TRIUMF: Canada's national laboratory for particle and nuclear physics

Annual report scientific activities, 1996 TRIUMF Oct 31, 1997

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TRIUMFANNUAL REPORT SCIENTIFIC ACTIVITIES 1996CANADA'S NATIONAL MESON FACILITY OPERATED AS A JOINT VENTURE BY: ASSOCIATE MEMBERS:UNIVERSITY OF ALBERTA SIMON FRASER UNIVERSITY UNIVERSITY OF VICTORIA  UNIVERSITY OF BRITISH COLUMBIAUNIVERSITY OF MANITOBA  UNIVERSITE DE MONTREAL UNIVERSITY OF TORONTO  UNIVERSITY OF REGINAUNDER A CONTRIBUTION FROM THE NATIONAL RESEARCH COUNCIL OF CANADA October 1997TRIUMFANNUAL REPORT SCIENTIFIC ACTIVITIES1996Postal Address: TR IUM FPublications O ffice  4004 Wesbrook Mall Vancouver, B.C. Canada V6T  2A3The contributions on individual experiments in this report are out­lines intended to demonstrate the extent of scientific activity at TRIUMF during the past year. The outlines are not publications and often contain preliminary results not intended, or not yet ready, for publication. Material from these reports should not be reproduced or quoted without permission of the authors.IVFOREWORDDuring 1996 TRIUMF firmly established a course in pursuit o f its five year plan. The four presidents o f the universities o f the Joint Venture -  Alberta, SFU, UBC and Victoria -  signed the NRC Contribution Agreement in June. This document formally puts in place the multiyear funding scenario which is a welcome change and a relief for a laboratory which has lived through too many uncertain years o f annual funding.In September TRIUMF signed with CERN, and on behalf o f Canada, a Contri­bution Agreement to the Large Hadron Collider, which is being built in the CERN laboratory near Geneva. TRIUMF will contribute $30M ‘ in kind’ and thus help to assure access for Canadian physicists to science at the energy frontier.Throughout the year the governing committees of TRIUMF have begun to func­tion. The Advisory Committee on TRIUMF (ACOT) has held three meetings. This is a high-level scientific advisory group which reviews the work of TRIUMF and reports to the NRC. The second committee is the Agency Committee on TRIUMF (ACT) which also met twice in 1996. This body is comprised o f representatives of NRC, NSERC, Industry Canada and Western Economic Diversification. As chairman o f the TRIUMF BOM, I sit on ACOT and attend ACT as part o f the TRIUMF delegation. It has been an interesting time as the committees, the laboratory and the NRC seek out a good working relationship.At last I believe we can say that the funds are secured, the scientific program de­fined and the reporting mechanisms in place. The future now rests fairly and squarely in the hands of the TRIUMF staff which, after all, is where it should be!Colin JonesChairman, Board of ManagementTRIUMF was established in 1968 as a laboratory operated and to be used jointly by the University o f Alberta, Simon Fraser University, the University o f Victoria and the University o f British Columbia. The initial consortium has been expanded to include the University o f Manitoba, Universite de Montreal, the University of Toronto and the University o f Regina as associate members. The facility is also open to other Canadian as well as foreign users.The experimental program is based on a cyclotron capable of producing three simultaneous beams of protons, two of which are individually variable in energy, from 180-520 MeV, and the third between 70 and 100 MeV. The potential for high beam currents -  100 pA at 500 MeV to 300 fiA at 400 MeV -  qualified this machine as a ‘meson factory’ .Fields of research include basic science, such as particle and nuclear physics and condensed matter research, as well as life sciences based primarily on isotope research. There is also a biomedical research facility which uses 7r mesons and soon protons in cancer research and treatment.The ground for the main facility, located on the UBC campus, was broken in 1970. Assembly of the cyclotron started in 1971. The machine produced its first full-energy beam in 1974 and its full current in 1977.The laboratory employs approximately 375 staff at the main site in Vancouver and 19 based at the participating universities. The number of university scientists, graduate students and support staff associated with the present scientific program is about 625.VICONTENTSINTRODUCTION ....................................................................................................................................................................  1SCIENCE DIVISION ............................................................................................................................................................... 3Introduction and Overview .....................................................................................................................................................  3Particle Physics ..........................................................................................................................................................................  5(Expt. 497) Measurement o f the flavour conserving hadronic weak interaction .............................................. 5(Expt. 705) BNL Experiments 885, 813 and 836: Double strangeness physics at the AGS: Experiment to detect AA hypernuclei (BNL 885) using gas micro-strip chambers (Expt. 705); and two searches forthe H  particle (BNL 813 and 836) ................................................................................................................................. 7The ATLAS experiment on the LHC .............................................................................................................................  8(BNL787) Study o f rare K  decays ............................................................................................................................... 14(KEK246) Search for T  violation in 3 decay ........................................................................................................  15(TJNAF91-117) Measurement of the flavour singlet form factors o f the proton ............................................  16Nuclear and Atomic Physics .................................................................................................................................................... 18(Expt. 560) Low energy n^p  analyzing powers with CHAOS .............................................................................. 18(Expt. 570) Gamma-neutrino angular correlation in muon capture on 28Si .....................................................  19(Expt. 624) The (7r, 2tt) reaction, a tool to determine scattering lengths and coupling constants ............. 20(Expt. 633) A measurement of pp —> pnn+ at 420 and 500 MeV ........................................................................ 21(Expt. 700) Measuring cross sections o f long-lived radionuclides produced by 200-500 MeV protons inelements found in lunar rocks and meteorites ..............................................................................................................  22(Expt. 704) Charge symmetry breaking in np —> dn° close to threshold ..........................................................  23(Expt. 715) Weak interaction symmetries in /?+ decay o f optically trapped 37>38mK .................................... 28(Expt. 719) 4He(7r+ , n~pp) invariant mass measurement with CHAOS ............................................................  29(Expt. 721) The delta nucleon reaction in CHAOS ................................................................................................  30(Expt. 722) Pion initial state interactions in the 12C (7r+,ppp) reaction ............................................................  31(Expt. 723) Study o f pion-nucleus double-scattering reactions ...........................................................................  31(Expt. 725) Pionic double charge exchange on 4He ................................................................................................  32(Expt. 741) Beta-delayed proton decay o f 17Ne to a-emitting states in 160  ..................................................  32(Expt. 742) Scattering o f muonic hydrogen isotopes ..............................................................................................  35(Expt. 766) The ortho-para transition rate in muonic molecular hydrogen ....................................................  37(Expt. 778) 7r± p differential cross sections in the Coulomb-nuclear interference region ................................ 37(Expt. 781) Investigations o f the 7T7t invariant mass distributions o f nuclear (ir+ , n~n+ ) reactions withthe CHAOS detector ...........................................................................................................................................................  38(Expt. 785) Pion double charge exchange on 3He with CHAOS .........................................................................  38Research in Chemistry and Solid-State Physics ...............................................................................................................  40(Expt. 640) Magnetic correlations and spin dynamics in Kondo systems o f type RTX ................................ 40(Expt. 671/720/750) Muonium’s pH-dependence ....................................................................................................  41(Expt. 684) pSR spin relaxation studies o f small molecules in the gas phase ................................................  45(Expt. 687) pSR in frustrated antiferromagnets pyrochlores A 2B2O7 .............................................................  48(Expt. 691) T, if-dependence o f the coherence length £a(, in YBa2Cu3O6.60 ..................................................  50(Expt. 692/693/775) Muon radiolysis and quantum diffusion in cryocrystals and other insulators  51(Expt. 710) Muonium dynamics in Ge and G a A s ...................................................................................................  