AMS 02 TRD meeting
16th/17th July 2002, CERN

Introduction

Tuesday 16 July 2002 Morning: TRD detector and gas supplies

• K. Luebelsmeyer - TRD Production status
  (This talk consists of several seperate pages. See listing here ).
  The connection to the USS is newly designed.
  (Almost) No interference with ToF any more.
  Goal is (besides mechanical stability) maximal thermal isolation.
  FE analysis was made for new (lighter) M-structure, with M-structure stand-alone and together with the TRD octagon. Eigenfrequencies are 49.9 Hz and 55 Hz for the stand-alone and the combined system, respectively.
  There are no changes on weight (compared to status of AMS TIM in May 2002).
  Vibration test of octagon honeycomb in good agreement with calculation.
  


• A. Ostaptchuk - Octagon Quality Control ppt file , pdf file
  
  A Wenzel RS-1618 machine with precision 20 + (l / 50mm) micrometer was used.
  On each wall 12 zylindrical inserts: 7 on top, 5 on bottom flange.
  Individual support for each wall on 3 points to aviod mechanical stress.
  Only 4 of all 96 inserts in specs.
  Can start octagon assembly.
  After assembly final global survey (including slits) will be made.
  


• K. Luebelsmeyer - TRD Thermal Status ppt file , pdf file
  Starting point: model from LM & CGS.
  OHB inserted all properties (mechanical and thermal) of TRD and zenith radiator.
  Simulations for beta=0 (worst cold case) and beta=75 (worst hot case).
  Two options: TRD with dedicated radiator or without.
  

  TRD Radiator	beta=0	beta=75
  YES	-17.6	+18.6
  NO	-2.1	40.9

  
  


• T. Kirn - Module Production status pdf file
  Endpieces O_2 plasma treated to increase surface tension by 1/3.
  Leakeage: 2.4E-4 mbar/s
  Glue Araldit AW134 survived space qualification tests, EPO-TEK353ND didn't.
  Leaky long modules forced developments:
  new gas connectors/fittings: 1E-6 mbar/s
  new endpieces: 3E-5 mbar/s
  improvement of assembly machine: e.g. removed burrs
  4 new modules for space qualification produced. Qualification will last till October.
  Afterwards start long term test with gas Box C (1500mm long modules).
  


• T. Siedenburg - Beta-angle and SLF pdf file
  The beta angle is the angle between the orbit plane and the direction to the sun.
  Superposition of two harmonic oscillations:
  large period of 365 days (1 degree per day) due to earth around sun
  short period of 60 days (5 degrees per day) due to precession of satellite around ellipsoidal earth
  most probalbe value: +/-30; abs(beta) > 70 only for 1-2% of time.
  sun light fraction (SLV) depends on beta:
  

  beta=0	beta=30	beta=75
  62 %	65 %	100 %

Tuesday 16 July 2002 Morning: TRD gas supplies

• U. Becker - TRD gas supplies and Gas supply "S" system
  (This talk was scanned in. Find the individual pages here ).
  Commercial Module of Box S in production, some valves delivery pending
  all valves of Box S moved 'out' due to magnetic field (see B. Demirkoz)
  flow restrictors tested to 400 bar
  Marotta valves MV100: electric connection chandeg to gain space, 4 of 24 pieces leaking !
  substitute with MV197: weld tight, electrical identical, but no status output !
  To determine the remaining gas amount in the tanks one needs very accurate p & T measurements. Emperical formula Peng-Robinson (in good agreement with sloshing study by Boing) shows minimal slope (Delta p)/p = 4% for Xe and (Delta p)/p = 1.5% for CO_2
  What accuracy is reasonable and/or available?
  


• B. Demirkoz - "B" Field and flow measurements
  (no complete presentation available, please have a look at this page , one directory up you find more info/pictures about the gas system)
  B-field strength in Box S: 1200 (inner border) down to 200 (outer border) Gauss
  Valves at positions with 300-380 Gauss (angle 32-24 degree)
  GP50: pressure and temperature sensors, tested up to 550 Gauss (1000 mbar), variation of +/-3 %
  Lee company flow restrictors: 4 pieces in Box S, measurements in agreement with technical data sheets, almost not dependant on temperature (few % over full range)
  


• R. Henning - TRD Gas System Slow Ctrl at MIT ppt file , pdf file
  Prototype system running as closed system for several months
  USCM programming ongoing
  First outline of Mixing Operation


• R. Henning - Box S Solenoid Valve Testing ppt file , pdf file
  MV100 acceptance tests: electrical characteristics, leak, endurance, 25 of 27 pieces (94% finished) no new leaks during testing, i.e. valves did not become worse by test under stress
  several pieces leak at T < 0 degree C. Box S should stay above 0 degree C !!
  The 4 valves for the pressure vessels will be changed to MV197.
  


