TOF Status Report TIM at CERN, Geneva, 27 Oct' 1 Nov' 2003 F'Palmonari, INFN

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TOF Status ReportTIM at CERN, Geneva, 27 Oct.
1 Nov. 2003F.Palmonari, INFN University of
Bologna

• Summary
• Overview
• Mechanics
• Electronics

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Overview of work done since last TIM

• Tenders for TOF planes mechanics started
• Much work to optimize the design of TOF-ACC
  electronics to save weight and cure thermal
  issues
• Preparation of the Test run on the Ion beam

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G.F. 5000 cm2 sr Exposure gt 3 yrs
dP/P2 0.004 ? MDR 2.5 TV, h/e 10-6 (ECAL
TRD)
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The TOF Scintillation Counters

• 4 planes of plastic scintillation counters slabs
  1 cm thick
• 8( X ) 8( Y ) counters Upper TOF above Magnet
• 10( Y ) 8( X ) counters Lower TOF below Magnet
• 34 counters seen at both ends by a pair of R5946
  Hamamatsu PM
• 144 PMs in total, giving Anode and 3rd-last
  Dynode signals
• 68 HV channels
• 68 Anodes 68 (144 tbd) Dynodes signals

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AMS II TOF Mechanics
FEM model finished (with USS displacement) The
goal is to mount the complete Lower TOF Spring
2004 to perform a vibration test to check The
adopted design solutions PMTs fixation, Light
guides bending, internal cabling
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AMS II TOF Mechanics
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AMS II TOF Mechanics
Lower TOF
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AMS II TOF Mechanics
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Overview on electronics

• Most progresses concern the electronics Hardware
  of the TOF system
• Both LV and HV Power supplies have been
  simplified to gain weight
• The TOF-ACC scintillator crate SCR has also been
  redesigned
• The Dynode ADCs have been moved on the detector
  to simplify cabling and save weight
• See Guido Castellini report on Thursday

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The previous Scintillator Crate
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The 1500-2300 V HV regulator channel.Paking is
optimized for complete potting.
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The previous S-Crate modules
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Test run preparation in Bologna

• The team of young people (Diego and Beppe are
  old). From left Lorenzo Villa, Lucio Quadrani,
  Roberto Martelli, Veronica Bindi, Dafne
  Baldassari, Cristina Sbarra, Fernando Massera,
  Luca Amati. (Francesca Giovacchini and Alberto
  Oliva are not there)

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Purposes of the test run

• Take relativistic Ion data on 4 counters like in
  AMS-02 to study
• 1)overall resolution in Z
• 2)multiple hit, fragmentation in plastic
  scintillator
• 3)saturation effects
• We use counters with different light-guides
• Two straight light-guides as in planes 1 and 4
• One bended (counter 302)
• One bended and twisted (counter 205 )
• Test the EM front-end cards SFET and SFEC, mainly
  for thresholds and ADC dynamic range setting

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TOF Planes Assembly Plan

• Phase 1 - PMs assembly started mid February
  ENDED.
• Phase 2 - PMs calibrations started in March,
  ENDED 192 PM done (144 will be mounted
• Phase 3 - The flight scintillation counter slabs
  machined and ready for light-guides glueing have
  been delivered. Glueing and wrapping
  started in September
• Phase 4 - Scintillation counters
  characterisation.
• Phase 5 - Counters assembly with PMs, vacuum test
  and calibration with cosmic rays will start in
  January with Lower TOF.

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Study of the optimisation of the PM disposition
to take into account that we have to power them
in pairs to save weight and power.

• Each of 245 PMs ( in a relational database) is
  characterized by many quantities
• Gain as function of HV
• Gain derivative at the setting HV
• Photocatode luminous sensitivity
• Dark current, etc..
• When mounted the PM response depends also on at
  least two other quantities
• The trasmission coefficient of his lightguide
• The gain change due to the magnetic field in his
  position
• To take into account all effects when two PMs are
  powered together and find the best way to choose
  144 PMs out of the 200 we have is not simple.
• An optimisation program using a genetic algorithm
  has been developed.

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Counters characterisation is made inside a
light-tight box.Infact they are prepared with
the aluminized mylar wrapping alone.
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Preparation of the BENT and TWIST LG CountersPM
chosen from optimisation table
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Results of the characterisation on the Cosmic Ray
Telescope
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The new SFET on the test bench
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The ADC card using the RICH Chip under test
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Conclusions

• The TOF counters preparation is going on within
  schedule
• The counters calibration will help in the final
  setting of all parameters of the front end
  electronics