53(Expt. 713) Muonium chemistry in supercritical water ........................................................................................  54(Expt. 749) Muonium-substituted free radicals .......................................................................................................  55(Expt. 752) Muonium dynamics in semiconductors ................................................................................................ 57(Expt. 758) Electronic structure o f muonium and muonium-lithium complexes in graphite andrelated compounds ...............................................................................................................................................................  59(Expt. 776) Rare earth materials with disordered spin structures .....................................................................  60(Expt. 777) Vortex state o f s-wave superconductors investigated by muon spin rotation ............................ 61Life Sciences Research ...............................................................................................................................................................  63PET p rogram ........................................................................................................................................................................  63A platform for the design o f position encoding multicrystal detectors ................................................................. 63viiTomograph detector development .....................................................................................................................................  64PET radiopharmaceuticals ..................................................................................................................................................  64TR13 cyclotron .......................................................................................................................................................................  65Theoretical Program .................................................................................................................................................................... 66Introduction .............................................................................................................................................................................  66Electroweak physics ...............................................................................................................................................................  66Hadron physics .......................................................................................................................................................................  67Experimental Facilities ................................................................................................................................................................ 73TISOL ....................................................................................................................................................................................... 73DASS/beam  line 4B ..............................................................................................................................................................  73fiSR user facility .....................................................................................................................................................................  75Proton therapy facility .......................................................................................................................................................... 79Proton irradiation facility ....................................................................................................................................................  79Computing services ...............................................................................................................................................................  79Com puting/data acquisition ............................................................................................................................................... 82GEANT4 ..................................................................................................................................................................................  83Sudbury Neutrino Observatory ........................................................................................................................................... 84CYCLOTRON OPERATIONS DIVISION ...........................................................................................................................  86Introduction ................................................................................................................................................................................... 86Beam Production .........................................................................................................................................................................  87Beam schedules 88 and 89 ..................................................................................................................................................  87Shutdowns ................................................................................................................................................................................  92Beam schedule 90 ...................................................................................................................................................................  92Developments ................................................................................................................................................................................. 92Energy modulation ................................................................................................................................................................ 92Stripping foil lifetime ............................................................................................................................................................ 92Hockey stick foil .....................................................................................................................................................................  93Magnet shim adjustment ......................................................................................................................................................  93Probes and beam line diagnostics .....................................................................................................................................  93RF Systems ....................................................................................................................................................................................  94RF operations .........................................................................................................................................................................  94RF booster ............................................................................................................................................................................... 94RF support ............................................................................................................................................................................... 94ISIS and POLISIS ......................................................................................................................................................................... 94ISIS ............................................................................................................................................................................................  94POLISIS ................................................................................................................................................................................... 94Beam Lines ..................................................................................................................................................................................... 97Primary beam lines ...............................................................................................................................................................  972A ..............................................................................................................................................................................................  97Miscellaneous projects .......................................................................................................................................................  972C operations ......................................................................................................................................................................... 97Controls ........................................................................................................................................................................................ 98Controls upgrade .................................................................................................................................................................  98Beam line 2A ......................................................................................................................................................................... 99ISAC ........................................................................................................................................................................................  99Central control system .......................................................................................................................................................  