• R. Becker - Mechanics of Box 'S' and 'C'
  two constraints for the position of Box S & C:
  magnetic field decreases with more distance from magnet => push out
  space is limited inside by magnet/flange for cryocollers and outside by radiator
  


• B. Monreal - Box 'C' design, testing
  Lifetime of pumps is o.k. for half speed, i.e. with 12V (almost no flow), but only if operation before mission is strictly reduced
  plastic components of valves, etc. inside an aluminum box, which is filled with gas (semi-open volume)
  The 4 calibration tubes are mounted on the outside of box C
  


• J. Burger - Manifolds
  Try to mount all 16 gas manifolds on the octagon (top of +/-Y wall)
  B-field strength there is 140-175 Gauss with angle to horizontal line smaller than 20 degree
  


• A. Werner - Monitor tube readout ppt file , pdf file
  4 short tubes with Fe55 source
  signal is shaled and read out by multichannel analyzer MCA8000A
  1 board with 4 shapers and 1 Mux, power dissipation 300mW
  test board to be produced soon
  final board available in September 02
  


• C. Gargiulo - Structural design of 'S' and 'C' ppt file , pdf file
  See also detailed documents on this page in Roma .
  upper fixation clamped, lower fixation with spring
  during acceleration movement of upper fixation is 0mm, but lower fixation is 9mm ! !
  Finite-Element analysis of Box S plate gives max. movement of 1mm at any point in any direction
  modal analysis: eigenfrequencies > 70Hz
  drawings in finalizing stage, production in preparation
  DECISION: get a written agreement from LM (Trend Martin) before the start of production

Tuesday 16 July 2002 Afternoon: Physics with AMS

• V. Choutko - Anomalous cosmic rays with AMS1
  


• T. Siedenburg - Test beam results pdf file
  MC of test beam improved with beam profile, calibration, electronics
  Corrections for dE/dx and TR generation
  Approx. proton rejection: 1E-3 for energies < 100 GeV, 1E-2 for energies >= 200 GeV
  For energies >= 200 GeV still discrepancies between data & MC
  


• G. Lamanna - TRD contribution to AMS Physics pdf file
  TRD in AMS MC: rejection of protons by energy (loss) cut, track finding, gamma conversion
  Rates for e+ and e- a 100th of protons
  No extra-gallactic contribution for e+ and e-
  Measured anti particle (e+ and p-) spectra give room for speculations about (clumpy) Dark Matter Halo.
  Need AMS for precise measurement.
  


• V. Choutko - Use in AMS-02
  


• G. Carosi - e+/p separation
  


• W. de Boer - Dark Matter from SUSY
  

Wednesday 17 July 2002 Morning: TRD Electronics

• G. Schwering - Short overview & Cabling ppt file , pdf file
  


• M. Capell - Crate mechanics and arrangement ppt file , pdf file
  First AMS crate produced by Taiwan, currently under test
  Ucrate with 21 slots (T crate, too), UGcrate with 13 slots
  Final drawings in September 2002
  Aachen produces 2 QM Ucrates, then decides about Tcrate (1 QM) and UGcrate (1 QM + 2 FM/SM?)
  Procurement of accessories to be decided when drawings in Aachen
  


• W. Karpinski - Front End Electronics: Status
  


• C.H. Chung - Front End Electronics: Testing ppt file , pdf file
  40 VA32 chips tested (2 malfunctioning), 12 UFE boards tested, problem in production detected
  Two test systems: a) VA32 chip only ('IDE box') b) UFE board (Aachen setup)
  a) pedestal values < 100mV, noise < 1mV, gain = 1.2mV/fC
  b) typical pedestal spread: 150-400 ADC counts, noise: 1.7 ADC counts, linearity: gain=2 ADC counts/fC over ADC range of 3000 counts
  All results in data base, available via WWW


• F. Hauler - DAQ Crate Electronics pdf file
  Guido board setup running, but external trigger and calibration does not work yet
  2 UDRs delivered, 1 UPSFE on the way, test backplane in preparation
  2 Guido board and 2 (UDR+UPSFE+backplane+PCI) available in September 2002
  CAEN's objections against thin lines on UBP and TBP are obsolete: They used old space specs.
  Backplane development: WP1 (small backplane) must contain 2 USCMs.
  


• S. Ro - DC/DC converter testing ps file (talk) ps file (diagram) pdf file (circuit)
  Detailed test procedures developed
  Goal is automation: need progammable power supply, output load and capacitor
  Data of each DC/DC converter will be recorded by PC and filled in data base
  


• V. Koutsenko - UHVG pdf file
  Communicatin with USCM: 'LeCroy protocol' with 6 I/O and 6 output only LVDS lines
  PCB of UHVG is completely filled, no space for linear regulator
  Need new DC/DC converter with 6V and 120V regulated. New offer from CAEN will be asked.
  First 2 EM of UHVG to be produced at CERN, available in Aachen in September 2002.
  Need to find production facility (in Europe) for 6 beam modules, which may be assembled with only half components (no redundancy).
  CSIST production enough for Ucrate (23) and UGcrate (3) (QM, FM, SM)
  


• A. Bartoloni - Gas Crate & Manifold Electronics ppt file , pdf file
  Boards in UGcrate have normal dimensions, but UGFV has larger front panel due to many connectors. May be reduced.
  Manifold electronics ('piggy backs') are 12x8cm: Too big! Do not fit on octagon. In the meantime there is a new design, which is only 12x4 cm.
  MOSFETs are (too) dangerous (latch-up) to be used for control of critical hardware (pressure valves, etc.)