newspaper advertisements, etc. • Computing procedures and analysis of requirements. • Industrial automation. • Turning and Milling. • Temperature measurement technology. Students • Techniques for communications and meetings Students working at ILL during the summer vacation can be The course organisers unanimously report that ILL par­ accommodated in University hostels on the campus. This re­ ticipants are open to new ideas, motivated and keen to im­ cent solution seems to be well accepted by the persons con­ prove working methods by making the best use of new cerned. techniques.

Guest scientists We have at present 20 furnished flats, most of which are not REPROGRAPHY far from Grenoble station and buses for ILL. Eighty persons or families have used these flats during 1986. The ILL reprography workshop now has modern equipment, permitting it to deal with increasing demands and to limit costs. A 'Maison du Chercheur' project is under consideration jointly The many jobs completed in 1986, some of which were by CËNG, ILL, CNRS and ESRF. This would be within walk­ ing distance of ILL and ESRF and provide furnished rooms previously done outside the ILL, include: for scientists on short visits. • Research proposal forms: approximately 10 000 copies for the preparation two Scientific Councils per year. • The 'Yellow Book' (neutron research facilities at ILL): 400 copies, a total of almost 80 000 pages. • The Appendix to the Annual Report, 200 copies and 50 000 pages. INTERNATIONAL EDUCATION • The preparatory documents for the Steering Committee and its subcommittee almost 10 000 copies for each meeting Houille blanche primary school In 1986 a total of 93 documents were duplicated on the Offset This has 125 pupils, of whom half are French and half children machine, amounting to approximately 700 000 pages, bound of German and English mother tongue, and there is a very in 2 635 documents and 298 documents were reproduced on warm and dynamic atmosphere. A new headmaster, Mr. Don- the KODAK photocopier, representing more than 2 000 000 zel, was appointed in September 1986. pages and 3 300 documents.

123' MISCELLANEOUS "Zero point fluctuations in periodic arrays of Josephson junctions". LIST OF SEMINARS J. V. JOSE, Northeastern University and ILL. "What is a voltage measurement ?" M. BUTTIKER. IBM, Yorktown. COLLEGE 2 "Localisation et relaxation dc spin dans les systèmes désordonnés avec diffusion spin- orbit". Theory D.R. GREMPEL, ILL. "Normal He and heavy electrons : examples of a localized Fermi "Conduction non linéaire par ondes dc densité dc charge : le rôle des liquid". défauts de PODC". D. VOLLHARDT, Max Planck Institut fur Physik und Ashophysik, D. FEINBERG, CNRS Grenoble. Munich. "Quelques résultats exacts sur l'effet Hall quantique entier". "Dynamique Quantique en présence de dissipation ohmique". H. KUNZ, Ecole Polytechnique dc Lausanne. N. POTT1ER, Groupe de Physique des Solides de TENS. "1-dimensional systems with incommensurate potentials : fractal spec­ "Hierarchy in the low temperalure excitations of a one-dimensional in­ trum, mobility edges, and optical absorption". commensurate structure". K. CHAO, University of Linképing, (Sweden). S. AUBRY, CEN Saclay. "Sélection des formes de croissance en solidification. Beaucoup de ques­ tions - quelques éléments de réponse". COLLEGE 3 C. CAROL1, Groupe dc Physique des Solides dc PENS. "Transition commensurable-incommensurable dans les systèmes Fundamental and Nuclear Physics macroscopiques". P. COULLET, Laboratoire dc Physique Théorique, LInivcrsilé dc Nice. "Exotic hadrons". J.M. RICHARD, ILL. "Localisation faible en présence d'imeraclions fori es". M.T. BEAL-MONOD, Laboratoire dc Physique des Solides, Orsay. "New developments in proportional chambers and position sensitive detectors". "Crystallography of aperiodic crystals", A. OED. ILL. S. ALEXANDER, Université de Jérusalem. "Quark effects in nuclei". "Symmclry breaking and measurement theory". P. GUICHON, Université de Lyon, G. ZIMANY1, Central Research Institute, Budapest. "Neutrino mass measurements :ii the Institute of Nuclear Study in "Spin coherence effeets in disordered strongly interacting 2-d svslems". Tokyo". P.C.E. STAMP, CNRS Grenoble. H. KAWAKAMI, University ol"Tokyo. "New results for vortices in Fermi-super- fluids: the case of 'He-B". "GAMS 4 - past, present, future". N. SCHOPOHL, IFF der KFA. Julich. E.G. KESSLER, Jr., NBS Washington. "Spin chains with competing interactions". "Recent results on thermal neutron induced (n.p), (n.a) and (n.f) V. EMERY, Brookhaven National Laboratory and IBM Zurich. reactions". C. WAGEMANS, SCK/CEN Mol. "Phonons and electrons in incommensurate crystal phases". T. JANSSEN, Nijmegen Universitv (Netherlands). "Isomers in deformed nuclei". P.C. SOOD, Banaras Hindu University, India. "Mean field dynamics of nucleation". P. LITTLEWOOD, ATT Bell Laboratories and CNRS Grenoble. "Temperature effects during s-process iiueleo- synthesis'". F. KÂPPELER, KFK Karlsruhe. "Are mixed valence and heavy Fcrmion systems understood from the theoretical point of view ?" "Double beta-decay of s"Se". H. KEITER, University Dortmund. A. HAHN. University of California. Irvine. "Localized superconductors". "Progress toward the development of gamma-ray lasers". G. FORGACS, Central Research Institute, Budapest, and CEN Saclay. G.C. BALDWIN, Los Alamos National Laboratory. "Theory of structural transitions in close- packed metals". "Solar neutrinos". A. ZANGWILL, Georgia Institute of Technology, Atlanta. F. VON FEILITZSCH, TU Mûnchen. "Urbach tails, Lifshitz tails and disorder". H.R. GLYDE, University of Delaware, Newark. "PN8 - past, present, future". F. GÔNNENWEIN, University of Tubingen. "Scmiclassical approach to the mixed valence problem : I. Introduction : The generalized Anderson model and the slave boson. "The fine structure constant, tests of quantum electrodynamics and ab­ Concept of 'almost broken svmmetrv." solute gamma ray spectroscopy", P. COLEMAN, ILL. or "Scmielassical approach to the mixed valence problem : "How and whv to weigh a Photon ?". II. Fluctuation in the 1-impurily problem". G.I.. GREENE, NBS Washington. P. COLEMAN, ILL. "Emission of neutrons during competitive dc excitation of excited nuclei". "Semiclassical app""""i'"h to the mixed valence problem : P. GRANGE, CRN Strasbourg. III. Many sites, th*. ry so far". P. COLEMAN, ILL. "Experiments at the on-line isotope separators ISOLDE (CERN)". H.J. KLUGE. CERN, Geneva. "Mechanism of incommensurate compositional order in metallic allovs". B.L. GYORFFY, University of Bristol. "The fission process from saddle to scission : a phcnomenological perspective". "Propriétés Ihcrmodynamiqucs et magnétiques d'un supraconduteur à B. WILKINS, Argonne National laboratory. paires locales". J. RANN1NGER, CNRS Grenoble. "(n.Y) spectroscopy with the bent crystal spectrometer at ihe BR2 reac­ tor in Mol". "Propagation de la lumière dans les milieux désordonnés : fluctuations E. KAERTS, CEN/SCK Mol. et transition dc localisation". E. AKKERMANS. ILL. "New detector concepts". J. KEMMER. TU Mùnchcn. "Symmetry and spacial dependence of the order parameter of superHuid *Hc at the A-B phase boundary". "Radioactive .secondary beams ai existing accelerator facilities". N. SCHOPOHL, ILL. R.B. P1ERCEY, Space Astronomy Laboratory, Gainesville.

126 "Beta decay of neutron-rich transuranic nuclei". "Neutron scattering studies of martensilic phase transformations". R.W. HOFF, Lawrence Livermore National Laboratory. S.M. SHAPIRO, Brookhaven National Laboratory and L.L.B. Saclay. "The U(6/20) supersymmetry and its application to the A = 130 region". "Crvstal field sysiematics in dilute rare- earth metals". 1. JOLIE, 1NW Gent. B. FRICK, ILL. "Eight lectures on quarks, leptons, gauge interactions and chirality". "Dynamic behaviour in Rbi-*(NH..)*H;!P04 proton glasses". R.E. MARSHAK, Virginia State University. V.H. SCHMIDT, Montana State University. "High resolution neutron scattering instrumentation at the ILL". "Characterization of superconducting amorphous alloys with critical cur­ C. ZEYEN, ILL. rent measurements". V. FRANK, University of Mainz. "Review seminar on OSTIS (SN6)". K.L. KRATZ, University of Mainz F. MUNNICH, TU Braunschweig "Neutron studies on reentrant spin glasses : Nii-sMn> and amorphous H. WOLLN1K, University of Giessen U. STÔHLKER, ILL. Fci-vMn*." M. HENNION, L.L.B. Saclay. "Microscopic theory of interactive Boson models". P. RING, TU MUnchen. "Recent study on incommensurate phase transitions in JAERI". K. GESI, JAERI, Tokai (Japan). "Recent results from the neutron-EDM search". M. PENDLEBURY, University of Sussex. "Spin dynamics of actinide materials". G.H. LANDER, Euratom Karlsruhe. "New limits for spatial anisotropy using oplically-pump mercury". S. LAMOREAUX, University of Washington, Seattle. COLLEGE 5 COLLEGE 4 Crystal and Magnetic structures Structural and Magnetic excitations "Electron condensation in HgCdTe Alloy". G. NIMTZ, University of Cologne. "Inelastic X-ray scattering possibilities for the future". J.11. HASTINGS, NLS, Brookbaven. "Texture analysis of coarse grained rock-salt by neutron diffraction". H.G. BROKMEIER, Geeslhacht. "Microelcctronvoll - resolution on three-axis spectrometers". A. HE1DEMANN, ILL. "Solving structures by direct methods using experimentally observed triplets". "Collisions due to solitons in magnetic chains". FRODE MO, University of Trondheim, Norway. J.P. BOUCHER, DRF. CEN Grenoble. "Neuraminidase structure and variations'*. "Non-equilibrium phase transitions in the conductivity of high-purity J. VARGHESE, CSIRO, Melbourne. semiconductors". W. PRETTL, University of Regcnsburg. "The neutron Fizeau effect". A. RUMPF, ILL. "High-temperature studies of uranium dioxide". M. HUTCHINGS, AERE, Harwell. "Long-range incommensurate magnetic order in a Dy-Y multilayer". J.J. RHYNE, National Bureau of Standards, Gaithersburg. "Longitudinal fluctuations in isotropic ferromagncts". P.W. MITCHELL, University of Manchester. "Report on DB21 and its 2-d PSD data reduction system". M. ROTH, ILL. "Neutron studies of quantum liquids : recent insights and future pro­ spects". "Présentation du programme ABFFIT ; nouveaux développements des H.R. GLYDE, University of Delaware, Newark. techniques de traitement des diagrammes de diffraction de poudres". A. ANTONIADIS, University of California. Irvine. "Icosahedral crystal, quasicrystals : new paths in crystallography". T. JANSSEN, Université Dijon. "Structural phase transitions and related kinetics - diffraction studies at Trombay". "Raman scattering from plasmons in superlattices". S. BHAKAY-TAMHANE. Bhabha Atomic Research Centre, Trombay, R. PRANGE, University of Maryland. Bombay. "Systematics of disorder in quasiperiodic materials". "Optical experiments with neutrons and molecules". P.M. HORN, IBM, Yorktown Heights. A.G. KLEIN, Melbourne. "Paramagnetic scattering from an exchange enhanced metal". "Reverse Fourier TOF powder diffraction on the Leningrad reactor". N. BERNHOEFT, Durham University. H. PÔYRY, Technical Research Centre, Helsinki. "A new mechanism for non-linear electrical conductivity in charge- "Polarized neutron beams by Zeeman splitting and the new ILL special densiiy-wavc systems". instrument S21". S. AUBRY, LLB, Saclay. C. ZEYEN, ILL. "Polarized neutrons at the Rutherford Appleton Laboratory". "Structure field maps of the ABX? halidcs". J. MAYERS, Rutherford Appleton Laboratory. D. VISSER, Inorganic Chemistry. Oxford. "Structure factor for neutron scattering from tunneling centres in metals". S. DATTAGUPTA, University of Hydrabad, India. COLLEGE 6 "Collective excitations in CeAl;". M. LÔWENHAUPT, IFF-KFA, Jiilich. Liquids, Disorder and Defects in materials "Magnetic and quadrupolar response in an itinerant electron model of "Quasiclastic coherent neutron scattering ;-ir atomic diffusion". uranium compounds". K. SCHROEDER, KFA Jiilich. D.M. EDWARDS, Imperial College and ILL. "Anomal« :s diffusion in the bec-phase of IV- metals and their alloys". "Charge density wave conductors - Collective non-linearity in solids". C. HERZ t. Institut fur Metallforschung, Univcrsitàt Munster. L. SNEDDON, Brandeis University.Massachusetts. "Ordering 11 semifiexiblc polymers'". "Surface phonons". DO Y. YOON. IBM Almadcn Research Center. San Jose, California. G. BENEDEK, University or Milano. "New experiments with hydrogen in metals". "The electron-volt spectrometer at IPNS". R. GR1ESSEN, University of Amsterdam. K. CRAWFORD, Argonnc National Laboratory. "Micron-size particles and void determination using multiple small angle "Conductance fluctuations in micron-size devices : symmetry in a neutron scattering". magnetic field and scaling behaviour". K. HARTMANN-RHYNE. National Bureau of Slandards, Washington A. BENOIT. CNRS Grenohle. DC.

127 "Solute site of fast diffusers in metals, a diffuse scattering approach". "Localisation intramoléculaire de déterminants antigéniques d'hémo- A. HEIMING, ILL. cyanines par immunomicroscopie électronique et analyse d'image". J. LAMY, Faculté de Pharmacie, Tours. "Hydrogen diffusion in hydrides using Mossbauer spectroscopy". P. RAJ, Bhabha Atomic Research Centre, Bombay. "Régulation de l'expression génétique de quelques aminoacides tRNA synthetases". "Relaxation effects in the inelastic neutron scattering spectra of hydrogen- S. BLANQUET, Ecole Polytechnique, Paris. metal systems". A. KLAMT, M.P.I, fur Metallforschung, Stuttgart. "New isomorphous replacement principle in small-angle neutron scat­ tering". "Structural approach to quasicrystals". I.N. SERDYUK, Institute of Protein Research, Pushchino (USSR). P. GUYOT, Institut National Polytechnique de Grenoble. "Use of synchrotron radiation in macromolecular crystallography". "The structure of amorphous metals and close- packed oxide glasses". J. HELLIWELL, York University. P.H. GASKELL, Cavendish Laboratory, Cambridge. "Superparamagnetic precipitates in volcanic glass from the East African Rift and their origin : explosive volcanism in the age of early hominids". COLLEGE 9 CM. SCHLINGER, University of Utah, Salt Lake City. "(1-radiation detected Li diffusion in the fast ionic conductor LJ3N". Chemistry B. BADER, Universitat Marburg. "Neutron scattering study and theoretical calculation of the rotational "Neutron resonance spin echo". potential of the methyl group in the solid nitromethane". B. GOLUB, T.U. Munchen. D. CAVAGNAT, Université de Bordeaux 1. "SANS as a technique for the investigation of colloid stability". 1. MARKOVIC, University of Bristol. COLLEGE 8 "Systèmes modèles en photosynthèse. Etude photophysique des pigments photosynthéliques en monocouches lipidiques et en milieu micelïaîrc". Biochemistry J.P. CHAUVET, Ecole Normnlc Supérieure de Saint-Cloud. "Structure of a membrane protein-complex : photosynthetic reaction cen­ "Proton transfer in carboxylic acid crystals". tre from rhodop- seudomonas viridis". S. HAYASHI, Institut for Chemical Research, Kyoto University. H. MICHEL, Max-Planck Institut fur Biochemie, Martinsricd. "Theory and experiment of surface vibrations of crysials". "DNA-dependent RNA polymerase and gene expression in ar- F.W, DE WETTE, University of Texas, Austin. chaebacteria". W. ZILL1G, Max-Planck Institut fîir Biochemic, Martinsried. "The maximum entropy method applied to SANS data". P.J. FEENEY, ILL. "tRNA genes in chloroplasts and plant mitho- chondria". J.H. WEIL, I.B.M.C. Strasbourg. "X-ray absorption spectroscopy on synthetic metals". G. WORTMANN, Freic Universitat Berlin. "a-cristallines : interactions and quaternary structure". "SANS study of deformed polymer rubberr and melts : check of Brow- A. TARD1EU, CNRS Gif-sur-Yvette. nian elasticity". "Crystallisation and spectroscopic investigation of antenna and reaction F. BOUE, S.R.M., CEN Saclay. centre-antenna complexes of purple bacteria". "Neutron resonance spin echo". W. WELTE, Freiburg. B. GOLUB, T.U. Mùnchen. "ADN polymerases et topoisomérases chez les archaebactérics. Activité gyrase reverse chez sulfolobus". Thursday colloquia M.P. FORTERRE, Institut de Recherches sur le Cancer, Villejuif. "Colloids and magnetic holes". "Structural studies on the 7S RNP particle from oocytes of Xenopus A.T. SKJELTORP, Institute for energy technology, Kjeller (Norway). Laevis". 1) "ESRF and ILL : A European interdisciplinary research centre in R.S. BROWN, EMBL Heidelberg. Grenoble ?" "Probing the dynamics of proteins". 2) "Recent advances in solid state and surface spectrocopies". R. LEVY, Rutgers University (USA). M. CAMPAGNA, Institut fur Festkôrperforschung, Julien. "Heavy electron metals and anisotropic super- conductors". "Phosphorylation des protéines ribosomiques et régulation de la traduc­ T.M. RICE, E.T.H. Zurich. tion chez les eucaryotes". J.J. MADJAR, Faculté de Médecine Alexis Carrel, Université Claude "Structure and dynamics of physisorbed over layers". Bernard, Lyon. M. KLEIN, Trinity College, Cambridge. "Dynamics of sliding charge density waves. A. ZAWADOWSKI, Cen­ "Structure and functional mechanism of ribonuclease Ti". tral Research institute for Physics, Budapest. W. SAENGER, Institut fur Kristallographie, Freie Universîtàt, Berlin. "ISIS, its instruments and first scientific results". "Molecular and cellular biology of the prosome". A.J. LEADBETTER, Rutherford Appletoi. Laboratory. K. SCHERRER, Institut Jacques Monod, Paris. "Polarized neutron interferometry". H. RAUCH, Atominstitut der Osterreichischen Univcrsilaten, Wien. "Traduction in vitro des ARN messagers mito- chondriaux de D. "The responsibility of scientists and academic ethics". Melanogaster". H. MAIER-LEIBNITZ, Munich. R. DURAND, Université de Clermont-Ferrand. "On the properties of the nuclear quantum liquid". "Mechanism of transcription in the E.coli system". S. BJORNHOLM, The Niels Bohr Institute Copenhagen and CEN H. HEUMANN, M.P.I, fur Biochemie, Martinsried. Grenoble. "Grand unification and double p" decay". "Recent studies on the mechanism of DNA gyrase". A. FÂSSLER, University of Tubingen. M. GELLERTT National Institutes of Health, Washington DC. "Nuclear clocks and thermometers in astrophysics". "Dynamics and structures of linear and supercoiled DNAs". G. SCHATZ, KFK Karlsruhe. J.M. SCHURR, University of Washington, Seattle. "Charge density wave conduction : A "novel" collective transport phenomenon in solids". "Membrane protein folding". G. GRUNER, University of California, Los Angeles. D.M. ENGELMAN, Yale University. "Heavy particles in metals". "What can BPTI tell us about rational protein design ?". J. KONDO, Tsukuba Research Center, Ibaraki. H.J. H1NZ, Universitat Regensburg. "Atomic clocks". N.F. RAMSEY, Harvard University, Cambridge. "Sequence - directed DNA curvature". "Physics at the CERN pp collider". S. DIEKMANN, MPI fur Biophysikalische Chemie, Gottingen. L. DI LELLA, CERN Geneva. "Reconstitution of membrane proteins : a new approach". "Physics with ultra-cold neutrons". N.A. DENCHER, Free University, Berlin. A. STEYERL, Technische Universilat Munchen.

128 I.L.L. WORKSHOPS AND CONFERENCES Organised by the I.L.L. in 1986 Published in 1986 Biviers, France, 19-21 March, 1986. Colloque National "Biologie Geilo, Norway, 8-19 April, 1985. NATO ASI Series B n" 133, "Scal­ Moléculaire et Cristallographie", (organized jointly by the EMBL, ing Pheno- mena in Disordered Systems", edited by R. Pynn, the CENG and the ILL: S. Cusack, A. Lewit-Bentley, G. Buisson, A. Skjeltorp, (1985, Plenum Press)[86PY470) E. Duée, M. Lehmann, M. Roth, B. Maier). l.L.L. 8-12 July, 1985. "Third International Conference on the Struc­ I.L.L. 7-8 April, 1986. Workshop on "Structure and Dynamics of ture of Non-Crystalline Materials", edited by C. Janot, A.F. Wright. Interfaces and Colloids. Can Neutrons help applied Science ?" Journal de Physique. Colloques, Vol. 46, Colloque C8, (organized by J.P.Beaufils, B. Maier, R.C. Oberthttr, R. Ottewill, 1985.[86JA4711 D. Richter). [Abstracts: ILL Internal Report 86IL04T) I.L.L. 15-16 July, 1985. "Workshop on Investigations of Higher i.L.L. 24-26 September, 1986. Workshop on "Quantum Aspects of Order correlation Functions", edited by J.B. Suck, D. Quitmann, Molecular Motions in Solids." (organized jointly by the ILL and B. Maier. Journal de Physique. Colloques, Vol. 46, Colloque C9, KFA/Jiilich: A. Heide- mann, A. Magerl, B. Maier, M. Prager, D. 1985.[86SU473] Richter, T. Springer). [Abstracts: ILL Internal Report 86IL08T). To be published in "Pro­ Jiillch, F.R.G., 2-4 October. 1985. "Atomic Transport and Defects ceedings in Physics", Springer-Verlag, 1987. in Metals by Neutron Scattering", edited by C. Janot, W. Petry, D. Richter, T. Springer. Springer Proceedings in Physics, Vol. 10 (1986, Springer-Verlag). [86JA4721 Sponsored by the I.L.L. in 1986 I.L.L. 4-6 November, 1985. "Evaluation of Single-Crystal Diffrac­ Grenoble, 7-11 July, 1986. ICAREA. International Conference on tion Data from 2-D Position-Sensitive Detectors", edited by A. Filhol, "Anomalous Rare Earths and Actinidcs. Valence Fluctuation and B. Maicr, S.A. Mason, G.J. Mclntyre, M. Roth, A. Lewit-Bcntlcy, Heavy Fermions." (organized jointly by the CNRS, the CENG, the G.A. Bentley, G. Bricognc, R. Kahn. Journal de Physique. Collo­ ILL : J. Flouquct, J.Rossat- Mignod). ques, Vol. 47, Colloque C8, 1986.[86FI466]

THESES RELATED TO EXPERIMENTAL WORK BY 111 THESIS STUDENTS PERFORMED AT THE ILL

CHAIX-PLUCHERY O. - Thèse de Doctoral d'Etat ès-Sciences ANNE M. - Thèse de Doctorat d'Etat, Université Scientifique et Physiques, Université de Bourgogne, Décembre 1986. Transforma­ Médicale et Institut National Polytechnique de Grenoble, Septem­ tions volumiques préréactionnelles. Cas de la décomposition endother- bre 1985. Mécanismes de transports ionique et protonique dans les mique de l'hydroxyde de calcium en oxyde. composés de type alumine p etP". GELTENBORT P. - Dissertation zur Erlangung des Grades 'Doktors BOUKELLAL A. - Thèse de Doctoral d'Etat, Université de Bordeaux der Natun i-senschaften' der Fakultat fur Physik der Eberhardt- I, Juillet 1986. Contribution à l'étude des corrélations masses-énergies Kai >-Universitat zu Tubingen, 1985. Fragmentgeschwindigkeiten, cinétiques. Charges nucléaires des fragments de fission à l'aide du Energien und Massen fur die durch thermische Neutronen induzierte spectromètre "Cosi Fan Tutte". Spaitung von 2"Uran, 2JSUran, "'Plutonium. CAITUCOLI F. - Thèse de Doctorat d'Etat ès-Scienccs, Université MARET M. - Thèse de Doctorat d'Etat ès-Sciences Physiques, de Bordeaux 1, Juillet 1985. Mécanisme de fission nucléaire : con­ Université Scientifique et Médicale et Institut National Polytechni­ tribution à l'étude des différents modes de fragmentation du noyau. que de Grenoble, Janvier 1986. Etude de la structure et des propriétés thermodynamiques des alliages amorphes NijsYav et CujjYin. CHATER R. - Thèse de Doctoral d'Etat, Université Pierre et Marie Curie, Paris VI, Mars 1986. Etude des antimonites MeSb2Û4 à basse MARTINEZ G. - Thèse de Doctorat d'Etat, Université de Bordeaux température. Evolution structurale, thermodynamique, propriétés I, Juillet 1986. Etude des distributions en masse, en charge nucléaire élastiques et magnétiques anisotropes. Modélisation. et en énergie cinétique des fragments de fission formés par la réac­ 7 tion " Np (2n,h,0. LANDESMAN J.P. - Thèse de 3ème cycle, spécialité: Sciences de la Matière, Université Louis Pasteur de Strasbourg, Janvier 1985. STEYRER G. - Dissertation, Fakultat fur Physik der Ludwig- Etude de la stabilité de phases ordonnées dans les carbures et nitrures Maximilians- Universitàt in Mùnchen, Juni 1986. Untersuchung sous-stoechiométriques de métaux de transition. makroskopischer Dichtefluktuationen von Wasserstoff in Niob mit Neutronen -Radiographie und -Beugung. TJAN KIE - Inaugural Dissertation zur Erlangung der Dpktorwurde STROTH U.- Dissertation zur Eriangung des Grades 'Doktor der des Fachbereichs Physik der Freien Universitàt Berlin, 1985. Naturwissenschaften' am Fachbereich Physik der Technischen Tiefenverteilung und Ausheizverhalten von implantierten 6Li - Hochschule Darmstadt, 1986. Semiklassiche Théorie fur die nukleare Atomen in verschiedenen Metallen. Responsefunktion. Quasielastische Elektronstreuung. TROST W. - Dissertation zur Erlangung der Wurde 'Doktor der Naturwissenschaften' , Fakultat Physik der Universitàt Stuttgart, April 1986. Bestimmung der Gleich- gewichtskonzentration von Eigenfehlstellen durch Messung der thermischen Ausdehnung mit- tels Neutronenstreuung und Laserinterferometrie.

129 860E14T OED A. : usr OF Détecteur à gaz utilisant une anode à microbandes.(Brevet no. 86 10810 du 25 Juillet 1986) PUBLICATIONS 1986 TECHNICAL REPORT 860P1ST OPPENLAENDER A., DORNER B., BLETRY J., CHABLY A. : INTERNAL REPORTS An experiment on the elastic constants of gallium-arsenide. Ex­ perimental report. TECHNICAL REPORT T = Technical Reports G = General Reports 86MA16G MAIER B. (Ed.) : Neutron Research Facilities at the ILL High Flux Reactor. (Edition 86TH1T June 1986) THUERWAECHTER R., MAGERL A. : GENERAL REPORT. (AVAILABLE FROM SCAPRO). Computer-Simulationen zum geplanten IN10C. TECHNICAL REPORT 86TA17T TASSET F., DORN A. : 86AN2T D3. Notice d'utilisation du SAS "PESTICIDE". Procédure détaillée ANTONIAD1S A„ BERRUYER J.. FILHOL A. : pour l'introduction, sans contact avec l'atmosphère, d'échantillons Affinement de spectres de diffraction de poudre par la méthode du dans le puits étanche du cryoaimant 4.6 Tesla Oxford Instru­ maximum de vraisemblance. ment/Modifie ORANGE-ILL. TECHNICAL REPORT TECHNICAL REPORT

86CA3G CASTETS C. : 1985 ILL Experimental reports and theory college activities. GENERAL REPORT PAPERS PUBLISHED IH 86IL4T SCIENTIFIC PERIODICALS, BEAUF1LS J.P., MAIER B., OBERTHUER R.C., OTTEW1LL R„ R1CHTER R. : Structure and dynamics of interfaces and colloids. Can neutrons help BOOKS AND CONFERENCE applied science ? Workshop held at ILL, Grenoble, 7-8 April 1986. Abstracts. TECHNICAL REPORT PROCEEDINGS, 1986

86KIST KITZIA S. : 86DUI01 Step power 1 - Schrittmotorsteuerung. DURAND-LE FLOCH M..PANNETIER J., DENES G. : TECHNICAL REPORT Multiple sites and mobility in ionic conductors by NM R dipolar tran­ sient effects. PHYSICAL REVIEW B VOL. 33, PP. 632-634 (1986) 86CA6G CASTETS C, LANDAS N. : 1985. ILL Abstracts of publications, 86BE102 GENERAL REPORT BELLISSARD J., GREMPEL D.R., MARTINELLI F. , SCOP- POL A E. : Localization of electrons with spin-orbit or magnetic interactions in 86MA7T a two-dimensional disordered crystal. MAY R.P., THOMAS M. : PHYSICAL REVIEW B VOL. 33, PP. 641-644 (1986) D22 - A new low-q scattering instrument at the second cold source of the ILL. 86MA103 TECHNICAL REPORT MAGERL A., D1ANOUX A.J., WIPF H., NEUMA1ER K., ANDERSON I.S. : 86IL8T Concentration dependence and temperature dependence of hydrogen HEIDEMANN A., MAGERL A„ MAIER B., PRAGER M., tunneling in Nb(OH)x. RICHTER D., SPRINGER T. : PHYSICAL REVIEW LETTERS VOL. 56, PP. 159-162 (1986) Workshop on Quantum Aspects of Molecular Motions in Solids, Grenoble, France, September 24-26, 1986. Abstracts. 86EN104 TECHNICAL REPORT ENDERBY J.E. : The structure of ionic solutions. 86C09T IN 'TRENDS IN PHYSICS 1984', 6TH GENERAL CONFERENCE COLVIN G.. CIZEWSKI J.A., BOERNER H.G., GELTENBORT OF THE EPS, PRAGUE, 1984/08/27-31 (EUROPEAN PHYSICAL P., HOYLER F., KERR S.A., SCHRECKENBACH K. : SOClETY),PP.380-387 Gamma rays observed in the reaction "3Ir(n,Y)1,JIr. TECHNICAL REPORT 86HI105 H1GHFIELD R.R., HUMES R.P., THOMAS R.K., CUMMINS P.G., GREGORY D.P., MINGINS J., HAYTER J.B..SCHAERPF 86BL10T O. : BLANC J.Y. : Critical reflection of neutrons from a soap film. Simulation de données en provenance d'expérience de diffractometrie. JOURNAL OF COLLOID AND INTERFACE SCIENCE, VOL. 97, TECHNICAL REPORT PP. 367-373 (1984) 86AN12T 86FE106 ANTONIADIS A., BERRUYER J., FILHOL A. : FELDERHOF B.U., JONES R.B. : Détection de perturbations dans un signal bruité. Spectral broadening in suspensions of metallic spheres. TECHNICAL REPORT ZEITSCHRIFT FUER PHYSIK B VOL. 62, PP. 43-50 (1985)

86GE13T 86TO107 GERVAIS R., AGERON P. : TOUDIC B., CAILLEAU H., LECHNER R.E., PETRY W. : Procédé de réalisation d'une pièce telle qu'un conduit d'un faisceau Direct observation of critical phenomena by incoherent neutron scat­ énergétique comportant au moins une surface de très faible rugosité. tering. (Brevet n° 85 01650 du 6 février 1985) TECHNICAL REPORT PHYSICAL REVIEW LETTERS VOL. 56, PP. 347-350 (1986)

130 86DU108 86BE120 DURAND D., DENOYER F.. LAMBERT M., CURRAT R., VET- BELL1SSENT R., MENELLE A., CHENEVAS-PAULE A-, TIER C, BERNARD L. : CHIEUX P. : Modulated phases in thiourea and sodium nitrite. a-Si : Short range order by neutron scattering. FERROELECTRICS VOL. 53, P. 239 (1984). JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, COLLOQUE ROCEEDINGS OF THE 5TH EUROPEAN MEETING ON "FER- C8.PP. C8-93-C8-96 (1985). PROCEEDINGS OF THE 3RD INTER­ ROELECTRICITY",MALAGA,1983/09/26-3O, PT.l. NATIONAL CONFERENCE ON "THE STRUCTURE OF NON­ CRYSTALLINE MATERIALS ", JULY 8-12, 1985, I.L.L., 86SA109 GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. SAINT-GREGOIRE P., BARTHES M., ALMAIRAC R., NOUET J., GESLAND J.Y., FILIPPINI C, STEJGENBERGER U. : 86BEI21 On the incommensurate phase in BaMnF4 : BERGMAN C, BICHARA C, CHIEUX P. , GASPARD J.P. : A neutron scattering study. Effect of the pressure. On the atomic structure of liquid GaAs. FERROELECTRICS VOL. 53, PP. 307-310 (1984). PROCEEDINGS JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, COLLOQUE OF THE 5TH EUROPEAN MEETING ON "FERROFLECTRICI- C8, PP. C8-97-C8-100(1985). PROCEEDINGS OF THE 3RD IN­ TY",MALAGA, 1983/09/26-30, PT.l. TERNATIONAL CONFERENCE ON "THE STRUCTURE OF NON-CRYSTALLINE MATERIALS", JULY 8-12, 1985, I.L.L., 86BA110 GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. BARUCHEL J., PATTERSON C, GU1GAY J.P. : Neutron diffraction investigation of the nuclear and magnetic extinc­ 86JA122 tion in MnP. JANOT C, GEORGE B., TETE C. : ACTA CRYSTALLOGRAPHICA A VOL. 42, PP. 47-55 (1986) Structure and microslructure in (Fei.

131 86JA128 86MA136 JACUCCI G., RONCHETTI M., SCHIRMACHER W. : MARION G., ALMAIRAC R. ,RIBET M., STEIGENBERGER U., Computer simulation of the liquid L14PD alloy. VETTIER C, SAINT-GREGOIRE P. : JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, COLLOQUE Temperature-pressure phase diagram of deuterated tetramethylam- C8,PP. C8-385-C8-389 (1985). PROCEEDINGS OF THE 3RD IN­ monium tetrachlorozincate. TERNATIONAL CONFERENCE ON "THE STRUCTURE OF FERROELECTRICS VOL. 53, PP. 277-280 (1984) NON-CRYSTALLINE MATERIALS ", JULY 8-12, 1985, I.L.L., GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. 86CA137 CAILLEAU H., GIRARD A., MESSAGER J.C., DELU- 86R012» GEARD Y., VETTIER C. : RODMACQ B., BILLARD L., MANGIN P., CHAMBEROD A. : Influence of pressure on structural phase transitions in p-polyphenyls. Computer ; nutation of hydrogenated and deuterated CuTi amor­ FERROELECTRICS VOL. 54, PP. 257-260 (1986) phous alloy.*. JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46.COLLOQUE 86BR138 C8.PP. C8-415-C8-4!9(1985). PROCEEDINGS OF THE 3RD IN­ BROWN P.J. : TERNATIONAL CONFERENCE ON "THE STRUCTURE OF Magnetism of ferromagnetic metals above their Curie temperature. NON-CRYSTALLINE MATERIALS", JULY 8-12, 1985, I.L.L., EUROPHYSICS NEWS VOL. 17, PP. 25-28 (1986) GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. 86S0139 SOUBEYROUX J.L., FIORANI D. .AGOSTINELLI E. : 86DU130 Spin-glass behaviour in cobalt oxyspinel CoGa204. DUBOIS J.M., DEHGHAN K., JANOT C, CHIEUX P., JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS CHENAL B.: VOL. 54-57, PP. 83-84 (1986). Small angle scattering and structure factor neutron measurements of PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, an amorphous AboSinFeu alloy. AUGUST 1985. 86G0131 86BO140 GOUDEAU P., NAUDON A., RODMACQ B., MANGIN P., BOUMAZOUZA D., TETE C, DURAND J., MANGIN P., CHAMBEROD A. : SOUBEYROUX J.L. : The medium range structure of hydrogenated Cu-Ti amorphous alloys Evidence of irreversibilities in the subcritical scattering from the amor­ studied by anomalous small-angle scattering of x-rays and neutron phous reentrant spin glasses (FcCri^sPisCio. diffraction. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, COLLOQUE VOL. 54-57, PP. 95-96 (1986). C8.PP.C8-461-C8-466 (1985). PROCEEDINGS OF THE 3RD IN­ PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, TERNATIONAL CONFERENCE ON "THE STRUCTURE OF AUGUST 1985. NON-CRYSTALLINE MATERIALS ", JULY 8-12, 1983, I.L.L., GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. 86ER141 ERWIN R.W., LYNN J.W., MAGERL A. : SSG0131 Reentrant spin-glass order parameter in (FeojNio.7)7sPi6B6Al3. GOUDEAU P., NAUDON A., RODMACQ B., MANGIN P., JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS CHAMBEROD A. : VOL. 54-57, PP. 101-102 (1986). The medium range structure of hydrogenated Cu-Ti amorphous alloys PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, studied by anomalous small-angle scattering of x-rays and neutron AUGUST 1985. diffraction. JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, COLLOQUE 86VVI142 C8.PP. C8-479-C8-483 (1985). PROCEEDINGS OF THE 3RD IN­ WIEDENMANN A., MEZEI F. : TERNATIONAL CONFERENCE ON "THE STRUCTURE OF Edwards-Anderson type relaxation in the frustrated quasi-ID spin NON-CRYSTALLINE MATERIALS ", JULY 8-12, 1985, I.L.L., glass FeMgBOa. GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57, PP. 103-104 (1986). 86R0132 PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, RODMACQ B„ MANGIN P., CHAMBEROD A. : AUGUST 1985. Contribution to S.A.N.S. of the surface state of PdsoSi» amorphous alloys. 86MC143 JOURNAL DE PHYSIQUE COLLOQUES VOL. 46, COLLOQUE MCEWEN K.A., LEBECH B., FORT D. : C8.PP. C8-499-C8-503 (1985). PROCEEDINGS OF THE 3RD IN­ Modulated antiferromagnetic structure of Ndi-»Prx single crystals. TERNATIONAL CONFERENCE ON "THE STRUCTURE OF JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS NON-CRYSTALLINE MATERIALS ", JULY 8-12, 1985.I.L.L., VOL. 54-57, PP. 457-458 (1986). GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, AUGUST 1985. 86WR133 8611A144 WRIGHT A.F., MUKHERJEE S.P., EPPERSON J.E. : Nature of the 30 Â texture in polymeric Ti02 gel. BALLOU R., DEPORTES J., GORGES B., LEMAIRE R., JOURNAL DE PHYSIQUE COLLOQUES VOL. 46, COLLOQUE OUSSET J.C. : C8.PP. C8-521-C8-525 (1985). PROCEEDINGS OF THE 3RD IN­ Anomalous thermal variation of the bulk anisotropy in GdCos. TERNATIONAL CONFERENCE ON "THE STRUCTURE OF JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS NON-CRYSTALLINE MATERIALS ", JULY 8-12, 1985, I.L.L., VOL. 54-57, PP. 465-466 (1986). GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, AUGUST 1985. 86SC134 86BA14S SCHUMACHER G-, PETRY W., KLAUMUENZER S., BALLOU R., DEPORTES J., KEBE B., LEMAIRE R. : WALLNER G., WECK G. : Magnetic transitions in ErM] compounds. Defect production by fast neutrons and thermal recovery in amor­ JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS phous Pd8oSi2o. VOL. 54-57, PP. 494-496 (1986). JOURNAL DE PHYSIQUE .COLLOQUES VOL. 46, COLLOQUE PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, C8.PP. C8-603-C8-608 (1985). PROCEEDINGS OF THE 3RD IN­ AUGUST 1985. TERNATIONAL CONFERENCE ON "THE STRUCTURE OF NON-CRYSTALLINE MATERIALS ", JULY 8-12, 1985, I.L.L., 86BAI46 GRENOBLE, EDITED BY C. JANOT, A.F. WRIGHT. BALLOU R., GIGNOUX D., GORGES B., LEMAIRE R. : Magnetic properties of the pseudobinary system (Lai-xNdx)2Coi.7. 86IS13S JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS ISHIKAWA Y., NODA Y., ZIEBECK K.R.A., GIVORD D. : VOL. 54-57, PP. 497-498 (1986). Origin of hidden magnetic excitations in an Invar alloy Fe66Ni35. PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, SOLID STATE COMMUNICATIONS VOL. 57, PP. .31-534 (1986) AUGUST 1985.