99Operational Services .....................................................................................................................................................................100Remote handling .....................................................................................................................................................................100Power su pp lies..........................................................................................................................................................................101Electrical systems ...................................................................................................................................................................101Mechanical systems ................................................................................................................................................................ 102vmISAC P R O J E C T ............................................................................................................................................................................104Introduction ....................................................................................................................................................................................104Schedule ........................................................................................................................................................................................... 104Conventional Facilities .................................................................................................................................................................105Technical facilities .................................................................................................................................................................. 105Scientific Program at ISAC ........................................................................................................................................................105Target Maintenance Building, Shielding and Engineering .................................................................................................108Shielding ....................................................................................................................................................................................108Engineering .............................................................................................................................................................................. 1092A Extraction Probe .................................................................................................................................................................... 109Beam Line 2A ................................................................................................................................................................................ 110Ion Source Test S ta n d .................................................................................................................................................................. 112ISAC Mass Separator ...................................................................................................................................................................112Specifications ............................................................................................................................................................................112Ion optics ..................................................................................................................................................................................112Mass separator .........................................................................................................................................................................112Matching section 1 ................................................................................................................................................................. 113Pre-separator stage .................................................................................................................................................................113Matching section 2 ................................................................................................................................................................. 114Main mass separation stage ................................................................................................................................................. 114Matching section 3 ................................................................................................................................................................. 114RF structures ...........................................................................................................................................................................114Prototype simulation ............................................................................................................................................................. 114Drift tube linac ........................................................................................................................................................................ 115Buncher cavity .........................................................................................................................................................................116Medium energy beam transport (MEBT) ........................................................................................................................116LEBT Optics Design .....................................................................................................................................................................116RFQ System ....................................................................................................................................................................................117RFQ prototype ........................................................................................................................................................................ 117Power measurements ..............................................................................................................................................................117RFQ accelerator ...................................................................................................................................................................... 118RFQ Beam D ynam ics...................................................................................................................  118Reference design ...................................................................................................................................................................... 118RFQ entrance studies .............................................................................................................................................................118PARMTEQ .............................................................................................................................................................................. 119Vane profiles and field correction ........................................................................................................................................119Sensitivity analysis o f beam injection errors ................................................................................................................... 119Sensitivity analysis to vane position errors ..................................................................................................................... 120Commissioning strategy ........................................................................................................................................................120RFQ Task Force  ...........................................................................................................................................................................120Diagnostic station ...................................................................................................................................................................120Commissioning strategy ........................................................................................................................................................120Separated Function Drift Tube Linac ...................................................................................................................................... 121Introduction ..............................................................................................................................................................................121Beam dynamics ....................................................................................................................................................................... 121Specifications ............................................................................................................................................................................ 122Variable energy operation ..................................................................................................................................................... 122High Energy Beam Transport ....................................................................................................................................................123Beam Diagnostics .......................................................................................................................................................................... 123ACCELERATOR TECHNOLOGY DIVISION ....................................................................................................................125Introduction ....................................................................................................................................................................................125Accelerator Research ....................................................................