SCHERRER FNSTTTU i PAULSCHERRERINSTITUT Annual Report 1993 Annex F3A PSI Condensed Matter Research and Material Sciences Edited by: H.W. Gaggeler, R. Lorenzen '*' I t \ Cover: 3D-CAD view showing ihc slalc of Uic build up of SINQ (Spallation-Ncuironsource). The picture shows the fixed part of the target block and the rooms for auxiliary plant. For the scientific exploitation of the astrophysical data from this detectors we seek close collaboration with •>•, . Foreword institutions from the universities (Geneva. Basel! and ETHZ. The laboratory is also responsible for a special The annual report is a good opportunity to present again a proton beam at the PSl-accelerator facility, by means of somewhat more elaborate progress report of the SINQ- which radiation conditions in space can be simulated. This project. We feel obliged to do so. since we are aware that a facility is widely used for testing microelectronic community of users of this facility is eagerly waiting for its components by external users like ESA. NASA, JPL and commissioning. The scientific contributions of the others. Laboratory for Neutron Scattering and its extensive external net of collaborations with the universities is While providing 65 9c of the beam time at the Tandem evidence for this situation. Accelerator facility for mass spectroscopy, the Laboratory I still feel sad about the disagreeable circumstances which for Ion Beam Physics has increasingly devoted their work led to the delays for this project in the late eighties. On the to the application of the facility to material science. New other hand. I believe that SINQ has gained by being able to experimental techniques have been developed, existing lake advantage of new developments. Only now, backed up ones have been improved - no doubt this is one of the by the successful results in the development of qualities of this research group. supermirrors described in this report, can we make use of Furthermore a new research project in nanostructuring has this chance. So. after all things have turned to the better, been started as a joint effort with the F3B-department. and there is all reason to look into the future with confidence (Fis. 1). The gas-jet systems at the reactor "SAPHIR" and at Injector 1 are a main tool for the experimental activities of the Laboratory for Radio- and Environmental Chemistry. The operation of the new ECR-Ionsource (Electron-Cyclotron Resonance) at Injector I opens up new possibilities. Although the chase for element 106 is one of their drives, the development of the corresponding experimental methods with lighter homologes delivers also deep insight into the physics and chemistry of aerosol- particles and their surfaces. Concerning the research activities 'in the field' to quote "during winter air masses as Jungfraujoch are decoupled from the polluted air masses below, whereas during the wanner seasons polluted air is transported to this site by thermal convection" a good example of reading nature by means of the incredible sensitivity of radiochemical methods. I do not comment here the list of publications from our research department - a glance at it will convince that the Fix- I Participants of the 1993 Zuoz-Summerschool on laboratories play a vital role in their scientific community; Neutron Scattering observing nature in the Natural Park and this in spite of their considerable load in running and up-grading the delicate user-facilities they are responsible First successful steps have been made in the demonstration for. Obviously this would not be possible without a of an increased moderation efficiency for the positron competent and valuable support from our colleagues of the source. The whole premoderation phase has been Technical Department (BK). May I take this occasion to demonstrated with express to them my appreciation. i) an 82 9r efficiency for the magnetic confinement and Furthermore, I have the pleasure to congratulate Dr. Peter the slowing down to a few keV. Allenspach of the Laboratory of Neutron Scattering for his ii) an 83 7r efficiency for the extraction of 7 keV "TIT-ETH award 1994". Finally I would like to thank to positrons from the slowing down path. all the colleagues of our department for their dedication to Next year we expect the demonstration of a high quality our case. positron microbeam and its use for first experiments. In 1993 the Laboratory for Astrophysics (formerly in Dept. F3B) joined our research department. Its research emphasis consists in the development of space born detectors for charged particles and electro-magnetic radiation in the spectral domain of EUV and soft X-rays. A first detector - REM. for Radiation Environment Monitor - W.E. Fischer is expected to be sent to space in spring 1994 by an Head of Dept. F3A "Anane". TABLE OF CONTENTS PROJECTS: • SINQ STNO -The New Spallation-Bascd Neutron Source 2 Experience with Supcrmirror Production at PSI 9 Measurement of Temperature Distribution of Cooling Water in a Rod Structure of SiNQ Target 12 Experimental Measurement of the Modulated Waves in a Rotating Coucltc System by Ultrasonic Doppler Method 15 * High Intensity Posilron Source Status of the Positron Beam Project - Summary and Outlook 17 Electrostatic Posilron Beam 19 Field Assisted Positron Moderation 23 Slow Positron Beam Extraction from High Magnetic Ficlu's 25 LABORATORY FOR ION BKAM PHYSICS The PSI/f-TH Tandem Accelerator Facility 28 The New High Current Cs Sputter Ion Source for the PSI/ETH AMS Facility 30 The 3''CI System at the Zurich AMS Facility 32 kobar Discrimination in Accelerator Mass Spcclrometry by Projectile X-Ray Detection 34 Solar Variability and Climate Traced by Cosmogenic Isotopes 36 '"He Fluxes to a Sediment Core from South of the Antarctic Polar Front 38 f-x|H>stire Dating of the Sirius Formation, Antarctica, Using AMS Measured 1(1Bc and 26A1 40 Constraints on Ocean GCMs from 14C Measurements in the Main Thcrmoclinc, Atlantic Ocean 42 Reconstruction of the Terrcstical Lapse Rale in ihc Western United States during the Last Glacial Maximum Using the Noble Gas Palcothcrmomeler 44 The Man in the Ice: Radiocarbon Dates 46 Uncertainties in Radiocarbon Dating 48 Determination of Cross Sections for the P-lnduccd Production of 36CI in Ca, Ti and Fc 50 "'Cl in Polar Ice Cores 52 A "'Cl Depth Profile of a Limestone Core from Vuc des Alpcs 54 Liquid Meuil Ion Source Emitter Preparation 56 A Timc-of-Flight Spectrometer for Thin Layer Analysis 58 LABORATORY FOR RADIOCHF:MISTRY • (Jeochemislry Sorption of Cobalt 62 Uranium Infiltration from a River to Shallow Groundwatcr 64 Chemical Processes in Riverbed Sediments 65 • Trace Elements The Composition of Spruce Needles (Picca abics): Multivariatc Interpretation of Multiclcmcntal Analyses 67 The Composition of the Aerosols on the Surface of Spruce Needles 69 The Biodynamics of Trace Elements in Conifer Needles 71 • Aerosol and Analytical Chemistry Development of a Carbon Aerosol Generator with Helium as Carrier Gas 73 Interaction of Single HI, HBr, and NOi Molecules with Aerosol Particles 74 Adsorption of Volatile Fission Products on KCI Aerosols 75 13 Use of Posilron-Emiuing N for Sludics of the Sclcciivc Reduction of NO by NH3 over Vanadia/Tilania Catalyst 77 /J II 11 Low Temperature Thermochromalography with i3N-Labelcd Nitrogen Oxides and Fission Rare Gases 78 Hygroscopic Behavior of Combustion Aerosols 79 , Aerosol Measurements at High-Alpine Sites with the Epiphaniomcter 80 Radon, Thoron and :i(lPb Measurements at Jungfraujoch, Switzerland 81 \ Trajectory Analysis of Aerosol Measurements by an Epiphaniometcr at the High-Alpine Site Jungfraujoch 83 ' Chemical Fractionalion between Aerosol, Cloud and Ice Phase during Snowfall at Junfraujoch 84 Determination of Cu, Mn, and Pb in Aerosol and Snow Samples from Jungfraujoch 85 Ammonium Concentrations in Firn Cores from Monte Rosa 86 Source Identification of Bromide in Firn Samples 87 Snou Pit Sampling Intercomparison within the Alpine-Wide Programme SNOSP 88 Transport of Organonitrogen and Organophosphorus Compounds to Remote Areas 89 Cross Sections of the Spallation Reaction 40Ar(p,X)36CI 90 First Results from 32Si Measurements at Jungfraujoch 91 • Heavy Elements Evidence for a New a-Fission Decay Chain Found in Chemistry Experiments with Hahnium 92 On the Volatility of Hahnium Pcntabromidc 93 Prediction of Chemical Properties of Element 106 95 Contribution to the Evaluation of Thcrmochromatographic Experiments 96 OLGA III: A Further Step in the Development of the On-Line Gas Chemistry Apparatus 97 < )n-l.inc Gas Phase Isothermal Chromatography of Mo- and W Oxichlorides as Homologs of Elements 106 with OLGA 111 98 •. Gas Chromatographic Studies of Tungsten in Humid Oxygen 99 i. Cias Chromatographic Studies of Molybdenum in Humid Oxygen 101 ! ()n-I.ine Gas Phase Isothermal Chromalography of NbCl5 and NbOCl3 with OLGA III 103 I On-Line Gas Phase Isothermal Chromatography of U-Chloridcs with OLGA III 104 Thcriiiochromaiography Experiments with Carrier Free Zr and Nb Chlorides and Oxichloridcs 105 Separation of W from Mo Using Ion Exchange from HCI/HF Solution 106 Fast Solvent Extractions with SISAK 3 as a Test for Chemical Studies of Element 106 107 ;• A Liquid Scintillation Detector for On-Linc a- and Spontaneous Fission Measurements 108 • Cement Chemistry Cementation of Aclinidc Waste Solutions 109 LABORATORY FOR NEUTRON SCATTERING Neutron Scattering: Introductory Remarks 112 Pcrcolativc Superconductivity: Estimation of the Cluster Size as a Function of Doping in ErE^Ct^O, (6<x<7) 113 Temperature Dependence of