132 S6BA147 86MI15f- BALLOU R., GIGNOUX D., LEMAIRE R,, MENDIA- MITCHELL P.W., PAUL D.MCK. : MONTERROSO , SCHWEIZER J. : Low temperature spin wave excitations in nickel. Magnetic and structural properties of the intermetallic La2Coi.7, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Pr2Coi.7 and NdT.Coi.7 compounds. VOL. 54-57,PP. 1154-1156(1986). JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, VOL. 54-57, PP. 499-500 (1986). AUGUST 1985. PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, AUGUST 1985. 86ST157 STANLEY H.B., MCEWEN K.A., STIRLING W.G. : 86CH148 Magnetic excitations in neodymium. CHATTOPADHYAY T., BURLET P., ROSSAT-MIGNOD J., JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS BARTHOLIN H., VETTIER C, VOGT O. : VOL. 54-57.PP. 1167-1168 (1986). Effects of hydrostatic pressure on the magnetic ordering in CeSb. PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS AUGUST 1985. VOL. 54-57, PP. 503-504 (1986). PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, 86PA158 AUGUST 1985. PAUL D.MCK., MITCHELL P.W., HIGGINS S.A. : Magnetic excitations of ordered PdsFe and disordered PdFe alloys. 86Z0149 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS ZOCHOWSKI S„ MCEWEN K.A. : VOL. 54-57.PP. 1171-1172. (1986). Thermal expansion study of the magnetic phase diagram of PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, neodyinium. AUGUST 1985. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57, PP. 515-516 (1986). 86LUS9 PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, LINDLEY E.J., RAINFORD B.D., PAUL D.MCK., CYW1NSKI AUGUST 1985. R„ BURKE S.K. : Spin waves in PdNi and CuNi alloys near the critical concentration.' 86PA150 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS PALMER S.B., BATES S., MC1NTYRE G.J., SOUSA J.B., FORT VOL. 54-57.PP. 1177-1178 (1986). D., BEAUDRY B.J. : PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, The antiferromagnetic phase of Gd-Y alloys : AUGUST 1985. A new type of triple point ? JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 86HAI60 VOL. 54-57, PP. 519-520 (1986). HARRISON A., VISSER D., DAY P., ZIEBECK K.R.A. : PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, The effect of impurities on the magnetic structure of RbFeCb.' AUGUST 1985. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57.PP. 1273-1274 (I98t>). PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, 86FR151 AUGUST 1985. FRINGS P.H., FRANSE J.J.M., MENOVSKY A., ZEMIRLI S., BARBARA B. : Magnetic properties of single-crystalline UNÎ2. 86ST161 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS STEIGENBERGER U., LEBECH B., GALAZKA R.R. : VOL. 54-57, PP. 541-542 (1986). Neutron scattering studies of a dilute magnetic semiconductor : PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, Cdi.xMn.Te.' AUGUST 1985. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57,PP. 1285-1286 (1986). PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, 86HU152 AUGUST 1985. HUTCHINGS M.T., DAY P., JANKE E., PYNN R. : Critical spin dynamics in RbzCrCU : 86WE162 A nearly two-dimensional easy-plane ferromagnet. WEBSTER P.J., ZIEBECK K.R.A., MANK1KAR R.M. : JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Magnetic order in new silver-based Heusler alloys.' VOL. 54-57, PP. 673-674 (1986). JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS PROCEEDINGS OF THE "ICM*85", SAN FRANCISCO, USA, VOL. 54-57.PP. 1355-1356 (1986). AUGUST 1985. PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, AUGUST 1985. 86MC153 MCWHAN D.B., VETTIER C, GYORGY E.M., KWO J., BUNT- 86BA163 SCHUH B.M., BATTERMAN B. : BAUHOFER W„ CHATTOPADHYAY T., MOELLENDORF M„ Magnetic x-ray scattering from superlattices. GMELIN E., SCHNERING H.G. VON.STEIGENBERGER U., JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS BROWN P.J. : VOL. 54-57, PP. 775-776 (1986). Magnetic phases diagram of EuAsj.' PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS AUGUST 1985. VOL. 54-57.PP. 1359-1360 (1986). PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, 86KA1S4 AUGUST 1985. KAKURA1 K., STEINER M., PYNN R. .DORNER B. : Study of the linear and nonlinear excitations in CsNiF3 by means of 86BA164 polarized neutron scattering. BARTOLOME J., GARCIA J., R1LLO C, PALACIOS E., BAC- JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS MANN M., FRUCHART D., FRUCHART R., CHENEVIER B. : VOL. 54-57, PP. 835-836 (1986). Magnetic phase transitions of the ternary phosphide MnRuP.' PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS AUGUST 1985. VOL. 54-57.PP. 1499-1500 (1986). PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, 86KA1SS AUGUST 1985. EL KADIRI M., BARUCHEL J., RODRIGUEZ F., MORENO M., HENRY J.Y. : 86SA165 Impurity related memory effect of the antiferromagnetic domains in SARK1SSIAN B.V.B., THOLENCE J.L. : MnF2. The critical fields of the magnetic superconductor Y->C07.' JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57, PP. 853-854 (1986). VOL. 54-57.PP. 1525-1526 (1986). PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, AUGUST 1985. AUGUST 1985.

133 86H0166 86BE177 HODEAU J.L., BORDET P., WOLFERS P., MAREZIO M.. BEE M. .LONGUEVILLE W., AMOUREUX J.P., FOURET R. : REMEIKA J.P. : Reorientations in pivalic acid (2,2-dimethyl propanoic acid).II.In- Magnetic structure of the reentrant superconductor coherent quasielastic neutron scattering study.'

[Sn( i )o.58Er( 1 )o.42] Er(2)4Rh6Sn 18. JOURNAL DE PHYSIQUE VOL. 47, PP. 305-320 (1986) JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57,PP. 1527-1528 (1986). 86F0178 PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, FORD G.W., LEWIS J.T., O'CONNELL R.F. : AUGUST 1985. Stark shifts due to black-body radiation.' JOURNAL OF PHYSICS B VOL. 19, PP. L4I-L46 (1986) 86SA167 SARKISSIAN B.V.B., SALCE B., KHODER A.F. : 86WI179 The thermal conductivity of Y9C07 and Y9(Coo.97Nio.o3)7' WIEDENMANN A., REGNARD J.R. : JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Neutron diffraction study of the magnetic ordering in pyroxenes

VOL. 54-57,PP. 1531-1533 (1986). FesMi-,Si03. PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, SOLID STATE COMMUNICATIONS VOL. 57, PP. 499-504 (1986) AUGUST 1985. 86AM180 86BA168 AMOUREUX J.P., FOULON M., MULLER M., BEE M. : BACMANN M., CHENEVIER B., FRUCHART D., LABORDEStructure s of ethane, hexameihylethane and hexatnethyldisilane in O., SOUBEYROUX J.L. : their plastic phases. Magnetic structures and magnetoresistivity of MnRhAs.' ACTA CRYSTALLOGRAPHICA B VOL. 42. PP. 78-84 (1986) JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57,PP. 1541-1542(1986). 86VE181 PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, VETT1ER C, MCWHAN D.B., GYORGY E.M., KWO J., BUNT- AUGUST 1985) SCHUH B.M., BATTERMAN B.W. : Magnetic x-ray-scattering study of interfacial magnetism in a Gd-Y 86PAI69 superlattice. PALMERS.B.,BARUCHELJ.,DRILLATA.,PATTERSONC, PHYSICAL REVIEW LETTERS VOL. 56, PP. 757-760(1986) FORT D. : Influence of the purity on the domains and the clastic constants in 86GR182 the helimagnetic phases of Ho and Tb.' GREENE G.L., KESSLER E.G., DESLATTES R.D., BOERNER JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS H.G.: VOL. 54-57,PP. 1626-1628 (1986). New determination of the dcutcron binding energy and the neutron PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, mass. AUGUST 1985. PHYSICAL REVIEW LETTERS VOL. 56, PP. 819-822 (1986) 86BA170 86MA183 BARUCHEL J., AUBERT G. .PALMER S.B., SCHLENKER M. : MAGERL A., RUSH J.J., ROWE J.M. : Observation of ferro-helimagnetic phases coexistence in Tb crystals. Local modes in dilute metal-hydrogen alloys. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS PHYSICAL REVIEW B VOL. 33, PP. 2093-2097 (1986) VOL. 54-57.PP. 1631-1632 (1986). PROCEEDINGS OF THE "ICM'85", SAN FRANCISCO, USA, 86BR184 AUGUST 1985. BROWN P J., CAPELLMANN H., DEPORTES J., GIVORD D., JOHNSON S.M., ZIEBECK K.R.A. : 86PY171 The paramagnetic response of nickel at high temperature.' PYNN R , SKJELTORP A. [Eds.] : JOURNAL DE PHYSIQUE VOL. 47, PP. 491-496 (1986) Scaling phenomena in disordered systems. PROCEEDINGS OF A NATO ADVANCED STUDY INSTITUTE 86KE185 HELD APRIL 8-19. 1985, IN GEILO, NORWAY. NATO ASI, KEARLEY G.J. : SERIES B, VOL. 133 (PLENUM PRESS, 1985). A profile-refinement approach for normal-coordinate analyses of in­ elastic neutron-scattering spectra.' 86ZI172 JOURNAL OF THE CHEMICAL SOCIETY. FARADAY TRAN­ ZIMAN T. : SACTIONS II VOL. 82, PP. 41-48 (1986) Low frequency dynamics of dilute antiferromagnets at percolation. IN 'SCALING PHENOMENA IN DISORDERED SYSTEMS', 86DU186 PYNN R., SKJELTORP A. EDS., GEILO, NORWAY, APRIL 8-19, DUBBERS D. : 1985, NATO ASI B 133 (PLENUM PRESS, 1985), PP. 361-363 Simple formula for multiple mu-metal shields. NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS 86HI173 RESEARCH A VOL. 243, PP. 511-517 (1986) H1GGINS S.A., VLAK W. A.H.M., HAGEN M., COWLEY R.A., ARTS A.F.M., WIJN H.W.DE : 86B0187 Magnetic excitations in KiConFei-xF-i : BOPP P., DUBBERS D., HORNIG L., KLEMT E., LAST J., a mixed magnetic system with competing spin anisotropics. SCHUETZE H., FREEDMAN S.J., SCHAERPF O. : IN 'SCALING PHENOMENA IN DISORDERED SYSTEMS', Beta-decay asymmetry of the neutron and gA/gv. PYNN R., SKJELTORP A., EDS, GEILO, NORWAY, APRIL 8-19, PHYSICAL REVIEW LETTERS VOL. 56, PP. 919-922 (1986) 1985.NATO ASI B 133 (PLENUM PRESS, 1985), PP. 455-460 86PE188 86RU74 PEPY G., ROSTA L., FRANCOIS B., MATHIS C, MC1NTYRE RICHTER D-, EWEN B. : G.J., STANSFIELD R.F.D. : Dynamical scaling in polymer solutions. Structural determination by neutron diffraction of oriented deuterated IN 'SCALING PHENOMENA IN DISORDERED SYSTEMS', trans-polyacetylene. PYNN R., SKJELTORP A., EDS, GEILO, NORWAY, APRIL 8-19, ANNALES DE PHYSIQUE VOL. 11, COLLOQUE Cl, PP. 81-82 1985,NATO ASI B 133 (PLENUM PRESS, 1985), PP. 491-506 (1986) 86UW175 86HE189 UWAHA M., NOZIERES P. : HENDR1KX Y., CHARVOLIN J., RAW1SO M. : Flow-induced instabilities at the supcrfluid-solid interface of 'He.' Uniaxial-biaxial phase transition in lyotropic nematic solutions : JOURNAL DE PHYSIQUE VOL. 47, PP. 263-271 (1986) Local btaxiality in the uniaxial phase. PHYSICAL REVIEW B VOL. 33, PP. 3534-3537 (1986) 86L0176 LONGUEVILLE W.. BEE M., AMOUREUX J.P., FOURET R. : 86WI190 Reorientations in pivalic acid (2,2-dimethyl propanoic acid).(.In­ WIESMANN F.J., ZEIDLER M.D., BERTAGNOLLI H., CHIEUX coherent neutron scattering law for dynamically independent P. : molecular and intramolecular reorientations.' A neutron diffraction study of liquid formamide. JOURNAL DE PHYSIQUE VOL. 47, PP. 291-304 (1986) MOLECULAR PHYSICS VOL. 57, PP. 275-285 (1986)

134 86FE19I 86TR202 FENDER B.E.F., FIGGIS B.N., FORSYTH J.B., REYNOLDS TRAUTVETTER HP.. BECKER H.W., HE1NEMANN U., P.A., STEVENS E. : BUCHMANN L., ROLFS C, KAEPPELER F., BAUMANN M., Spin density and bonding in Mn(H20)

86FE192 86JO203 FENDER B.E.F., FIGGIS B.N., FORSYTH J.B. : JOBIC H. .RENOUPREZ A., BEE M., POINSIGNON C. : Spin density and bonding in (ND4)2Ni(S04>2 6D2O. Quasi-elastic neutron scattering study of the molecular motions of PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON A methanol adsorbed on H-ZSM-5. VOL. 404, PP. 139-145 (1986) JOURNAL OF PHYSICAL CHEMISTRY VOL. 90, PP. 1059-1065 (1986) 86CU193 CURRAT R. : 86LA204 Neutron scattering studies of phase and amplitude modes. LALIGANT Y., LEBLANC M., PANNETIER J., FEREY G. : IN 'PROCEEDINGS OF THE 2ND INTERNATION \L CON­ Ordered magnetic frustration: IV.The two magnetic structures of the FERENCE ON PHONON PHYSICS'.J.KOLLAR & AL. EDS inverse weberite Fe2F<(H20)2: An example of the thermal evolution (WORLD SC1ENT1FIC,198S),PP. 250-259 of the frustration character. JOURNAL OF PHYSICS C VOL. 19. PP. 1081-1095 (1986) 86T0194 TOLEDANO J.C., SCHNECK J„ ERRANDONEA G., CUR­ 86HE20S RAT R„ PET1TGRAND D. : HEISELBERG H., JENSEN A.S., MIRANDA A., OADES G.C., Neutron scattering and x-ray investigations of barium sodium niobatc RICHARD J.M. : in the range of the quasi-commensurate phase. Microscopic calculation of antiproton-nuclcus elastic scattering. IN 'PROCEEDINGS OF THE 2ND INTERNATIONAL CON­ NUCLEAR PHYSICS A VOL. 451, PP. 562-580 (1986) FERENCE ON PHONON PHYSICS'.J.KOLLAR & AL.EDS (WORLD SCIENTIFIC1985), PP. 290-292 86DU206 DURAND D., DENOYER F., CURRAT R., LAMBERT M. : 86ST19S Incommensurate phase in NaN02. STIRLING W.G. : IN 'INCOMMENSURATE PHASES IN DIELEC­ New high-resolution neutron scattering investigations of excitations TRICS.2.MATERIALS'.R.BLINC, A.P. LEV AN YUK, EDS in liquid helium-4. (NORTH-HOLLAND,1986), PP. 101-127 IN 'PROCEEDINGS OF THE 2ND INTERNATIONAL CON­ FERENCE ON PHONON PHYSICS'.J.KOLLAR & AL EDS 86DE207 (WORLD SCIENTIFIC, 1985),PP. 829-835 DENOYER F., CURRAT R. : Modulated phases in thiourea. 86LA196 IN 'INCOMMENSURATE PHASES IN DIELEC­ LAUTER H.J., GODFRIN H., WIECHERT H. : TRICS.2.MATERIALS'.R.BLINC,A.P. LEVAN YUK, EDS 4 (NORTH-HOLLAND.I986), PP. 129-160 Excitations in He-films. IN 'PROCEEDINGS OF THE 2ND INTERNATIONAL CON­ FERENCE ON PHONON PHYSICS'.J.KOLLAR & AL.EDS 86CU208 (WORLD SCIENTIFIC, 1985),PP. P42-849 CURRAT R., BERNARD L., DELAMOYE P. : Incommensurate phase in p-ThBr^. IN 'INCOMMENSURATE PHASES IN DIELECTRICS. 86ST197 2.MATERIALS'.R.BLINC,A.P.LEVANYUK, EDS (NORTH- STRAUCH D., DORNER B. : HOLLAND, 1986), PP. 161-204 Phonon eigenvector determination in GaAs at the X and L points. IN 'PROCEEDINGS OF THE 2ND INTERNATIONAL CON­ FERENCE ON PHONON PHYSICS'.J.KOLLAR & AL.EDS 86BR209 (WORLD SCIENTIFIC, 1985).PP. 940-942 BROWN P.J. : Magnetic structure. PHYSICA B VOL.137, PP. 31-42 (1986). 86WAI98 PROCEEDINGS OF THE CONFERENCE ON "FRONTIERS OF WAGEMANS C, D'HONDT P., SCHILLEBEECKX P.. NEUTRON SCATTERING", CAMBRIDGE, USA, SEPTEMBER BRISSOT R.: 23-24,1985 . Triton and alpha emission in the thermal-neutron-induced ternary fission of 233U, 23ÎU, :39Pu, and 24lPu. PHYSICAL REVIEW C VOL. 33, PP. 943-953 (1986) 861.E210 LEHMANN M.S., FENDER B.E.F. : Chemical physics employing neutron crystallographic methods. 86TH19» PHYSICA B VOL. 137, PP. 159-168 (1986) . THORNTON G., TOFIELD B.C., HEW AT A.W. : PROCEEDINGS OF THE CONFERENCE ON "FRONTIERS OF A neutron diffraction study of LaCoOi in the temperature range NEUTRON SCATTERING", CAMBRIDGE, USA, SEPTEMBER 4.2

135 86SE213 86FA224 SEEGER P.A., PYNN R. : FARAGO B., MEZEI F. : Resolution of pulsed-source small-angle neutron scattering. Study of magnon dynamics in Fe near Tc by modified neutron spin NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS echo techniques. RESEARCH A VOL. 245, PP. 115-124 ;1986) PHYSICA B VOL. 136, PP. 100-102 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON 86HE214 "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, HERBST L., HOFFMANN H., KALUS J., THURN H., IBEL K., 1985. MAY R.P.: Orientational relaxation of aligned rod-like micelles on a time scale of 300 ms. 86ST225 CHEMICAL PHYSICS VOL. 103, PP. 437-445 (1986) STOECKLI A., FURRER A., SCHOENENBERGER C, MEIER B.H., ERNST R.R., ANDERSON I.S. : 86LA215 Dynamics of hydrogen bonds in carboxylic acids. LAHIOUEL R., GALERA R.M.. MURANI A.P., PIERRE J., PHYSICA B VOL. 136, PP. 161-164 (1986). SIAUD E. : PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON Ground state properties, anisotropy and spin relaxation in diluted " NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, Kondo systems Yi-xCexZn. 1985. ZE1TSCHRIFT FUER PHYSIK B VOL. 62, PP. 457-462 (1986) 86FI216 86F0226 FITCH A.N., JOB1C H., RENOUPREZ A. : FONTANA M.P., M1GLIARDO P., MAISANO G., BELLISSENT- Localization of benzene in sodium-Y zeolite by powder neutron dif­ FUNEL M.C., DIANOUX A.J. : fraction. Low frequency dynamics in water and ZnC12 solutions by quasi-elastic JOURNAL OF PHYSICAL CHEMISTRY VOL. 90, PP.1311-1318 and inelastic neutron scattering. (1986) PHYSICA B VOL. 136, PP. 179-182 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON 86DU217 "NEUTRON SCATTERING", SANTA FE, USA. AUGUST 19-23, DUBOIS J.M., JANOT C, PANNETIER J. : 1985. Preliminary diffraction study of icosahedral quasi-crystals using isomorphous substitution. 86ZA227 PHYSICS LETTERS A VOL. 115, PP. 177-181 (1986) ZACCAI G. : Lipids, membrane proteins and natural membranes studied by neutron 86BA218 scattering and diffraction: A review, BATALLAN F„ ROSENMAN I., MAGERL A., FUZELLIER H. : Study of the melting of HNOj intercalated in graphite by quasi- PHYSICA B VOL. 136, PP. 227-231 (1986). elastic neutron scattering. PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PHYSICA B VOL. 136, PP. 12-14 (1986). "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON 1985. "NEUTRON SCATTERING, SANTA FE, USA, AUGUST 19-23, 1985) 86TR228 TREWHELLA J., POPOT J.L., ENGELMAN D.M., ZACCAI G. : 86SI21» Neutron diffraction studies of bacteriorhodopsin. SIMON C, BATALLAN F., ROSENMAN 1., PEPY G„ LAUTER PHYSICA B VOL. 136, PP. 249-251 (1986). H.J. : PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON The anisotropy of the Cu shear constant in bromine-graphite inter­ "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, calation compound: A precursor effect of the anisotropic melting. 1985. PHYSICA B VOL. 136, PP. 15-17 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, 86TU229 1985) TURNER J., FINNEY J.L., BOUQUIERE J.P., NEILSON G.W., CUMMINGS S. .BOUILLOT J. : 86TE220 Neutron scattering studies of hydration of molecules of biological TETE C, VERGNAT M., MANGIN P., PANNETIER J., importance. LEBLANC M. : PHYSICA B VOL. 136, PP. 260-264 (1986). Neutron diffraction measurements of the kinetics of crystallization PROCEEDINGS OF THE INTERNATIONAL CONFERENCE O..' of amorphous FePC and FeFj, xHF. "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, PHYSICA B VOL. 136, PP. 42-44 (1986). 1985. PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING ", SANTA FE, USA, AUGUST 19-23, 86MI230 1985 . MITCHELL P.W., HIGGINS S.A., PAUL D.MCK. : 86R0221 Short wavelength magnetic excitations in random ferromagnets. RODMACO B., BILLARD L.. CHAMBEROD A., MANGIN P. : PHYSICA B VOL. 136, PP. 307-310 (1986). Determination of the location of hydrogen in the CuTi amorphous PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON alloys by neutron diffraction. "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, PHYSICA B VOL. 136, PP. 45-48 (1986). 1985. PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING", SANTA FE. USA, AUGUST 19-23, 86DU231 1985. DURAND D., BERNARD L., MEZEI F., CURRAT R., DENOYER F. .LAMBERT M. : 86PY222 Incommensurate phase transition in sodium nitrite: A study of the PYNN R. : dynamics by neutron spin echo technique. Inelastic neutron scattering with polarisation analysis. PHYSICA B VOL. 136, PP. 325-327 (1986). PHYSICA B VOL. 136, PP. 75-79 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERIN'G. SANTA FE, USA, AUGUST 19-23, "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, 1985. 1985. 86ST22J 86RE232 STEIGENBERGER U., SCHAERPF O. : REGNAULT L.P., BOUCHER J.P., ROSSAT-M1GNOD J., A polarized neutron study on the development of magnetic ordering BOUILLOT J., PYNN R., HENRY J.Y., RENARD J.P. : in a diluted antiferromagnet. Nonlinear excitations in Id and 2d magnetic systems. PHYSICA B VOL. 136, PP. 87-89 (1986). PHYSICA B VOL. 136, PP. 329-334 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, 1985. 1985.

136 86M0233 86DA243 MONCEAU P., BERNARD L., CURRAT R., LEVY F., DAY P., MOORE M.W., WILKINSON C, Z1EBECK K.R.A. : ROUXEL J. : Modelling of magnetic satellite intensity in the neutron diffraction Inelastic neutron scattering study of Peierls instabilities in (TaSe4)2l of an incommensurate helical structure: NiBr2 and Nio.9Feo.1Bn. and NbSes. PHYSICA B VOL. 136, PP. 461-464 (1986). PHYSICA B VOL. 136, PP. 352-355 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, 1985. 1985. 86RE234 86AB244 ABIS S.. CACIUFFO R., COPPOLA R., MAGMANI M., RENKER B., GOMPF F., SUCK J.B., RIETSCHEL H., RUSTICHELL1 F. .STEFANOK M. : FRINGS P.H. : Small angle neutron scattering investigation of the ageing process in Lattice dynamics of heavy-fermion compounds. Al-Mg-Si alloy. PHYSICA B VOL. 136, PP. 376-378 (1986). PHYSICA B VOL. 136, PP. 469-472 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, 1985. 1985. 86MC235 MCEWEN K.A. : 86B0245 Multiple-o. modulated structures and magnetic excitations in the light BOUILLOT J., COQUET E., PANNETIER J.. CRETTEZ J.M. : rare-earth elements praseodymium and neodymium. Neutron powder diffraction studies of LilOj and (HIO3, 2LiIO.i). PHYSICA B VOL. 136, PP. 385-390 (1986). PHYSICA B VOL. 136, PP. 493-497 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, 1985. 1985. 86LA23C 86IB246 LASSAILLY Y. .VETTIER C, HOLTZBERG F„ BURLliT P. : IBEL K., POLAND G.A. .BALDWIN J.P., PEPPER D.S., Evidence of 4-q magnetic structure in TmS. LUSCOMBE M., HOLBROOK J.J. : PHYSICA B VOL. 136, PP. 391-393 (1986). Low-resolution structure of the complex of human blood platelet 1 ac­ PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON tor 4 with heparin determined by small-angle neutron scattering. "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, BIOCHIMICA ET BIOPHYSICA ACTA VOL. 870, PP. 58-63 1985. (1986) 86S0237 SOSNOWSKA I., STEICHELE E., HEW AT A.W. : 86B0247 Reorientation phase transit'on in NdFe03. BOUCHER J.P.. REGNAULT L.P., PYNN R., BOUILLOT J., PHYSICA B VOL. 136, PP. 394-396 (1986). RENARD J.P. : PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON Collision damping and renormalization of Sine-Gordon solitons in "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, TMMC. 1985. EUROPHYSICS LETTERS VOL. I, PP. 415-422 (1986) 86ST238 STANLEY H.B., BROWN P.J., MCEWEN K.A., RAIN- 86BI248 FORD B.D. : BIZOT D., CHASSAING J., PANNETIER J., LEBLANC M., LE Magnetic form factor and susceptibility of neodymium. BAIL A., FEREY G. : PHYSICA B VOL. 136, PP. 400-402 (1986). Fluorocomplexes of niobium IV- Part V. The magnetic structure of PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON MnNbFe. "NEUTRON SCATTERiNG", SANTA FE, USA, AUGUST 19-23, SOLID STATE COMMUNICATIONS VOL. 58, PP. 71-74(1986) 1985. 86WA249 86LA23» WALTER U., SLEBARSKI A., STEIGENBERGER U. : LANDER G.H., STIRLING W.G., ROSSAT-MIGNOD J., The crystal field scheme of PrCus as obtained by inelastic neutron SPIRLET J.C., REBIZANT J., VOGT O. : scattering. Magnetic excitations in plutonium monoantimonidc. JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN VOL. 55, PHYSICA B VOL. 136, PP. 409-41" '<• •). PP. 650-655 (1986) PROCEEDINGS OF THE INTERNA ' CONFERENCE ON "NEUTRON SCATTERING", SAN i'A 'SA, AUGUST 19-23, 86CL250 1985. CLERC H.-G., LANG W., MUTTERER M., SCHMITT C, 86ST240 THEOBALD J.P., QUADE U., RUDOLPH K., ARM- STIRLING W.G., MCEWEN K.A., LOONG C.K. : BRUSTER P., GOENNENWEIN F., SCHRADER H., ENGEL- HARDT D. : Intermultiplet transitions in rare-earth metals. : PHYStCA B VOL. 136, PP. 420-423 (1986). Cold fragmentation in thermal-neutron-induced fission of "U and PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, NUCLEAR PHYSICS A VOL. 452, PP. 277-295 (1986) 1985. 86LE2SI 86BE24I LEBLANC M., FEREY G., DE PAPE R., PANNETIER J. : BERNHOEFT N.R., LONZARICH G.G., PAUL D.MCK., MIT­ Nuclear and magnetic structures of ND.jMnFeF6 at 4.2 K. CHELL P.W. : SOLID STATE COMMUNICATIONS VOL. 58, PP. 165-169 (1986) Magnetic fluctuation spectra of very weak itinerant ferromagnets. PHYSICA B VOL. 136, PP. 443-446 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON 86LE252 "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, LEBLANC M., DE PAPE R., FEREY G., PANNETIER J. : 1985. Ordered magnetic frustration -V. Antiferromagnetic structure of the hexagonal bronzoid HTB-FeFj ; Comparison with the non frustrated 86S0242 rhombohedral form. SOUBEYROUX J.L., SALMON R., FOURNES L., LE FLEM G. : SOLID STATE COMMUN/-ATIONS VOL. 58, PP. 171-176(1986) Magnetic properties of NaFeP^O? studied by neutron diffraction and Moe^sbauer resonance techniques. 86W0253 PHYSICA B VOL. 136, PP. 447-450 (1986). WOOD J.S., 8ROWN R.K., LEHMANN M.S. : PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON Structure of hexakis(pyridine N-oxide)cobalt(II) perchlorate by "NEUTRON SCATTERING", SANTA FE, USA, AUGUST 19-23, neutron diffraction at 90 K. 1985. ACTA CRYSTALLOGRAPHICA C VOL. 42, PP. 410-413 (1986)

137 86Z0254 86ST266 ZOUZOU Z., SILVESTRE-BRAC B„ GIGNOUX C, RICHARD STROTH U., HASSE R.W., SCHUCK P. : J.M. : On the longitudinal charge response in the quasielastic peak region. Four-quark bound states. PHYSICS LETTERS B VOL. [71, PP. 339-342 (1986) ZEITSCHRIFT FUER PHYSIK C VOL. 30, PP. 457-468 (1986) 86SC267 86SC2S5 SCHULZ H.J., ZIMAN T. : SCHOENFELD B., KLAIBER F., KOSTORZ G., ZAUNE U., Finite-length calculations of h and phase diagrams of quantum spin MCINTYRE G.J. : chains. Diffuse neutron scattering and short-range order in Ni-19.4 at % Cr. PHYSICAL REVIEW B VOL. 33, PP. 6545-6548 (1986) SCRIPTA METALLURG1CA VOL. 20, PP. 385-387 (1986) 86JA2S6 86SI268 SIMON C, BATALLAN F., ROSENMAN 1., FURDIN G., JANOT C, ROTH M., MARCHAL G., P1ECUCH M., BRU- VANGELISTI R., LAUTER H.J., SCHWEIZER J., AYACHEC, SON A.: PEPY G. : Relaxation and diffusion study by small angle neutron scattering Magnetic structures and properties of FeCb and CoCb graphite in­ technique in amorphous semiconductor superlattices. tercalation compounds. JOURNAL OF NON-CRYSTALLLiNE SOLIDS VOL. 81, PP. ANNALES DE PHYSIQUE COLLOQUES VOL. 11, COLLOQUE 41-51 (1986) NO. 2, PP. 143-1S3 (1986) 86RE2S7 RENAUDIN J., PANNET1EP J., KOZAK A. DE SAMOUEL M., 86MA269 FEREY G. : MARET M., WAGNER C.N.J., ETHERINGTON G., SUPER A., Complex copper(Il) fluorides. IV. Crystal structure of Ba6CunF]4 : TANNER L.E. : First evidence of trinuclear edge-sharing units and defective NaCl- Structural study of Bc4:iHf*Zrs7* metallic glasses by x-ray and type blocks in crystal chemistry of fluorides. neutron diffraction. JOURNAL OF SOLID STATE CHEMISTRY VOL. 62, PP. 164-',71 JOURNAL DE PHYSIQUE VOL. 47, PP. 863-871 (1986) (1986) 86BR270 86LA258 BRUNEL Y., COULOMBEAU C. .COULOMIiEAU CH., LALIGANT Y., PANNETIER J., LABBE P., FEREY G. : JOBIC H.: A new refinement of the crystal structure of the inverse weberite Optical and neutron inelastic scattering study of 2,3-diniclhyl- Fe:F,(H20)2. norbornanes. JOURNAL OF SOLID STATE CHEMISTRY VOL. 62, PP. 274-277 .IOURNA L OF PHYSICAL CHEMISTRY VOL. 90, PP. 2008-2015 (1986) (1986)

86BE259 86FE271 BERGE B., BACHHE1MER J.P., DOLINO G., VALLADE M., FELDERHOF B.U. : ZEYEN C.M.E. : Transmission and reflection of waves in a one-dimensional disordered Inelastic neutron scattering study of quartz near the incommensurate array. phase transition. JOURNAL OF STATISTICAL PHYSICS VOL. 43, PP. 267-279 FERROELECTR1CS VOL. 66, PP. 73-84 (I986)(SPECIAL ISSUE (1986) ON INCOMMENSURATE PHASE TRANSITIONS, A.R.BISHOP & AL EDS.) 86TH272 86CA260 THOMAS J.O., MCINTYRE G.J., DENUZZIO J. : CA1LLEAU H., MESSAGER J.C., MOUSSA F., BUGAUT F., An alternative fabrication route to Hj0' fj-alumina via NH4' /H3O* ZEYEN C.M.E., VETTIER C. : P-alumina. Main characteristic properties of incommensurate biphenyl. FER- SOLID STATE IONICS VOL. 18 & 19, PP. 642-644 (1986). ROELECTRICS VOL. 67, PP. 3-14 (1986) (SPECIAL ISSUE ON PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON INCOMMENSURATE PHASE TRANSITIONS, A.R.BISHOP & "SOLID STATE IONICS", LAKE TAHOE, AUGUST 1985, AL. EDS) EDITED BY BOYCE J.B., ET AL.

86SA261 86BI273 SAINT-GREGOIRE P., ALMAIRA^. R. .FREUND A., GES- BIRCHALL T., DENES G., RUEBENBAUER K., PANNETIER J.: LAND J.Y. : A neutron diffraction and mSn Moessbauer study of PbSnFa and Barium manganese fluoride BaMnF4 as at: improper ferroelastic. BaSnF4. FERROELECTRICS VOL. 67, PP. 15-21 (1986) (SPECIAL ISSUE HYPERFINE INTERACTIONS VOL. 29, PP. 1331-1334 (1986) ON INCOMMENSURATE PHASE TRANSITIONS, A.R.BISHOP & AL EDS.) 86TA274 TACHEZ M., MERCIER R., MALUGANI J.P., DIANOUX A.J. : 86VE262 Quasielastic and inelastic neutron scattering from AgPOj-AgI glass. VETTIER C, MORIN P., FLOUQUET J. : SOLID STATE IONICS VOL. 20, PP. 93-98 (1986) Magnetic ground state of CePbj. PHYSICAL REVIEW LETTERS VOL. 56, PP. 1980-1983 (1986) 86MA27S MARCUS-SAUBAT B., BEAUFILS I.P., BARBAUX Y. : 86DU2 i Effect of the surface structure on the departure from stoichiometry DURAND-LE FLOCH M.,PANNETIER J., DOREM1EUX- of COJOJ. MOR1N CARRIBART H. : JOURNAL DE CHIMIE PHYSIQUE VOL, 83, PP. 317-321 (1986) 'H NMR structural rigid lattice and dynamical study of the defect pyrochlores HiTa:0(„ HTaWOa, and their hydrates. JOURNAL OF CHEMICAL PHYSICS VOL. 84, PP. 4760-4768 86SC276 (1986) SCHMIDT H.H., STOEFFL W., EG1DY T. VON, HUNGERFORD P., SCHEERER H.J., SCHRECKENBACH K., BOERNER H.G., 86DI264 WARNER D.D., CHRIEN R.E., GREENWOOD R.C., REICH DIANOUX A.J., BUCHENAU U., PRAGER M., NUECKER N. : C.W. : Low frequency excitations in vitreous silica. The level structure of '"Gd from (n,y), (d,p) and (d,t) „ludies. PHVSICA B VOL. 133, PP. 264-268 (1986) JOURNAL OF PHYSICS G VOL. 12, PP. 411-441 (1986)

86J026S 86AG277 JONES D.J., ROZIERE J., LEHMANN M.S. : AGERON P., MAMPE W. : Very short OHO hydrogen bonds in a binuclear transition-metal com­ Cold and ultra cold neutron beams for fundamental physics research plex. Neutron-diffraction study at 120 K or [Co2(H2N(CH;)2OH)j( al the Institute Laue-Langevin.

