Central Muon Scintillation Counter Commissioning and Calibration

1
Central Muon Scintillation CounterCommissioning
and Calibration

• Steven Doulas
• Northeastern University
• D0 Muon Upgrade Group

2
Group Effort

• D. Hedin, S. Dychkant
• NIU
• V. Bodyagin
• Moscow State U.
• H. Mao
• China
• L1Muon- K.Johns, R. McCroskey, J. Temple
• Arizona U.
• T. Christiansen
• Munich
• T. Diehl, A. Ito, M. Zanabria, V. Podstakov, T.
  Fitzpatrick
• FNAL
• A. Bannanjes, S. Bheesette, S. Dugad, N. Mondal
• Tata Institute

3
Before Shutdown

• Prior to shutdown (Valid starting from Run
  132948)
• A-layer Trigger Gate width for hits to L1 was
  reduced from 88 ns -gt 34 ns.
• B-layer Trigger Gate width for hits to L1 was
  reduced from 88 ns -gt 50 ns.
• C-layer Trigger Gate width for hits to L1 was
  reduced from 88 ns -gt 46 ns.
• Bottom C-layer (Octants 5 6) from 88 ns -gt 60
  ns.
• Reduction in overall A.C trigger rate by a factor
  of 2.5.
• Single muon trigger prescale has been reduced,
  scales w/luminosity.
• Ex. At L3.6E30 single muon prescale reduced from
  140 to 50.
• In-time muon peaks for 3 of 8 octants were
  shifted 18.8ns earlier in the readout crossing.

4
Activities during shutdown

• Front-End and Readout Electronics
• Modified all Scintillator Readout Cards (SRCs).
• Correct occasional Turn Number mismatch.
• Reduce noise seen during data transfer to L2
  L3, BIST tests.
• Modified all Scintillator Front-End Cards
  (SFEs).
• Corrected timing for TOF gate.
• Replaced and tested Muon Readout Card (MRC).
• Had large error rate for L3 BIST tests, now see 0
  errors for given bit transfer rate.
• Testing readout chain using TFW and local DAQ
  systems.
• LED Calibration System
• Added additional LED system to the bottom hole
  counters, now east and west are separated.
• L1 Trigger
• Due to geometry of the bottom trigger counter
  layers, still debugging and understanding L1
  trigger for counters in octants 5 6.

5
TOF Gate Width Correction
Before
After
6
Activities During Shutdown (contd)

• Calibration
• Using local DAQ to obtain the following
• ADC Pedestal values for all SFE channels.
• Beginning to measure ADC gain curves for all SFE
  channels.
• Beginning LED calibration runs to begin gain
  calibration of PMTs so we can determine the
  threshold values for individual PMTs.
• Currently set to a minimal nominal value for all
  PMTs.
• Central scintillation counter geometry check.
• Using internal pulsing of front-ends, we can
  verify physical location of counters w/muon
  geometry (w/D0Scan, D0ve)
• Cosmic ray muon runs
• Primarily for A-layer counters, needed as final
  step to link current LED gain data w/Cosmic ray
  data from original counter/PMT matching.
• Make sure electronics work and we dont have
  corrupted data.

7
Plans After Shutdown

• We plan to start data-taking with
• L2 Hotlink data transfer enabled.
• L2 can start looking at formatted data, great
  check of DSP code.
• Initial set of T0s with current Trigger gate
  width delays.
• Individual PMT threshold setting for a fraction
  of A/C-layer counters.
• This will affect muon timing spectrum so there
  will be an in some incremental changes during the
  first 2 weeks.
• Additional adjustment(reduction) of A-layer TG to
  reduce background without cutting into
  efficiency.
• Measure the effectiveness of new A-layer
  shielding.