H2N(CH2)20;3] [CI04]i.5H20. IN 'THE INVESTIGATION OF FUNDAMENTAL INTERAC­ JOURNAL OF THE CHEMICAL SOCIETY. DALTON TRAN­ TIONS WITH COLD NEUTRONS',G.L. GREENE ED.NBS SACTIONS PP. 651-655 (1986) SPECIAL PUBL. 711(1986), PP. 16-24

158 86DU278 86PE290 DUBBERS D. : PETRY W., VOGL G., FLOTTMANN T., HE1DEMANN A. : In-beam neutron lifetime measurements at the Institut Laue-Langevin. Quasielastic neutron scattering study of fast diffusion of Co in (S-Zr. IN THE INVESTIGATION OF FUNDAMENTAL INTERAC­ IN 'ATOMIC TRANSPORT AND DEFECTS IN METALS BY TIONS WITH COLD NEUTRONS'.G.L. GREENE ED.NBS NEUTRON SCATTERING',PROCEEDINGS OF AN IFF-ILL SPECIAL PUBL.711 (1986),PP.54-58 WORKSHOP, JUELICH, FRG, OCTOBER 2-4, 1985, C. JANOT ET AL. EDITORS, SPRINGER PROCEEDINGS IN PHYSICS 86MA279 VOL. 10(SPRINGER-VERLAG,1986), PP. 134-138 MAMPE W. : Neutron lifetime measurements with bottled neutrons at ILL. 86WI291 IN 'THE INVESTIGATION OF FUNDAMENTAL INTERAC­ WIPF H., MAGERL A., NEUMAIER K. :

TIONS WITH COLD NEUTRONS', G.L. GREENE ED.NBS H tunneling and local diffusion in NbO

Fractal dimensionality of percolation clusters in (FenNii.p)aoP;a. NEUTRON SCATTERING', PROCEEDINGS OF AN ILL-1FF PHYSICAL REVIEW B VOL. 33, PP. 7837-7840 (1986) WORKSHOP, JUELICH, FRG, OCTOBER 2-4, 1985, C.JANOT ET AL. EDITORS. SPRINGER PROCEEDINGS IN PHYSICS 86D0282 VOL. 10(SPRINGER-VERLAG,I986), PP. 170-175 DORNER B., BURKEL E., PE1SL J. : An x-ray backscattering instrument with very high energy resolution. 86ST293 NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS STEYRER G., PE1SL J. : RESEARCH A VOL. 246, PP. 450-451 (1986) Neutron radiography studies of spinodal decomposition in NbH*. IN 'ATOMIC TRANSPORT AND DEFECTS IN METALS BY 86S0283 NEUTRON SCATTERING',PROCEEDINGS OF AN IFF-ILL SOURISSEAU C, GUILLAUME F., LUCAZEAU G., D1A- WORKSHOP, JUELICH, FRG, OCTOBER 2-4, 1985, C.JANOT NOUX A.J.: ET AL. EDITORS. SPRINGER PROCEEDINGS IN PHYSICS Inelastic and quasielastic neutron scattering study of the rcorienta- VOL. 10 ISPRINGER-VERLAG, 1986), PP. 181-185 tional motions in the layer-type compound (NHi(CH.2)iNH.i)MnCU. MOLECULAR PHYSICS VOL. 58, PP. 413-437 (1986) 86GR294 GRAEFENSTEDT M., KEYSER U., MUENN1CH F., 86B0284 PAHLMANN B., PFEIFFER B., WEIKARD H. : BONSE U., RUMPF A. : Beta-decay energies of neutron-rich nuclei in the mass region Interferometric measurement of neutron Fizeau effect. I42

Hydrogen diffusion in amorphous liquM-quenched Pd*Sii->Hv PROKOF.IEV P.T., BONDARENKO V.A., GUSEVA T.V., measured by QNS. IN 'ATOMIC TRANSPORT AND DEFECTS KRAMER N.D.. SIMONOVA L.I., TAMBERGS J.J.. IN METALS BY NEUTRON SCATTERING',PROCEEDINGS OF SCHRECKENBACH K.. DAVIDSON W.F., PINSTON J.A., AN IFF-ILL WORKSHOP, JUELICH FRG, OCTOBER 2-4, 1985, WARNER D.D., VAN ASSCHE P.H.M.. SPITS A.M.J. : C. JANOT ET AL. EDITORS. SPRINGER PROCEEDINGS IN Levels of '"Eu from thermal neutron capture. NUCLEAR PHYSICS VOL. 10 (SPRINGER-VERLAG,1986),PP. 126-131 PHYSICS A VOL. 455, PP. 1-39 (1986)

139 86MA301 86MC312 MAJKRZAK CF., CABLE J.W., KWO J., HONG M., MCWHAN MCKERGOW M.W., GILBERD P.W., P1CTON D.J., ROSS D.K., D.B., YAFET Y., WASZCZAK J.V., VETTIER C. : FRATZL P., BLASCHKO O., ANDERSON I.S., HAGEN M. : Observation of a magnetic antiphase domain structure with long-range Interatomic potentials and lattice distortions in PdDo.n. order in a synthetic Gd-Y superlatlice. ZEITSCHRIFT FUER PHYSIKALISCHE CHEM1E.NF VOL. 146, PHYSICAL REVIEW LETTERS VOL. 56, PP. 2700-2703 (1986) PP. 159-169 (1985)

86TA302 86HA313 TACHEZ M., MERCIER R. .MALUGANI J.P., D1ANOUX A.J. : HAGUE A.M.I., CASTEN R.F., FOERSTER I., GELBERG A., Quasielastic and inelastic neutron scattering from AgPOs-AgI glass. RASCHER R., RICHTER R., BRENTANO P.VON .BAR­ SOLID STATE IONICS VOL. 18 & 19, PP. 372-373 (1986). REAU G., BOERNER H.G., KERR S.A., SCHRECKENBACH K., PROCEEDINGS OF THE 5TH INTERNATIONAL CON­ WARNER D.D. : FERENCE ON "SOLID STATE IONICS" , LAKE TAHOE, A study of the low-lying states in l78Hf through the (n,v) reaction. AUGUST 1985). NUCLEAR PHYSICS VOL. A 455, PP. 231-293(1986) 86LU303 LUCAZEAU G., GAVARRI J.R., DIANOUX A.J. : 86DA3I4 Study of Na+ motions in BAI2O3 by quasi-elastic neutron scattering. DAY P., FYNE P.J., HELLNER E„ HUTCHINGS M.T., MUEN- SOLID STATE IONICS VOL. 18 & 19, PP. 603-607 (1986). NINGHOFF G., TASSET F. : PROCEEDINGS OF THE 5TH INTERNATIONAL CON­ Polarized neutron diffraction study of the magnetization density FERENCE ON "SOLID STATE IONICS", LAKE TAHOE, USA, distribution in Rb2CrCU:A two-dimensional ionic ferromagnet. AUGUST 1985. PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON VOL. A406.PP. 39-61 (1986) 86BO304 BORDET P., HODEAU J.L. .WOLFERS P., MIRAGLIA S., 86TE31S BENOIT A., MAREZIO M., REMEIKA J.P. : TERLAIN A., LARHER Y., ANGERAND F., PARETTE G., Magnetic structures of SnEujRruSnu and (Sno.5«Erci.«)Er.iRh<,SniK. LAUTER H.J., BASSIGNAGNA I.C. : PHYSICA B VOL. 136, PP. 432-435 (1986). Neutron diffraction study of the structure of the crystal monolayer PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON of CJNJ adsorbed on graphite (0001). "NEUTRON SCATTERING", SANTA FE, USA, AUGUST MOLECULAR PHYSICS VOL.58, PP. 799-813 (1986) 19-23,1985. 86PA316 86LU30S PANNETIER J. : LUCAZEAU G., BARJ M., SOUBEYROUX J.L., DIANOUX A.J., Tir '.-resolved neutron powder diffraction. DELMAS C. : CWEMICA SCRIPTA VOL.26A, PP. 131-139 (1986) . Neutron scattering and diffraction study of Na3Cr2P30i2, PAPER PRESENTED AT THE FRENCH SWEDISH CON­ NaZrjP30i2, and NajZrMgPjOu. FERENCE ON "ADVANCES IN POWDER DIFFRACTION SOLID STATE IONICS VOL. 18 & 19, PP. 959-963 (1986). CRYSTALLOGRAPHY ", SWEDEN, 8-9 MAY. 1985. PROCEEDINGS OF THE 5TH INTERNATIONAL CON­ FERENCE ON "SOLID STATE IONICS", LAKE TAHOE, USA, AUGUST 1985. 86HE317 HEWAT A.W. : High-resolution neutron and synchrotron powder dilii^:*'on. 86AN306 CHEMICA SCRIPTA VOL. 26A, PP. 119-130 (1986). ANDREJTSCHEFF W., PETKOV P., PROTOCHR1STOW C, PAPER PRESENTED AT THE FRENCH-SWEDISH CON­ ROSTOV L.K., HAMILTON W.D., HOYLER F. : FERENCE ON "ADVANCES IN POWDER DIFFRACTION", A mixed symmetry or quasineutron pair interpretation of the r SWEDEN, 8-9 MAY, 1985. K" = 03* level in 'Vb. JOURNAL OF PHYSICS G VOL. 12, PP. L151-L156 (1986) 86WE3I8 86ST307 WEISSENBERGER E.. GELTENBORT P., OED A., GOENNEN- STEYERL A., NAGEL H., SCHREIBER F.X., STE1NHAUSER WEIN F., FAUST H. : K.A., GAEHLER R., GLAESER W. .AGERON P., ASTRUC J.M., Energy calibration of surface barrier detectors for fission fragments. DREXEL W., GERVAIS R., MAMPE W. : NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS A new source of cold and ultracold neutrons. RESEARCH VOL. A248, PP. 506-515 (1986) PHYSICS LETTERS A VOL. 116, PP. 347-352 (1986) 86SC3I9 86SA308 SCHUBERT U., SCHOLZ G., MUELLER J., ACKERMANN K., SARKISSIAN B.V.B. : WOERLE B., STANSFIELD R.F.D. : Resistivity, thermopower and susceptibility of Y«COT and local-mode Hydrido-Silyl-Komplexe. VII. Strukturchcmische und MSi-NMR- effects. Spekstroskopische untersuchungen an C5R\<(CO)(L)Mn(H)SiRj. JOURNAL OF PHYSICS F VOL. 16, PP. 755-768 (1986) Einfluss der substituenten R und R' sowie des Liganden L auf die Mn.H.Si-dreizentrenbindung. 86JO309 JOURNAL OF ORGANOMETALLIC CHEMISTRY VOL. 306, JOHNSON S.M., BENOIT A., BROWN P.J., CAPELLMANN H., PP. 303-326 (1986) FLOUQUET J., FRANSE J.J.M., FRINGS P.H., ZIEBECK K.R.A.: 86ST320 Direct observation of magnetic fluctuations in UPti both above and STEINMETZ K.H., VOGL G., PETRY W., SCHROEDER K. : below the superconducting transition temperature. Diffusion of iron in copper studied by Moessbauer spectroscopy on ZEITSCHR1FT FUER PHYSIK B VOL. 63, PP. 335-341 (1986) single crystals. PHYSICAL REVIEW B VOL. 34, PP. 107-116 (1986) 86RO310 ROTH M. : On absolute scaling in protein crystallography using sums of low- 86S0321 resolution intensities and Wilson statistics at low resolution. SOLYOM J., TIMONEN J. : ACTA CRYSTALLOGRAPHICA A VOL. 42, PP. 230-240 (1986) Anisotropic Heisenberg chain with composile spin. PHYSICAL REVIEW B VOL. 34, PP. 487-489 (1986) 86LK31I LEDERERH..MAY R.P., KJEMS J.K., SCHAEFER W, CRESPI 86CH322 H.L., HEUMANN H. : CHATTOPADHYAY T., BROWN P.J., THALMEIER P., Deuterium incorporation into Escherischu coli proteins. A neutron- SCHNERING H.G.VON : scattering studv of DNA-dependent RNA polymerase. Incommensurate magnetic phase in EuAsi with zone-boundary EUROPEAN JOURNAL OF BIOCHEMISTRY VOL. 156, PP. lock-in. 655-659 (1986) PHYSICAL REVIEW LETTERS VOL. 57, PP. 372-375 (1986)

140 86N0323 86RI33S NOZIERES P., QUEMADA D. : RICHTER D., DRIESEN G., HEMPELMANN R., ANDER­ A possible instability mechanism for plug formation in a sheared SON I.S.: suspension flow. Hydrogen-diffusion mechanism in amorphous Pdn5Sii5H7.5: A EUROPHYSICS LETTERS VOL.2, PP. 129-135 (1986) neutron scattering study. PHYSICAL REVIEW LETTERS VOL. 57, PP. 731-734 (1986) 86CH324 CHAIX-PLUCHERY O., NIEPCE J C. : 86D0336 Answer to "Comment on the Raman study of the thermal transfor­ DOSCH H„ PEISL J., DORNER B. : mation of calcium hydroxide". Attenuation of phonon scattering intensities by point defects. JOURNAL OF SOLID STATE CHEMISTRY VOL. 63, PP. 346-347 ZEITSCHRIFT FUER PHYS1K B VOL. 63, PP. 479-485 (1986) (1986) 86AG337 AGERON P., MAMPE W., MATES S.C., PENDLEBURY J.M. : 86BL325 UCN storage in fluid walled boules: A method for a neutron lifetime BLIN A.H., HASSE R.W., HILLER B., SCHUCK P., YAN- measurement. NOULEAS C. : NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS On the evaluation of semiclassical nuclear many-particle many-hole RESEARCH, VOL. A249, PP. 261-264 (1986) level densities. NUCLEAR PHYSICS VOL. A456, PP. 109-133 (1986) 86G0338 GOELTZ G., KRONMUELLER H., SEEGER A., SCHEUER H., 86BE326 SCHMATZ W. : BENHAM M.J., ROSS D.K., LARTIGUE C, PERCHEROH- Investigation of the dislocation arrangements in plastically deform­ GUEGAN A : ed Fe single crystals using magnetic small-angle scattering of neutrons. inelastic neutron scattering studies of multiply cycled lanthanum- PHILOSOPHICAL MAGAZINE A VOL. 54, PP. 213-235 (1986) nickel hydride. ZEITSCHR1FT FUER PHYSIKAL1SCHE CHEMIE.NF VOL. 36RD339 147.PP.219-229 (1986) ROTH M.. I EWIT-BENTLEY A. : Integration >f single crystal neutron data using a P.S.D : A case of Lige, weak and often overlapping reflections. 86RI327 JOURNA1 DE PHYSIQUE. COLLOQUES VOL. 47, PP. RICHARD J.M. : C5-27-C5-34 (1986). Spin dependenl forces in quark systems. PROCEEDINGS OF THE INTERNATIONAL WORKSHOP ON IN " THE QUARK STRUCTURE OF MATTER" M "EVALUATION OF SINGLE-CRYSTAL DIFFRACTION DATA JACOB, K. WINTER EDS, (WORLD SCIENTIFIC, 1986), PP. FROM 2-D POSITION-SENSITIVE DETECTORS", GRENOBLE, 373-382 NOVEMBER 4-6, 1985.

86IM328 86LE340 IMA1 B.S., YAU P., BALDWIN J.P., IBEL K., MAY R.P., BRAD­ LEHMANN M.S., ROBINSON T.E., WILKINS S.W. : BURY E.M. : Bragg-peak location employing a maximum-entropy formalism. Hyperacetylation of core histones does not cause unfolding of JOURNAL DE PHYSIQUE. COLLOQUES VOL. 47, PP. nucleosomes. C5-55-C5-62 (1986). PROCEEDINGS OF THE INTERNATIONAL THE JOURNAL OF BIOLOGICAL CHEMISTRY VOL. 261, WORKSHOP ON "EVALUATION OF SINGLE-CRYSTAL DIF­ PP.8784-8792 (1986) FRACTION DATA FROM 2-D POSITION-SENSITIVE DETEC­ TORS", GRENOBLE, NOVEMBER 4-6, 1985.

86BE329 86MC341 BELLISSENT-FUNEL M.TE1XEIRA J., BOSIO L., DORE J.C., MCINTYRE G.J., VISSER D. : CHIEUX P. : Integration of overlapping peaks in position-sensitive-detector (PSD) Spatial correlations in deeply supercooled water. data by least-squares fitting. EUROPHYSICS LETTERS VOL. 2, PP. 24-245 (1986) JOURNAL DE PHYSIQUE. COLLOQUES VOL. 47, PP. C5-75-C5-85 (1986). PROCEEDINGS OF THE INTERNATIONAL 86GA330 WORKSHOP ON "EVALUATION OF SINGLE-CRYSTAL DIF­ GABRYS B., HIGGINS J.S., SCHAERPF O. : FRACTS DATA FROM 2-D POSlTiON-SENSITIVE DETEC­ Contamination by coherent scattering of elastic incoherent structure TORS", GKENOBLE, NOVEMBER 4-6, 1985. factor observed in neutron scattering experiments. JOURNAL OF THE CHEMICAL SOCIETY. FARADAY TRAN­ 86BA342 SACTIONS I, VOL. 82, PP. 1923-1927 (1986) BARTUNH H.D., BOULIN C, SCHWAB H. : Real-time reduction of area detector data by hardware (DACOM) for static ard time-resolved crvsiallography. 86GA331 JOURNAL DE PHYSIQUE. COLLOQUES VOL. 47, PP. GABRYS B., HIGGINS J.S., SCHAERPF O. : C5-157-C5-.66 (1986). PROCEEDINGS OF THE INTERNA­ Short-range order in amorphous poly(methyl methacrylate). TIONAL WORKSHOP ON "EVALUATION OF SINGLE- JOURNAL OF THE CHEMICAL SOCIETY, FARADAY TRAN­ CRYSTAL DIFFRACTION DATA FROM 2-D POSITION- SACTIONS I, VOL. 82, PP. 1929-1934 (1986) SENSITIVE DETbCTORS", GRENOBLE, NOVEMBER 4-6, 1985.

86BI332 86PI343 BIRCHALL T., DENES G., RUEBENBAUER K., PANNETIER J.: P1LOTTI M.U., MCINTYRE G.J. : Goldanskii-Karyagin effect in a-SnF:: A neutron diffraction and Graphical isplay of three-dimensional (3-D) intensity data from Moessbauer absorption study. single-crysi \ reflections. HYPERFINE INTERACTIONS, VOL. 30, PP. 167-183 (1986) JOURNA1 DE PHYSIQUE. COLLOQUES VOL, 47, PP. C5-I83-C5- 86 (1986). PROCEEDINGS OF THE INTERNA­ TIONAL VORKSHOP ON "EVALUATION OF SINGLE- 86GR333 CRYSTAI DIFFRACTION DATA FROM 2-D POSITION- GRONDEY S. .PRAGER M., PRESS W., HEIDEMANN A. : SENS1TIV1 DETECTORS", GRENOBLE. NOVEMBER 4-6, 1985. Rotational excitations and orientationai disorder in solid mixtures of CHA and Kr. 86RI344 JOURNAL OF CHEMICAL PHYSICS, VOL. 85, PP. 2204-2210 RIMMER D.E. : (1986) Fast treatment of two-dimensional detector data using processor arrays. 86MC334 JOURNA1 DE PHYSIQUE. COLLOQUES VOL. 47, PP. MCEWEN K.A., WALKER M.B. : C5-189-C5 92 (1986). PROCEEDINGS OF THE INTERNA­ Free-energy analysis of the single-q and double-q magnetic structures TIONAL VORKSHOP ON "EVALUATION OF SINGLE- of neodymium. CRYSTAL DIFFRACTION DATA FROM 2-D POSITION- PHYSICAL REVIEW B VOL. 34, PP. 1781-1783 (1986) SENSITIVf DETECTORS", GRENOBLE, NOVEMBER 4-6, 1985.

141 86WI34S 86LI3S7 WILSON S.A., STANSFIELD R.F.D. : L1PINSKI S., CAPELLMANN H. : Possible use of OCCAM and transputers in P.S.D. data treatment. On the magnetization fluctuations in the completely disordered JOURNAL DE PHYSIQUE. COLLOQUES VOL. 47, PP. parpmagnetic medium. C5-193-C5-197 (1986). PROCEEDINGS OF THE INTERNA­ ZL'TSCHRIFT FUER PHYSIK B VOL. 64, PP. 211-216 (1986) TIONAL WORKSHOP ON "EVALUATION OF SINGLE- CRYSTAL DIFFRACTION DATA FROM 2-D POSITION- 86HE3S8 SENSITIVE DETECTORS", GRENOBLE, NOVEMBER 4-6, 1985. HEMPELMANN R., DRIESEN G., RICHTER D. : Hydrogen diffusion in amorphous PdsoSi2oH3 - A quasielastic 8 46 neutron scattering study. .c'H A.N. : IN 'HYDROGEN IN DISORDERED AND AMORPHOUS nigh resolution powder neutron diffraction. SOLIDS', G.BAMBAKIDIS.R.C.BOWMAN EDS (PLENUM, 1986) MATERIALS SCIENCE FORUM VOL. 7, PP. 45-54 (1986) (NATO ASI B 136), PP. 273-282 86R03S9 86CH347 RODMACQ B., MANGIN P., BILLARD L., CHAMBEROD A. :

CHRISTENSEN A.N., JORGENSEN J.E., PINTSCHOVIUS L., Hydrogen in amorphous CuxTii.K alloys : GOMPF F., REICHARDT W., LEHNER N. : Neutron diffraction and computer simulation studies. Lattice dynamics of the A15 compound MojSi. IN 'HYDROGEN IN DISORDERED AND AMORPHOUS PHYSICAL REVIEW B VOL. 34, PP. 2751-2756 (1986) SOLIDS', G, BAMBAK1DIS, R.C.BOWMAN EDS (PLENUM, 1986)(N,\TO ASI B I36),PP. 303-314 86FR348 86DI360 FRANCO H., RAPP R.E., GODFRIN H. : 3 DIANOUX A.J., RODMACQ B., MANGIN P., CHAMBEROD A.: Nuclear ferromagnetism of two-dimensional He. Quasi-elastic and inelastic neutron scattering study of CuTi amor­ PHYSICAL REVIEW LETTERS VOL. 57, PP. 1161-1164 (1986) phous hydrides. IN 'HYDROGEN IN DISORDERED AND AMORPHOUS 86MU349 SOLIDS', G.BAMBAKIDIS.R.C.BOWMAN FDS. (PLENUM, MURANI A.P. : 1986) (NATO ASI B 136),PP. 3I5-325 Comparison of polarised and unpolarizcd neutron inelastic scatter­ ing from CeSnj. 86LA361 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LARTIGUE C, DIANOUX A.J., PERCHERON-GUEGAN A., VOL. 61, PP. 212-217 (1986) ACHARD J.C. : Dynamical disorder of hydrogen in LaNij.yMy hydrides studied by quasi-elastic neutron scattering. 86CA3S0 IN 'HYDROGEN IN DISORDERED AND AMORPHOUS CAPELLMANN H., BROWN P.J., JOHNSON S.M., ZlEBfc'CK SOLIDS', GBAMBAKIDIS,R.C.BOWMAN EDS. (PLENUM, K.R.A., BOOTH J.G. : 1986) (NATO ASI B I36),PP. 327-337 A comment on "the comparison of polarized and unpolarized neutron inelastic scattering from CeSnj". 86DU362 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS DUBOIS J.M., JANOT C, PANNETIER J., PIANELLI A. : VOL. 61, P. 218 (1986) Diffraction approach to the structure of decagonal quasi-crystals. PHYSICS LETTERS A VOL. 117, PP. 421-427 (1986) 86LA3S1 LANGEL W. : 86RI363 Single particle scattering and momentum distributions in solid RIDOU C, ROUSSEAU M., PERNOT B., BOUILLOT J. : hydrogen. High-temperature mean square ionic displacements in KZnF.i. JOURNAL OF MOLECULAR STRUCTURE VOL. 143, PP. 1-4 JOURNAL OF PHYSICS C VOL. 19, PP. 4847 4853 (1986) (1986) 86GI364 GILMER J.W., WISWE D., ZACHMANN H.G., KUGLER J., 86KN352 FISCHER E.W. : KNOEZINGER E., KOLLHOFF H., SCHREMS O., LANGEL W. : Changes in molecular conformations on polyethylene [erephthalate) [ntermolecular interactions and dynamics of molecules and clusters produced by crystallization and drawing as determined by neutron isolated in solid argon and CCU matrices. scattering. JOURNAL OF MOLECULAR STRUCTURE VOL. 141, PP. POLYMER VOL. 27, PP. 1391-1394(1986) 399-404 (1986) 86CF.36S 86SU3S3 CEVA T., GOLDMANN M., MARTI C. : SUBBER A.R.H., PARK P., HAMILTON W.D., KUMAR K., X-ray diffraction of krypton and :.enon mixtures adsorbed on SCHRECKENBACH K., COLVIN G. : graphite. EO transitions in the gamma-unstable nucleus IMTe. JOURNAL DE PHYSIQUE VOL. 47, PP. 1527-1532 (1986) JOURNAL OF PHYSICS G VOL.12, PP. 881-902 (1986) 86T0366 TORBET J. : 86R0354 Magnetic birefringence study of fibrin formation and chylomicron ROBINSON S.J., HAMILTON W.D., HUNGERFORD P., PFEIF- behaviour in human blood plasma. FER B., JUNG G., SNELL1NG D.M. : IN 'BIOPHYSICAL EFFECTS OF STEADY MAGNETIC Levels and transition in IJ0Ba populated following the p decay of FIELDS', G. MARET & AL. EDS (SPRINGER-VERLAG,1986), PP. 23-27 JOURNAL OF PHYSICS G VOL. 12, PP. 903-933 (1986) 86T0367 86R03SS TORBET J. : ROBINSON R.A., PYNN R., ECKERT J., GOLDSTONE J.A. : Fibrin assembly in human plasma and fibrinogen/albumin mixtures. The Los Alamos constant-q spectrometer. BIOCHEMISTRY VOL. 25, PP. 5309-5314 (1986) PROCEEDINGS OF THE 8TH MEETING OF THE "INTERNA­ TIONAL COLLABORATION ON ADVANCED NEUTRON 86WE368 SOURCES", (ICANS-VHI), RUTHERFORD, UK, JULY 8-12, WENK H.R., BUNGE H.J., JANSEN E., PANNHTIER J. : 1985.RAL 85-10-110, VOL.2, PP.600-611. Preferred orientation of plagioclasc-neutron diffraction and U-stage data. TECTONOPHYSICS VOL. 126, PP. 271-284 (1986) 86DU356 DUMBRAJS O., HEISELBERG H., JENSEN A.S., MIRANDA A., 86ST369 OADES G.C., RICHARD J.M. : STEYRER G., PE1SL J. : Microscopic calculation of antiproton atomic-like bound states in light On the total cross-section for thermal neutrons of hydrogen in nuclei. niobium. NUCLEAR PHYSICS A VOL. 457, PP. 491-517 (1986) ZEITSCHRIFT FUER PHYSIK B VOL. 64, PP. «25-428 (1986)

142 86PR370 86KE380 PRAGER M., HEIDEMANN A., HAEUSLER W. : KEYSERU., MUENNICH F., PAHLMANN B., GRAEFENSTEDT Coupled pairs of quantum rotors in (CFbhSnCh: An inelastic M., FAUST H., WEIKARD H. : neutron scattering study. Experimental beta-decay energies of very neutron-rich light fission ZEITSCHRIFT FUER PHYSIK B VOL. 64, PP. 447-452 (1986) products. RADIATION EFFECTS VOL. 92-96 (1986). IN 'NUCLEAR DATA 86SM371 FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. SMITH J., CUSACK S., PEZZECA U., BROOKS B. KAR- (GORDON & BREACH, 1986), VOL. 1, PP. 713-716. PRO­ PLUS M.: CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ Inelastic neutron scattering analysis of low frequency motion in pro­ TA FE, USA, MAY 13-17, 1985. teins: A normal mode study of the bovine pancreatic trypsin inhibitor. JOURNAL OF CHEMICAL PHYSICS VOL. 85, PP. 3636-3654 (1986) 86G0381 GOENNENWEIN F. : 86GE372 Basic nuclear physics with thermal neutrons: cold fragmentation and GEISSLER E., HECHT A.M., TORBET J. : odd-even effects in fission. Spontaneous birefringence and photoelasticity of polyacrylamide gels. RADIATION EFFECTS VOL. 92-96 (1986).IN 'NUCLEAR DATA POLYMER VOL. 27, PP. 1489-1492 (1986) FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. 86BI373 (GORDON & BREACH, 1986), VOL. 1, PP. 879-900. PRO­ BILJAKOVIC K., LASJAUNIAS J.C., ZOUGMORE F., CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ MONCEAU P., LEVY F., BERNARD L., CURRAT R. : TA FE, USA, MAY 13-17, 1985. Contributions of phasons and of low-energy excitations to the specific heat of the quasi one-dimensional compound (TaSe4)2l. 86MA382 PHYSICAL REVIEW LETTERS VOL. 57, PP. 1907-1910 (1986) MAMPE W. : Investigation of basic properties of the neutron at ILL. 86AK374 RADIATION EFFECTS VOL. 92-96 (1986). IN 'NUCLEAR DATA AKER E., ENGELHARDT D., BRISSOT R., GELTENBORT P., FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. GOENNENWEIN F., OED A., GINDLER J., WILKINS B. : 24 (GORDON & BREACH, 1986), VOL. 1, PP. 923-926. PRO­ Mass and energy distribution of fission fragments in 'Cf(n,h,f). RADIATION EFFECTS VOL. 92-% (1986). IN 'NUCLEAR DATA CEEDINGS OF THE INTERNATIONAL CONFERESNCE, SAN­ FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. TA FE, USA, MAY 13-17, 1985. EDS.tGORDON & BREACH, 1986), VOL. I, PP. 337-340. PRO­ CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ 86GE383 TA FE, USA, MAY 13-17,1985. GELTENBORT P., GOENNENWEIN F., OED A., PERRIN P. : Mass spectrometry of fission fragments by simultaneous energy and 86PA375 lime-of-flight measurements. PANNICKE J., MUTTERER M., THEOBALD J.P., HEEG P., RADIATION EFFECTS VOL. 92-96(1986). IN 'NUCLEAR DATA WEINGAERTNER K., BARREAU G., LEROUX B. GOENNEN­ FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG A AL. EDS. WEIN F. : (GORDON & BREACH, 1986), VOL. 2, PP. 1331-1335. PRO­ Long range alpha particle associated neutron induced fission of U-235. CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ RADIATION EFFECTS VOL. 92-965 (1986). IN 'NUCLEAR TA FE, USA, MAY 13-17, 1985. DATA FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. (GORDON & BREACH, 1986), VOL. I, PP. 381-384. PROCEEDINGS OF THE INTERNATIONAL CONFERENCE, 86WE384 SANTA FE, USA, MAY 13-17, 1985. WEISSENBERGER E., GELTENBORT P., OED A., GOENNEN­ WEIN F. : 86K0376 Energy calibration of surface barrier detectors and ionization KOCZON P., MUTTERER M., THEOBALD J.P., MOORE M.S., chambers for fission fragments. GOENNENWEIN F., GELTENBORT P., OED A., PANNICKE J.: RADIATION EFFECTS VOL. 92-96 (1986). IN 'NUCLEAR DATA Mass and energy distribution of fragments from the 245Cm(nth,f) FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. reaction. (GORDON & BREACH, 1986), VOL. 2, PP. 1389-1393. PRO­ RADIATION EFFECTS VOL. 92-96 (1986). IN 'NUCLEAR DATA CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. TA FE, USA, MAY 13-17, 1985. (GORDON & BREACH, 1986), VOL. 1, PP. 385-388. PRO­ CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ 86MI385 TA FE, USA, MAY 13-17, 1985. MICHAUDON A. : 86GE377 Summary talk covering sessions on basic physics. GELTENBORT P., GOENNENWEIN F., OED A. : RADIATION EFFECTS VOL. 92-96(1986). IN 'NUCLEAR DATA Precision measurements of mean kinetic energy release in thermal- FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. neutron -induced fission of 233U, 2Î!U and n Pu. (GORDON & BREACH, 1986), VOL. 2, PP. 1661-1668. PRO­ RADIATION EFFECTS VOL. 92-96 (1986). IN 'NUCLEAR DATA CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. TA FE, USA, MAY 13-17, 1985. EDS.(GORDON & BREACH, 1986), VOL. 1, PP. 393-396. PRO­ CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ 86BU386 TA FE, USA, MAY 13-17, 1985. BUCHENAU U., PRAGER M., NUECKER N., DIANOUX A.J., AHMAD N., PHILLIPS VV.A. : 86SI378 Low-frequency modes in vitreous silica. SICRE A., BARREAU G., BOUKELLAL A., CA1TUCOLI F. DOAN T.P., LEROUX B., GELTENBORT P., GOENNENWEIN PHYSICAL REVIEW B VOL. 34, PP. 5665-5673 (1986) F., OEb A., ASGHAR M. : High resolution study of U235(nih,f) and Th229(nih,f) with Cos! Fan 86ZA387 Tulte mass spectrometer. ZABEL H., HARDCASTLE S.E., NEUMANN D.A., SUZUKI M., RADIATION EFFECTS VOL. 92-96(1986). IN 'NUCLEAR DATA MAGERL A. : FOR BASIC AND APPLIED SCIENCE' P.G. YOUNG & AL. EDS. Dynamics of two-dimensional melting on a periodic substrate. (GORDON & BREACH, 1986), VOL. I, PP. 401-404. PRO­ PHYSICAL REVIEW LETTERS VOL. 57, PP. 2041-2044 (1986) CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ TA FE, USA, MAY 13-17, 1985. 86BR388 86AS379 BRAGANZA L.F., WORCESTER D.L. : ASGHAR M., BOCQUET J.P., BRISSOT R., DJEBARA M , Hydrostatic pressure induces hydrocarbon chain inierdigitation in MAUREL M., N1FENECKER H.. 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143 86LA390 86FE402 LANDER G.H., BROWN P.J., SPIRLET M.R., REBIZANT J., FENGLA1 HE., COWLAM N., CARR G.E., SUCK J.B. : KANELLAKOPULOS B., KLENZE R. : Evidence of chemical short range order in molten CuTi alloys. Spin-density study of UCU-discovery of covalency effects. PHYSICS AND CHEMISTRY OF LIQUIDS VOL. 16, PP. 99-112 JOURNAL OF THE LESS-COMMON METALS VOL. 121, PP. (1986) 301-305 (1986) 86MA403 86JA391 MACONNACHIE A., DIANOUX A.J., SHIRAKAWA H., JANOT C, BRUSON A., MARCHAL G. : TASUMI M. : Neutron scattering measurements of imerdiffusion in amorphous Incoherent inelastic neutron scattering from polyacetylenes in the 3i/Ge multilayers. 3500- 400 cm"1 region. JOURNAL DE PHYSIQUE VOL. 47, PP. 1751-1756 (1986) SYNTHETIC METALS VOL. 14, PP. 323-327 (1986) 86PA392 PANNETIER J. : 86JA404 Real-time neutron powder diffraction : JANOT C. : A technique for the study of solid state reactions. Les amorphes métalliques et leurs propriélés magnétiques. BER1CHTE DER BUNSENGESELLSCHAFT FUER REVUE DE PHYSIQUE APPLIQUEE VOL. 21, PP. 635-647 (1986) PHYSIKALISCHE CHEMIE VOL. 90, PP. 634-638 (1986) 86PO40S 86AV393 POINSIGNON C, RAMSAY J.D.F. : AVENIER M., CAVAIGNAC J.F., KOANG D.H., VIGNON B., Neutron scattering of supercooled water in silica gels. HART R., WILSON R. : JOURNAL OF THE CHEMICAL SOCIETY. FARADAY TRAN­ Measurement of the photon asymmetry in capture of polarized SACTIONS I VOL. 82, PP. 3447-3459 (1986) neutrons by deuterons. NUCLEAR PHYSICS A VOL. 459, PP. 335-358 (1986) 86KN406 KNOEZ1NGER E., KOLLHOFF H., LANGEL W. : 86B0394 Cluster formation of hydrogen cyanide in solid and liquid CCU BOUCHER B., CHIEUX P., CONVERT P., TOURBOT R., TOUR- matrices. NARIE M. : JOURNAL OF CHEMICAL PHYSICS VOL. 85, PP. 4881-4889 'Seedy magnetic' order in amorphous TbCuj.j-i investigated by small- (1986) and large-angle neutron scattering and by magnetic measurements. JOURNAL OF PHYSICS F VOL. 16, PP. 1821-1843 (1986) 86PR407 PRAGER M., LANGEL W. : 86NE39S Intermolecular interaction in Sn(CH.i)j: An inelastic neutron scatter­ NEUMANN K.U., CAPELLMANN H., FISK Z., SMITH J.L., ing study of matrix isolated molecules. Z1EBECK K.R.A. : JOURNAL OF CHEMICAL PHYSICS VOL. 85, PP. 5279-5285 Observation of antiferromagnetic correlations in UBeu. (1986) SOLID STATE COMMUNICATIONS VOL. 60, PP. 641-643 (1986) 86KU396 86CH408 KUHS W.F., LEHMANN M.S. : CHATTOPADHYAY T., PANNETIER J., SCHNERING Oxygen disorder and the geometry of the water molecule in ice lh. H.G.VON : IN 'WATER AND AQUEOUS SOLUTIONS', G.E.NEILSON, J.E. Neutron diffraction study of the structural phase transition in SnS ENDERBY EDS. (COLSTON PAPERS, VOL.37) (A.H1LGER, and SnSe. 1986), PP. 75-82 JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS VOL. 47, PP. 879-885 (1986) 86TE397 TEIXE1RA J., BELLISSENT-FUNEL M., CHEN S.H., DOR- 86AL409 NER B.: ALLEN A.J., OBERTHUER R.C., PEARSON D., Observation of collective excitations in heavy water by neutron scat­ SCHOFIELD P., WILDING C.R. : tering. The development of the fine porosity and gel structure of hydrating IN 'WATER AND AQUEOUS SOLUTIONS', G.W. NEILSON, cement systems. J.E. ENDERBY EDS. (COLSTON PAPERS, VOL.37) (A.HILGER, REPORT AERE R 12187. 1986), PP. 99-104 86ST410 86BE398 STEYRER G., PEISL J. : BELLISSENT-FUNEL M.D1ANOUX A.J., FONTANA M.P., Coherent phase transition in NbHx studied by neutron radiography. MA1SANO G., MIGLIARDO P. : EUROPHYSICS LETTERS VOL. 2, PP. 835-841 (1986) Low-frequency dynamics in aqueous ZnCb solutions. IN 'WATER AND AQUEOUS SOLUTIONS', G.W. NEILSON, 86CA4I1 J.E. ENDERBY EDS. (COLSTON PAPERS, VOL.37) (A.HILGER, CAVAGNAT D., MAGERL A„ VETT1ER C, CLOUGH S. : 1986), PP. 199-206 Methyl tunnelling in a-crystallised toluene by inelastic neutron scat­ tering: temperature and pressure effects. 86TU399 JOURNAL OF PHYSICS C VOL. 19, PP. 6665-6672 (1986) TURNER J., FINNEY J.L., BOUQUIERE J.P., NEILSON G.W., CUMMINGS S., BOUILLOT J. : 86BR412 A neutron-scattering study of urea hydration using isotopic BRAGANZA L.F., WORCESTER D.L. : substitution. IN 'WATER AND AQUEOUS SOLUTIONS', G.W. NEILSON, Structural changes in lipid bilayers and biological membranes caus­ J.E. ENDERBY EDS. (COLSTON PAPERS, VOL.37) (A.HILGER, ed by hydrostatic pressure. 1986), PP. 277-286 BIOCHEMISTRY VOL. 25, PP. 7484-7488 (1986) 86BE400 86MA413 BERNAS H., TRAVERSE A., JANOT C. : MANGIN P., BROWN P.J., TETE C. : Amorphous metallic hydrides: A biased view of recent progress. Magnetic short range order above Tc in an amorphous iron based IN 'AMORPHOUS METALS AND SEMICONDUCTORS', alloy. P.HAASEN, R.I.JAFFEE EDS. (PERGAMON PRESS, 1986), JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS PP. 435-464 VOL. 62, PP. 127-133 (1986) 86BR40I 86F0414 BROWN P.J. : FORST R..BOYSEN H..FREY F..JAGODZ1NSKI H..ZEYEN C: Interpretation of magnetization density measurements in concentrated Phase transitions and ordering in urea inclusion compounds with n- magnetic systems : paraffins. Exploitation of the crystal translational symmetry. JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS VOL. CHEMICA SCRIPTA VOL. 26, PP. 433-439 (1986) 47, PP. 1089-1097 (1986)

144 86AR41S 86SK427 ARCHER J.M., LEHMANN M.S. : SKIPPER N.T., CUMMINGS S., NEILSON G.W., ENDERBY A simple adjustable mount for a two-stage cryorefrigerator on an J.E.: Eulerian cradle. Ionic structure in aqueous electrolyte solution by the difference JOURNAL OF APPLIED CRYSTALLOGRAPHY VOL. 19, PP. method of x-ray diffraction. 456-458 (1986) NATURE VOL. 321, PP. 52-53 (1986) 860E416 86EN428 OED A., GELTENBORT P., GOENNENWEIN F., STUETZ B. : ENDERBY J.E., NEILSON G.W. : Bragg curves of fission fragments in gases. Diffraction techniques for the study of pure water and aqueous RADIATION EFFECTS VOL. 92-96 (1986).IN 'NUCLEAR DATA solutions. FOR BASIC AND APPLIED SCIENCE'.P.G.YOUNG & AL. IN 'BIOMEMBRANES-PROTONS AND WATER: STRUCTURE EDS.fGORDON & BREACH, 1986), VOL. 2, PP. 1395-1398. AND TRANSLOCAT10N'(METHODS IN ENZYMOLOGY, PROCEEDINGS OF THE INTERNATIONAL CONFERENCE, VOL.127KAC. PRESS, 1986), PP. 319-328 SANTA FE, USA, MAY 13-17, 1985. 86AR429 86ST417 ARAI M., JOHNSON R.W., PRICE D.L., SUSMAN S., GAY M. STUHRMANN H.B., SCHAERPF O., KRUMPOLC ENDERBY J.E. : M., NIINIKOSKI T.O., RIEUBLAND M., RIJLLART A. : The structure of phosphorus-selenium glasses. II.Results from neutron Dynamic nuclear polarisation of biological matter. diffraction with isotope substitution. EUROPEAN BIOPHYSICS JOURNAL VOL. 14, PP. 1-6 (1986) JOURNAL OF NON-CRYSTALLINE SOLIDS VOL. 83, PP. 80-90 (1986) 86ZA418 ZACCAI O, WACHTEL E., EISENBERG H. : 86FI430 Solution structure of halophilic malate dehydrogenase from small- FITCH A.N. : angle neutron and x-ray scattering and ultracentrifugation. Some disordered systems studied by high resolution neutron powder JOURNAL OF MOLECULAR BIOLOGY VOL. 190, PP. 97-106 diffraction. (1986) IN 'HIGH RESOLUTION POWDER DIFFRACTION', C.R.A. CATLOW ED., (TRANS TECH PUBL. 1986), MATERIALS 86HA419 SCIENCE FORUM VOL.9, PP. 113-128. HASSE R.W. : Semiclassical description of muttiparticle-multtriole excitations in 86ME431 nuclei. MERCIER R., MALUGANI J.P., TACHEZ M., DIANOUX A.J. : IN 'PHASE SPACE APPROACH TO NUCLEAR DYNAMICS', Etude du verre conducteur cationique 0,65 AgPOj-0,35 AgBr par DI TORO & AL. EDS (WORLD SCIENTIFIC, 1986), PP. 685-711 diffusion quasiélastique et inélastique des neutrons. COMPTES RENDUS DE L'ACADEMIE DES SCIENCES SERIE 86NY420 II, VOL. 303, PP. 345-348 (1986) NYSTROM B., ROOTS J., HIGGINS J.S., GABRYS B. PEIFFER D.G., MEZEI F., SARKISSIAN B. : 86MA432 Dynamics of polystyrene sulfonate ionomers in solution. A neutron MARTIN A., RICHARD J.M., TAXIL P. : spin-echo study. About convexity properties of the baryon mass spectrum. JOURNAL OF POLYMER SCIENCE. PART C: POLYMER LET­ PHYSICS LETTERS B VOL. 176, PP. 224-228 (1986) TERS VOL. 24, PP. 273-281 (1986) 86KU433 86SC421 KUHS W.F. : SCHULTZ A.J., WANG H.H., WILLIAMS J.M., FILHOL A. : Methods for the study of water in ice phases. Effect of structural disorder on organic superconductor: A neutron IN 'BIOMEMBRANES-PROTONS AND WATER: STRUCTURE diffraction study of "high Tc"p*-(BEDT-TTF)!lj al 4.5K and 1.5 AND TRANSLOCATION' (METHODS IN ENZYMOLOGY, kbar. VOL.127) (AC. PRESS, 1986), PP. 303-318 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY VOL. 108, PP. 7853-7855 (1986) 86BI434 BIGGIN S., CUMMINGS S., ENDERBY J.E., BLANDER M. : 86F0422 The structure of equimolar LiCl-AICb melt by neutron scattering. FOURN1ER J.M., BOEUF A., FRINGS P., BONNET M. PROCEEDINGS OF THE ELECTROCHEMICAL SOCIETY VOL. BOUCHERLE J.X., DELAPALME A., MENOVSKY A. : 86, PP. 81-96 (1986) Polarized neutron diffraction study of UNÎ2. JOURNAL OF THE LESS-COMMON METALS VOL. 121, PP. 86NE435 249-252 (1986) NEILSON G.W., ENDERBY J.E. [Editors], : Water and aqueous solutions. 86BA423 PROCEEDINGS OF THE 37TH SYMPOSIUM OF THE COL­ BARTSCHER W., REB1ZANT J., BOEUF A., CACIUFFO R., STON RESEARCH SOCIETY HELD IN THE UNIVERSITY RUSTICHELLI F., FOURNIER J.M., KUHS W.F. : OF BRISTOL IN APRIL 1985 (COLSTON PAPERS VOL. 37) Distribution of deuterium in the cubic Laves phases ThZrîD*. (A. HILGER, 1986) (BOOK). JOURNAL OF THE LESS-COMMON METALS VOL. 121, PP. 455-460 (1986) 86LE436 LEDERER H., MAY R.P., KJEMS J.K., BAER G., HEU- 86BR424 MANN H.: BRUECKELT., KOEBLER U., PRANDL W., WEINMANN R. : Solution structure of a short DNA fragment studied by neutron scat­ Magnetisation phenomena due to magnetic disorder in the partly tering. frustrated compounds (FexCn-s)aCa3(Ge04)3. EUROPEAN JOURNAL OF BIOCHEMISTRY VOL. 161, PP. SOLID STATE COMMUNICATIONS VOL. 59, PP. 29-33 (1986) 191-196 (1986) 86AN425 86ZU437 ANTONSSON B., LEBERMAN R., JACROT B., ZACCAI G. : ZULAUF M., TIMMINS P.A., GARAVITO R.M. : Small-angle neutron scattering study of '.he ternary complex formed Neutron crystallography of a membrane protein. Localization of between bacterial elongation factor Tu, guanosine 5'-triphosphate, detergent and protein at 20-Â resolution. and valyl-tRNA™. BIOPHYSICAL JOURNAL VOL. 49, PP. 96-98 (1986) BIOCHEMISTRY VOL. 25, PP. 3655-3659 (1986) 86ZA438 86FR426 ZACCAI G., BUNICK G.J., EISENBERG H. : FRUCHART D., ANNE M., WOLFERS P. .LARTIGUE C. Denaturation of a halophilic enzyme monitored by small-angle ROUDAUT E. : neutron scattering. Structural investigations using a position-sensitive neutron detector. JOURNAL OF MOLECULAR BIOLOGY VOL. 192, PP. 155-157 CHEMICA SCRIPTA VOL. 26A, PP. 107-113 (1986) (1986)

145 86BE439 86MI4S0 BERTHET-COLOMINAS .BOULANGER P., DEVAUX MIANE J.L., FILHOL A., ALMEIDA M., JOHANNSEN I.: C, JACROT B., T1MM1NS P.A. : Principal electrical conductivities in the organic conductors TEA. Structural studies of adenovirus type 2 and an assembly mutant. (TCNQ)î and TTF.TCNQ: The microwave approach. BIOPHYSICAL JOURNAL VOL. 49, PP. 21-22 (1986) MOLECULAR CRYSTALS AND LIQUID CRYSTALS VOL. 136, PP. 317-334(1986) 86ST440 STROTHMANN H., SCHAERPF O. : 86GA451 Determination of temperature dependence of Bloch wall thickness GALLOIS B., GAULTIER J., HAUW C, LAMCHARFI in Fe(4 at % Si) single crystals by means of neutron refraction. T., FILHOL A.: IN 'SOFT MAGNETIC MATERIALS 7' .PROCEEDINGS OF THE Neutron low-temperature (4 and 20 K) and X-ray high-pressure BLACKPOOL CONFERENCE, AUGUST 27-30, 1985 (EURO­ (6.5xl02 and 9.8xl02 MPa) structures of the organic superconduc­ PEAN PHYSICAL SOCIETY), PP. 102-104 tor Di(2,3,6,7-tetramethyl- 1,4,5,8-tetraselenafulvaIenium) hex- afluorophosphate, (TMTSF)jPF6. 86TR441 ACTA CRYSTALLOGRAPHICA B VOL. 42, PP. 564-575 (1986) TROST W., DIFFERT K., MAIER K., SEEGER A. : Point defects in metals in thermal equilibrium. 86UW452 IN 'ATOMIC TRANSPORT AND DEFECTS IN METALS BY UWAHA M., BAYM G.: NEUTRON SCATTERING'.PROCEEDINGS OF AN ILL-IFF Ultrasonic attenuation in electron-hole liquids. WORKSHOP, JUELICH, OCTOBER 2-4,1985, C.JANOT & AL. PHYSICAL REVIEW B VOL. 34, PP. 4074-4087 (1986) EDS. SPRINGER PROCEEDINGS IN PHYSICS VOL. 10, (SPRINGER-VHRLAG, 1986), PP. 219-224. 86SI453 86HA442 SIEGER D., TIETZE H..GEICK R., BATES S., HAHN K„ LEY G., SCHULLER H., OBERTHUER R.C. : COWLEY R.A., TREUTMANN W., STEIGENBERGER U. : On particle coalescence in latex films. Dispersionless magnetic cluster excitations coexisting with wave-like COLLOID AND POLYMER SCIENCE VOL. 264, PP. 1092-1096 magnons within the same frequency band in the randomly disordered (1986) magnetic system RbjMno.7Cro,.iCl4. SOLID STATE COMMUNICATIONS VOL. 60, PP. 847-851 (1986) 86ST443 STROTH U., HASSE R.W., SCHUCK P. : 86BE4S4 On the longitudinal charge response in the quasielastic peak region. BECKER P., COHEN-ADDAD C, DELLEY B., HIRSCHFELD IN 'WEAK AND ELECTROMAGNETIC INTERACTIONS IN F.L., LEHMANN M.S.: NUCLEI', PROCEEDINGS OF THE INTERNATIONAL SYM­ A theoretical study of short S...0 'non-bonded' interactions. POSIUM, HEIDELBERG, JULY 1-5, 1986, H.V. KLAPDOR ED. IN 'APPLIED QUANTUM CHEMISTRY'. PROCEEDINGS OF (SPRINGER-VERLAG, 1986), PP. 427-430 THE NOBEL LAUREATE SYMPOSIUM, HONOLULU, HI, DECEMBER 16-21, 1984, W.H.SMITH & AL. EDS (RE1DEL 86DU444 PUBL., 1986), PP. 361-373 DUBBERS D.: The beta decay of the neutron. 86MA455 IN 'WEAK AND ELECTROMAGNETIC INTERACTIONS IN MATTERN K., FELDERHOF B.U.: NUCLEI', PROCEEDINGS OF THE INTERNATIONAL SYM­ Rate of diffusion-controlled reactions in a random array of monopole POSIUM, HEIDELBERG, JULY 1-5, 1986, H.V. KLAPDOR ED. sinks. (SPRINGER-VERLAG, 1986), PP. 516-522 PHYSICA A VOL. 135, PP. 505-518 (1986) 86SC445 86KJ456 SCHRECKENBACH K., HAHN A.A., GELLETLY W., FEI- KJEMS J.K., FRELTOFT T., RICHTER D., SINHA S.K.: LITZSCH F.VON, COLVIN G., KRUSCHE B. : Neutron scattering from fractals. Reactor core antineutrino spectra. PHYSICA B VOL. 136, PP. 285-290 (1986). PROCEEDINGS OF IN 'WEAK AND ELECTROMAGNETIC INTERACTIONS IN THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ NUCLEI', PROCEEDINGS OF THE INTERNATIONAL SYM­ TERING", SANTA FE, USA, AUGUST 19-23, 1985. POSIUM, HEIDELBERG, JULY 1-5, 1986, H.V. KLAPDOR ED. (SPRINGER-VERLAG, 1986), PP. 759-763 86ËL4S7 EL JAZOULI A., SOUBEYROUX J.L., DANCE J.M., LE 86FR446 FLEM G.: FREEDMAN S.J., ARNOLD M., DOEHNER J., LAST J., DUB­ The Nasicon-like copper(II) titanium phosphate Cuo..wTiz(P04)j. BERS D.: JOURNAL OF SOLID STATE CHEMISTRY VOL. 65, PP. 351-355 Search for short-lived axions emitted from neutron capture on (1986) protons. IN 'WEAK AND ELECTROMAGNETIC INTERACTIONS IN NUCLEI', PROCEEDINGS OF THE INTERNATIONAL SYM­ 86BA458 POSIUM, HEIDELBERG, JULY 1-5, 1986, H.V. KLAPDOR ED. BALLOU R., GIGNOUX D., LEMAIRE R.: (SPRINGER-VERLAG, 1986), PP. 871-874 Hybridation d, instabilité du magnétisme et apparition de la supracon­ ductivité dans les alliages entre métaux de transition. 86TR447 IN 'MAGNETISME, LIQUIDE DE FERMI, SUPRACONDUC­ TREWHELLA J., POPOT J.L., ZACCAI G., ENGELMAN D.M.: TIVITE' RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN Localization of two chymotryptic fragments in the structure of VERCORS. renatured bacteriorhodopsin by neutron diffraction. EMBO JOURNAL VOL. 5, PP. 3045-3049 (1986) 86B04S9 BORDET P., MIRAGLIA S., HODEAU J.L., MAREZIO 86MU448 M., ELFASSI S., WEISS F., GENICON J.L., MONDONDANON MURANI A.P.: J.P., TOURNIER R.: Paramagnetic spectral response in some Ce and Yb based mixed Contrôle de la composition DF(Sni-*ErOEr-iRri6Sni8 et ses relations valence material. avec les propriétés supraconductrices et magnétiques. IN 'PROCEEDINGS OF THE SOLID STATE PHYSICS SYM­ IN 'MAGNETISME, LIQUIDE DE FERMI, SUPRACONDUC­ POSIUM', NAGPUR, INDIA, DECEMBER 27-30, 1985, VOL. TIVITE', RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN 28A, PP. 115-132 VERCORS 86ZA449 86FO460 ZACCAI G.: FOURN1ER J.M., BOEUF A., BONNET M., BOUCHERLE J.X., Measurement of density and location of solvent associated with DELAPALME A., FRINGS P., MENOVSKY A.: biomolecules by small-angle neutron scattering. Polarized neutron diffraction study of UNh. IN 'BIOMEMBRANES-PROTONS & WATER: STRUCTURE IN 'MAGNETISME, LIQUIDE DE FERMI, SUPRACONDUC­ AND TRANSLOCATION'(METHODS IN EN- TIVITE', RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN ZYMOLOGY.VOL.127) (ACADEMIC PRESS, 1986) PP.6I9-629. VERCORS

146 86MU461 86JA471 MURAN1 A.P.: JANOT C, WRIGHT A.F., [Editors]: Paramagnetic spectral response in some Ce and Yb based mixed Third International Conference on the structure of non-crystalline valence materials. materials. IN 'MAGNETISME, LIQUIDE DE FERMI, SUPRACONDUC­ JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, COLLOQUE TIVITE', RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN C8 (1985). PROCEEDINGS OF THE THIRD INTERNATIONAL VERCORS CONFERENCE ON "THE STRUCTURE OF NON­ CRYSTALLINE MATERIALS", ILL, JULY 8-12, 1985. 86N0462 NOZIERES P.: 86JA472 3He superfluide: notions simples sur la superfluidité de paires dans JANOT C, PETRY W., RICHTER D., SPRINGER T.[Editors]: un état multiplet. Atomic transport and defects in metals by neutron scattering. IN 'MAGNETISME, LIQUIDE DE FERM1, SUPRACONDUC­ SPRINGER PROCEEDINGS IN PHYSICS VOL. 10 (SPRINGER- TIVITE', RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN VERLAG, 1986). PROCEEDINGS OF AN IFF-ILL VERCORS WORKSHOP.JUELICH, FRG, OCTOBER 2-4, 1985. 86SU473 86SA463 SUCK J.B., QUITMANN D., MAIER B., [Editors]: SARKISS1AN B.V.B.: Workshop on investigations of higher order correlation functions. Magnetism and superconductivity in Y9C07. JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, COLLOQUE IN 'MAGNETISME, LIQUIDE DE FERMI, SUPRACONDUC­ C9 (1985). PROCEEDINGS OF THE WORKSHOP ON "IN­ TIVITE', RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN VESTIGATIONS OF HIGHER ORDER CORRELATION FUNC­ VERCORS TIONS", ILL, JULY 15-16, 1985.

85N0454 86ME474 NOZIERES P., SCHIRMACHER W.: MEZEI F.: Critical temperature and correlation functions in itinerant fer- Neutron spin echo spectroscopy. Applications in magnetism. romagnets. EUROPHYS1CS NEWS, VOL. 17, PP. 129-131 (1986) IN 'MAGNETISME' LIQUIDE DE FERMI, SUPRACONDUC­ TIVITE', RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN 86KE475 VERCORS KEARLEY G.J..PRESSMAN H.A., SLADE C.T.: The geometry of the H5O2' ion in (HsOj' )J(PWI20«I' ~) studied by inelastic neutron scattering vibrational spectroscopy. 86WE465 JOURNAL OF THE CHEMICAL SOCIETY, CHEMICAL COM­ WEISS F., EL FASSI S. .BOURSIER D., BORDET P., MUNICATIONS, PP. 1801-1802(1986) HODEAU J.L.: Mesures de susceptibilité sur les stannures de terre rare et de métaux 86KE476 précieux. Phase 1 ~ phase II' dans le stannure de rhodium et d'yt- KEARLEY G.J., COCKCROFT J.K., FITCH A.N., FENDER terbium. B.E.F.: IN 'MAGNETISME, LIQUIDE DE FERMI, SUPRACONDUC­ The inelastic neutron scattering spectrum of rotational tunnelling in TIVITE', RCP-CNRS, 14-17 OCTOBRE 1985, RENCUREL EN phase III of NH«PF6. VERCORS JOURNAL OF THE CHEMICAL SOCIETY CHEMICAL COM­ MUNICATIONS^. 1738-1740 (1986) 86FI466 FILHOL A., MAIER B., MASON S.A., MC1NTYRE G.J., ROTH 86EL477 M., LEWIT-BENTLEY A., BENTLEY G.A., BR1COGNE ELARBY-AOUIZERAT A„ CHIEUX P., CLAUDY P., DUPUY G., KAHN R. .[Editors]: J.. JAL J.F., LETOFFE J.M.: Evaluation of single-crystal diffraction data from 2-D position- Structural effects in the electrolyte glass (LiCl)xHjO and the nuclea- sensitive detectors. tion of metastable phases. JOURNAL DE PHYSIQUE. COLLOQUES VOL. 47, COLLOQUE JOURNAL DE PHYSIQUE COLLOQUES, VOL. 46, COLLOQUE C5 (1986). PROCEEDINGS OF THE INTERNATIONAL C8 PP. C8-629-C8-633 (1985). PROCEEDINGS OF THE THIRD WORKSHOP ON "EVALUATION OF SINGLE-CRYSTAL DIF­ INTERNATIONAL CONFERENCE ON "THE STRUCTURE OF FRACTION DATA FROM 2-D POSITION-SENSITIVE DETEC­ NON- CRYSTALLINE MATERIALS", ILL, JULY 8-12, 1875. TORS", GRENOBLE, NOVEMBER 4-6, 1985. 86BA478 BARTSCH E., BERTAGNOLLI H„ CHIEUX P.: 86KR467 A neutron and x-ray diffraction study of the binary liquid aromatic KRUEGER E., NISTLER W., WEIRAUCH W.: system benzene-hexafluorobenzene .II. The mixtures. Determination of h/mn. BERICHTE DER BUNSELLGESELLSCHAFT FUER METROLOG1A VOL. 22, PP. 172-173 (1986) PHYSIKALISCHE CHEMIE VOL.90, PP. 34-46 (1986)

86BE468 86WI479 BEE M„ JOBIC H., CAUCHETEUX C: WINTER C, KRUSCHE B., LIEB K.P., SCHMIDT H.H., EGIDY Molecular reorientations in the two plastic crystalline phases of nor- VON T..HUNGERFORD P., HOYLER F., BOERNER H.G.: bornane. An investigation from incoherent quasielastic neutron scat­ Level structure of ,7Sr from the 86Sr(n,7) and 86Sr(d,p) reactions. tering. NUCLEAR PHYSICS VOL. A460 , PP. 501-528 (1986) JOURNAL DE CHIMIE PHYSIQUE VOL. 83, PP. 623-629(1986) 86JA480 JANOT C, PANNETIER J., DUBOIS J.M., FRUCHART R.: 86AN469 Isomorphism in quasiperiodic structures. ANTONIADIS A., BERRUYER J., FILHOL A.: PHYSICS LETTERS A, VOL. 119, PP. 309-312 (1986) Statistical methods applied to PSD data: Characterization on the detector response. JOURNAL DE PHYSIQUE. COLLOQUES VOL. 47, PP. 86GE48I C5-17-C5-25 (1986). PROCEEDINGS OF THE INTERNATIONAL GERVASIO G., MASON S.A., MARESCA L., NAT1LE G. : WORKSHOP ON "EVALUATION OF SINGLE-CRYSTAL DIF­ Neutron diffraction analysis (T= 120 K) of FRACTION DATA FROM 2-D POSITION-SENSITIVE DETEC­ [Pt(QH4)Cl(Me2NCH2CH2NMe2)](CI04). TORS", GRENOBLE, NOVEMBER 4-6, 1985. INORGANIC CHEMISTRY VOL. 25 PP. 2207-2211 (1986) 86ZA482 86PV470 ZABEL V., SAENGER W., MASON S.A. : PYNN R., SKJELTORP A. [Editors]: Neutron diffraction study of the hydrogen bonding in b-cyc!odextrin Scaling phenomena in disordered svstems. undecahydrate at 120K : from dynamic flip-flops to static PROCEEDINGS OF A NATO ADVANCED STUDY INSTITUTE, homodromic chains. GE1LO, NORWAY, APRIL 8-19, Î985. NATO ASI B VOL 133 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY VOL. (PLENUM PRESS, 1985) 108.PP. 3664-3673 (1986)

147 86SA483 86BO1008 SAENGER W., BETZEL C, ZABEL V., BROWN G.M., H1NGER- BOUCHERLE J.X., FILLION G., FLOUQUET J., GIVORD F., TY B.E., LESYNG B., MASON S.A. : LEJAY P., SCHWEIZER J. : Hydrogen bonding patterns and dynamics in the hydration of Influence of composition on the form factor measured in CeSm. biological macromolecuies. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS JOURNAL OF BIOSCIENCES SUPPLEMENT VOL. 8, N.l-2, PP. VOL. 54-57, PP. 421-422 (1986). PROCEEDINGS OF THE INTER­ 437-450(1985). IN "PROCEEDINGS OF THE INTERNATIONAL NATIONAL CONFERENCE ON "MAGNETISM, ICM'85", SAN SYMPOSIUM ON BIOMOLECULAR STRUCTURE AND IN­ FRANCISCO, USA, 26-30 AUGUST 1985. TERACTIONS", 17-22 SEPTEMBRE 1984, BANGALORE.INDIA 86LO1009 86SC484 LOTTERMOSER W., MUELLER R., FUESS H. : SCHRECKENBACH K. : Antiferromagnetism in synthetic olivines. Experimental methods for the determination of the neutron lifetime. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS IN "86 MASSIVE NEUTRINOS IN ASTROPHYSICS AND IN VOL. 54-57.PP. 1005-1006 (1986). PROCEEDINGS OF THE IN­ PARTICLE PHYSICS", PROCEEDINGS OF THE SIXTH TERNATIONAL CONFERENCE ON "MAGNETISM, ICM'85", MORIOND WORKSHOP, T1GNES, JANUARY 25-FEBRUARY SAN FRANCISCO, USA, 26-30 AUGUST 1985. 1, 1986, O. FACKLER J.TRAN THANH VAN EDS. (EDITIONS FRONTIERES, 1986),PP. 313-319. 86CY1010 CYWINSKI R., OKPALUGO D.E., BURKE S.K., BOOTH J.G. : Magnetisation density in CoGa. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS VOL. 54-57.PP. 1009-1010 (1986). PROCEEDINGS OF THE IN­ TERNATIONAL CONFERENCE ON "MAGNETISM, ICM'85", PUBLICATIONS RECEIVED SAN FRANCISCO, USA, 26-30 AUGUST 1985. CONCERNING EXPERIMENTAL 86AL1011 ALLEN A.J., SCHOFIELD P. : WORK PERFORMED AT THE Possible fractal structure of cemem gels. IN 'SCALING PHENOMENA IN DISORDERED SYSTEMS', R.PYNN & AL. EDS. (PLENUM PRESS, 1985)(NATO ASI B 133), I.L.L, BUT WITHOUT 111. PP. 189-192 AUTHORS : 86RA1012 RAMSEY N.F. : 86HO1001 Neutron magnetic resonance. HOWE M.A., MCGRIiEVY R.L. .MITCHELL E.W.J. : ANNALES DE PHYSIQUE VOL. 10, PP. 945-953 (1985). PRO­ Diffuse neutron scattering from a-Agl. CEEDINGS OF SYMPOSIUM "ALFRED KASTLER", PARIS, ZEITSCHRIFT FUE* PHYSIK B VOL. 62, PP. 15-19 (1985) JANUARY 9-12, 1985.

86CO1002 86DA10J3 COULOMB J.P., BIENFAIT m. : DAVIDSON N.S., lilCHARDS R.W., MACONNACHIE A. : Diffusive motions in 2D phases of ethane adsorbed on graphite. Determination of correlation lengths in swollen polymer networks JOURNAL DE PHYSIQUE VOL. 47, PP 89-96 (1986) by small-angle ntutron scattering. MACROMOLECULES VOL. 19, PP. 434-441 (1986)

86TA1003 86GE1014 TABONY J. : GEYER A.DE .TABONY J. : Formation of cubic structures in microemulsions containing equal Small-angle neutron scattering evidence for a bicontinuous structure volumes of oil and water. in a microemulsion containing equal volumes of oil and water. NATURE VOL. 319, P. 400 (1986) CHEMICAL PHYSICS LETTERS VOL. 124, PP. 357-360 (1986)

86BE1004 86CU1015 BEVAN D.J.M., GREY I.E., WILLIS B.T.M. : CUSACK S., RU1GROK R.W.H., KRYGSMAN P.C.J., The crystal structure of p-U.*09-y. MELLEMA J.E. : JOURNAL OF SOLID STATE CHEMISTRY VOL. 61, PP. 1-7 Structure and composition of influenza virus. A small-angle neutron (1986) scattering study. Appendix 1 : The spherical shell model-fitting techni­ que. Appendix 2: Simulation of scattering from surface spikes on 86ST1005 spherical viruses. STEEB S., LAMPARTER P. : JOURNAL OF MOLECULAR BIOLOGY VOL. 186, PP. 565-582 Recent structural results with amorphous alloys using neutron dif­ (1985) fraction. JOURNAL DE PHYSIQUE. COLLOQUES VOL. 46, PP. 86BA1016 C8-247-C8-253 (1985). PROCEEDINGS OF THE THIRD INTER­ BACON G.E., GRIFFITHS R.K. : NATIONAL CONFERENCE ON "THE STRUCTURE OF NON­ Texture, stress and age in the human femur. CRYSTALLINE MATERIALS", ILL, GRENOBLE, JULY 8-12, JOURNAL OF ANATOMY VOL. 143, PP. 97-101 (1985) 1985. 86MA1017 86GR1006 MARKOVIC I., OTTEW1LL R.H. : GREAVES C, THOMAS M.A. : Small angle neutron scattering studies on nonaqueous dispersions of Refinement of the structure of deuterated nickel hydroxide, calcium carbonate. Part 2.Determination of the form factor for con­ Ni(OD)î, by powder neutron diffraction and evidence for structural centric spheres. disorder in samples with high surface area. COLLOID AND POLYMER SCIENCE VOL. 264, PP. G5-76 (1986) ACTA CRYSTALLOGRAPHICA B VOL. 42, PP. 51-55 (1986) 86HE1018 86MI1007 HEITJANS P. : MIREBEAU I., JEHANNO G., CAMPBELL LA., HIPPERT F. Use of beta radiation-detected NMR to study ionic motion in solids. H , HENNION B., HENNION M. : SOLID STATE IONICS VOL. 18 & 19, PP. 50-64 (1986) Magnetic order and canting in a reentrant alloy studied by magnetiza­ tion, Moessbauer and neutron scattering. 86TA1019 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS TABONY J. : VOL. 54-57, PP. 99-100 (1986). PROCEEDINGS OF THE INTER­ Occurrence of liquid-crystalline mesophases in microemulsion NATIONAL CONFERENCE ON "MAGNETISM, ICM'85", SAN dispersions. FRANCISCO, USA, 26-30 AUGUST 1985. NATURE VOL. 320, PP. 338-340 (1986)

148 86DE1020 86DU1032 DETTENMA1ER M., MACONNACHIE A., HIOGINS J.S., DUNN S.P., BALDWIN J.P., WYNS L. .MUYLDERMANS S., KAUSCH H.H., NGUYEN T.Q. : LASTERS 1., POLAND G.A., STAYNOV D.Z., RATTLE Neutron scattering studies of the chain conformation of poIy(methyt H.W.E., WOOD M.J. : methacrylate) deformed below the glass transition temperature. Neutron scattering of chromatin multinucleosomes. MACROMOLECULES VOL. 19, PP. 773-778 (1986) PHYSICA B VOL. 136, PP. 265-267 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ 86BA1021 TERING", SANTA FE, USA, AUGUST 19-23, 1985. BATTLE P.D. .CHEETHAM A.K., HARRISON W.T.A., LONG G.J. : 86KA1033 The crystal structure and magnetic properties of the synthetic lang- KAKURAI K., STEINER M. : beinite KBaF«(PO.i)j. Neutron scattering study on the thermodynamic and dynamic pro­ JOURNAL OF SOLID STATE CHEMISTRY VOL. 62, PP. 16-25 perties of Sine -Gordon like solitons in CsNiFî. (1986) PHYSICA B VOL. 136, PP. 349-351 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ 86MO1022 TERING", SANTA FE, USA, AUGUST 19-23, 1985. MONTAGUE D.G., DORE J.C. : Structural studies of liquid alcohols by neutron diffraction.IV. 86ME1034 CD3OH and CD3OD at various temperatures. MOLECULAR MEZEI F. : PHYSICS VOL. 57, PP. 1035-1047 (1986) Critical dynamics in EuO at the ferromagnetic Curie point. PHYSICA B VOL. 136, PP. 417-419 (1986). PROCEEDINGS OF 86DO1023 THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ DOSCH H., PEISL J. : TERING", SANTA FE, USA, AUGUST 19-23, 1985. Local defect structure of highly mobile deuterium in niobium. PHYSICAL REVIEW LETTERS VOL. 56, PP. 1385-1388 (1986) 86BOI03S BONNET M., BOUCHERLE J.X., FLOUQUET I., HOLTZ- 86ST1024 BERG F., JACCARD D., SCHWEIZER J., STUNAULT A. : STEYERL A., MALIK S.S. : Anomalous form factor in the insulating state of TmSe. New developments in cold and ultracold neutron research. PHYSICA B VOL. 136, PP. 428-431 (1986). PROCEEDINGS OF PHYSICA B VOL. 137, PP. 270-281 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ THE CONFERENCE ON "FRONTIERS OF NEUTRON SCAT­ TERING", SANTA FE. USA, AUGUST 19-23, 1985. TERING", CAMBRIDGE, USA, SEPTEMBER 23-24,1985. 86JO1036 86ME1025 JOSWiG W. .AMTHAUER G., TAKEUCHI Y. : MEZEI F. : Neutron-diffraction and Moessbauer spectroscopic study of clintonite La nouvelle vague in polarized neutron scattering. (xanthophyllite). PHYSICA B VOL. 137, PP. 295-308 (1986).PR0CEED1NGS OF AMERICAN MINERALOGIST VOL. 71, PP. 1194-1197 (1986) THE CONFERENCE ON "FRONTIERS OF NEUTRON SCAT­ TERING", CAMBRIDGE, USA, SEPTEMBER 23-24, 1985) 86TR1037 TREIMER W., SE1FERT R. : 86BR1026 Study of Bloch wall junctions in nickel single crystals by neutron scat­ BRUNEL Y., COULOMBEAU C, COULOMBEAU CH., tering. JOBIC H., RASSAT A. : Mise en évidence du couplage entre les modes de torsion de groupes PHYSICA B VOL. 136, PP. 455-457 (1986). PROCEEDINGS OF méthyles vicinaux par diffusion inélastique des neutrons. THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ COMPTES RENDUS DES SEANCES DE L'ACADEMIE DES TERING", SANTA FE, USA, AUHUST 19-23, 1985. SCIENCES SERIE II VOL. 302, PP. 699-702 (1986) 86CO1038 86GR1027 COPPOLA R., RE FIORENTIN S. : GREENE G.L. : Small-angle neutron scattering study of the gamma'-phase precipita­ The fundamental properties of the neutron. tion in alloy 800. PHYSICA B VOL. 136, PP. 121-125 (1986). PROCEEDINGS OF PHYSICA B VOL. 136, PP. 465-468 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ TERING", SANTA FE, USA, AUGUST 19-23, 1985. TERING", SANTA FE, USA, AUGUST 19-23, 1985. S6H11028 86AD1039 HIGGINS J.S. : ADAMS J.M., REES L.V.C. : Dynamics of polymer molecules. The structure of a dehydrated partially magnesium exchanged zeolite PHYSICA B VOL. 136, PP. 201-206 (1986). PROCEEDINGS OF A (HMg2Na8-A) by neutron profile refinement. JOURNAL OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ SOLID STATE CHEMISTRY VOL. 62, PP. 184-190 (1986) TERING", SANTA FE, USA, AUGUST 19-23, 1985. 86CO1040 86BA1029 COSGROVE T., VINCENT B. .CROWLEY T.L. .COHEN BALDWIN J.P. : STUART M.A. : Chromatin structure studies using neutron beams. Segment density profiles of adsorbed polymers. PHYSICA B VOL. 136, PP. 236-240 (1986). PROCEEDINGS OF IN 'POLYMER ADSORPTION AND DISPERSION STABILITY*, THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ E.D.GODDARD.B.VINCENT EDS.(AMERICAN CHEMICAL TERING", SANTA FE, USA, AUGUST 19-23, 1985. SOCIETY,1984)(ACS SYMPOSIUM SERIES 240), PP. 147-159

86MU030 86DA1041 MIDDENDORF H.D. : DAWKINS J.V. .TAYLOR G. .GHAEM-MAGHAMI G., HIG­ Time-of-flight and backscattering spectroscopy of proteins: Some re­ GINS J.S. : cent results and key problems. Nonaqueous polymer dispersions. Anchoring of diblock copolymers PHYSICA B VOL. 136, PP. 241-244 (1986). PROCEEDINGS OF of polystyrene and poly(dimethyl siloxane) on polymer particles. THE INTERNATIONAL >~ . -RENCE ON "NEUTRON SCAT­ IN 'POLYMER ADSORPTION AND DISPERSION STABILITY', TERING", SANTA FE, uiA, AUGUST 19-23, 1985. E.D.GODDARD.B.VINCENT EDS. (AMERICAN CHEMICAL SOCIETY, 1984) (ACS SYMPOSIUM SERIES 240), PP. 267-279 86CU1031 CUSACK S. .SMITH J., FINNEY J.L., KARPLUS M., 86TJ1042 TREWHELLA J. : TJAN K. ,FINK D. .BIERSACK J.P. .STAEDELE M. : Low frequency dynamics of proteins studied by neutron time-of-flight Implantation profiles of Li in metals. spectroscopy. NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS PHYSICA B VOL. 136, PP. 256-259 (1986). PROCEEDINGS OF RESEARCH B VOL. 15, PP. 54-57 (1986). PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON "NEUTRON SCAT­ THE 7TH INTERNATIONAL CONFERENCE ON "ION BEAM TERING", SANTA FE, USA, AUGUST 19-23, 1985. ANALYSIS", BERLIN, JULY 7-12, 1985.

149 86F11043 86GI1055 FINK D., BIERSACK J.P., STAEDELE M., TJAN K., BLHAR M., GIRAUD M. .MOR1N P. .ROUCHY J. ,SCHMITT D. : FICHTNER P.F.P., 0LIV1ERI C.A., SOUZA J.P. DE, Magnetic and quadrupolar properties of the TmMg compound. ZAWISLAK F.C. : JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Range profiles of ions in double-layer structures. VOL. 59, PP. 255-265 (1986) NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH B VOL. 15, PP. 71-74 (1986). PROCEEDINGS OF 86AL1056 THE 7TH INTERNATIONAL CONFERENCE ON "ION BEAM ALLEN M.P. .HOVENDEN C.B. ,HUMES R.P. .METHA S.K., ANALYSIS", BERLIN, JULY 7-12, 1985. THOMAS R.K. .WHITE M.A. : Neutron-scattering spectra from the hindered rotation of methane 86BI1044 in methane + krypton mixtures adsorbed on graphite. BIERSACK J.P. ,FINK D. .MIEKELEY W. ,TJAN K. : FARADAY DISCUSSIONS OF THE CHEMICAL SOCIETY 1-3 MeV alpha and triton stopping powers in LiF and Li alloys. VOL. 80, PP. 171-182 (1985) NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH B VOL. 15, PP. 96-100 (1986). PROCEEDINGS OF 86HO1057 THE 7TH INTERNATIONAL CONFERENCE ON "ION BEAM HOLLAND-MORITZ E. .SEVERING A. : ANALYSIS", BERLIN, JULY 7-i?., 1985. Anomaly in the density of phonon states of Tmo.os Yn.ssSe. ZEITSCHRIFT FUER PHYSIK B VOL. 63, PP. 313-319 (1986) 86FI1045 FINK D. .BIERSACK J.P. ,STUMPFF C. .SCHLOSSER S. : 86BU1058 Background reduction in light element depth profiling by a coin­ BURKEL E. .FENZL W. ,PEISL J. : cidence technique. Microscopic density fluctuations of deuterium in niobium. NUCLEAR INSTRUMENTS AND METHODS IN .• HYSICS PHILOSOPHICAL MAGAZINE A VOL.L 54. PP. 317-323 (1986) RESEARCH B VOL. 15, PP.740-743 (1986). PROCEEDINGS OF THE 7TH INTERNATIONAL CONFERENCE ON "ION BEAM 86FE10S9 ANLYSIS", BERLIN, JULY 7-12, 1985. FENDER B.E.F. : Neutron scattering. 86WI104« NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS WILLIAMS D.E.G. .JEZIERSKI A. : RESEARCH A VOL. 249, PP. 1-11 (1986). PROCEEDINGS OF THE WORKSHOP ON "ADVANCED STEADY-STATE Magnetic order in crystttllographically ordered PM.vf>1n>Cri.>)» alloys. NEUTRON FACILITY", GAITHERSBURG.USA, DECEMBER JOURNAL OF MAGNETISM AND MAGNETIC M, liRIALS 16-18,1985. VOL. 59, PP. 41-56 (1986) 86HI1060 HIGGINS J.S., DAWKINS J.V., MAGHAMI G.G., SHAKIR S.A.: 86MO1047 Study of micelle formation by the diblock copolymerpolystyrcne-b- MORKEL C. .GLAESER W. : (ethylene -co-propylene) in dodecane by small-angle neutron scat­ Single-particle motion in liquid sodium. tering. PHYSICAL REVIEW A VOL. 33, PP. 3383-3390 (198GI POLYMER VOL. 27, PP. 931-936 (1986) 86MU1048 86GUI061 MURRAY A.D. .CATLOW C.R.A. ,BEECH F. .DRENNAN J. : GUIGAY J.P. .SCHLENKER M. .BARUCHEL J. : A neutron powder diffraction study of the low- and high-te nperature Neutron scattering in almost perfect magnetic crystals. structures of Bii2PbOi9. IN 'APPLICATIONS OF X-RAY TOPOGRAPHIC METHODS TO JOURNAL OF SOLID STATE CHEMISTRY VOL. 62, I' '. 290-2% MATERIALS SCIENCE'.S.WEISSMANN & AL. EDS (PLENUM (1986) PRESS,1984),PP.171-183 86BA1049 86BA1062 BALDO-CEOLIN M. : BARUCHEL J. .SCHLENKER M. : Cold neutrons and neutron oscillations. Neutron diffraction topography. IN 'THE INVESTIGATION OF FUNDAMENTAL INTERAC­ IN 'APPLICATIONS OF X-RAY TOPOGRAPHIC METHODS TO TIONS WITH COLD NEUTRONS'.G.L. GREENE ED.(NBS MATERIALS SCIENCE'.S.WEISSMANN & AL. EDS. (PLENUM SPECIAL PUBL 711HN.B.S., 1986),PP. 130-135 PRESS. 1984) PP. 59-74 86FRIOS0 86BA1063 FRICK B. .LOEWENHAUPT M. : BATTLE P.D., CATLOW C.R.A.. HEAP J.W., MORONEY L.M.: Crystal field spectroscopy by inelastic neutron scattering I. Single Structural and dynamical studies of delta-Bi203 oxide ion conduc­ ion properties. tors. l.The structure of (Bi;0))i.,(Y;Oi), as a function of x and ZEITSCHRIFT FUER PHYS1K B VOL. 63, PP. 213-2J0 (1986) temperature. JOURNAL OF SOLID STATE CHEMISTRY VOL. 63, PP. 8-15 86FR1051 (1986) FRICK B. .LOEWENHAUPT M. : Crystal field spectroscopy by inelastic neutron scattering II. Con­ 86MA1064 centration effects. MARMEGG1 J.C. : ZEITSCHRIFT FUER PHYSIK B VOL. 63, PP. 23I-: to (1986) Study on photographic film of the polychromatic neutron diffrac­ tion effects related to structural phase transitions. 86CHI0S2 JOURNAL DE PHYSIQUE. COLLOQUES VOL. 47, PP. CHAMPENEY DC. JOARDER R.N. ,DORE J.C. : C5-123-C5-128 (1986). PROCEEDINGS OF THE INTERNA­ Structural studies of liquid D-glycerol by neutron diffraction. TIONAL WORKSHOP ON "EVALUATION OF SINGLE- MOLECULAR PHYSICS VOL. 58, PP. 337-347 (1986 CRYSTAL DIFFRACTION DATA FROM 2-S POSITION- SENSITIVE DETECTORS", GRENOBLE, SEPTEMBER 4-6, 86PII053 1985. PIERRON-BOHNES V. .CADEV1LLE M.C. : High T-depcndence of local order in magnetic FeM n loys from 86GR106S neutron diffuse scattering. GREEN R.M. .HORSEW1LL A.J. : IN 'ATOMIC TRANSPORT AND DEFECTS IN Ml ALS BY A study of methyl group dynamics and barrier heights in a NEUTRON SCATTERING', PROCEEDINGS OF \N IFF- homologous series of unbranched ketones. ILLWORKSHOP.JUEL1CH, FRG, OCTOBER . 4, 1985, MOLECULAR PHYSICS VOL. 57, PP. 887-899 (1986) C.JANOT& AL. EDS. SPRINGER PROCEEDINGS IN I'HYSICS VOL. H), (SPR1NGLR \ HRLACi, 1986), PP. 28-31. 86PF.10A6 PERKINS S.J. : 86MA1054 Protein volumes and hydration effects. The calculations of partial MARKOV1C 1. .OTTEWILL R.H. : specific volumes, neutron scattering matchpoinls and 280-nm absorp­ Small angle neutron scattering studies on non-aqueous dispersions tion coefficients for proteins and glycoproteins from amino acid se­ of calcium carbonate. Part III. Concentrated dispersions. quences. COLLOID AND POLYMER SCIENCE VOL. 264, PP. 454-462 EUROPEAN JOURNAL OF BIOCHEMISTRY VOL. 157, PP. (1986) 169-180 (1986)

150 86GU067 86DA1078 GIBAUD A., LE BAIL A., BULOU A. : DAVIDSON N.S., RICHARDS R.W. : A re-investigation of the room-temperature phase of KAlFa : Dimensions of labeled chains in randomly cross-linked polystyrene evidence of antiphase domains. networks at swelling equilibrium by small-angle neutron scattering. JOURNAL OF PHYSICS C VOL. 19, PP. 4623-4633 (1986) MACROMOLECULES VOL. 19, PP. 2576-2588 (1986)

86RI1068 86RA1079 RIEKEL C, HAMWI A., TOUZAIN P. : RAMSAY J.D.F. : A neutron diffraction study of the reaction of potassium with highllghly Neutron and light scattering studies of aqueous solutions of oriented pyrolytic graphite (HOPG). polynuclear ions. SYNTHETIC METALS VOL. 15, PP. 345-352 (1986) IN 'WATER AND AQUEOUS SOLUTIONS', G.W.NEILSON.J.E.ENDERBY EDS. (COLSTON 86PE1069 PAPERS,VOL.37);A.HILGER.1986), PP. 207-218. PRO­ PERKINS S.J., SIM R.B. : CEEDINGS OF THE 37TH SYMPOSIUM OF THE COLSTON Molecular modelling of human complement componert C3 anid its RESEARCH SOCIETY, BRISTOL, APRIL 1985. fragments by solution scattering. EUROPEAN JOURNAL OF BIOCHEMISTRY VOL. 157, PP. 155-168 (1986) 86PR1080 PRAGER M., BADUREK G. : Inelastic neutron scattering study of the rotational potential of 86MC1070 + NH4 in (NH^PdCU and (NH^PtCU. MCGAREY B., RICHARDS R.W. : JOURNAL OF PHYSICS C VOL. 19, PP. 6105-6112 (1986) The size of phase separated regions in poly(dimethylsilox- ane)/polystyrene sequential interpenetrating networks determined by small-angle neutron scattering. 86CO108I POLYMER VOL. 27, PP. 1315-1324 (1986) COSGROVE T., OBEY T.M., VINCENT B. : The configuration of sodium poly(styrenc sulfonate) ill 86FL1071 polystyrene/solution interfaces. FLETCHER P.D.I., ROBINSON B.H., TABONY J. : JOURNAL OF COLLOID AND INTERFACE SCIENCE VOL. Ill, A quasi-elastic neutron scattering study of water-in-oil microemul- PP. 409-418 (1986) sions stabilised by aerosol-OT. Effect of additives including solubilisée! protein on molecular motions. 86GH1082 JOURNAL OF THE CHEMICAL SOCIETY. FARADAY TRANAN-­ GHEDIRA M., ANNE M., CHENAVAS J., MAREZIO M., SACTIONS 1 VOL. 82, PP. 2311-2321 (1986) SA YET AT F. : Powder neutron diffraction studies of the low-temperature phase tran­ 86HO1072 sitions in stoichiometric BaVSi. HOWE A.M., TOPRAKCIOGLU C, DORE J.C., RO-­ JOURNAL OF PHYSICS C VOL.19, PP. 6489-6503 (1986) BINSON B.H.: Small-angle neutron scattering studies of microemulsions stabiliselised 86GR1083 by aerosol-OT. Part 3. The effects of additives on phase stability anand GREAVES C, MALSBURY A.M., THOMAS M.A. : droplet structure. Structure of the mixed conductor NiiOsH by powder neutron dif- JOURNAL OF THE CHEMICAL SOCIETY. FARADAY TRANAN*­ fraction. SACTIONS I VOL. 82, PP. 2411-2422 (1986) SOLID STATE IONICS VOL. 18 & 19, PP. 763-767 (1986) 86RO1073 86GR1084 ROSS D.K., FAUX D.A., MCKERGOW M.W., WILSON D.L.T.T , SINHA S.K. : • ' GREAVES C, BUKER R.A. : The defect structure of SnFeTiOô-*. Coherent quasi-elastic scattering of neutrons from lattice gas systemspmc . IN 'ATOMIC TRANSPORT AND DEFECTS IN METALS RBYV MATERIALS RESEARCH BULLETIN VOL. 21, PP. 823-833 NEUTRON SCATTERING', PROCEEDINGS OF AN IFF-IL•ILL <1986> WORKSHOP, JUELICH, FRG, OCTOBER 2-4, 1985, C.JANOgoTT & AL.EDS. SPRINGER PROCEEDINGS IN PHYSICS VOL.. 1010,, 86GRI08S (SPRINGER VERLAG,19S6),PP. 116-121. GREAVES C. : Rietveld analysis of powder neutron diffraction data displaying 86BA1074 anisotropic crystallite size broadening. BADUREK G., RAUCH H., TUPPINGER D. : JOURNAL OF APPLIED CRYSTALLOGRAPHY VOL. 18, PP. Neutron interferometric double-resonance experiment. PHYSICA:AL 48-50 (1986) REVIEW A VOL. 34, PP. 2600-2608 (1986) 86COI086 86CA1075 COLLOMB A., WOLFERS P., OBRADORS X. : CAITUCOL1 F., ASGHAR M., BARREAU G., LEROUX B.,, Neutron diffraction studies of some hexagonal ferrites: BaFeuOw, PERR1N P., MAUREL M., DOAN T.P., SICRE A. : BaMg:-W and BaCoi-W. Fission fragment mass energy correlation for 13 actinides ranging frorom JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Th to Cf. VOL. 62, PP. 57-67 (1986) RADIATION EFFECTS VOL. 92-96 (1986). IN 'NUCLEAR DATA FOR BASIC AND APPLIED SCIENCE' P.G YOUNG & AL. EDS. (GORDON & BREACH, 1986) VOL. 1, PP. 333-336. PRO­ 86RA1087 CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN­ RAMSAY J.D.F. : TA FE, USA, MAY 13-17, 1985. Recent developments in the characterization of oxide sols using small angle neutron scattering techniques. CHEMICAL SOCIETY REVIEWS VOL. 15, PP. 335-371 (1986) 86DO1076 DOAN T.P., BARREAU G., SICRE A„ CAITUCOLI F., LEROUX B., THEOBALD J.P., MUTTERER M., KOCZON P. : 86SE1088 Light nuclei from the thermal neutron induced fission of USU. SEIFF F., WALLAT I., WESTERHAUSEN J.. HEYN M.P. : RADIATION EFFECTS VOL. 92-96 (1986). IN 'NUCLEAR DATA Location of chemically modified lysine 41 in ù:e structure of FOR BASIC AND APPLIED SCIENCE'.P.G. YOUNG & AL. EDS. bacteriorhodopsin by neutron diffraction. (GORDON & BREACH, 1986), VOL. 1, PP. 397-400. PRO­ BIOPHYSICAL JOURNAL VOL. 50, PP. 629-635 (1986) CEEDINGS OF THE INTERNATIONAL CONFERENCE, SAN TA FE, USA, MAY 13-17, 1985. 86SE1089 SEIFF F., WESTERHAUSEN J., WALLAT I., HEYN M.P.: 86MAI077 Location of the cyclohexene ring of the chromophore of MARKOVIC 1., OTTEWILL R.H., UNDERWOOD S.M.M-,, bacteriorhodopsin by neutron diffraction with selectively deuterated TADROS T.F. : retinal, Interactions in concentrated nonaqueous polymer laticesces.. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES LANGMUIR VOL. 2, PP. 625-630 (1986) OF THE USA VOL. 83, PP. 7746-7750 (1986)

151 86SE1090 86TR1094 SEIFF F., WALLAT I., ERMANN P., HEYN M.P. : TRhIMER W., SEIFERT R. : A neutron diffraction study on the location of the polyene chain of Stu dy of Bloch wall junctions in nickel single crystals by neutron retinal in bacteriorhodopsin. scattering. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES PHYSICA B VOL. 136, PP. 455-457 (1986) OF THE USA VOL. 82, PP. 3227-3231 (1986) 86GR1095 GRONDEY S. : 86KE1091 Fingefrorene Orientierungsunordnung und Rotationsanregungen in KEYSER U., MUENNICH F. : festen Mischungen von Methan und Krypton (Neutronenstreuex- Absolute measurement of the sum beta-spectra of all fissionproduct s ! perimente). from "U(n,b,f) and "'Pu(n,h,f). REPORT JUEL-2083 (KFA, 1986) (DISSERTATION, IN 'WEAK AND ELECTROMAGNETIC INTERACTIONS IN TECHNISCHE HOCHSCHULE, AACHEN) NUCLEI', H.V. KLAPDOR ED. (SPRINGER-VERLAG, 1986), PP. 764-765. PROCEEDINGS OF THE INTERNATIONAL SYM­ 86VA1096 POSIUM, HEIDELBERG, JULY 1-5, 1986. VANGELISTI R., LELAURAIN M., BATALLAN F. : Phases et transformation de phase dans les composés graphite-AICh 86RAI092 de 1er stade. RAMSAY N.F. : CARBON VOL. 24, PP. 654-656 (1986) Search for a neutron electric dipole moment. IN 'WEAK AND ELECTROMAGNETIC INTERACTIONS IN 86WO1097 NUCLEI', H.V. KLAPDOR ED. (SPRINGER-VERLAG, 1986), WORCESTER D.L., MICHALSKI T.J., KATZ J.J. : PP. 861-865. PROCEEDINGS OF THE INTERNATIONAL SYM­ Small-angle neutron scattering studies of chlorophyll micelles: Models POSIUM, HEIDELBERG, JULY 1-5, 1986. for bacterial antenna chlorophyll. PROCEEDINGS OF " AE NA­ TIONAL ACADEMY OF SCIENCES OF THE U.S.A. VOL ', PP. 3791-3795 (1986) 86RA1093 RAMDANI A., GERARD1N R., GLEITZER C, GAVOILLE G., 86NE1098 HUBSCH J., CHEETHAM A.K. : NEUBAUER G., HOFFMANN H., KALUS J., SCHWAND- Desordre atomique, magnétique et électronique dans les ferrites NER B.:

Zni.»Ge,Fe3O4(x = 0,2 - 0,5 - 0.75). The shape of hexadccyloctydimcthylammoniumbromide micelles in JOURNAL OF SOLID STATE CHEMISTRY VOL. 65, PP. 309-321 aqueous solutions. (1986) CHEMICAL PHYSICS VOL. 110, PP. 247-253 (1986)

152 BARREAU G. 86HA313 BIRCHALL T. 86B1273 86PA375 86B1332 AUTHOR 86SI378 BIZOT D. 86BI248 86CA1075 BLANC J.Y. 86BL10T INDEX 86DO1076 BLANDER M. 86EN434 BARTHES M. 86SAI09 BLASCHKO O. 86MC312 BARTHOLIN H. 86CHI48 BLETRY J. 860P15T PUBLICATIONS AW BARTOLOME J. 86BA164 BLIN A.H. 86BL325 BARTSCH E. 86BA478 BOCQUET J.P. 86AS379 INTERNAL REPORTS BARTSCHER W. 36BA423 BOERNER H.G. 86C09T BARTUNIK H.D. 86BA342 86GR182 ABIS S. 86AB244 BARUCHEL J. 86BAII0 86SC276 ACHARD J.C. 86LA361 86KA155 86SC297 ACKERMANN H. 86FR201 86PA169 86HA313 ACKERMANN K. 86SC319 86BAI70 86WI479 ADAMS J.M. 86AD1039 86SC211 BOEUF A. 86F0422 AGERON P. 86GE13T 86GUI061 86BA423 86AG277 86BA1062 86FO460 86ST307 BASSIGNAGNA I.C. 86TE315 BONDARENKO V.A. 86PR300 86AG337 BATALLAN F. 86BA2I8 BONNET M. 86F0422 AGOSTINELLI E. 86S0139 86SI219 86FO460 AHMAD N. 86BU386 86SI268 86BO1035 AKER E. 86AK374 86VA1096 BONSE U. 86B0284 ALLEN A.J. 86AL409 86AL1011 BATES J.C. 86AG337 BOOTH J.G. 86CA350 ALLEN M.P. 86ALL0S6 BATES S. 86PA150 86CY1010 ALMAIRAC R. 86SA109 86SI453 BOPP P. 86B0187 86MA136 BATTERMAN B.W. 86MC153 BORDET P. 86H0166 86SA261 86VEI8I 86BO304 ALMEIDA M. 86MI295 BATTLE P.D. 86BA1021 86B0459 86MI450 86BA1063 86WE465 AMOUREUX J.P. 86L0176 BAUHOFER W. 86BAI63 BOSIO L. 86BE329 86BE177 BAUMANN M. 86TR202 BOUCHER B. 86B0394 86AM180 BAYM G. 86UW452 BOUCHER J.P. 86RE232 AMTHAUER G. 86JO1036 BEAUDRY B.J. 86PA150 86B0247 ANDERSON I.S. 86MA103 BEAUFILS J.P. 861L4T BOUCHERLE J.X. 86F0422 86ST225 86MA275 86FO460 86MC312 BECKER H.W. 86TR202 86BO1008 86RI335 BECKER P. 86BE454 86BO1035 ANDONOV P. 86ANI19 BEEM. 86LOI76 BOU1LLOT J. 86TEI25 ANDREJTSCHEFF W. 86AN306 86BE177 86TU229 ANGERAND F. 86TE315 86AM180 86RE232 ANNE M. 86FR426 86JO203 86B0245 86GH1082 86BE468 86B0247 ANTONIADIS A. 86AN2T BEECH F. 86MU1048 86RI363 86AN12T BEHAR M. 86F11043 86TU399 86AN469 BELAKHOVSKY M. 86MA124 BOUKELLAL A. 86SI378 ANTONSSON B. 86AN425 BELLISSARD J. 86BE102 BOULANGER P. 86BE439 ARAI M. 86AR429 BELLISSENT R. 86BE120 BOULIN C. 86BA342 ARCHER J.M. 86AR415 BELLISSENT-FUNEL M.C. 86F0226 BOUMAZOUZA D. 86TE125 ARMBRUSTER P. 86CL250 86BE329 86BO140 ARNOLD M. 86FR446 86TE397 BOUQUIERE J.P. 86TU229 ARRIBART H. 86DU263" 86BE398 86TU399 ARTS A.F.M. 86HI173 BENHAM M.J. 86BE326 BOURSIER D. 86WE465 ASGHAR M. 86SI378 BENOIT A. 86BO304 BOYSEN H. 86F0414 86AS379 86JO309 BRADBURY E.M. 86IM328 86CA1075 BENTLEY G.A. 86F1466 BRAGANZA L.F. 86BR388 ASTRUC J.M. 86ST307 BERGE B. 86BE259 86BR412 ATZMON M. 86WR126 BERGMAN C. 86BE121 BRENTANO P.VON 86HA313 AUBERT G. 86BA170 BERNARD L. 86DU108 BRICOC'E G. 86FI466 AVENIER M. 86AV393 86CU208 BRISSOT R. 86WA198 AYACHE C. 86SI268 86DU231 86AK374 BACHHEIMER J.P. 86BE259 86M0233 86AS379 BACMANN M. 86BA164 86BI373 BROOKS B. 86SM371 86BAI68 BERNAS H. 86BE400 BROWN G.M. 86SA483 BACON G.E. 86BA1016 BERNHOEFT N.R. 86BE24I BROWN P.J. 86BRI38 BADER B. 86FR201 BERRUYER J. 86AN2T 86BA163 BADUREK G. 86BA1074 86AN12T 86BR184 86PR1080 86AN469 86BR209 BAER G. 86LE436 BERTAGNOLLI H. 86WI190 86ST238 BALDO-CEOL1N M. 86BA1049 86BA478 86J03Û9 BALDWIN J.P. 86IB246 BERTHET-COLOMINAS 86BE439 86CH322 86IM328 BETZEL C. 86SA483 86CA350 86BA1029 BEVAN D.J.M. 86BE1004 86LA390 86DU1032 BICHARA C. 86BE12J 86BR401 BALIBAR S. 86GA389 BItNFAITM. 86C0299 86MA413 BALLOU R. 86BA144 86CO1002 BROWN R.K. 86W0253 86BA145 BIERSACK J.P. 86TJ1042 BRUECKEL T. 86BR424 86BA146 86FII043 BRUNEL Y. 86BR270 86BA147 86BI1044 86BR1026 86BA458 86FI1045 BRUSON A. 86JA256 BALODIS M.K. 86SC297 BIGGIN S. 86EN434 86JA391 BANTLE S. 86HU280 BILJAKOVIC K. 86BI373 BUCHENAU U. 86DI264 BARBARA B. 86FR151 BILLARD L. 86R0129 86BU386 BARBAUX Y. 86MA27S 86R0221 BUCHMANN L. 86TR202 BAR J M. 86LU305 86R0359 BUGAUT F. 86CA260

153 BUKER R.A. 86GR1084 COHEN-ADDAD C. 86BE454 86LU305 BULOU A. 86GI1067 COLLOMB A. 86CO1086 86DI360 BUNGE H.J. 86WE368 COLVIN G. 86C09T 86LA361 BUNICK G.J. 86ZA438 86SU353 86BU386 BUNTSCHUH B.M. 86MCI53 86SC445 86BE398 86VE181 CONVERT P. 86B0394 86MA403 BURCHARD W. 86HU280 COPPOLA R. 86AB244 86ME431 BURKE S.K. 86LI159 86CO1038 DIFFERT K. 86TR441 86CY10I0 COQUET E. 86B0245 DJEBARA M. 86AS379 BURKEL E. 86D0282 COSGROVE T. 86CO1040 DOAN T.P. 86S1378 86BU1058 86CO1081 86CA1075 BURLET P. 86CH148 COULOMB J.P. 86C0299 86DOI076 86LA236 86CO1002 DOEHNER J. 86FR446 CABLE J.W. 86MA30I COULOMBEAU C. 86BR270 DOLINO G. 86BE259 CACIUFFO R. 86AB244 86BR1026 DORE J.C. 86BE329 86BA423 COULOMBEAU CH. 86BR270 86MO1022 CADEVILLE M.C. 86PII053 86BR1026 86CH1052 CA1LLEAU H. 86TO107 COWLAM N. 86FE402 86HOI072 86CA137 COWLEY R.A. 86HI173 DOREMIEUX-MORIN C. 8SDU263 86CA260 86SI453 DORN A. 86TA17T CAITUCOLI F. 86SI378 CRESPI H.L. 86LE311 DORNER B. 860P15T 86CA1075 CRETTEZ J.M. 86B0245 S6KAI54 86DO1076 CROWLEY T.L. 86COI040 86STI97 CAMPBELL LA. 86M11007 CUMMINGS S. 86TU229 86DD282 CAPELLMANN H. 86BR184 86TU399 86CA298 86D0336 86SK427 86TE397 86JO309 8CEN434 86CA350 DOSCH H. 86D0336 CUMMINS P.G. 86HII05 86DOI023 86L1357 CURRAT R. 86DUI08 86NE395 DRENNAN J. 86MUI048 86CU193 DREXEL W. 86ST307 CARR G.E. 86FE402 86T0I94 CASTEN R.F. 86SC297 DR1ESEN G. 86DR289 86HA313 86DU206 86H335 86DE207 CASTETS C. 86CA3G 86HE358 86CA6G 86CU208 DR1LLAT A. 86PA169 86DU231 CATLOW C.R.A. 86MUI048 86M0233 DUBBERS D. 86DU186 86BAI063 86B0187 86BI373 86DU278 CAUCHETEUX C. 86BE468 CUSACK S. 86SM371 CAVAGNAT D. 86CA411 86CU1015 86DU444 CAVAIGNAC J.F. 86AV393 86CU1031 86FR446 CEVA T. 86CE365 86DU130 CYWINSKI R. 86LI159 DUBOIS J.M. CHABLY A. 860PI5T 86CY1010 86DU2I7 CHAIX-PLUCHERY O. 86CH324 86DU362 CHALUPKA A. 86SC297 D'HONDT P. 86WA198 DANCE J.M. 86EL457 86JA480 CHAMBEROD A. 86R0129 DUMBRAJS O. 86DU356 86G0131 DAVIDSON N.S. 86DA10I3 86DA1078 DUNN S.P. 86DU1032 86R0132 DU PU Y J. 86EL477 86R0221 DAVIDSON W.F. 86PR300 DAWKINS J.V. 86DA1041 DURAND D. 86DU108 86R0359 8fJU206 86DI360 86HI1060 DAY P. 86HUI52 86DU23I CHAMPENEY D.C. 86CHI052 DURAND J. 86BO140 86HE189 86HA160 CHARVOL1N J. 86DA243 DURAND-LE FLOCH M. 86DU101 CHASSAING J. 86BI248 86DU263 CHATTOPADHYAY T. 86CHI48 86DA314 DE PAPE R. 86LE123 ECKERT J. 86RI292 86BA163 86R0355 86CH322 86LE251 86LE252 EGIDY T. VON 86SC276 86CH408 86SC297 86BA102I DEHGHAN K. 86DU130 CHEETHAM A.K. DELAMOYE P. 86CU208 86WI479 86RA1093 EISENBERG H. 86ZA418 CHEN S.H. 86TE397 DELAPALME A. 86F0422 86FO460 86ZA438 CHENAL B. 86DU130 EL FASS1 S. CHENAVAS J. 86GH1082 DELLEY B. 86BE454 86B0459 CHENEVAS-PAULE A. 86BE120 DELMAS C. 86LU305 86WE465 CHENEVIER B. 86BA164 DELUGEARD Y. 86CA137 EL JAZOULI A. 86EL457 86BA168 DENES G. 86DU101 EL KADIRI M. 86KA155 CHIEUX P. 86AN119 86BI273 ELARBY-AOUIZERAT A 86EL477 86BE120 86BI332 ENDERBY J.E. 86EN104 86BE121 DENOYER F. 86DU108 86SK427 86DU130 86DU206 86EN428 86WII90 86DE207 86AR429 86YA287 86DU231 86EN434 86BE329 DENUZZIO J. 86TH272 86NE435 86B0394 DEPORTES J. 86BA144 ENGELHARDT D. 86CL250 86EL477 86BA14S 86AK374 86BA478 86BRI84 ENGELMAN D.M. 86TR228 CHRIEN R.E. 86SC276 DESLATTES R.D. 86GR182 86TR447 CHRISTENSEN A.N. 86CH115 DESRE P 86YA287 EPPERSON J.E. 86WR133 86CH212 DETTENMA1ER M. 86DE1020 ERMANN P. 86SEI090 86CH347 DEVAUX C. 86BE439 ERNST R.R. 86FIII1 C1ZEWSKI J.A. 86C09T DIANOUX A.J. 86MA103 86ST225 CLARE A.G. 86WR126 86F0226 ERRANDONEA G. 86T0194 CLAUD Y P. 86EL4''7 86DI264 ERWIN R.W. 86ERI41 CLERC H.-G. 86CL250 86TA274 ETHER1NGTON G. 86MA269 CLOUGH S. 86CA4I1 S5S0283 EWEN B. 86RII74 COCKCROFT J.K. 86KE476 86TA302 FARAGO B. 86FA224 COHEN STUART M.A. 86CO1040 86LU303 86K028S

154 FAUST H. 86WE318 FREEDMAN S.J. 86B0187 GOELTZ G. 86G0338 86KE380 86FR446 GOENNENWEIN F. 86TR202 FAUX D.A. 86RO1073 FREIESLEBEN H. 86TR202 86CL250 FEILITZSCH F. VON 86SC445 FREILAENDER P. 86FR201 86WE318 FELDERHOF B.U. 86FEI06 FRELTOFT T. 86KJ456 86AK374 86FE116 FREUND A. 86SA261 86PA375 86FE1I7 FREY F. 86F0414 86K0376 86FE118 FRICK B. 86FR1050 86GE377 86FE27I 86FR1051 86SI378 86MA455 FF.INGS P. 86F0422 86G0381 FENDER B.E.F. 86FE191 86FO460 86GE383 8fiFE192 FRINGS P.H. 86FRI5I 86WE384 86LE210 86RE234 860E416 86KE476 86JO309 GOERLITZ D. 86K0285 86FE1059 FRIT B. 86LA200 GOLDMANN M. 86CE365 FENGLAI HE. 86FE402 FRUCHART D. 86BAI64 GOLDSTONE J.A. 86RI292 FENZL W. 86BU1058 86BA168 86R0355 FEREY G. 86LEI23 86FR426 GOMPF F. 86RE234 86LA204 FRUCHART R. 86BAI64 86CH347 86BI248 86JA480 GORGES B. 86BA144 86LE251 FUESS H. 86LO1009 86BA146 86LE252 FURDIN G. 86SI268 GOUDEAU P. 86G0131 86RE257 FURRER A. 86ST225 GRAEFENSTEDT M. 86GR294 86LA258 FUZELLIER H. 86BA218 86KE380 FETTERS L.J. 86HU280 FYNE P.J. 86DA3I4 GREAVES C. 86GR1006 FICHTNER P.F.P. 86FI1043 GABRYS B. 86GA330 86GR1083 FIGGIS B.N. 86FEI9I 86GA331 86GR1084 86FE192 86NY420 86GR108S FILHOL A. 86AN2T GAEHLER R. 86ST307 GREEN R.M. 86GR1065 86AN12T GALAZKA R.R. 86ST161 GREENE G.L. 86GR182 86MI295 GALERA R.M. 86LA215 86GRI027 86SC421 GALLET F. 86GA389 GREENWOOD R.C. 86SC276 86MI450 GALLOIS B. 86GA451 GREGORY D.P. 86HII05 86GA451 GARAVITO R.M. 86ZU437 GREMPEL D.R. 86BE102 GARCIA J. 86BA164 GRENECHE J.M. 86LE123 86FI466 GASPARD J.P. 86BE121 GREY I.E. 86BE1004 86AN469 GAULTIER J. 86GA451 GRIFFITHS R.K. 86BA10I6 FILIPPINI C. 86SA109 GAVARRI J.R. 86LU303 GRONDEY S. 86GR333 FILLION G. 86BO1008 GAVOILLE G. 86RAI093 86GR1095 FINK D. 86TJI042 GAY M. 86AR429 GUIGAY J.P. 86BA110 86FI1043 GEICK R. 86SI453 86GU1061 86BI1044 GEISSLER E. 86GE372 GUILLAUME F. 86S0283 86FI1045 GELBERG A. 86HA313 GUSEVA T.V. 86SC297 FINNEY J.L. 86TU229 GELLETLY W. 86SC445 86PR300 86TU399 GELTENBORT P. 86C09T GYORGY E.M. 86MC153 86CU1031 86TR202 86VE181 FIORANI D. 86S0139 86WE318 HAEUSLER W. 86PR370 FISCHER E.W. 86GI364 86AK374 HAGEN M. 86HU73 FISCHER P. 86FI111 86K0376 86MC312 F1SK Z. 86NE395 S6GE377 HAGUE A.M.I. 86HA313 FITCH A.N. 86FI216 86SI378 HAHN A.A. 86SC445 86FI346 86GE383 HAHN K. 86HA442 86FI430 86WE384 HAMILTON W.D. 86AN306 86KE476 860E416 86SU353 FJELLVAG H. 86CHU5 GENICON J.L. 86B0459 86R0354 86CH212 GEORGE C. 86JA122 HAMWI A. 86RI1068 FLANK A.M. 86MA124 86JA286 HANNON A.C. 86WR126 FLETCHER P.D.I. 86FL1071 GERARDIN R. 86RA1093 HARDCASTLE S.E. 86ZA387 FLOTTMANN T. 86PE290 GERVAIS R. 86GE13T HARRISON A. 86HA160 FLOUQUET J. 86VE262 86ST307 HARRISON W.T.A. 86BA1021 86JO309 GERVASIO G. 86GE481 HART R. 86AV393 86BO1008 GESLAND J.Y. 86SA109 HASSE R.W. 86ST266 86BO1035 86SA261 86BL325 FOERSTER I. 86HA313 GEYER A.DE 86GE10I4 86HA419 FONTANA M.P. 86F0226 GHAEM-MAGHAMI G. 86DAI04I 86ST443 86BE398 GHEDIRA M. 86GH1082 HAUW C. 86GA451 FORD G.W. 86F0178 GIBAUD A. 86GI1067 HAYTER J.B. 86HI105 FORST R. 86F0414 GIGNOUX C. 86Z0254 HEAP J.W. 86BA1063 FORSYTH J.B. 86FE191 GIGNOUX D. 86BA146 HECHT A.M. 86GE372 86FE192 86BA147 HEEG P. 86PA375 FORT D. 86MC143 86BA458 HEIDEMANN A. 86IL8T 86PA150 GILBERD P.W. 86MC312 86PE290 86PA169 GILMER J.W. 86GI364 86GR333 FOULON M. 86AM180 GINDLER J. 86AK374 86PR370 FOU RET R. 86L0176 GIRARD A. 86CA137 HEINEMANN U. 86TR202 86BEI77 GIRAUD M. 86GI1055 HEISELBERG H. 86HE205 FOURNES L. 86S0242 GIVORD D. 86ISI35 86DU3S6 FOURNIER J.M. 86F0422 86BRI84 HEITJANS P. 86FR201 86BA423 GIVORD F. 86BO1008 86HE1018 86FO460 GLAESER W. 86ST307 HELLNER E. 86DA314 FRANCO H. 86FR348 86MO1047 HEMPELMANN R. 86HE288 FRANCOIS B. 86PEI88 GLEITZER C. 86RA1093 86DR289 FRANSE J.J.M. 86FR151 GMELIN E. 86BA163 86RI292 86JO309 GODFRIN H. 86LA196 86ri335 FRATZL P. 86MC312 86FR348 86HE358

155 HENDRIKX Y. 86HE189 JEHANNO G. 86MI1007 KUMAR K. 86SU353 HENNION B. 86MI10O7 JENSEN A.S. 86HE205 KWO J. 86MC153 HENNION M. 86MI10O7 86DU356 86VE18I HENRY J.Y. 86KAI55 JEZIERSKI A. 86WU046 86MA30I 86RE232 JOARDER R.N. 86CH10S2 LABBE P. 86LA258 HERBST L. 86HE214 JOBIC H. 86JO203 LABORDE 0. 86BA168 HEUMANN H. 86LE311 86FI216 LAHIOUEL R. 86L',215 86LE436 86BR270 LALIGANT Y. 86LA204 HEWAT A.W. 86FU11 86BE468 86LA258 86TH199 86BR1026 LAMBERT M. 86DU108 86S0237 JOHANNSEN I. 86MI29S 86DU206 86HE317 86MI4S0 86DU231 HEYN M.P. 86SE1088 JOHNSON R.W. 86AR429 LAMCHARFI T. 86GA451 86SE1089 JOHNSON S.M. 86BR184 LAMPARTER P. 86ST1005 86SE1090 86JO309 LANDAS N. 86CA6G HIGGINS J.S. 86GA330 86CA350 LANDER G.H. 86LA239 86GA331 JOHNSON W.L. 86WRI26 86LA390 86NY420 JONES D.J. 86J0265 LANG W. 86CL250 86DE1020 JONES R.B. 86FE106 LANGEL W. 86LA112 S6HI1028 86FE116 86LA113 86DA1041 86FE117 86LA351 86HI1060 86FE118 86KN352 HIGGINS S.A. 86PA158 JORGENSEN J.D. 86FI111 86KN406 86HI173 JORGENSEN J.E. 86CH347 86PR407 86MI230 JOSWIG W. 86JO1036 LARHER Y. 86TE3I5 HIGHFIELD R.R. 86HI105 JUNG G. 86R0354 LART1GUE C. 86BE326 HILLER B. 86BL32S KAEPPELER F. 86TR202 86LA161 HINGERTY B.E. 86SA483 KAHN R. 86F1466 86FR426 HIPPERT F. 86MIJ007 KAKURAI K. 86KA1S4 LASJAUNIAS J.C. 86BI373 HIRSCHFELD F.L. 86BE454 86KA1033 LASSAILLY Y. 86LA236 HODEAU J.L. 86H0166 KALUS J. 86HE214 LAST J. 86B0187 86BO304 86NE1098 86FR446 86B0459 KANE W.R. 86SC297 LASTERS I. 86DU1032 86WE465 KANELLAKOPULOS B. 86LA390 LAUTER H.J. 86LAI96 HOFFMANN H. 86HE214 KARPLUS M. 86SM371 86S1219 86NE1098 86CU1031 86S1268 HOLBROOK J.J. 86IB246 KATZ J.J. 86WO1097 86TE315 HOLLAND-MORITZ E. 86HO1057 KAUSCH H.H. 86DE1020 LAVAL J.P. 86LA20O HOLTZBERG F. 86LA236 KEARLEY G.J. 86KE185 LE BAIL A. 86LE123 86BO103S 86KE475 86BI248 HOLZHEY C. 86H0127 86KE476 86GI1067 HONG M. 86MA301 KEBE B. 86BA145 LE FLEM G. 86S0242 HORNIG L. 86B0187 KERR S.A. 86C09T 86EL457 HORSEWILL A.J. 86GR1065 86SC297 LEBECH B. 86MC143 HOVENDEN C.B. 86AL1056 86HA313 86ST161 KESSLER E.G. 860R182 HOWE A.M. 86HO1072 KEYSER U. LEBERMAN R. 86AN42S HOWE M.A. 86HO1001 86GR294 LEBLANC M. 86LE123 HOYLER F. 86C09T 86KE380 86LA204 86AN306 86KE1091 KHODER A.F. 86SA167 86TE220 86WI479 KIESE G. 86FR201 86BI248 HUBER K. 86HU280 KITZIA S. 86KI5T 86LE2S1 HUBSCH J. 86RA1093 KJEMS J.K. 86LE311 86LE252 HUMES R.P. 86HI105 86LE436 LECHNER R.E. 86TO107 86AL1056 86KJ4S6 LEDERER H. 86LE311 HUNGERFORD P. 86SC276 KLAIBER F. 86SC255 86LE436 86SC297 KLAUMUENZER S. 86SC134 LEHMANN M.S. 86CH115 86R0354 KLEMT E. 86B0187 86LE210 86WI479 KLENZE R. 86LA390 86CH212 HUTCHINGS M.T. 86HU152 KNOEZINGER E. 86LA112 86W0253 86DA314 86LAII3 86J0265 IBEL K. 86HE214 86KN352 86LE340 86IB246 86KN406 86KU396 86IM328 KOANG D.H. 86AV393 80AR415 IMAI B.S. 86IM328 KOCZON P. 86K0376 86BE454 ISH1KAWA Y. S61S135 86DO1076 LEHNER N. 86CH347 JACCARD D. 86BO1035 KOEBLER U. 86BR424 LEJAY P. 86BO1008 JACROT B. 86AN425 KOETZLER J. 86K0285 LELAURA1N M. 86VA1096 86BE439 KOLLHOFF H. 86LA1I2 LEMA1RE R. 86BA144 JACUCC1 G. 86JA128 86LA1I3 86BAI45 JAGODZINSK1 H. 86F0414 86KN352 86BA146 JAL J.F. 86EL477 86KN406 86BA147 JANKE E. 86HU152 KOSTORZ G. 86SC255 86BA458 JANOT C. 86JA122 ROSTOV L.K. 86AN306 LEROUX B. 86PA375 86DU130 KOZAK A. DE 86RE257 86SI378 86DU217 KRAMER N.D. 86PR300 86CA1075 86JA256 KRONMUELLER H. 86G0338 86DO1076 86JA286 KRUEGER E. 86KR467 LESYNG B. 86SA483 86DU362 KRUMPOLC M. 86ST417 LETOFFE J.M. 86EL477 86JA391 KRUSCHE B. 86SC445 LEVY F. 86M0233 86BE400 86WI479 86BI373 86JA404 KRYGSMAN P.C.J. 85CU1015 LEWIS J.T. 86F0178 86JA471 KUGLER J. 86GI364 LEWIT-BENTLEY A. 86R0339 86JA472 KUHS W.F. 86KU396 86FI466 86JA480 86BA423 LEY G. 86HA442 JANSEN E. %WE368 86KU433 LIEB K.P. 86W1479

156 LINDGARD P.A. 86ZI114 MATHIS C. 86PE188 MOUSSA F. 86CA260 LINDLEY E.J. 86LI1S9 MATTERN K. 86MA455 MUELLER J. 86SC319 LIPINSKI S. 86LI357 MAUREL M. 86AS379 MUELLER R. 86LO1009 LOEWENHAUPT M. 86FR1050 86CA1075 MUENNICH F. 86GR294 86FR1051 MAY R.P. 86MA7T 86KE380 LONG G.J. 86BA1021 86HE214 86KE1Û91 LONGUEVILLE W. 86LOI76 86LE311 MUENNINGHOFF G. 86DA314 86BE177 86IM328 MUKHERJEE S.P. 86WR133 LONZARICH G.G. 86BE24I 86LE436 MULLER M. 86AM180 LOONG C.K. 86ST240 MCEWEN K.A. 86MC143 MURANI A.P. 86LA215 LOTTERMOSER W. 86LO1009 86ZOI49 86SA281 LUCAZEAU G. 86S0283 86ST157 86MU349 86LU303 86MC235 86MU448 86LU305 86ST238 86MU461 LUETKE-STETZKAMP H 86TR202 86ST240 MURRAY A.D. 86MU1048 LUSCOMBE M. 86IB246 86MC334 MUTTERER M. 86CL250 LYNN J.W. 86ER141 MCGAREY B. 86MC1070 86PA37S MACONNACHIE A. 86MA403 MCGREEVY R.L. 86HO1001 86K0376 86DA1013 MCINTYRE G.J. 86PA150 86DO1076 86DE1020 86PE188 MUYLDERMANS S. 86DU1032 MAGERL A. 86TH1T 86SC255 NAGEL H. 86ST307 86IL8T 86TH272 NATILE G. 86GE481 86MA103 86MC341 NAUDON A. 86G0131 86ER141 86PI343 NEILSON G.W. 86TU229 86MA183 86FI466 86TU399 86BA218 MCKERGOW M.W. 86MC312 86SK427 86WI291 86ROI073 86EN428 86ZA387 MCWHAN D.B. 86MC153 86NE435 86CA411 86VE181 NEUBAUER G. 86NE1098 MAGHAMI G.G. 86HI1060 86MA301 NEUMAIER K. 86MAI03 MAGNANI M. 86AB244 MEIER B.H. 86FI111 86WI29I MAIER B. 86IL4T 86ST22S NEUMANN D.A. 86ZA387 86IL8T MELLEMA J.E. 86CU1015 NEUMANN K.U. 86NE395 86MA16G MENDIA-MONTERROSO 86BA147 NGUYEN T.Q. 86DE1020 86FI466 MENELLE A. 86BE120 NIEPCE J.C. 86CH324 86SU473 MENOVSKY A. 86FR151 NIFENECKER H. 86AS379 MAIER K. 86TR441 86F0422 NIINIKOSKI T.O. 86ST417 MAISANO G. 86F0226 86FO460 NISTLER W. 86KR467 86BE398 MERCIER R. 86TA274 NODA Y. 86ISI35 MAJKRZAK CF. 86MA30I 86TA302 NOUET J. 86SA109 MALIK S.S. 86ST1024 86ME431 NOZIERES P. 86UW175 MALSBURY A.M. 86GR1083 MERDRIGNAC F. 86MA124 86N0323 MALUGANI J.P. 86TA274 MESSAGER J.C. 86CA137 86GA389 86TA302 86CA260 86N0462 86ME431 METHA S.K. 86AL1056 86N0464 MAMPE W. 86AG277 MEZEI F. 86WII42 NUECKER N. 86DI264 86MA279 86FA224 86BU386 86ST307 86DU231 NYSTROM B. 86NY420 86AG337 86K0285 O'CONNELL R.F. 86F0178 86MA382 86NY420 OADES G.C. 86HE205 MANGIN P. 86TE125 86ME474 86DU356 86WR126 86ME1025 OBERTHUER R.C. 861L4T 86R0129 86ME1034 86RA296 86G0131 MIANE J.L. 86MI295 86AL409 86R0132 86MI450 86HA442 86BO140 MICHALSKI T.J. 86WO1097 OBEY T.M. 86COI081 86TE220 MICHAUDON A. 86MI385 OBRADORS X. 86CO1086 86R0221 MIDDENDORF H.D. 86M1I030 OED A. 860E14T 86R03S9 MIEKELEY W. 86BII044 86WE318 86D1360 MIGLIARDO P. 86F0226 86AK374 86MA413 86BE398 86K0376 MANKIKAR R.M. 86WE162 MIKOU A. S6LA200 86GE377 MARCHAL G. 86TEI25 MINGINS J. 86HI10S 86SI378 86JA256 MIRAGLIA S. 86BO304 86GE383 86JA391 86B0459 86WE384 MARCUS-SAUBAT B. 86MA275 MIRANDA A. 86HE205 860E416 MARESCA L.L 86GE481 86DU356 OKPALUGO D.E. 86CY1010 MARET M. 86MA124 MIREBEAU I. 86MI1007 OLIVIERI C.A. 86FI1043 86MA269 MITCHELL E.W.J. 86HO1001 OPPENLAENDER A. 860P15T MAREZIO M. 86HOI66 MITCHELL P.W. 86MI1S6 OTTEWILL R.H. 861L4T 86BO304 86PA158 86MA1017 86B0459 86MI230 86MA1054 8JGH1082 86BE241 86MA1077 MARION G. 86MAI36 MOELLENDORF M. 86BAI63 OUSSET J.C. 86BA144 MARKOVIC t. 86MA1017 MONCEAU P. 86M0233 PAHLMANN B. 86GR294 86MA1054 86BI373 86KE380 86MA1077 MONDONDANON J.P. 86B0459 PALACIOS E. 86BAI64 MARMEGGI J.C. 86MA1064 MONTAGUE D.G. 86MO1022 PALMER S.B. 86PA150 MARTI C. 86CE36S MOORE M.S. 86K0376 86PA169 MARTIN A. 86MA432 MOORE M.W. 86DA243 86BA170 MARTINELLI F. 86BE102 MORENO M. 86KAI55 PANNETIER J. 86DUI0I MASON S.A. 86FI466 MORIN P. 86VE262 86LE123 86GE481 86GI1055 86LA20O 86ZA482 MORKEL C. 86MO1047 86LA204 85SA483 MORONEY L.M. 86BA1063 86DU2I7

157 86TE220 PROTOCHRISTOW C. 86AN306 ROLFS C. 86B0245 PYNN R. 86HU152 ROLLEY E. 86BI248 86KA154 RONCHETT1 M. 86LE251 86PYI71 ROOTS J. 86LE252 86SE213 ROSENMAN 1. 86RE257 86PY222 86LA258 86RE232 86DU263 86B0247 ROSS D.K. 86BI273 86R0355 86PA316 8(>PY470 86BI332 QUADE U. 8iSCL250 ROSSAT-MIGNOD J. 86DU362 QUEMADA D. 86N0323 86WE368 QUITMANN D. 86SU473 86PA392 RAGNET"rI M. 86RA296 ROSTA L. 86CH408 RAINFORD B.D. 86LI159 ROTELLA F.J. 86JA480 86ST238 ROTH M. PANNICKE J. 86PA375 RAMDANI A. 86RA1093 86K0376 RAMSAY J.D.F. 86PO405 PARETTE G. 86TE3I5 86RA1079 PARK P. 86SU353 86RA1087 ROUCHY J. PATTERSON C. 86BA110 RAMSAY N.F. 86RA1092 ROUDAUT E. 86PA169 RAMSEY N.F. 86RA1012 ROUSSEAU M. PAUL D.MCK. 86MI156 RAPP R.E. 86FR348 ROUXEL J. 86PA158 RASCHER R. 86HA3I3 ROWE J.M. 86LI159 RASSAT A. 86BR1026 86MI230 RATTLE H.W.E. 86DU1032 ROZ1ERE J. 86BE241 RAUCH H. 86BA1074 RUDOLPH K. PEARSON D. 86AL409 RAWISO M. 86HE189 RUEBENBAUER K. PEIFFER D.G. 86NY420 RE FIORENTIN S. 86CO1038 PEISL J. 86D0282 REBIZANT J. 86LA239 RUIGROK R.W.H. 86ST293 86LA390 RUMPF A. 86D0336 86BA423 RUSH J.J. 86ST369 REES L.V.C. 86AD1039 86ST410 REGNARD J.R. 86W1179 RUSTICHELLI F. 86DO1023 REGNAULT L.P. 86RE232 86BU1058 86B0247 SAENGER W. PENDLEBURY J.M. 86AG337 REICH C.W. 86SC276 PEPPER D.S. 86IB246 REICHARDT W. 86CH347 SAINT-GREGOIRE P. PEPY G. 86PE188 REMEIKA J.P. 86HOI66 86SI2I9 86BO304 86SI268 RENARD J.P. 86RE232 SALAMON M.B. PERCHERON-GUEGAN A 86BE326 86B0247 SALCE B. 86LA361 RENAUDIN J. 86RE257 SALMON R. PERKINS S.J. 86PE1066 RENKER B. 86RE234 SAMOUEL M. 86PE1069 RENOUPREZ A. 86JO203 SARK1SSIAN B.V.B. PERNOT B. 86FI216 86RI363 REYNOLDS P.A. 86FE191 PERRIN P. 86GE383 RIBET M. 86MA136 86CA1075 RICHARD J.M. 86HE20S PETITGRAND D. 86T0194 86Z0254 SAYETAT F. PETKOV P. 86AN306 86RI327 SCHAEFER W. PETRY W. 86TO107 86DU356 SCHAERPF 0. 86SC134 86MA432 86PE290 RICHARDS R.W. 86DA1013 86ST320 86MC1070 86JA472 86DA1078 PEZZECA U. 86SM371 RICHTER D. 86IL8T PFEIFFER B. 86GR294 86RI174 86R03S4 86HE288 SCHEERER H.J. PHILLIPS W.A. 86BU386 86DR289 PIANELLI A. 86DU362 86RI292 SCHEUER H. PICTON D.J. 86MC312 86ri335 SCHILLEBEECKX P. PIECUCH M. 86JA2S6 86HE358 SCHIRMACHER W. PIERRE J. 86LA215 86KJ456 PIERRON-BOHNES V. 86PI1053 86JA472 PILOTTI M.U. 86PI343 R1CHTER R. 86IL4T SCHIRMER A. PINSTON J.A. 86PR3O0 86HA313 SCHLENKER M. PINTSCHOVIUS L. 86CH347 R1DOU C. 86RI363 POINSIGNON C. 86JO203 RIEKEL C. 86RI1068 86PO405 RIETSCHEL H. 86RE234 POLAND G.A. 86IB246 RIEUBLAND M. 86ST417 SCHLOSSER S. 86DU1032 RIJLLART A. 86ST417 SCHMATZ W. POPOT J.L. 86TR228 RILLO C. 86BA164 SCHMIDT H.H. 86TR447 RIMMER D.E. 86RI344 PRAGER M. 86IL8T RISTORI C. 86AS379 86DI264 ROBINSON B.H. 86FL1071 SCHMITT C. 86GR333 86HO1072 SCHMITT D. 86PR370 ROBINSON R.A. 86R0355 SCHNECK J. 86BU386 ROBINSON S.J. 86R0354 SCHNERING H.G.VON 86PR407 ROBINSON T.E. 86LE340 86PR1080 RODMACQ B. 86R0129 PRANDL W. 86BR424 86G0131 SCHOENENBERGER C. PRESS W. 86GR333 86R0132 SCHOENFELD B. PRESSMAN H.A. 86KE475 86R0221 SCHOFIELD P. PRICE D.L. 86AR429 86R0359 PROKOFJEV P.T. 86SC297 86D1360 SCHOLZ G. RODRIGUEZ F.

158 SCHRECKENBACH K. 86C09T STEEB S. 86ST1005 TIMMINS P.A. 86ZU437 86SC276 STEFANON M. 86AB244 86BE439 86SC297 STEICHELE E. 86S0237 TIMONEN J. 86S032I 86PR300 STEIGENBERGER U. 86SA109 TJAN K. 86TJ1Û42 86HA313 86MA136 86FII043 86SU353 86ST161 86BII044 86SC445 86BA163 TOFIELD B.C. 86THI99 86SC484 86ST223 TOLEDANO J.C. 86TOJ94 SCHREIBER F.X. 86ST307 86WA249 TONKS D. 86RI292 SCHREMS 0. 86KN352 86SI453 TOPRAKCIOGLU C. 86HO1072 SCHROEDER K. 86ST320 STEINER M. 86KAI54 TORBET J. 86T0366 SCHUBERT U. 86SC319 86KAI033 86T0367 SCHUCK P. 86ST266 3TEINHAUSER K.A. 86ST307 86GE372 86BL325 STEINMETZ K.H. 86ST320 TOUDIC B. 86TO107 86ST443 STEVENS E. 86FEI91 TOURBOT R. 86B0394 SCHUETZE H. 86B0187 S^'EYERL A. 86ST307 TOURNARIE M. 86B0394 SCHULLER H. 86HA442 86ST1024 TOURNIER R. 86B0459 SCHULTZ A.J. 86SC421 SVEYRER G. 86ST293 TOUZAIN P. 86R11068 SCHULZ H.J. 86SC267 86ST369 TRAUTVETTER H.P. 86TR202 SCHUMACHER G. 86SC134 86ST4I0 TRAVERSE A. 86BE400 SCHWAB H. K6BA342 STIRLING W.G. 86ST157 TREIMER W. 86TR1037 SCHWANDNER B. S6NEKWP 86ST195 86TRI094 SCHWEIZER J. 86BAU7 86LA239 TREUTMANN W. 86SI4S3 86SI268 86ST240 TREWHELLA J. 86TR228 86BO1008 STOECKU A. 86ST225 86TR447 86BO1035 STOECKMAN^ H.J. 86FR201 86CU1031 SCOPPOLA E. 86I1EI02 STOEFFL W. 86SC276 TROST W. 86TR44I SEEGER A. 86G0338 STRAUCH D. 86STI97 TUPPINGER D. 86BA1074 86TR441 STROTH U. 86ST266 TURNER .1. 86TU229 SEEGER P.A. 86SE2I3 86ST443 86TU399 SEIFERT R. 86TR1037 STROTHMANN H. 86ST440 UNDERWOOD S.M. 86MA1077 UWAHA M. 86TR1094 STUETZ B. S60E4I6 86UW175 SEIFF F. 86SE1088 STUHRMANN H.B. 86ST417 86UW452 86SE1089 STUMPFF C. 86FI1045 VALLADE M. 86BE259 86SE1090 VAN ASSCHE P.H.M. 86PR300 STUNAULT A. 86BO1035 SEVERING A. 86HO1057 VANGELISTI R. 86S1268 SUBBER A.R.H. 86SU353 SHAKIR S.A. 86HI1060 86VA1096 SUCK J.P 86RE234 VARRET F. SHIRAKAV'A H. 86MA403 86FE402 86LE123 SIAUD E. 86LA215 VERGNAT M. 86TE220 86SU473 SICRE A. 86S1378 VETTIER C. 86DU108 SUSMAN S. 86AR429 86CA1075 86MA136 86ZA387 86DO1076 SUZUKI M. 86CA137 86TA1003 SIEGER D. 86SI453 TABONY J. 85CHI48 86GE1014 SILVESTRE-BRAC B. 86Z0254 86MC153 86TA1019 SIM ;ï.B. 86PEI069 86VE181 SIMON C. 86SI219 86FLI071 86LA236 86TA274 86S12S8 TACHEZ M. 86CA260 S1MONOVA L.I. 86PR300 86TA302 86VE262 SINCLAIR R.N. 86WR126 86ME431 86MA301 SINHA S.K. 86KJ456 TADROS T.F. 86MA1077 86CA411 86RO1073 TAKEUCHI Y. 86JOI036 VIGNON B. 86AV393 SKIPPER N.T. 86SK427 TAMBERGS J.J. 86SC297 VINCENT B. 86CO1040 SKJELTORP A. 86PY171 86PR300 86CO1081 86PY470 TANNER L.E. 86MA269 VISSER D. 86HA160 SLADE R.C.T. 86KE475 TASSET F. 86TA17T 86MC341 SLEBARSKI A. 86WA249 86DA314 VLAK W.A.H.M. 86HII73 SMITH J. 86SM371 TASUMI M. 86MA403 VOGL G. 86PE290 86CU1C3I TAX1L P. 86MA432 86ST320 SMITH J.L. 86NE395 TAYLOP G. 86DA1041 VOGT O. 86CHI48 SNELLING D.M. 86R0354 TEIXEIRA J. 86BE329 86LA239 SOLYOM J. 86S032I 86TE397 WACHTEL E. 86ZA418 SOPER A. 86MA269 TERLAIN A. 86TE315 WAGEMANS C. 86WA198 SOSNOWSKA I. 86S0237 I ETE C. 86JA122 WAGNER C.N.J. 86MA269 SOUBEYROUX J.L. 86S0139 86TE125 WALKER M.B. 86MC334 86BO140 86BO140 WALLAT I. 86SE1088 86BA168 86TE220 86SE1089 86S0242 86MA413 86SE1090 86LU305 THALMEIER P. 86CH322 WALLNER G. 86SC134 86EL457 THEOBALD J.P. 86CL250 WALTER J.L. 86SA281 SOURISSEAU C. 86S0283 86PA375 WALTER U. 86WA249 SOUSA J.B. 86PA150 86K0376 WANG H.H. 86SC421 SOUZA J.P. DE 86FI1043 86DOI076 WARNER D.D. 86SC276 SP1RLET J.C. 86LA239 THOLENCE J.L. 86SA165 86SC297 SP1RLET M.R. 86LA390 86SA281 86PR300 SPITS A.M.J. 86PR300 THOMAS J.O. 86TH272 86HA313 SPRINGER T. 86IL8T THOMAS M. 86MA7T WASZCZAK J.V. 86MA301 86JA472 THOMAS M.A. 86GR1006 WEBSTER P.J. 86WE162 STAEDH'.E M. 86TJ1042 86GR1083 WECK G. 86SC134 86FI1043 THOMAS R.K. 86HI105 WEIKARD H. 86GR294 STANLEY H.B. 86ST157 86AL1056 86KE380 86ST238 THOREL P. 86C0299 WEINGAERTNER K. 86PA375 STANSF1ELD R.F.D. 86PEI88 THORNTON G. 86THI99 WEINMANN R. 86BR424 86SC319 THUERWAECHTER R. 86TH1T WEIRAUCH W. 86KR467 86WI345 THURN H. 86HE214 WEISS F. 86B0459 STAYNOV D.Z. 86DU1032 TIETZE H. 86SI453 86WE465

159 WEISSENBERGER E. 86WE318 WOERLE B. 86SC319 86TR447 86WE384 WOLFERS P. 86H016* 86ZA449 WENK H.R 86WE368 86BO304 ZACHMANN H.G. 86G1364 WESTERHAUSEN J. 86SEI088 86FR426 ZAUNE U. 86SC255 86SE1089 86CO1086 ZAWISLAK F.C. 86FI1043 WHITE M.A. 86AL1056 WOOD J.S. 86W0253 ZEIDLER M.D. 86WI190 WOOD M.J. 86DU1032 ZEMIRLI S. 86FR151 WIECHERT H. 86LA196 ZEYEN C. 86F04I4 WIEDENMANN A. 86WI142 WORCESTER D.L. 86BR388 86BR412 ZEYEN C.M.E. 86TE125 86WI179 86WO1097 86BE259 WIESMANN F.J. 86WI190 WRIGHT A.C. 86WRI26 86CA260 WIJN H.W.DE 86HI173 WRIGHT A.F. 86WR133 ZIEBECK K.R.A. 86IS135 WILDING C.R. 86AL409 86JA471 86HA160 WILKINS B. 86AK374 86WE162 WYNS L. 86DU1032 86BR184 WILKINS S.W. 86LE340 YAFET Y. 86MA301 WILKINSON C. 86DA243 86DA243 YANNOULEAS C. 86BL325 86JO309 WILLIAMS D.E.G. 86WI1046 YAUP. 86IM328 86CA350 WILLIAMS J.M. 86SC42I YAVARI R. 86YA287 86NE395 WILLIS B.T.M. 86BE1004 ZABEL H. 86ZA387 ZIMAN T. 86Z1114 WILSON D.L.T. 86RO1073 ZABEL V. 86ZA482 86ZI172 WILSON R. 86AV393 86SA483 86SC267 WILSON S.A. 86WI345 ZACCAI G. 86ZA227 ZOCHOWSKI S. 86Z0149 WINTER C. 86WI479 8STR228 ZOLLIKER P. 86FIU1 WIPF H. 86MA103 86ZA418 ZOUGMORE F. 86BI373 86W1291 86AN425 ZOUZOU Z. 86Z0254 WISWE D. 86GI364 86ZA438 ZULAUF M. 86ZU437

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JOURNAL OF PHYSICS G. GREMPEL D.R. : Localization in the presence of spin-dependent scattering : a renormalization croup study. VITTOZ P., OLIVER R.A., VIVIER G.. KERR S.A., HOYLER JOURNAL OF PHYSICS C. F. : Concentration of B, SM and GD in twenty-three geological reference materials by neutron-capture prompt gamma-ray activa­ HOROVITZ B., SOLYOM J. : Interaction and disorder in charge tion analysis (PGAA). GEOSTANDARDS. density waves. Application to polyacetylene. SYNTHETIC METALS. WHITE D.H., BOERNER H.G., HOFF R.W., SCHRECKEN­ IHLE G., PIRNER H.J., RICHARD J.M. : Testing quark rearrange­ BACH K., DAVIDSON W.F., EGIDY T. VON, WARNER D.D., ment in NN annihilation. PHYSICS LETTERS B. JEUCH P., BARREAU G., KANE W.R., STELTS M.L., CHRIEN R.E., CASTEN R.F., LANIER R.G., LOUGHEED R.W.. KOUZES NIEBUR E., SOLYOM J. : Mean-Field like variational and renor- R.T., NAUMANN R.A., DEWBERRY R. : Nuclear structure of malizalion group studies of ( 1 + 1 )-dimensional spin models. JOUR­ :"Th from neutron capture and (d,p) reaction meas jrements. NAL OF PHYSICS. PHYSICAL REVIEW C.

161 GALLOIS B., GAULTIER J., LAMCHARFI T., BECHTEL F., 4. STRUCTURAL AND FILHOL A., DUCASSE L., ABDERRABBA M. : Crystallographic structures of (TMTSF)2 PFs under constraint evidence of a change MAGNETIC EXCITATIONS in the electronic structure. PHYSICA B (PROCEEDINGS YAMADA CONFERENCE, TOKYO, MAY 1986). BURKEL E., PE1SL J., DORNER B. : Observation of inelastic X- ray scattering from phonons. EUROPHYSICS LETTERS. GALLOIS B., GAULTIER J., BECHTEL F„ FILHOL A., VET­ TIER C. : Low temperature and high pressure (1.7 K & 7 If/ MPa) CURRAT R. : Displacive phase transitions. IN 'TECNICAS EX­ structure of the first superconducting organic salt (TMTSF)2 PFA. PERIMENTALES EN HACES DE NEUTRONES', ED. J. BAR- MOLECULAR CRYSTALS AND LIQUID CRYSTALS. TOLOME (CURSO IN JACA, SPAIN, OCT. 86). KUHS W.F., LEHMANN M.S.: The Structure of Ice Ih. VOL.2, CURRAT R. : Dynamics of incommensurate phase. IN 'TECNICAS •WATER SCIENCE REVIEW' (CAMBRIDGE UNIVERSITY EXPERIMENTALES EN HACES DE NEUTRONES', ED. J. BAR- PRESS). TOLOME (CURSO IN JACA, SPAIN, OCT. 86). KUHS W.F., LEHMANN M.S. : The geometry and orientation of CURRAT R., JANSSEN T. : Excitations in incommensurate crystal the water molecule in ice Ih. JOURNAL DE PHYSIQUE- phases. IN 'SOLID STATE PHYSICS : MODULATED STRUC­ COLLOQUES (PROC. 7TH SYMPOSIUM ON 'THE PHYSICS TURES' (ACADEMIC PRESS). AND CHEMISTRY OF ICE', GRENOBLE, SEPTEMBER 86). JANSSEN T., CURRAT R. : Elastic and inelastic scattering from KUHS W.F., BLISS D.F., FINNEY J.L.: High-resolution neutron quasi-periodic structures. PROC. NATO ASI ON 'STRUCTURAL powder diffraction study of ice Ic. JOURNAL DE PHYSIQUE- INSTABILITY IN CRYSTALS AND QUASI-CRYSTALS', COLLOQUES (PROC. 7TH SYMPOSIUM ON 'THE PHYSICS BOULDER COLORADO, JULY 1986. AND CHEMISTRY OF ICE', GRENOBLE, SEPTEMBER 1986). JENSEN J., McEWEN K.A., STIRLING W.G. : Magnetic excita­ LARTIGUE C, LE BAIL A., PERCHERON-GUEGAN A. : A new tions in the longitudinally polarized antifcrromagnctic phase of study of the structure of LnNhDt,.7 using a modified Rietveld praseodymium. PHYSICAL REVIEW B. method for refinement of neutron powder diffraction data. JOUR­ NAL OF THE LESS COMMON METALS (PROCEEDINGS KOMURA S„ TAKEDA T., SARKISSIAN B.V.B., CHAMBEROD ISPAMH V, MAUBUISSON, FRANCE, MAY 1986). A. : Spin fluctuation in an FessNiu invar alloy. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS. LEHMANN M.S., CHRISTENSEN A.N., FJELLVAG H., FEI- DENHANS'L R., NIELSEN M.: Structure determination employ­ LOEWENHAUPTM., REICHARDT W., PYNN R., LINDLEY E.: ing pattern decomposition and the Rietveld method on X-ray and The unusual excitation spectrum of CeAb. JOURNAL OF neutron powder data ; the structures of AljYaOv and I2O4. JOUR­ MAGNETISM AND MAGNETIC MATERIALS (PROCEEDINGS NAL OF APPLIED CRYSTALLOGRAPHY. ICAREA, GRENOBLE, JULY 86). RANGANATHAN R., THOLENCE J.L., SARKISSIAN B.V.B.: PYNN R. : Neutron scattering studies of non-linear systems. PROC. Magnetism in Y«(Coo.99 ZrooiK SOLID STATE COM­ CONFERENCE ON 'NON-LINEAR PHENOMENA', LOS MUNICATIONS. ALAMOS, MAY 1986. SARKISSIAN B.V.B.: Neutron spin echo and neutron spin STEINER M., KAKURAI K.. KJEMS J.K., PETITGRAND D., depolarization. JOURNAL OF PHYSICS F. PYNN R. : Inelastic neutron scattering studies of 1-D-near-Heisenberg antiferromagnets : a test of the Haldane conjecture. PROC. SCHULTZ A.J., WANG H.H., WILLIAMS J.M., FILhOL A.: The MAGNETISM AND MAGNETIC MATERIALS CONFERENCE, structure of beta-(BEDT-TTF)2l< at 4.5 K and 1.5 Kbar. PHYSICA BALTIMORE, USA, 1986. B (PROCEEDINGS YAMADA CONFERENCE, TOKYO, MAY VETTIER C, BURLET P., ROSSAT-M1GNOD J. : Neutron scat­ 1986). tering studies of anomalous rare earth compounds. JOURNAL OF SOUBEYROUX J.L., FRUCHART D., DERDOUR S., VUIL- MAGNETISM AND MAGNETIC MATERIALS. LET P., ROUAULT A.: Localization of hydrogen (deuterium) in

Hf: Fe Dx, x = O to 5. JOURNAL OF THE LESS COMMON METALS. SOUBEYROUX J.L., PERCHERON-GUEGAN A., ACHARD 5. CRYSTAL AND J.C.: Localization of hydrogen (deuterium) in jlpha-LaNi

162 DIANOUX A.J., PAGE J.N., ROSENBERG H.M. : Inelastic JANOT C, GEORGE B., PANNETIER J., BOUMAZOUZA D.: neutron scattering in the amorphous and the crystalline state. The Time-resolved neutron thermodiffractometrv with (Fe,Mn)8oP20 phonon-fracton density of states. PHYSICAL REVIEW LETTERS. amorphous alloys. IN 'KEY ENGINEERING MATERIALS' (TRANS. TECH. PUBLICATIONS, PROC. INT. CONFERENCE DIFFERT K., SEEGER A., TROST W. : The interpretation of high- ON 'METALLIC AND SEMICONDUCTING GLASSES', temperature experiments on metals in terms of defect concentrations. HYDERABAD, INDIA, DECEMBER 1986). IN 'MATERIALS SCIENCE FORUM', C. ABROMEIT & H. WOLLENBERGER EDS., TRANS TEC. PUBLICATIONS KADONO R., MATSUZAKI T., NAGAMINE K., YAMAZAKI T., (PROC. INT. CONFERENCE ON 'VACANCIES AND IN- RICHTER D., WELTER J.M. : Diffusion of positive muons in cop­ TERSTITIALS IN METALS AND ALLOYS', BERLIN 1986). per detected by zero field n-SR. HYPERFINE INTERACTIONS (PROC. 4TH INT. CONF. ON 'MUON SPIN - ROTATION, DUBOIS J.M., JANOT C, PANNETIER J., FRUCHART R. : RELAXATION, RESONANCE', UPPSALA, JUNE 1986). Neutron diffractometry with Al-lransition metal quasi-crystals. IN 'KEY ENGINEERING MATERlALS'fTRANS. TECH. PUBLICA­ I.ECLERCQ F., DAMAY P., DIANOUX A.J., PRESS W.J.: Quan­ TIONS, PROC. INT. CONFERENCE ON 'METALLIC AND tum rotation of ammonia molecules in disordered Ca(NHi)&. PROC. SEMICONDUCTING GLASSES'. HYDERABAD, INDIA, WORKSHOP ON 'QUANTUM ASPECTS OF MOLECULAR MO­ DECEMBER 1986). TIONS IN SOLIDS', 1LL-KFA JUFLICH, GRENOBLE, SEPT. 86. LUCAZEAU G., GAVARRI J.R., Dl\NOUX A.J. : Study of Na' ELARBY-AOU1ZERAT A., JAL J.F., DUPUY J., SCHILD- motions in beta-Ah0.i by quasi-clastic neutron scattering. JOUR­ BERG H.P., CHIEUX P. : Comments on the ice Ic structure and NAL OF PHYSICS AND CHEMISTRY OF SOLIDS. Ic to In phase transformation mechanism : a neutron scattering in­ vestigation of ice precipitates in glassy LiCl.D:0. JOURNAL DE MARET M.. CHIEUX P., HICTER P., ATZMON M., JOHNSON PHYSIQUE. W.L. : Partial structure factors and chemical short range order in NijiYt,- and CujjYm metallic glasses. JOURNAL OF PHYSICS F. ENDERBY J.E., BARNES A.C. : Liquid alloys and the metal non- metal transition. ZE1TSCHRIFT FUER PHYS1KALISCHE MAI UCiANI J.P., TACHEZ M., MERCIER R., DIANOUX A.J., CHEMIE (PROCEEDINGS LAM6, CONFERENCE ON 'LIQUID CHILUX P. : Small angle, quasiclastic and inelastic neutron scat­ AND AMORPHOUS METALS', GARMISCH, AUGUST 1986). tering from 0.85 AgPOi - O.I5 Pbl; glass. SOLID STATE IONICS. ENDERBY J.E. : The structure of molten salts. IN 'MOLTEN SALT CHEMISTRY', ED. G. MAMANTOV, PROC. NATO ASI MARET M., CHIEUX P., HICTER P. : Small-angle neutron scat­ MEETING, CAMERINO, ITALY, AUGUST 1986. tering of Y-based metallic glasses. ZEITSCHRIFT FUER PHYSIKALISCHE CHEMIE (PROC. LAM6, CONF. ON 'LI­ ENDERBY J.E. : Diffraction studies of aqueous ionic solutions. QUIDS AND AMORPHOUS MFTALS', GARMISCH, RFA, PROC. NATO ASI ON 'THE PHYSICS & CHEMISTRY OF AUGUST 1986). AQUEOUS IONIC SOLUTIONS', CARGESE, CORSICA, JUNE- JULY 86. MAGERL A., DIANOUX A.J., WIPF H., STEINBINDER D., NEUMAIER K., GUTSMIEDL P. : The influence of electrons on ENDERBY J.E., GULLIDGE P.M.N.: Ionic solutions. IN 'ME­ the tunneling state of a hydrogen atom in a metal. PROC. THODS OF EXPERIMENTAL PHYSICS - NEUTRON SCATTER­ WORKSHOP ON 'QUANTUM ASPECTS OF MOLECULAR MO­ ING' (ACADEMIC PRESS). TIONS IN SOLIDS', ILL-KFA JUELICH, GRENOBLE, SEPT. 86. McKERGOWM.W., ROSSD.K.. BONNET J.E„ ANDERSON I.S., FLOTTMANN T., PETRY W., VOGL G., HEIMING A. : Direct SCHAERPF O. : One dimensional ordering of deuterium in solu­ evidence for self-diffusion in beta-titanium via vacancies. IN tion in Yttrium. JOURNAL OF PHYSICS C. •MATERIALS SCIENCE FORUM', C.ABROMEIT & H. WOL­ LENBERGER EDS., TRANS. TEC. PUBLICATIONS (PROC. MUELLER P.. JUNG S., HEIDEMANN A. : Atomic motions in INT. CONFERENCE ON 'VACANCIES AND INTERSTITIALS Supercooled ZnClj. ZEITSCHRIFT FUER PHYSIKALISCHE IN METALS AND ALLOYS', BERLIN, SEPTEMBER 1986). CHEMIE (PROC. LAM6, CONF. ON 'LIQUIDS AND AMOR­ PHOUS METALS', GARMISCH, RFA, AUGUST 1986). FRE1LAENDER P., HE1TJANS P., ACKERMANN H., BA- DER B., KIESEG., SCHIRMER A., STOECKMANN H.J., VAN PANNETIER J., DUBOIS J.M., JANOT C, BILDE A. : Thermal DER MAREL C, MAGERL A., ZABEL H. : Diffusion processes transformation of icosahedral quasiperiodic crystals of the Al-Mn in LiCs studied by bela-NMR. ZE1TSCHRIFT FUER system. PHILOSOPHICAL MAGAZINE. PHYS1KALISCHE CHEMIE N.F. GODFR1N H.R. : Nuclear magnetic resonance investigations of two dimensional 3He. CANA­ PETRY W., VOGL G., HEIDEMANN A., STEINMETZ K.H. : DIAN JOURNAL OF PHYSICS (PROC. BANFF CONF. ON Af.?malously fast diffusion of cobalt in beta-zirconium : a quasielastic 'QUANTUM FLUIDS AND SOLIDS', OCTOBER 1986). neutron scattering (QNS) study. PHILOSOPHICAL MAGAZINE A. HARTMANN O., KARLSSON E., WAECKELGARD E., WAEP- PLING R., RICHTER D., HEMPELMANN R., NIIN1KOSKI T.O.: PETRY W., VOGL G. : Potential and limits of nuclear methods in Low temperature diffusion and trapping of muons in aluminium: non diffusion studies. PROC. INT. CONFERENCE ON 'VACANCIES experiments and comparison with theory. HYPERFINE INTERAC­ AND INTERSTITIALS IN METALS AND ALLOYS', BERLIN, TIONS (PROC. 4TH INT. CONF. ON 'MUON SPIN - ROTATION, SEPTEMEER 86. RELAXATION, RESONANCE'. UPPSALA, JUNE 1986). RICHTER D. : The motion of light interstitials in metals : recent HARTMANN O., KARLSSON E., WAEPPL1NG R., GUS- experiments. HYPERFINE INTERACTIONS (PROC. 4TH INT. TAVSON-SEIDEL A., RICHTER D., HEMPELMANN R., CONF. ON 'MUON SPIN - ROTATION, RELAXATION, KOSSLER W.J., HITTI B., KEMPTON J., LANKFORD W.F., RESONANCE', UPPSALA, JUNE 1986). STRONACH CE.: Muon diffusion in Nfc-H systems. HYPERFINE RICHTER D. : Quantum diffusion of light interstitials in metals. INTERACTIONS (PROC. 4TH INT. CONF. ON 'MUON SPIN - PROC. WORKSHOP ON 'QUANTUM ASPECTS OF ROTATION, RELAXATION, RESONANCE', UPPSALA, JUNE MOLECULAR MOTIONS IN SOLIDS', ILL-KFA JUELICH, 1986). GRENOBLE, SEPT.86. JAL J.F., MATHIEU C, DUPUY J., CHIEUX P., SADOC A. : SCHUMACHER G., KLAUMUENZER S., PETR^ W.. Partial structure factors of liquid K-KC1 in the metallic and strong WALLNER G., WECK G., DEDEK U. : Irradiation induced com­ scattering conductivity regime. ZEITSCHRIFT FUER positional and topological defccls in glassy CuTi and CuZr Alloys. PHYSIKALISCHE CHEMIE (PROCEEDINGS LAM6, CONFE­ ZEITSCHRIFT FUER PHYSIKALISCHE CHEMIE (PROC. RENCE ON 'LIQUIDS AND AMORPHOUS METALS', GAR­ LAM6, CONF. ON 'LIQUIDS AND AMORPHOUS METALS', MISCH, AUGUST 1986). GARMISCH, RFA, AUGUST 1986). JANOT C. : Multiiayered amorphous semiconductors : periodic and STEYRER G., PEISL J. : Macroscopic density fluctuations in the quasiperiodic superlattices. IN 'KEY ENGINEERING MATERIALS' niobium-hvdrogen svstem studied bv neutron radiography and com­ (TRANS. TECH. PUBLICATIONS, PROC. INT. CONFERENCE puterized'tomography. PROC.'2ND WORLD CONF. ON ON 'METALLIC AND SEMICONDUCTING GLASSES'. 'NEUTRON RADIOGRAPHY', PARIS, JUNE 1986, D. REIDEL HYDERABAD. INDIA, DECEMBER 1986). PUBLISHING COMPANY.

163 VAN DER MAREL C, HEITJANS P., ACKERMANN H., LAUTER H.J., SCHILDBERG H.P., GODFRIN H„ WIECHERT BADER B., FREILAENDER P., SCH1RMER A., STOECK- H., HAENSEL R. : Neutron diffraction studies of 2-D-quantim MANN H.J.: Nuclear spin-lattice relaxation in liquid lithium- systems. CANADIAN JOURNAL OF PHYSICS (PROC. BANFF germanium alloys. ZEITSCHRLFT FUER PHYSIKALISCHE CONF. ON 'QUANTUM FLUIDS AND SOLIDS', OCTOBER CHEMIE N.F. 1986). VAN DER MAREL C, HEITJANS P., BADER B., FREILAEN­ DER P., SCHIRMER A., FREYLAND W.: NMR and magnetic MAGERL A. : Vunneling of hydrogen in metals studied by neutron susceptibility measurements on liquid lithium up to high temperatures. spectroscopy. IN 'TECNICAS EXPERIMENTALES EN HACES ZEITSCHRIFT FUER PHYSIKALISCHE CHEMIE N.F. DE NEUTRONES', ED. J. BARTOLOME (CURSO IN JACA, SPAIN, OCT. 86). WINTER R., NOLL F., BODENSTEINER T., GLAESER W., CHIEUX P., HENSEL F.: Conductivity - and neutron scattering RITTER C. : Hydrogen intercalation compounds. ZEITSCHRIFT experiments on expanded fluid cesium in the metal-nonmetal transi­ FUER PHYSIKALISCHE CHEMIE (PROC. INT. SYMPOSIUM tion region. ZEITSCHRIFT FUER PHYSIKALISCHE CHEMIE ON 'MAGNETIC 1ŒSONANCE IN COLLOID AND INTER. N.F. SCIENCE', MUENSTER, JULY 86). YOSHIDA Y., MIEKELEY W., PETRY W., STEHR R., STE1NMETZ K.H., VOGL G. : Anomalously fast diffusion of Fe WARD R.C., LEADBETTER A.J., RICHARDSON R.M., STIRL­ in beta-Zr-Fe alloys, a Moessbauer study. PROC. INT. CON­ ING W.G. : Cooperative dynamics in the disordered phase of ter­ FERENCE ON 'VACANCIES AND INTERSTITIALS IN METALS tiary butyl cyanide. MOLECULAR PHYSICS. AND ALLOYS', BERLIN, SEPTEMBER 1986. WARD R.C., LEADBETTER A.J., RICHARDSON R.M., STIRL­ ING W.G. : Cooperative dynamics in the disordered phase of ter­ tiary butyl cyanide. IN 'DYNAMICS OF MOLECULAR 8. BIOCHEMISTRY CRYSTALS' (ELSEVIER SCIENCE :>UB., PROC. 4IST MEETING, GRENOBLE, JULY 1986). FINNEY J.L., LINDLEY P.F., SAVAGE H.F.J., T1MM!NS P.A.: High resolution neutron and X-ray refinement of vitamin BI2 coenzyme, C72H100 Ni«0i?PCo.l7H2O. ACTA CRYSTALLO- GRAPH1CA. PLOEHN H.J., BUELDT G., ZACCAI G. : The distribution of tetramethyl ammonium ions on the surface of purple membranes. EUROPEAN BIOPHYSICAL JOURNAL. TORBET J., TIMMINS P.A., LVOV Y : Packaging of DNA in cauliflower mosaic virus and bacteriophage SD studied with magnetic birefringence. VIROLOGY. ZACCAI G. : Structure and hydration of purple membranes in dif­ ferent conditions. JOURNAL OF MOLECULAR BIOLOGY.

9. CHEMISTRY

BEE M., FOULON M., AMOUREUX J.P., CAUCHETEUX C, POINSIGNON C. : The glassy-phase of 1-cyanoadamantane ; study of the molecular reorientations by high resolution quasielastic neutron scattering. JOURNAL OF PHYSICS C. BEE M., POINSIGNON C. : Single-crystal and partially-oriented mple studies. CH.8 IN 'APPLICATION OF QNS TO SOLID .ATE CHEMISTRY, BIOLOGY & MATERIAL SCIENCE', ADAMS & HILGER PUBLISHERS. GRONDEY S., PRAGER M., PRESS W„ HEIDEMANN A.: Rota­ tional excitations in (CH.O1-* Kr, solid mixtures. PROC. WORKSHOP ON 'QUANTUM ASPECTS OF MOLECULAR MO­ TIONS IN SOLIDS', ILL-KFA JUELICH, GRENOBLE, SEPT.86. GUILLAUME F., SOJRISSEAU C, LUCAZEAU G., DIANOUX A.J.: Reorientational motions and phase liansitions in some perov- skite type layered compounds (NH3(CHj)„NH3)MnCl4, n = 3,5. IN •DYNAMICS OF MOLECULAR CRYSTALS' (ELSEVIER SCIENCE PUB., PROC. 41ST MEETING, GRENOBLE, JULY 1986). HEIDEMANN A., ECKERT J., PASSELL L., HAEUSLER W.: Pressure dependence of tunneling and librational modes of coupled methyl groups in lithium acetate. ZEITSCHRIFT FUER PHYSIK B. HEIDEMANN A. : Rotational tunneling of coupled groups studied by inelastic neutron scattering. PROC. WORKSHOP ON 'QUAN­ TUM ASPECTS OF MOLECULAR MOTIONS IN SOLIDS', ILL- KFA JUELICH, GRENOBLE, SEPT 86. HEIDEMANN A., ABED K.J., BARKER C.J., CLOUGH S.: Pro­ ton spin conversion of coupled methyl groups in lithium acetate studied by inelastic neutron scattering. ZEITSCHRIFT FUER PHYSIK B. KEARLEY G., BLANK H., COCKCROFT J. : The hindrance poten­ tial and coupling of the NHj quantum rotors in Co(NHi)f.(PFfi)2. JOURNAL OF CHEMICAL PHYSICS.

164 3-06- 22 Discovery of a low-energy K':=3/2" band and SN 6 its description by the model IBFM/PTQM. PFEIFFER B., BRANT S., KRATZ K.-L. MEYER R.A., PAAR V. CARRIED OUT 3-06- 37 Pairing reduc'ion in the deformed nucleus SN 6 "Viv AT THE ILL. PFEIFFER B., KRATZ K.-L. 3-06- 70 Test measurement of the ion sources of the SN 6 The following is the list of experiments performed at the I.L.L. up mass separator OSTIS. to Oct. 1986 for which experimental reports were received before Jan. MUENNICH F., KEYSER U., 19th 1987. For a detailed study of the results, please refer to '1986 PAHLMANN B., GRAEFENSTEDT M , I.L.L. Experimental Reports and Theory college Activities". (Reports KEYSER U. WE1KARD H. marked with * are not available for publication). 3-06- 75 Measurement of the beta-decay energy of ""Ba SN 6 using the mass separator OSTIS. MUENNICH F., KEYSER U. COLLEGE 3: GRAEFENSTEDT M., SCHRE1BER F. Fundamental and Nuclear physics WEIKARD H. 3-01-145 Cold fragmentation in thermal neutron induced PN 1 3-06-76 Pirmcasuremenis with the negative ion source SN 6 fission of 2,9Pu. m at OSTIS. CLERC H.G., KOCZON P., SCHMITT C. 3-06-81 KRATZ K.L. THEOBALD J.P.. BRISSOT R. /83 GOENNENWEIN F.. FAUST H.R. 3-06- 78 Particle quadrupole-phonon coupling SN 6 description of N = 59 nuclei: the case of y7Sr. 3-01-169 Isomeric yield ratio and decay properties of PN1 KRATZ K.-L., PFEIFFER B„ «lll.liy LHERSONNEAU G., OHM H.L, DENSCHLAG H.O., FAUST H., SISTEMICH K., STOEHLKER U. GUETTLER U., HOERNER S., STUMPF P. 3-06-81 SEE 3-06- 76 3-01-170 Charge distribution of fission fragments in PN 1 /83 MCf(n,f). BRISSOT R., BOCQUET J.P., AKER E., 3-06- 84 QB-measuremepi of very neutron-rich Br SN 6 ENGELHARDT D., WILKINS B., FAUST H., isotopes at the mass separator OSTIS. CRANÇON J., R1STORI C, DJEBARA M., MUENNICH F., KEYSER U., GRAEFEN­ ASGHAR M., QUADE U., RUDOLPH K. STEDT M., SCHREIBER F., STOEHLKER U. 3-01-174 OfJ-measurements of very neutron rich light PN 1 3-07- 8 Search for parity violation in resonance PN 7 3-01-186 fission products with mass number A = 107 3-07-14 scattering of y-rays. H 22 and A = 108. BEDA A., BELYAEV S., BONDARENKO L. MUENNICH F., KEYSER U. DAN1LYAN G., GELTENBORT P. GRAEFENSTEDT M., SCHRE1BER F. GOENNENWEIN F., MARTEMYANOV A. MOSTOVOII Yu., SCHRECKENBACH K. 3-01-201 Q|5-measurements of very neutron rich light PN l fission products with mass numbers above 3-07- 10 Dynamic storage of neutrons, and a new direct SN 7 A = 100. measurement of the neutron life-time. MUENNICH F., KEYSER U., FAUST H.R. ARNOLD M., DOEHNER J., LAST J. GRAEFENSTEDT M., SCHRE1BER F. FREEDMAN S.J., BARKER P., DUBBERS D.

3-02-254 Study or the decav !l4Bi !,4Po with PN 4. PN 4 3-07- 10 Search for short-lived axions emitted SN7 f.om SN 7 MOUZE G., COMANDUCCI J.F. neutron capture on protons. MAILLARD D., YTHIER C, KERR S.A. FREEDMAN S.J., ARNOLD M., DOEHNER J., LAST J., DUBBERS D. 3-02-296 The antineutrino spectrum of u,Pu fission PN 2 products. 3-07- 13 SEE 3-05- 36 SCHRECKENBACH K., HAHN A.A. 3-07- 14 SEE 3-07- 8 GELLETLY W., VON FEILITZSCH F. COLVIN G., KRUSCHE B. 3-07- 15 Study of the 2"Um(ni>,,f) reaction. PN 7

l,5 NEVE DE MEVERGNIES M., D'EER A. 3-02-302 Lu (n,y) studies for the '"'Lu cosmic clock. PN 3 WAGEMANS C, GOENNENWEIN F. KAEPPELER F., SCHATZ G., KLAY N. GELTENBORT P., SCHRECKENBACH K. BEER H. MOORE M. 3-02-318 Absolute gamm': spectroscopy at high energies PN 3 3-07- 23 Observation of "Berry's topological phase" in SN 3 using a two-a\is flat crystal spectrometer neutron-spin rotation. (GAMS-4). DUBBERS D., BITTER T. DESLATTES R.D., GREENE G.L., KESSLER E.G. •3-08-11 Study of proton even-odd efrcct in (n,h,f) Tor SP BE ~*Th, 2J!Pu and :"U with a AE-E gas 3-02-321 Test of boson-fermion symmetry in PN 2 lwW PN 2 ionisation chamber. and "4W. ASGHAR M., N1FENECKER H. PEARCEY J., GELLETLY W„ COLVIN G.C. SCHRECKENBACH K., WARNER D.D. 3-08- 22 Detailed study of the .mass and energy pn & characteristics of the 24lPu(nih,f) fragments. 3-04-2 Determination of concentration profiles by (n,y) S 30 WAGEMANS C, GELTENBORT P., OED A. 3-04-6 and (n,p) - reactions. SCH1LLEBEECKX P.. GOENNENWEIN F. FINK D., B1ERSACK J.P., FICHTNER P.F., BEHAR M„ WEISER M. 3-13- 74 The beta-decay branch of the isomeric stare in SP.BE 7l,Se: A possibility to determine the temperature 3-05- 36 Dressed neutrons. SNS during stellar nucleosynthesis. 3-07- 13 DUBBERS D.. MUSKAT E., SCHAERPF O. KLAY N., KAEPPELER F. 3-05-38 Direct observation of enhanced 2D SN 5 3-13- 76 Lifetime measurements in the thermal neutron S 34 5-41-6/ magnetism... capture. 7/8 BLAND J.A.C., PESCIA D., WILLIS R.F., ANDREJTSCHEFF W., PETKOV P., MAMPE W., AGERON P. HAMILTON W.D.

165 3-13- 77 An experimental investigation into the H22F 4-03-345 Magnetic scattering in the heavy fermion IN 12 fundamental aspects of neutron tomography: superconductor UPt3. neutron transmission and prompt gamma-ray BUYERS W.J.L., KJEMS J.K., emission modes. GARRETT J.D., MCEWEN K.A., SPYROU N.M., KUSMINARTO GODFRIN H. NICOLAOU G.E. 4-03-347 Real soliton gas fluctuations in the planar IN 12 3-13- 78 Prompt gamma activation analysis of S 34 antiferromagnei TMMC. geological material. H22F BOUCHER J.?., REGNAULT L.P. OLIVER R.A., VITTOZ P., VIVIER G., BOUILLOT J. KERR S. 4-03-359 Crystal Field slates and line width IN 4 3-13- 83 Optical spin-orbit rotation in neutron S 21 4-05-129 effects in heavy fermion systems. IN 6 dynamical diffraction. KNOPP G„ SP1LLE H., LOIDL A. FORTE M, ZEYEN C. 4-03-361 Magnetic cluster excitations in IN 8 Rb2Mno,7oCriut>Clj mixed crystals. 3-13- 89 Systematic study of (n.a) and (n,f) reactions. H22D WAGLZMANS C, SCHILLEBEECKX P. GEICK R., COWLEY R., SIEGER D. D'EER A., BOCQUET J.P. TIETZE H., BATES S. 4-03-362 The spectral response of an exchange enhanced paramagnet. BERNHOEFT N.R., ;'AUL D. COLLEGE 4: 4-03-371 Excitations in CcAl:. IN 20 LOEWENHAUPT M., REICHARDT SV. Structural and Magnetic excitations 4-03-372 Single magnon and two magnon processes in IN 12 4-01-281 High-resolution study of Inng-wavclcnglh IN 12 planar Hciscnbcrg ferromagnct CsNiFi with IN 20 Peierls instability in (TaScj):!. transverse field. MONCEAU P., BERNARD L„ CURRAT R. KAKURAI K., STE1NER M. LEVY F„ ROUXEL J. d-03-37d Exchange competition and magnetic clustering 0 17 4-01-282 Search lor a Kohn anomaly in the 1-D CDW IN 8 in (NdivLaOiCoi.i. compound NbSe?. BALLOU R., GIGNOUX D., LEMAIRE R. MONCEAU P., LERNARD L., CURRAT R. ROTH M. LEVY F. 4-03-378 Polarisation analysis study of single- & multi- IN 20 4-01-283 Coupled rotational and translational excitations IN 3 magnon excitations in TMMC. in the molecular crystal (NaCN)i.»(KCN),. VOUCHER J.P., ENDOH Y., PYNN R. SCHRAEDER T., LOIDL A. REGNAULT L.P., ROSSAT-MIGNOD J. 4-01-291 Dispersion rurves and electron IN 3 4-03-381 Electron transfer phenomena and 4-01-305 phonon interaction in CdjMg. IN 8 antiferromagnetic coupling in trinuclear metal RUMIANTSEV A.YU .DORNER B. carboxylates. CHERNYSHOV A.A., ALEXEEV P.A. JAYASOOR1YA U.A., CANNON R.D. IVANOV A.S. 4-03-384 Local excitations in random chromium iron ferromagnets. 4-01-294 Determination of group velocities in GaAs for IN 8 MITCHELL P.W., LINDLEY E.J. off-symmetry direction. IN 3 STRAUCH D., DORNER B. 4-03-391 Magnetic excitation in NdBh. ERKELENS W.A.C., REGNAULT L.P., 4-01-295 Search for a zone center phonon gap in IN : ROSSAT-MIGNOD J., KUNII S., KASUYA T. incommensurate ethylene monolayer on graphite. 4-03-394 Magnetic excitations in DyzCon. IN 8 PA5ÎSEL L., R1CHTER D., HEIDEMANN A. SINNEMA S., FRANSE J.J.M., COLPA J. FRINGS P.H. 4-01-297 Lattice dynamical study of K-Hollandite. IN 8 ROSSHIRT E., FREY F., BOYSEN H. 4-03-399 Magnetic excitations in RE;FeuB. STEIGENBERGER U. LOEWENHAUPT M., HOEN1G H.E. WARLIMONT H. 4-01-302 High frequency phonons in pvrolytic graphite. IN 1 BURKEL E„ PE1SL J., DORNER B. 4-03-400 Collective excitations in HoVOa below IN II TN - 5 mK. 4-01-303 Fine structure of the phonon IN 3 dispersion IN 3 CLARK R.G., WELLS M.R., curves of y-tin. IN 8 NEEDHAM L.M., MEZEI F. RUMIANTSEV A.YU., IVANOV A.S 4-03-401 Crystal field excitations in holmium aluminium IN 4 DORNER B. garnet and holmium gallium garnet. IN 6 McCAUSLAND M.A.H., McMORROW D.F. 4-01-304 Phonon anomalies in the high temperature IN 3 MITCHELL P.W. PRAKASH O.M. phase of titanium. HE1MING A., FLOTTMANN T.. 4-03-421 Direct observation of anisotropic exchange IN 13 PETRY W., VOGL G. interactions in f-electron systems. FURRED A., GUEDEL H.U., HEIDEMANN A. 4-01-305 SEE 4-01-291 4-03-422 Polarized-neutron inelastic scattering experiment IN 12 4-02-190 Soft mode in the layered compound SnSc. on quasi-one dimensional S = I CHATTOPADHYAY T., KRESS W. antiferromagnetic (AF) :?eisenberg system SCHNERING H.G.V. CSNiC13. KAKURAI K., STEINER M., KJEMS J.K. 4-02-220 Determination of the drift velocity of the IN II BUYERS W.J.L. charge density wave in a qaasi-onc dimensional conductor below Peicrls transition. ^-03- Magnetic ground state of heavy fermion CcPb*. IN 3 MEZE1 F„ HOLCER K., M1HA1.Y G. TEST FLOUQUET J., MORIN P., VETTIER C. IN 8 FARAGO B. IN 12 4-02-227 Lattice dynamics and phase transitions in a IN 3 4-04-138 Spin dynamics of some intermediate valent Sm- IN 4 hrominc graphite intercalation compound. and Eu-compounds. BATALLAN F., RC^NMAN ]., SIMON C. HOLLAND-MORITZ E.

166 404-141 Longitudinal fluctuations in ferromagnetic IN 12 5-13-150 Orientational disorder and hydrogen bonding in D 9 europium oxide. high-pressure ices : Single crystal study of D2O COWLEY R.A., MITCHELL P.W. HEWITT ice VI at lGPa. M.A., MOOK H.A. KUHS W.F., FINNEY J.L., AHSBAHS H. LONDONO D. 4-04-144 Critical scattering from a dilute Heisenberg spin IN 3 glass in an external magnetic field. 5-13-154 Acrylic ethylene complexes of tungsten acrylic D 9B STEIGENBERGER U., GEBHARDT W. acid' : formation by reaction of CO2 on OBERMAIER R. ethylene complexes of tungsten. ALVAREZ R., POVEDA M.L., 4-04-148 Identification of fluctuating susceptibility IN 12 CARMONA E. SAVARIAULT J.M. components in the two-dimensional ionic ferromagnet Rb2CrCU. 5-15-266 A structural study of the onset of order in D 9 HUTCHINGS M.T., BRAMWELL S., DAY P. PbTiOj. NELMES R.J., TUN Z., KUHS W.F. 4-05- 97 The structure and dynamics of amorphous IN 6

Dy7Nij. Ill 5-15-273 The P-T dependence of the struciure of squaric D 15 WRIGHT AC, SINCLAIR R.N., acid. HANNON A.C. NELMES R.J., TUN Z., McINTYRE G.J. 4-05- 98 Search for magnetic correlations in CeCus. D 5 5-15-273 A diffraction study of structural ordering in D 9 FLOUQUET J., JACCAKD D„ BREWER W. squaric acid. WALKER M. NELMES R.J., TUN Z., KUHS W.F. 4-05- 99 Magnetic response in the intermediate valence IN 4 5-15-276 Structure of (HEThh at low temperature and D 15 compound CeNi. high pressure. G1GNOUX D., GALERA R.M.. MURANI A.P. SCHULTZ A.J., WANG H.H., WILLIAMS J.M., FILHOL A. 4-05-114 Polarization analysis experiment of spin v.rtves IN 20 in PuSb. 5-15-281 The pressure dependence of the structure of D 15 LANDER G.H., ROSSAT-MIGNOD J. PbHP04. SPIRLET J.C., STIRLING W.G. NELMES R.J., RESTOR1 R., TUN Z. MCINTYRE G.J. 4-05-118 Spin dynamics of sonic narrow band IN 6 5-15 282 A diffraction study of the structural phase D 9 Ce-systems. transition in PbHPO.1. HOLLAND-MORITZ E., SEVERING A. NELMES R.J., TUN Z., KUHS W.F. 4-05-119 Dynamical splitting in n ground stale svstems. IN 6 LOEWENHAUPT M., FRICK B., 5-15-283 A diffraction study of structural ordering in D 9 NEUHAUS W. squaric acid: II. NELMES R.J., TUN Z., RESTORI R. 4-05-120 Inelastic magnetic response in intermediate D 5 KUHS W.F. valence CePd3 cross over between Fermi liquid 5-15-284 Atomic disorder in PbTiOj. D 9 regime and Curie-Weiss behaviour. NELMES R.J., TUN Z., RESTORI R. GALERA R.M., PIERRE J., MURANI A.P. KUHS W.F. 4-05-122 Magnetic excitations in CeMgi; and IN 4 IN 4 5-15-288 Diffuse and Bragg scattering of neutrons on D 10 CelnCus compounds. single-crystal KTaOî doped with impurities. GALERA R.M., LAHIOUEL R., PIERRE J. JOFFRIN J., HOECHLI U.T., MURANI A.P. MAGLIONE M. ZEYËN C. 4-05-129 SEE 9-03-4S9 5-16-158 Residual flress determination in coarse grained D 10 materials. 4-05-138 Crystal field and relaxation in the Kondo IN 4 REIMERS W., CROSTACK H.A. system CeSiu*iGe<. PIERRE J., LAHIOUEl. R. 5-16-159 The glass transition in the alkali cyanide-alkali D 10 halide mixed crystals. 4-05-153 Energy analysis of the magnetic diffuse IN 6 LOIDL A. scattering from (Fe*Cr!..T)2Caj(GeOd)i. BRUECKEL T., PRANDL W. 5-16-166 Absolute measurement of the temperature D 9 dependence of TDS in Si. 4-05-154 Spin dynamics of the spin glass IN 10 ZEILINGER A., GRUBER M., McINTYRE G. (Fe.sCr.sfcCa Ge04)j near Ts. BRUECKEL t., PRANDL W. 5-16-167 Reflectivity VS wavelength for polarized D 5 neutrons: Tests of Kato's extinction theory. S 20 GUIGAY J.P., BARUCHEL J. SCHLENKER M., SCHWEIZER J. PATTERSON C. COLLEGE 5: 5-16-172 Surface acoustic wave diffraction of cold D 17 neutrons. Crystal and Magnetic structures KLEIN A.G., OPAT G.I., HAMILTON W.A. 5a - Crystallography 5-21-261 Structural study of simple and complex D 1A hydrides of aluminum and IA. metals. 5-11-161 Transition metal-hvdrogen-alkali metal bonds. D 10 BASTIDE J.P., CLAUDY P., FRUCHARD D. PROUT C.K.,WILLIS B.T.M. BANDY J.A. CHIEUX P. 5-12- 90 Thermal motion and bond lengths in D 9 5-21-263 Structure and hvdrogen bonding in D 1A hexamethylene tetramine (C6N4H12). MjHGejOï<,.4H20. HOWARD J.A.K.,WILLIS B.T.M. FENDER B.F.F., FITCH A.N. *5-13- Low temperature single crystal structure D 10 5-21-268 Crystal and magnetic structures of intercalated D 1A 48 analysis of mica analogues RNiAsOa (R = K*, H3O4 etc). [MoOi'-CsHv) (n\ V : C,2H»)J [CF3SO3]. DAY P., BRAMWELL S., BUCKLEY A. ORPEN DR. AG., BRAMME" L. 5-21-270 Direct determination of zeolite crystal structures D 1A 5-13-149 Oxygen disorder in ice Ih. D 9 from neutron powder diffraction data. KUHS W.F., LEHMANN M.S. ADAMS J.M., GOLAB M.

167 5-21-278 Structural studies of some bismuth oxides and D IA 5-31-183 Magnetic order of FeClj and C0CI2 intercalated D 17 carbonates. in graphite. GREAVES C, BLOWER S.K. SIMON C, BATALLAN F. 5-21-295 Deuterium sites in the bronze D,KyWO;. D IA 5-3I-I84 Study of order in mixed colloidal ferrofluid D II SLADE R.C.T., WEST B.C., RAMANAN A. 9-09-86 systems. CHARLES S.W., HAYTER J.B. SKJELTORP D IB 5-21-302 Crystal structures of AI((OD)i,5F..5)05D2O and A.T., PYNN R. AI(OD i.sFi.s. FOURQUET J.L., RIVIERE M. DE PAPE R. 5-31-188 The structure and dynamics of amorphous D 17 DyiNii. IV 5-22-252 Phase transitions in ZrCh-ceramics. D IB WRIGHT A.C., SINCLAIR R.N., KAMMERMEYER .SCHMID J., VOLLERT B. HANNON A.C., GRIMLEY n.!. 5-22-271 Structural mapping of the H2O and D2O ice D IA 5-31-191 Magnetic phase transitions in f.c.c. Fe thin D 17 phase diagrams. films. FINNEY J.L., KUHS W.F., LONDONO D. BLAND J.A.C., WILLIS R.F., PESCIA D. VETTIER C. 5-31-206 Powder investigation of magnetic ordering in [J- D IB 5-22-275 Phase transitions in NajNOj. D IA stabilised CeY and CeLa allovs. KREMMLER J., JANSEN M. FORGAN E.M., McEWEN K.A. GIBBONS E.P. 5-25-189 Texture in antlers. D IB BACON G.E., KITCHENER A.C., 5-31-211 Structure determination and magnetic study of P 1A VINCENT J.F.V. oxygen defect perovskites. RAVEAU B., MICHEL C. 5-25-193 Structure determinations from powder D 1A patterns or Ca2AI(OD)6C1.2D;0 and 5-31-212 Manganese location and magnetic siructure of D IB C04Al2OtCOj.llD2O. Mn2-W hexagonal ferrite. CHRISTENSEN A.N., FJELLVAC U. COLLOMB A. NORBY P., LEHMANN M.S. 5-31-213 Kinetics of the magnetic long range order in D IB 5-25-194 Dynamic neutron diffraction studies of DIB the partly frustrated anlifcrromagnel structural transformations occurring in (Fc.jCr.s)!Ca.i(GcO0.i. industrially important alumino-silicatcs. BRUECKEL T., PRAND1. W., CONVERT P. BARNES P., TARLING S.E., CLARK S.M., POLAK E. 5-31-215 Longitudinal spin fluctuations in Fc-Ni and IN II 5-34-217 FeiPt invar alloys. 5-25-195 Kinetic study of electrochemical intercalation of D IB CHAMBEROD A., KOMURA S., TAKEDA T. THF solvated potassium into graphite. MARCUS B., TOUZA1N P., 5-31-218 Field dependence of the SANS in two D II SOUBEYROUX J.L. representative reentrant systems. HENNION M., HIPPERT F., LEQUIEN S. 5-?5-196 A kinetic investigation of the reaction of a solid D IB with a solution: CaiiAluOjj + CaCk in D2O. 5-31-219 Measurement of the behavior of Blochwalls in D 11 CHRISTENSEN A.N., FJELLVAG H„ bulk nickel single crystals by induced magnetic LEHMANN M.S. fields and defined crystallographic misorientation. 5-25-197 Structure of SrcCojOsfR) and kinetic study of D IB TREIMER W„ STROTHMANN H.

the Sr2C0205(B)-Sr2C0205(R) transition. RODRIGUEZ J., COLLOMB A., 5-31-222 Magnetic correlations in the Kondo lattice D 7 CALBET J., ANNE M. CeMg. GALERA R.M., PIERRE J. 5-25-201 Investigations of stress gradients in D 1A polycrystalline materials. 5-31-223 Proximity induced superconductivity in D 17 REIMERS W„ CROSTACK H.A. Ag/Nb bilayers. BLAND J.A.C., WILLIS R.F. 5-25-203 Comparison of residual stress distributions in D 1A HEZAVEH A.A., SCHAERPF O. 5-25-204 thick section welds. WEBSTER P.J., WEBSTER G.A. 5-31-239 Magnetic phase diagram of D IB SMITH D.J., ZIEBECK K.R.A., MILLS G. (FexCri.»):Ca)(Ge04)j for nonzero field. McGILLlVRAY H.J. BRUECKEL T., PRANDL W., CONVERT P. 5-31-248 Magnetic structure of CC2S1U and CciSni. D IB 5b - Magnetism GIVORD F., SCHWEIZER J., STUNAULT A. 5-32-188 Magnetic ordering phenomena in EuAs.i in an D 15 5-31-155 Small angle neutron scattering studies of D II external magnetic field. enhanced paramagnets. MOELLENDORF M., BAUHOFER W. BERNHOEFT N., PAUL D. 5-32-208 Magnetic correlations in the paramagnetic state D 10 5-3J-169 Magnetic structure of Ui*Np<0: fluoritc solid D IB of La2Coi.7. solution. BALLOU R., G1GNOUX D., LEMAIRE R. BOEUF A., CACIUFFO R., REBIZANT J. SCHWL1ZER .1. RUSTICHELLI F., TABUTEAU A. 5-32-209 Magnetic shoi: in.' e order in D 10 5-31-171 Magnetic structures in the phase diagram of (Feo.sCro.sfcC ^eOi)> single crystals. the GdAgi-vZn* system. BRUECKEL ; PRANDL W. KOEBLER U., ZINN W. 5-32-215 Study of the static properties of S = 1, D 1A anliferromagnetic Heisenbcrg chain with weak 5-31-173 Magnetic order of Eu,Sn.,Te. D IB easy axis anisolropy. CsNiCb. MALETTA H., ZINN W. BOERGERMANN F.J., STE1GENBERGER U. KAKURAI K., STE1NER M. 5-32-217 Crystal and magnetic structure of the ionic D 15 5-31-174 Magnetic structures of NbOF2 and NbF4. D IA ferromagnet Rb2CrCliîîr. HASSAING J., BIZOT D., DELOBBE V. D IB DAY P., BRAMWELL S. 5-31-178 Magnetic structure of gra.hitc FeCh. D 15 5-32-221 Spin correlations in semimetallic Eu\SruASi. SIMON CH., ROSENMAN I., BATALLAN F. BAUHOFER W.

168 *5-32-222 Conduction electron polarisation in the spin D 15 5-35- 2 Neutron interferometric double resonance S 18 density wave of the Y-Gd alloys. experiment. CAUDRON R., FERT A., GIVORD D. RAUCH H., BADUREK G., TUPPINGER D. 5-32-226 Investigation of the antiferromagnetic D 10 5-35- 3 Investigations of inhomogeneous phase shifters S 18 structure of neodymium below 10K. in neutron inter- ferometry. RAUCH FORGAN E.M., GIBBONS E.P., H., TUPPINGER D., MCEWEN K.A. SUMMHAMMER J., VRANA M„ UEBBING H. 5-32-238 Critical behaviour and long range magnetic D 10 5-35- 4 Test of a nondispersive sample arrangement in S 18 order in the diluted anti ferromagnetic system neutron interferomelry. Eu3. SUMMHAMMER J., RAUCH H. CHATTOPADHYAY T., BROWN P.J., TUPPINGER D. SCHNERING H.G.V. 5-35- 65 Memory effects of the antiferromagnetic S 20 5-32-240 Effects of temperature and magnetic field on D 15 domain structures in MnF:. the incommensurate phase of EuAs3. BARUCHEL J., EL KADIRI M. CHATTOrADHYAY T., BROWN P.J., SCHNERING H.G.V. 5-35-X SEE 5-41 5-32-242 Investigation of coexistent long range and D 15 /Y/Z short range magnetic phases in Eu*Sricl-xAs.i. 5-41- 3 Characterization of magnetic domain structures S 20 BAUHOFER W., LOEHNEYSEN H.V., 5-35-X in the weak ferromagnet O-FCJOJ. STE1GENBERGER U. TANNER B.K., CLARK G.F., BARUCHEL J. 5-32-243 Antifcrromagnel-lo-spin-glass crossover in D 10 5-41-5 Neutron topography of an inlcrmctallic space- S 20 Eu,Sri-,Te. 5-35-Y grown crystal CcMg.i. MALETTA H., STEIGENBERGER U. PIERRE J..SCHLENKER M., BARUCHEL J. 5-32-247 A single-crystal neutron diffraction study of SEE 3-05 38 magnetic structure of EUC02P:. 5-41-6 REEHU1S M., MOELLER M.H., /7/8 JEITSCHKO W. 5-41- 9 The effects of magnetic field, applied stress and S 20 5-33-141 Diamagnetism in graphite. D 3 5-35-Z temperature on the chirality domain patterns of WILKINSON C, FORSYTH J.B., MnP and Tb. BROWN P.J., KEENE D. PALMER S.B., PATTERSON C, BARUCHEL J. 5-33-147 Magnetization density in UGe:. D 3 BALLOU R., FRANSE J., FRINGS P. GIGNOUX D., TASSET F. 5-33-155 Localisation of unpaired electrons in the D3 COLLEGE 6: cluster compound Nbfiln. D 15 SIMON A., BROWN P.J., AGERBARTH M. Liquids, Disordered Materials 5-33-168 Determination of the dynamic spin density in IN 20 and Metal Physics the invar compound PtFe.i. BROWN P.J., Z1EBECK K.R.A. 6-01- 87 Excitations in "He-films. IN 12 GODFRIN H., LAUTER H.J., LE1DERER P. 5-33-171 3D-polarisation analysis of the magnetic D 7 diffuse scattering of (Feo sCro.5Ï2Caî(Ge04Ï3. 6-01- 89 Effect of pressure on the lifetime and energy IN 11 BRUECKEL T., PRANDL W. of the roton and maxon excitation in superfluid He4. 5-33-174 Comparison of charge and spin density for an D3 MEZEI F., BROCHIER D., FARAGO B. S-state ion. D 9 BROWN P.J., COSTA M.M.R. 6-01- 91 Phonon dispersion in superfluid 4He at elevated IN 12 pressures. 5-33-182 Spin distribution and form factors study in D 3 STIRLING W.G. Nd;Coi 7. BALLOU R., GIGNOUX D., 6-01- 92 Roton-roton and roton-maxon coupling in IN 12 LEMAIRE R. TASSET F. supcrfluid 4Hc. STIRLING W.G. 5-33-203 Localisation of unpaired electrons in the D 3 cluster compound N'hv.11 j. 6-01- 94 Excitations in liquid 'He; pressure and IN 6 BROWN P.J., SIMON A., SAGERBARTH M. temperature dependence. BLANC Y., COWLEY R.A., DIANOUX A.J., 5-33-208 Study of the magnetic behaviour of the cerium D 3 FAK B., GODFRIN H., GUCKELSBERGER K. moments in the quasi- intermediate valent RAGAZZONI J.L., SCHERM R., compound CezSn?. STIRLING W.G. SCHWEIZER J., STUNAULT A., GIVORD F. 6-01- 97 Liquid structure factor of ''He from two to DIB 5-34-140 Rotation of neutron polarization by scattering D 5 three dimensions. from Cr;0.i. BROWN P.J.. FORSYTH J.B., TASSET F. GODFRIN H., LAUTER H.J., LEIDERER P. SCHILDBERG H.P. 5-34-207 Magnetism and the state of compositional D 5 6-02- 65 Structure factor of fluid rubidium and cesium D 4B order in FetNii^ alloys. GYORFFY B.L., JORDAN R., at sub and supercritical conditions. SOHAL M., Z1EBECK K.R.A. HENSEL F., WINTER R., GLAESER W. BODENSTEINER T. 5-34-208 Spin fluctation in CoS2. IN 20 SIMON A., BROWN P.J., ZIEBECK K.R.A. 6-02- 67 Measurement of Q-dependent effective D 7 diffusion constants by polarisation analysis, 5-35- 1 Harmonic suppression in neutron S 18 separation of coherent and incoherent scattering interferomelry. of liquid Na. BONSE U., RUMPF A., UEBBING H. SCHAFRPF O., MORKEL C, GLAESER W.

169 6-03-134 Neutron diffraction with molten Fe33Siô7. D 4 6-07- 86 Structural properties of K+ ions in aqueous D 4B SEDELMEYER B., LAMPARTER P., solutions. STEEB S. NEILSON G.W., SKIPPER NT. 6-03-138 Structure factor of liquid GaAs, CdTe and As. D 4B 6-07- 96 Ionic hydration in polyethylene oxide solution. D 4B GASPARD J.P., BERGMAN C, ENDERBY J.E., BREEN J., BARNES A.C. B1CHARA C, BELL1SSENT R. 6-08-141 Small angle neutron scattering (S.A.N.S.) DI1 6-03-139 Liquid semiconductors and the Mott D 4 study of the Scaebler Wronski effect. transition. CHENEVAS-PAULE A., BELLISSENT R. ENDERBY J.E., BARNES A.C. 6-08-142 a-Sias His short range order. D 4 6-03-141 Dynamics of concentration fluctuations in IN 6 CHENEVAS-PAULE A., MENELLE A., molten Na-Cs alloys. BELLISSENT R. GARTRELL-MILLS P., McGREEVY R.L., MITCHELL E.W.J. 6-08-147 Structure of fluoride glasses BaM/'UFs D 4 and BaM,'"UF9. 6-03-142 Partial structure factors of liquid NiwBsé. D 4B LE BAIL A., JACOBONI C. COWLAM N., NUNN S.C. 6-08-148 Influence of electrolyte glasses on the D 1A 6-05- 94 Polar group hydration using isotopic D 4 crystallisation at low temperatures. D IB substitution urea in light water. DUPUY J., ELARBY-AOUIZERAT A. FINNEY J.L., TURNER J., JAL J.F., CHIEUX P. NEILSON G.W. WILLS H.H. •6-08-149 Photoinduced structural changes in D 4 6-05-100 Polar group hydration using isotopic D 4 chalcogenide glasses. substitution null methyl-hydrogen acetamide. PHILLIPS R.T., SALMON P. FINNEY J.L., TURNER J. 6-08-156 Medium-range order in amorphous DIB 6-05-101 Hydrophobic hydration by nitrogen isotope D 4 CuTi alloys. substitution. CHAMBEROD A., GOUDEAU P., FINNEY J.L., TURNER J., HOWELLS W.S. NAUDON A. RODMACQ B. 6-05-103 Systematic variation of the dipolar interaction D4 6-08-161 Crystallization of iron base glasses of the DIB in molecular liquids. (Fe,Mn)P system. BERTAGNOLLI .ENGELHARDT T. GEORGE B., MALOUFI N., 6-05-104 Collective excitations in D2O. IN 8 JANOT C. TEIXEIRA J., BELLISSENT-FUNEL M.C., 6-08-162 Structure of amorphous alloys of the D 4 CHEN S.H., DORNER B. 6-08-192 (Fe,Mn)(P,C) system. Dll 6-05-105 Structure factor of HCI over a broad range of D 4 GEORGE B., TETE C, JANOT C. density up to supercritical temperatures. 6-08-163 Vibrational modes in amorphous silicon and IN 4 BERTAGNOLLI H., ENGELHARDT T. germanium. TOEDHEIDE K. BUCHENAU U., KAMITAKAHARA W.A., 6-06- 47 Structural analysis of the mixture Ko.e (KCIJtu. D 4 SHANKS H.K., REICHARDT W. DUPUY J., JAL J.F., MATHIEU C. 6-08-170 Low frequency vibration in electrolyte glasses : IN 6 6-06- 52 Collective excitations of liquid Rb perturbed IN 8 Role of the solvent. by the dissolution of molten RbCI. DUPUY J., El ARBY-AOUIZERAT A. DUPUY J., JAL J.F., MATHIEU C, JAL J.F., CHIEUX P. SUCK J.B. 6-08-171 Dynamics at supercooled water and the glass IN 5 6-06- 53 SEE 6-06- 59 transition. TEIXEIRA J., CHEN S.H. 6-06- 54 Soft modes in molten alkaline earth halides IN 6 FAIRBANKS M.C., HOWE M.A. 6-08-176 Investigaiion of the dynamics of liquid-glass IN 11 McGREEVY R.L., MITCHELL E.W.J. transition by NSE. FARAGO B., KNAAK W., MEZE1 F. 6-06- 56 Dynamics of molten lithium halides. IN 6 TITMAN J.M., COWLAM N., SUCK J.B. 6-08-180 Spectral dimension in the fractal system IN 5 Cab-O-Sil. 6-06- 58 The structure of molten Agi. D 4 RICHTER D., KJEMS J., FRELTOFT T. HOWE M.A., DAY S.E., McGREEVY R.L. MITCHELL E.W.J. 6-08-183 Partial pair correlation functions of D 4B amorphous Ni-Nb alloys. 6-06- 59 Dynamics of superionic and molten Ag'. IN 6 LAMPARTER P.. SCHAAL M., STEEB S. 6-06- 53 HOWE M.A., FAIRBANKS M.C., McGREEVY R.L., MITCHELL E.W.J. 6-08-185 Coordination complexes in amorphous D 4 chalcogenides. 6-06- 60 Structure factors in molten alkali halides at D IB ENDERBY J.E., BARNES A.C. low Q. FAIRBANKS M.C., McGREEVY R.L. 6-08-192 SEE 6-08-162 MITCHELL E.W.J. •6-08-205 Structural studies of polyacetylene, D 11 6-06- 61 Structural studies of molten nickel bromide, D 4B (CH)«and (CD)». NiBri. PORTERS.J., DORE J.C. HOWE R.A., WOOD N.D., ALLEN D.A. NEWPORT R.J. 6-08-206 The phonon-fracton spectrum of amorphous IN 6 materials. 6-07- 79 Isotope effects in NiCli solutions. D 4B ROSENBERG H.M., PAGE J.N. NEILSON G.W. 6-11- 15 Critical scattering near the glass transition of IN 10 6-07- 80 Aqueous solutions: Systems containing iron D 4B ZnCI2. salts. GLAESER W., MUELLER P., JUNG S. NEILSON G.W.,HERDMAN H. 6-12-58 Anisotropic growth of metallic glasses during Dll 6-07- 84 Dynamics of aqueous solutions. IN 10 heavy ion irradiation. ENDERBY J.E., SALMON P., KLAUMUENZER S., PETRY W., BELLISSENT-FUNEL M.C. SCHUMACHER G., STEINMETZ K.

170 6-12- 63 Magnetic small-angle scattering in nickel aUoys D 11 6-14- 75 Pressure-dependent hydrogen modes in VH* IN I containing precipitates. (0.05 < x < 0.06). CERRI A., KOSTORZ G., MUELLER P.P. WIPF H., STEINBINDER D.. MAGERL A. SCHOENFELD B. VETTIER C. 6-12- 64 The development of the larger scale calcium D 11 6-14- 80 Simultaneous measurement of coherent ai.d D 7 silicate hydrate gel structure in cement incoherent quasielastic scattering from Pd/D. systems. ROSS D.K., YAMAGUCH1 M. ALLEN A.J., PEARSON D., WILDING C.R. ANDERSON I.S., BENHAM M.J., FAUX D. 6-12- 65 Oxygen precipitation in silicon. D 11 6-14- 82 Quasi-elastic scattering from hydrogen in IN 10 HARWOOD N., MESSOLORAS S. Ni]5Ti65 metallic glass. STEWART R.J. TITMAN J.M., COWLAM N., HOWELLS W.S. CROUCH M.A. 6-12- 66 Kinetics study of thermal decomposition in D 11 CuNiFe. 6-14- 93 Proton conduction in CsHSOa. IN 10 WAGNER W., PETRY W. LASSEGUES J.C., COLOMBAN P. POINSIGNON C. 6-12- 69 High temperature dependence of local order in D 7 6-14- 95 Elementary jump process for fast diffusion of IN 5 single crystalline FeVo.2 alloy. Co in P-Zr. CADEVILLE M.C. FLOTTMANN T., PETRY W., VOGL G. 6-12- 78 Medium range order and defects in D 11 6-14- 97 Quasielastic neutron scatleriag on f5-titanium IN 10 aluminium-based amorphous allovs. single crystals, DUBOIS J.M., JANOT C. PETRY W., FLOTTMANN T., VOGL G. 6-12- 80 Multilayer structures. D 17 6-14-102 Neutron diffraction study or the order- D 10 HARWOOD N.. MESSOLORAS S. disorder process in a Y/D. STEWART R.J. ROSS DK, FAUX D.A., BONNET J.E., 6-12- 81 The effects of temperature and stress on a "'11 ANDERSON l.S. nimonic superalloy. 6-14-106 Lithium sublallicc ionic disorder at elevated IN 5 AL-HAZM1 F., MESSOLORAS S., temperature in the antifluorile LiiO. STEWART R.J., WINTERS R.A. HAYES W„ HUTCH1NCS M.T. 6-12- 82 Observation of the annealing cmbrittlement of D 17 HACKETT M.A., HULL S.. FARLEY T. amorphous Fe-B alloys by SANS. 6-14-108 Hydrogen diffusion in the cubic Laves phase, IN 10

LAMPARTER P., SCHAAL S., STEEB S. ZrV2H„ TITMAN J.M., CROUCH M.A., 6-12- 83 Short range order in Al-Mn quasicrystals. D IA COWLAM N., HOWELLS W.S. DUBOIS J.M., JANOT C. 6-14-111 Irradiation induced interdiffusion in Al-Gc D17 6-12- 85 Changes in calcium silicate hydrate gel D II multilayers. structures due to environmental damage in LE BOITE M.G., TRAVERSE A. cement systems. ALLEN A.J., WILDING C.R. 6-14-113 Elementary jutnp process for fast diffusion of IN 10 Co in p-ZrsoNbai single crystals. 6-12- 87 Precipitation in Al-Li allovs. D 17 FLOTTMANN T., PETRY W., VOGL G. AL-HAZMI F., MESSOLORAS S. STEWART R.J. 6-14-114 Quasielastic scattering of K-Hollandite. IN 5 BOYSEN H., FREY F. ROSSHIRT E. 6-12- 90 Nucleation and growth of point defect clusters D 11 BLANK H. in silicon. RAUH H., GE1CK R., SIEGER D. WRIGHT A. t>-t4-120 Neutron-spectroscopic test of H IN 5 superdiffusion in V. 6-12- 91 Huang diffuse scattering on (KBr)o.97(KCN)o.o3. D 10 WIPF H., STEINBINDER D., MAGERL A. WOCHNER P., BURKEL E., PE1SL J. VETTIER C. 6-12-92 Decomposition of Ni-Ti alloys Dll 6-14-121 Local diffusion of hydrogen in Nb(OH)». iN 6 BAENNINGER R., CERRI A., KOSTORZ G. WIPF H., STEINBINDER D., MAGERL A., SCHOENFELD B. RICHTER D. 6-12-93 Short-range order in a-Cu-Zn. D7 6-14-123 H-diffusion in amorphous PdusSiisHT.s. IN 10 KOSTORZ G., MUELLER P.P. DRIESEN G., HEMPELMANN R. REINHARD L., SCHOENFELD B. RICHTER D. 6-12- 95 SANS Study of the thermal embrittlement D 11 6-14-124 Phase transitions and hydrogen site 1NFB behaviour and of the homogeneity of iron- occupancies in the systems V2H and V2D. "K classes. RICHTER D., HEMPELMANN R. GEORGE B.. JANOT C. 6-14-126 Occupancy of H sites in ZrV^H». 1NFB 6-12-102 Scaling properties of TiH2 aggre gates formed D 17 HEMPELMANN R., RICHTER D. from amorphous CuTi hydrides. 6-14-127 Diffusion of Li in LiAl studied by quasielastic IN 13 RODMACQ B., CHAMBEROD A., neutron scattering. MANG1N P. HEITJANS P., MAGERL A., BRUN T.O., WEPPNER W., KIM H. 6-Î2-115 Cluster formation at the glass transition in D 17 orientational glasses. 6-14-129 Simultaneous determination of chemical aii.1 IN 5 SCHRAEDER T., LOIDL A. tracer diffusion coefficients for NbD<. HEMPELMANN R., RICHTER D., ROSS 6-12-116 Small polaron hopping. IN 12 D.K. FAUX D.A., SCHAETZLER R. HAYES W., McGREEVY R., KEEN D. 6-14-130 Pressure-dependent hydrogen diffusion in IN 5 6-14-63 Site occupancy in YH». IN IB niobium. ANDERSON I.S., ROSS D.K., BONNET J.E., WIPF H., STEINBINDER D., BENHAM M.J., GILBERT P. MAGERL A., VETTIER C. 6-14- 71 Hydrogen tunneling in NbO*Ho The influence IN 6 6-I4-I35 Study of diffusion in a porous system showing IN 11 of conduction electrons. fractal behaviour. WIPF H., STEINBINDER D., NEUMAIER K., ROSS D.K., HALL PL., GUTSCHMIEDL P., MAGERL A. TUCK J.J. VINEN W.F.

I7l 6-14-136 Identification of polarisation directions of 100 IN 1 8-05-130 Differences in the water and hydrogen D 16 meV and 140 meV peaks in aY/H. distribution between the ground stale and the ROSS D.K., BONNET J.E. ANDERSON I.S., M-intermediate of bacteriorhodopsin. BENHAM M.J. BUELDT G., DENCHER N.A. PAPADOPOULOS G., ZACCAI G. 6-14-147 Quasi-elastic scattering in hydrogenated NijsTi* IN 10 metallic glass. 8-05-131 Location of the (5-ionon ring of retinal in the D 16 T1TMAN J.M., COWLAM N., CROUCH M.A. structure of bacteriorhodopsin. SEIFF F., WESTERHAUSEN J., HEYN M.P. 6-14-152 Anisotropic H-diffusion in an one-domain IN 10 8-05-132 Location of cation binding sites in the purple D 16 fj V2H single crystal. IN 5 membrane. RICHTER D., HEMPELMANN R. SEIFF F., HEYN M.P.

6-14-154 Hydrogen modes in A-15 V3GaH(DK. IN 1 8-05-134 Specific location of helices in D 16 WIPF H., SCHLERETH, bacteriorhodopsin. STE1NBINDER D., MAGERL A.L. POPOT J.L., ENGELMAN M. TREWHELLA J., ZACCAI G. 6-14-155 Study of Na* motions in a single crvstal of IN 6 fJAIzOj. 8-05-140 Determination of the spatial extension of the D II LUCAZEAU G., DOHY D., FANJAT M. polysaccharide portion of bacterial lipopolysaccharide by neutron small-angle scattering. LABISCH1NSK1 H., BRADACZEK H., COLLEGE 8: MAY R., UEBACH W., VORGEL E. 8-05-146 Structural differences between suspensions of D 16 magnetically oriented 13-cis and all-trans D 17 Biology bacteriorhodopsin. 8-01- 66 Hydrogen exchange studies on haemoglobin by D 19 BUELDT G., DENCHER N.A. neutron diffraction. DRESSELHAUS D., ZACCAI G. 8-05-147 In-plane location of chemically modified d c( L1DDINGTON R.C., WALLER D.A. AspllS in the structure of bacteriorhodopsin. 8-01- 69 Low resolution crystallographic study of the DB 21 SEIFF F., WESTERHAUSEN J. large ribosomal subnnits of Eu' and SCHERRER P., HEYN M.P. Archaebacicria. YONATH A., BENTLEY A., ROTH M. 8-05-148 Location of the Schiff's base end of retinal in D 16 W1TTMANN H.G. the structure of bacteriorhodopsin. SEIFF F„ WESTERHAUSEN J., HEYN M.P. *8-0l-73 Low resolution crystallog:aphic study of the DB 21 8-05-152 Studies of detergent solubilizcd light-harvesting D 11 photoreaction center of Rps. viridis. proteins and a B875-reaction centre complex. MICHEL H., DEISENHOFER J., HUBER R. WELTE W. BENTLEY A. 8-02-131 Structure and function of the 50S subunit from D 11 8-05-156 Quaternary structure of H + -ATPase (II) D 11 E. Coli ribosomes. Structure and aggregational state of the N1ERHAUS K.H., MAY R.P., NOWOTNY V. membrane-bound portion EFo. IBEL K., ALTENDORF K.H., SCHMID R., NOWOTNY P. STEFFENS K., DECKERS-HEBESTRE1T G. 8-03-102 Filaments of recA protein. D 11 S-07- 73 Studies or ClnCIs: and Clinh or complement. D 11 TAKAHASH1 M., SCHNARR M.. DICAPUA E. 8-07- 81 PERKINS S.J., GREGORY L., BURTON D.R., 8-03-104 Conformational changes of RNA polymerase D II BOYD J., VILLIERS CL. ARLAUD G.J., and DNA during transcription. COLOMB M.G., MAY R.P. HEUMANN H., METZGER W., LEDERER H„ MAY R. 8-07- 74 Structure of C3 or complement. D 17 8-03-105 Filaments of RecA protein. D II 8-07- 85 PERKINS S.J., SIM R.B. 8-03-116 DICAPUA E., SCHNARR M., 8-07- 81 SEE 8-07- 73 TAKAHACHI M., TIMMINS P. 8-07- 85 SEE 8-07- 74 8-03-107 Conformational changes of RNA polymerase D II 8-07- 96 Determination or the a?.jal ratio of the D 11 and DNA during transcription. phosphatidylcholine transfer protein. HEUMANN H., METZGER W., WIRTZ K.W.A. LEDERER H. MAY R. 8-07- 98 Collagen-mineral interactions in hone. D 11 8-03-113 Conformational changes of RNA polymerase D 11 MILLER A., BRADSHAW J.P. and DNA during transcription. 8-07-102 Structure of the subclasses or human D 11 HEUMANN H., METZGER W., immunoglobulin G. LEDERER H. MAY R. BURTON D.R., DAVIES K.G., 8-03-116 SEE 8-03-105 BOYD J. JEFFERIS R. 8-04- 96 Coherent inelastic scatterinc from collacen. D IB 8-07-110 Quaternary structure or H +-ATPase D 11 JONES E.Y., MILLER A.. CUSACK S. IN 12 Sequestered solvent space in CF1 from chioroplasts. DORNER B. IBEL K., JUNGE W., WAGNER R. 8-04- 97 Low frequency dynamics of bovine pancreatic IN 6 ENGELBRECHT S., ANDREO C. trypsin inhibitor (BPTI). 8-07-112 Metal ATP complexes in aqueous solution. D 4B CUSACK S., SMITH .1. NE1LSON G.W, GULL1DGE P. 8-04-K/j Local lipid dynamics in bilayer membranes. IN 10 KNOLL W., PFE1FFER W. RICHTER D., SACKMANN E. 8-05-125 Quaternary structure of H + -ATPase D 11 COLLEGE 9: H + -ATP-syn(hasc (FoFI) from E.coli with deuterared subunils. IBEL K., ALTENDORF K.H.. Chemistry SCHMID R., STEFFI-NS K. 9a - Small Molecules 8-05-125 Quaternary structure 01 H + .ATPase: D II 9-03-341 Hindered rotation of coordinated H; in a IN 6 Sequestered solvent space in CFJ from tungsten complex. chloroplasts. ECKERT J., DIANOUX A.J. IBEL K., JUNGE W., WAGNER R., VERGAM1N1 P.J. ENGELBRECHT S. 172 9-Û3-386 Proton spin conversion in ammonium IN 10 9-03-454 Rotation and reptation of n paraffinic chains in IN 6 perchlorale (NH4CIO4). a channel inclusion compound. SCHERM R., GUCKELSBERGER K., LE BARS M., LAJZEROWICZ J. HEIDEMANN A., PRESS W., NEUMAIER K. 9-03-456 Search of coupling phenomena of tunneling IN 10 9-03-415 Tunneling of CHi groups in cubane tetramers. IN 5 CH3 groups in a high barrier system. HEIDEMANN A., SORAI M., SUGA H., SCHERM R., CLOUGH S., NEUMAIER K. HEIDEMANN A., NEUMAIER K., 9-03-416 Inelastic structure factor of coupled IN 13 FRIEDRICH H., GODFRIN H., PUJOL S. CH3-groups in lithium acetate. 9-03-457 Freezing of proton configuration in IN 5 HEIDEMANN A., CLOUGH S., ABED K.J. Rb.., (NH<)» H2PO,. BARKER G.J. MONKENBUSCH M., GRIMM H. 9-03-417 Pressure dependence of CH3 tunneling in IN 5 9-03-459 The rotational potentials of methyl groups in IN 10 lithium- and manganese-acetate. the methyl halides CHjl and CHjBr. CLOUGH S., HORSEW1LL A., VETTIER C. PRAGER M. HEIDEMANN A. 9-03-460 Rotational tunnelling in a two dimensional IN S 9-03-418 Study of spin diffusion in gamma irradiated IN 5 layer of coupled, weakly hindered methyl IN 10 lithium-acetate by inelastic neutron scattering. groups. HEIDEMANN A., CLOUGH S. FRIEDRICH H. PRAGER M. 9-03-419 Short time reptation of chains trapped in IN II polymer networks. 9-03-461 Oligomer diffusion in polymer melts. Motion of IN 10 R1CHTER D., EWEN B., OESER R. alkanes in polyethylene. PICOT C, HERZ J. STUEHN B., RENN1E A.R., PETRY W. 9-03-421 Hindered rotation of halomethanes on IN 5 9-03-463 Tunneling splitting and vibrational properties of IN 6 the ammonium ion in ammonium-tctr.iphenyl graphite. borate. THOMAS R.K.. CLARKE S.M. STRAUSS H.L., ROBERTS M.P., 9-03-422 Line shape of inelastic methyl tunnel peaks. IN 10 LUCAZEAUG.,BOCQUETJ.,DIANOUXAJ. CLOUGH S. 9-03-466 Dynamics in 12-tungstophosphoric acid IN 13 hcxaltydrate. 9-03-424 The behaviour of the incoherent scattering D 7 SLADE R.C.T., PRESSMAN H.A. from PMMA as a function of temperature. 9-03-467 Ammonia intercalates of host M0O1 and WO» IN 13 GABRYS B., H1GGINS J.S., SCHAERPF O. matrices. IN 6 9-03-425 The potential barriers hindering reorientation IN 10 SLADE R.C.T., WEST B.C.. WARD R.C., ofCHs. PRESSMAN H.A., RAMANAN A. HORSEWILL A.J., GREEN R.M. 9-03-469 Rotational tunnelling in Sn(CHj)j adsorbed on IN 5 9-03-426 Reorientation^ in hydrogen molybdenum IN 13 grafoil. bronzes HKMOOÎ. PRAGER M., MONKENBUSCH M. SLADE R.C.T., HIRST P.R., WEST B.C. 9-03-470 Rotational tunnelling of CHj groups in mat. x IN 5 WARD R.C., RITTER C. isolated M (CHjfc molecules, M = Sn, Ge. 9-03-427 Tunnelling of NH4* ion in ammonium IN 13 PRAGER M., LANGEL W. tungsten bronze. SLADE R.C.T., HIRST P.R., 9-03-471 The intermolecular interaction in tetramethyl IN 10 WEST B.C. WARD R.C., RITTER C. tin: Sn(CD.i)3CHj.

9-03-429 Ammonia tunnelling in Ni(NHj)6l2 and IN 5 PRAGER M., WEISS A., DA ZHANG

Ni(NHj)s(PF6)2. BLANK H., COCKCROFT J.K., 9-03-472 Isotopic dilution of a tunnelling system: IN 10 Sn(CH04 in Sn(CDj)4 and Ge(CDi)4. KEARLEY G.J. PRAGER M., WEISS A., DA ZHANG 9-03-432 Dynamics of the hydrogen bond in dimcr units IN 13 9-03-477 Reorientational dynamics of the (CH])4N ' ions IN 6 of pivalic acid. and order-disorder phase transition in TMMC. IN 13 LONGUEVILLE W., BEE M. COUZI M., GUILLAUME F., BEE M. IN 10 9-03-437 Phase transitions in urea-inclusion compounds. IN 5 9-03-479 Tunneling of coupled methyl groups : the IN 10 BOYSEN H., FREY F. 9-03-440 Reorientational and conformational motions in IN 10 isotope effect. long chains (OH:*. iNHjfcMnCI.! layer- IN 13 CLOUGi I S., FRIEDRICH H. HEIDEMANN A. structure compounds. 9-03-481 Effect of the isolopic dilution in the methyl IN 10 SOURISSEAU C, REY M., RICARD L., tunnelling spectra of the a crystallised toluene. GUILLAUME F. CAVAGNAT D., MAGERL A. 9-03-443 Proton exchange dynamics in the bisulfate- in ( 9-03-483 Anisotropic reorientation of benzene and IN 5 sulfate system. hexamethylbenzene in their crystalline states. IN 10 CAVAGNAT D., LASSEGUES J.C., FUJARA F., PETRY W. IN 13 WHITE J.W. 9-03-490 Molecular and ionic motions in IN 13 9-03^144 Methyl tunnelling in the a crystallised toluene : IN 10 12-tungstophosphoric acid 21-hydrale. effect of the ting deuteration. SLADE R.C.T., PRESSMAN H.A. CAVAGNAT D„ MAGERL A. 9-04-331 Rotations of CH3CI and CH3F in matrices. IN 5 *9-03-445 Measurements of the splitting of the first IN 13 KNOEZINGER E., KOLLHOFF H. LANGEL W. torsional level in nitromethane. 9-04-347 Vibrational spectrum of hexagonal hydrogen INlBeF ANDERSON I., CAVAGNAT D., tungsten bronze. SLADE R.C.T., HIRST P.R. VETTIER C. MAGERL A. 9-04-357 Acetonitrile clusters in a solution of CCU. D IB 9-03-448 Reorientational modes in plastic adamamane JN 13 LANGEL W., KNOEZINGER E. single crystal. DEISEROTH H.J., POPP S., SCHULLER W. BEE M., LECHNER R.E. 9-03-452 Determination of velocity cross correlation IN 5 9-04-359 Rotations of H2O in mixed argon nitrogen IN 3 function from neutron scattering experiments matrices. in D2O and DC1 mixtures. KNOEZINGER E., LANGEL W., POPP S. HERTZ H.G., BERTAGNOLLl H. SCHULLER W. 9-03-453 Quantum rotation of ammonia molecules in IN 6 9-04-362 The torsional splittings in the homologous IN 4

disordered Ca(NHj)6 and Ca(NDî)(,. IN 5 series of unbranched ketones. LECLERCQ F., DAMAY P., PRESS W., HORSEWILL A.J. CHIEUX P. 173 9-04-363 Investigation of the vibrational spectra of some IN 1B 9-07-103 Structure and phase boundaries of imidazole D IB transition metal oxide insertion compounds. monolayers on grafoil. DICKENS P.G., CHIPP1NDALE A.M. MONKENBUSCH M., GRIMM H. CLARIDGE D.A. 9-07-104 Structural investigation of multilayer oxygen D IB 9-04-365 Vibrational spectra of phases INlBeF films below the melting temperature of bulk

9-04-366 HxMoyWi-yOî and HnVsMoeO». solid oxygen. SLADE R.C.T., RAMANAN A., OOYAL P. KRIM J., COULOMB J.P., BOUZID1 J. 9-04-371 Dynamics of hydrogen bonds in benzoic acids. IN 10 9-07-105 Structures and phase transitions of para- D 16 ERNST R.R., FURRER A.. HEIDEMANN A. hydrogen monolayers on graphite. STOECKL1 A., ANDERSON I. FRE1MUTH H., LAUTER H.J., WIECHERT H. 9-05-312 Molecular dynamics of K(Na) palmitate water IN 5 9-07-106 Structures of trifluoromethane monolayers D IB systems. physisorbed on graphite. PINTAR M.M., SCHRE1NER L.J. WIECHERT H., FREIMUTH H. LAUTER H.J. 9-06-481 Comparison of the dynamics of benzene and IN 6 907-107 Second layer study of 'He on graphite. D 16 dimethyl-benzene in ZSM-5 zeolite. GODFRIN H„ LAUTER H.J. BEE M., JOBIC H., RENOUPREZ A. SCHILDBERG H.P. 9-06-498 Time resolved scattering experiments in aqueous D 11 9-07-110 Structural study and phase transitions of DIB micellar solutions II. D: adsorbed on (high homogeneous surface) KALUS J., HOFFMANN H., HERBST L. MgO-powder. NEUBAUER G., L/LBRICHT W., REHAGE DEGENHARDT D.. LAUTER H.J., H. SCHMELZER U., SEOUD O. HAENSEL R. 9-06-500 Mobility or CHj adsorbed on MgO(lOO). IN 5 COULOMB J.P., BIENFAIT M. 9b - Large Molecules - Colloids and Polymers 9-06-501 Translational diffusion near the melting point IN 5 in ethylene monolayers on graphite. 9-08- 28 Texture ond relaxation of lyonopic liquid D 11 HEIDEMANN A., RICHTER D. crystalline phases. WICKSTED J., PASSELL L. KALUS J., HOFFMANN H., HERBST [.., NEUBAUER G., ULBRICHT W.. 9-06-504 Molecular diffusion of HNOi intercalated in IN 5 REHAGE H. SCHMELZER U., SEOUD O. graphite. BATALLAN F., ROSENMAN I., SIMON C. 9-09- 27 The counter-ion distribulion around a charged D II colloidal particle. 9-06-505 Vibrational spectrum of HNOj intercalated in INlBeF OTTEWILL R.H., JEFFREY G.C., graphite. OBERTHUER R. BATALLAN F., ROSENMAN I., SIMON C. 9-09- 78 Critical fluctuations in binary lipid alloys.(a) D 11 9-06-508 Mobility of organic molecules complexing heavy IN 6 9-09-166 Pressure dependence of the phase behavior of D 17 alkaline in G.I.C. binary lipid mixtures.(b) GOLDMANN M., ESTRADE H., KNOLL W., SACKMANN E.. LECHNER M.D. CONARD J. BEGUIN F. 1BEL K.. HENKEL T., VENNEMANN N. 9-06-512 Molecular mobility and prewetting IN5 9-09- 84 Structure of dilute surfactant alcohol/brine D 11 phenomenon. mixtures showing different liquid crystalline D 17 COULOMB J.P., BIENFAIT M. BOUZ1DI J. mesophases. D 16 9-06-513 Measurement of the spectral dimension of a IN 11 TABONY J., GEYER A. de fractal surface in silica gel 9-09- 85 Occurence of liquid crystalline mesophases in D 11 PYNN R., SATIJA S., SINHA S.K. microemulsions containing approximately equal D 16 9-06-514 Grafted alkyl chains and inserted alkanes IN 5 volumes of oil and water. motion. TABONY J. BEAUF1LS J.P., MOREL D., SERPINET J. 9-09- 86 SEE 5-31-184 9-06-515 Dynamics of adsorbed imidazole on grafoil. IN 6 9-09- 90 Dynamics of supercooled water in porous oxide IN 6 MONKENBUSCH M., GRIMM H. gels. IN 10 9-06-517 Wetting of graphite by methane. D IB POINSIGNON C, RAMSAY J.D.F. MORRISON J.A., THOMAS R.K. 9-09- 97 Critical reflection to study black films. D 17 SHAPTON R.A. THOMAS R.K., GREGORY D„ 9-06-520 Molecular diffusion of HN03 intercalated in IN 10 CUMMINS P. THREADG1LL E.M., graphite. HUGHES-DAV1ES T. WILLATT A. BATALLAN F., ROSENMAN I., SIMON C. 9-09- 98 Structure and interactions in oxide sols at high D 11 9-06-522 Mobility of organic molecules complexing heavy IN 6 temperature alkaline in G.I.C. AVERY R.G., RAMSAY J.D.F. GOLDMANN M., ESTRADE H., 9-09- 99 Immobilization of water in water in oil IN 5 CONARD J. BEGUIN F., DIANOUX A.J. microemulsions by inclusion of enzymes and 9-07- 95 4He on graphite, 2nd layer. D 16 glycerol. HAENSEL R., LAUTER H.J. FLETCHER P.D.I., ROBINSON B.H., TABONY J. SCHILDBERG H.P. 9-09-100 Shear orientation of anisotropic micelles. D 11 9-07- 97 Structural study of "'Ar, CD4 and N; DIB 9-09-101 PENFOLD J., HAYTER J.B. monolayers on a highly homogeneous surface CUMMINS P.O.. STAPLES E. substrate with cubic symmetry (MgO grade). COULOMB J.P., MADIH K., CROSET B. 9-09-104 Small angle neutron scattering of colloidal D 11 LAUTER H.J. spheres in concentrated solutions. 9-07- 97 "Ar on MgO. D 1B MAY R.P., VR!J A., KRUIF C.G. de LAUTER H.J., COULOMB J.P. BRIELS W.J., MOS H. DEGENHARDT D., MADIH K., CROSET B. 9-09-107 Study of structural defects in lyotropic lamellar D 17 phases of the ternary system: sodium decyl 9-07- 99 Structure of the CFi film adsorbed on graphite D IB sulfate/1 -decanol/water. in the vicinity of the wetting transition. HENDR1KX Y., CHARVOL1N J. BIENFAIT M., GAY J.M., SUZANNE J. KEKICHEFF P., ROTH M. 9-07-102 Structures and , hase transitions of ortho- D IB 9-09-114 Water/fluorocarbons in fluorinaled surfactant D 16 deuterium monolayers on graphite. phase. WIECHERT H., LAUTER H.J., OBERTHUER R.. RAVEY J.C., STEBE M.J. SCHILDBERG P. 174 9-09-115 Mixed ionic/nonionîr reverse micelles D 16 9-11-118 Chain trajectory in physical gels of isotactic D 11 polyoxyethylene surfactants. polystyrene (iPS). D 17 RAVEY J.C., EUZIER M., OBERTHUER R. GUENET J.M. 9-09-119 Macrostructure of asphaltenes. D 17 9-11-119 Conformational changes of n-alkanes in the D 16 melt. RAVEY i.C, ESPINAT D., OBERTHUER R. PECHHOLD W., SAUTTER E. 9-09-120 Structures of liquid crystal in aqueous decane D 17 9-11-120 Quantitative study of the texture and structure D 17 water nonionic surfactant systems. of wet alkoxide silica gel. DUPONT G., OBERTHUER R., RAVEY J.C. SERUGHETTI J., BOVIER C, 9-09-122 Small angle neutron scattering of concentrated D II DUMAS J. WRIGHT A. colloidal suspension. 9-11-122 Star-branched polymers in solution. D 17 MAY R.P., VRIJ A., KRUIF C.G. de, 9-11-134 SQUIRES G.L., BOOTHROYD A.T., RENNIE A.R. BRIELS W.J. 9-09-128 Structure of oriented liquid crystal D 17 9-11-123 Real time molecular relaxation of star shaped D 11 macromolecules in the molten state. D 17 microemulsions. D 16 FROEL1CH D., PICOT C, MULLER R. TABONY J., BRAGANZA L.F. BARE A J.L. 9-09-130 Study of microemulsion droplet fluctuations. IN 11 9-11-124 Conformation of cross-linKcd polystyrene D 17 FARAGO B., HUANG J„ RICHTER D. molecules in diverse environments. 9-09-131 Shear induced deformation of partide form D II ANTONIETTI M., FUJARA F., SILLESCU H., EHLICH D. SCHUMACHER S. factors and of interparticle organisation. HIGGINS J., PENFOLD J., 9-II-I25 Backbone motion at the glass transition. IN 13 CUMMINS P.G. STAPLES E.G. BUCHENAU U., FRICK B., RICHTER D. 9-09-132 Shear induced structure transition in aqueous D 11 9-11-126 The behaviour of the cohercm scattering from D 7 PMMA as a function of temperature. polymer latices. GABRYS B„ HIGGINS J.S., SCHAERPF O. HESS S„ LAUN H.M., HAHN K., BUNG R. 9-11-129 Extremely slow chain diffusion in amorphous D 11 9-09-135 Growth and structures of floes. D 11 polymers and polymer blends. WONG K„ CABANE B., DUPLESSIX R. HELLMANN G.P., MEURER E. 9-09-136 On the structure of latex films. D 11 9-11-132 Chain trajectory in physical gels of isotactic D II HAHN K., LEY G. polystyrene (iPS). D 17 GUENET J.M. 9-09-137 Adsorption of random block copylymers on D 17 model surfaces. 9-11-134 SEE 9-11-122 COSGROVE T., HEATH T., l'INCH N. 9-11- Chain diffusion in polymers near the glass D 17 9-09-139 Flexibility of rodlike micelles. D 11 TEST transition temperature. (TEST) HELLMANN G.P. PENFOLD J., HAYTER J.B. CUMMINS P.G., STAPLES E. *9-12-26 The behaviour of polyelectrolytes in aqueous D 11 solution under high pressure. 9-09-140 Properties of oxide sols and oxide water IN 6 LECHNER M.D., STEINMEIER D., interfaces at high temperature. VENNEMANN N., IBEL K„ OBERTHUER R RAMSAY J.D.F., POINSIGNON C. 9-12- 27 Molecular mechanism of drag reduction by D II 9-09-141 Magnetic interactions in metallic ferrofluids. D II Xanthan in water from SANS. CHARLES S.W., POPPLEWELL J. GIESEKUS H., BEWERSDORFF H.W., FRINGS B., LINDNER P., OBERTHUER R. 9-09-146 Determination of segment density profiles of D 17 adsorbed polymer tails and rings from non­ 9-12- 28 Motion of counterions in a polyelectrolyte IN 6 aqueous solvent. solution. COSGROVE T., RYAN K. KANAYA T., HIGGINS J.S., GABRYS B. 9-09-157 Shear induced micellar structures. D 11 9-12- 29 Effects of interactions on ionomer D 11 conformation in dilute and semi-dilute HERBST L., HOFFMANN H., HUBER G., solutions. KALUS J., NEUBAUER G., HIGGINS J.S., MCKNIGHT W.J., SCHMELZER U., ULBRICHT W. PEIFFER D.J., LANTMAN C. 9-09-160 Orientation of stiff rodlike particles made from D II 9-12- 31 An exploration of the dilute-semi-dilute IN 11 teflon in an electric field. HOFFMANN H., transition as a function of molecular weight in KALUS J., HERBST L., HUBER G., polyelectrolyte solutions. HURYCH P., NEUBAUER G., KANAYA T., HIGGINS J.S., GABRYS B. SCHMELZER U., ULBRICHT W. 9-13- 50 Alternating layer Langmuir Blodgetl films. D 17 9-09-161 Alignment of lyotropic liquid crystalline phases D 17 RICHARDSON R.M., ROSER S.J. in a magnetic field of the order of 1 T. BUHAENKO M.R. KALUS J., HOFFMANN H., EBERT G., 9-14- 93 Spatial correlation betw-jen crosslinks in D 1! HERBST L., NEUBAUER G., OETTER G. polymer networks. D 17 SCHMELZER U., ULBRICHT W. PICOT C, HERZ J., OESER R. 9-09-162 Ordering in mixed magnetic and non-magnetic D 11 9-14- 98 Melting of oriented polyethylene crystals. D 11 colloids. SADLER D.M., BARHAM P.J. CHARLES S.W., PYNN R. SKJELTORP 9-14- 99 Surface structure of oriented polymer single D 17 A.T., HAYTER J.B. TREWHELLA J. crystals. SADLER D.M. 9-09-164 SANS-measurements of ringing gels. D 17 HOFFMANN H., KALUS J., EBERT G„ 9-14-100 Morphology and chain conformation in D 11 HERBST L., NEUBAUER G., OETTER G. stretched polyurethanes. SCHMELZER U., ULBRICHT W. FISCHER E.W., STRUTH U., ROESSLE W. 9-09-166 SEE 9-09- 78 9-14-101 Conformation of molecules in glassy polymers D 17 9-11-111 Effects of ionic interactions on dynamics of IN II deformed below the glass transition D 11 ionomers in solution. temperature. DETTENMAIER M., HELLMANN G.P., HIGGINS J.S., PEIFFER D.G., GABRYS B. ROESSLE W. 9-11-113 Measurement of the sizes of star branched D 17 polymers. 175 9-11-114 oSTEINME1ESQUIREThermodynamiWEIFFEBOOTHROYLECHNEf polymerSNR G.L.s J M.D..Runde D c D., A.T propertieHORTOr,, higOBERTHUEVENNEMAN. h pressuresNs anJ.C.d conformatioR,N . R.N,. IBELn K., D 11 9-14-102 Loss of affineness in permanent networks and D 11 9-15-135 The configuration of copolymers at the liquid D 17 melts in a transient experiment. D 17 liquid interface. BOUE F., BASTIDE J., BUZIER M., COSGROVE T., MALLACH L. COLLETTE C, RENNIE A. 9-15-137 Thermal evolution of microphas': separation in D 17 9-14-104 Dynamic study of conformation in deformed D II block copolymers. model networks. RICHARDS R.W., CONNELL J.G. PICOT C, RENNIE A.R., HERZ J., 9-15-139 Molten blends of linear and branched D I ! OBERTHUER R., OESER R. polyethylene. 9-14-104 Molecular behavior of bimodal networks by D 17 SADLER D.M., CROWLEY T.L. SANS. 9-15-142 The role of reinforcing fillers in the structure of D 11 PICOT C, LAPP A., HERZ J., elastomers. D 17 OESER R. RENNIE A. GEISSLER E., HECHT A.M., 9-14-108 Comparison of thermal fluctuations in melt and IN 11 DUPLESSIX R. in rubber strained and unstrained. 9-15-144 Correlation hole effect and interaction D 11 BASTIDE J., BOUE F., OESER R. parameter in block copo;ymer-homopolymer. D 17 RICHTER D., FARAGO B. MARIE P., SELB J., RAMEAU A., 9-14-113 Loss of ai'fineness in permanent networks and D 11 G ALLOT Y. melts in a transient experiment. D 17 9-15-147 The effect of changes in chemical structure on D 11 BASTIDE J.t BOUE F., BUZIER M., polymer-polymer. D 17 COLLETTE C, RENNIE A. MACONNACHIE A., HIGGINS J.S., 9-14-117 Molecular mechanism of drag reduction by D 11 TOMLINS P.E., FRIED .1. surfactants in water from SANS. 9-15-149 Thermal evolution of the long range structure D 11 BEWERSDORFF H.W., FRINGS B., of microphase separated block copolymers. LINDNER P., OBERTHUER R. RICHARDS R.W., CONNULL J.G. 9-15- 50 Phase separation in block copolymers: A time D 11 9-15-152 Scattering by polymer A - polymer B - solvent D II resolved studv. ternary dilute and semi-dilute solutions. RICHARDS R.W., CONNELL J.G. LAPP A.. PICOT C, STRAZIELLE C. 9-15-128 The structure of polymer blends containing stiff D 11 9-15-153 Direct measurement of the concentration profile D 17 chain segments. D 17 at the air- polvmer solution interface. KIRSTE R.G., K1RSCHEY M. SCHMITT- BLAND J.A.C.. WILLIS R.F., RENNIE A. STRECK S., HAHN K., PORTUGALL M. 9-15-154 The structure of polymer blends containing stiff D II 9-15-129 Growth and structures of floes. D 11 chain segments. D 17 CABANE B., DUPLESSIX R. KIRSTE R.G., HAHN K., KIRSCItl.Y M. 9-15-129 Micellization in polymer solutions. D 17 PORTUGALL M., SCHM1TT-STRLCKER S. CABANE B., DUPLESSIX R. 9-15-157 Investigation of orientation of intermicellar D 11 9-15-132 Determination of the temperature dependence D 17 structure in solutions of diblock copolymers. of the interaction parameter in oligomeric HIGGINS J.S. blends of polystyrene with polybutadiene. 9-15-160 Micellization in polymer solutions. D 17 TOMLINS P., HIGGINS J. CABANE B., DUPLESSIX R.

The compilation and editing of ihe lengthy list of publications 1986 (480 altogether), the author index and Ihe list ol" ex­ periments, were carried out by the Library stall'. We also acknowledge the work carried out by (he Physicists' Sccreiariat, who prepared the list of seminars and aeeepled publications.

176 ACKNOWLEGEMENT The Scientific Secretary, Bernd P. Maier, editor of this report, wishes to thank all contributors to the Annual Report 1986 for their collaboration. The work of the staff of SCAPRO, the Translation Office, the Department secretaries, the "Physicists Secretariat", and the collaboration of M. Grevaz and M. Hautin for the word processing operations, the drawing of figures by Frau Stadler are also greatly acknowledged. Photocomposed by Alcompo Printed in France by Technic Color Photographs: B. Maier Neyrtec Studio de la Rivirée EDEX (page ) W. Stirling (page )

ISSN 0181-0731