GLAST CAL Peer Design Review

1
GLAST LAT Calorimeter Subsystem
CAL Calibration Data Sources During Assembly,
Integration, and Test J. Eric Grove Naval
Research Laboratory j.eric.grove_at_nrl.navy.mil (202
) 767-3112
2
Calibration Constants for SAS

• SAS needs calibration constants for
• These 4 are necessary to measure energy in a
  crystal
• Integral non-linearity of electronics
• Crystal response maps (i.e. light asymmetry)
• Energy scale
• (aka gain, but more correctly, MeVperDAC)
• Pedestals
• To estimate missing energy in CAL
• Zero-suppression (LAC) threshold setting
• To understand trigger efficiency
• Low and high energy trigger (FLE, FHE) disc.
  setting

3
Sources of calibration data

• Where do these data come from?
• Muon runs
• CAL-only at NRL and at SLAC (receipt test)
• Approx 24-hour runs
• Multiple runs at NRL, but reference comes from
  pre-ship checkout after environmental test
  program
• CALTKR at SLAC
• Approx 2-week run
• Comprehensive Performance Test (CPT)
• Electronic Calibration Suite (ECS)
• CAL-only test suites at NRL
• Multiple runs at NRL, reference at pre-ship
• IT at SLAC

4
Functional Test Flow

• Comprehensive Performance Test (CPT)
• Test suite composed of 22 elements with following
  goals
• Verify full functionality of all CAL registers
  and proper communication with TEM
• Measure pedestal centroids and widths
• Verify stability of optical bonds for all CDEs
• Measure electronic gain, linearity, and integral
  non-linearity of each GCFE
• Characterize low and high energy (FLE and FHE)
  discriminators
• Characterize zero-suppression (LAC) threshold DAC
• Characterize auto-ranging (ULD) discriminator DAC
  
• Estimate event dead-time
• Test overload recovery circuitry
• Defined in LAT-MD-01370
• Runs in 2 hours
• Generates test reports, diagnostic plots,
  trending .csv,

5
Calibration Flow

• Electronic Calibration (ECS)
• Test suite to give detailed calibrations of
• Electronic gain, linearity, and integral
  non-linearity of each GCFE
• Low and high energy (FLE and FHE) discriminators
• Zero-suppression (LAC) threshold DAC
• Auto-ranging (ULD) discriminator DAC
• Muon Calibration (MuC)
• Calibrates optical gain of each CDE
• Optimizes time delay between trigger and peak
  hold
• Verifies calibration (energy units) in FLE/FHE
  from ECS
• Fits muon peak (with its known energy
  deposition), gives MeV/bin.
• Maps light taper and light asymmetry in each CDE
• Both are defined in LAT-MD-04187
• Generates test reports, summary plots, trending
  .csv,

6
Sources of calibration data

• What is the data and analysis flow?
• Integral non-linearity
• Charge-injection data
• On-line script calu_collect_ci_singlex16, part of
  CPT and ECS
• Produces table of input chg-inj DAC setting v.
  output ADC bin
• Linearized ADC bins in DAC units DAC
  linearized(ADC)
• Crystal response maps (i.e. light asymmetry)
• CAL-only or CALTKR muons
• On-line script calf_map_mu, part of MuC
• Produces tables of muon peak
• sqrt(Plus Minus), sqrt(plus minus), per
  xtal
• Produces tables of light asymmetry
• 12 values of log(P/M), log(p/m), per xtal
• MeVperDAC
• Derived from previous two results
• Muon energy loss 11.2 MeV
• MeVperDac 11.2 / linearized(sqrt(Plus x Minus))
  

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Sources of calibration data

• What is the data and analysis flow?
• Pedestals
• Muon data
• SAS analysis
• On-line script calf_map_mu, part of MuC
• Pedestal calibration
• On-line script calf_pedestals_ci, part of CPT and
  ECS
• Produces table of pedestals at all gain settings
• Zero-suppression (LAC) threshold
• LAC characterization or calibration
• On-line script calf_supp_p01, part of CPT and ECS
• Produces table of LAC setting v. threshold ADC
  bin
• LACMeV linearized(ADC bin) x MeVperDAC

8
Sources of calibration data

• What is the data and analysis flow?
• CAL trigger thresholds
• FLE, FHE characterization or calibration
• On-line script calf_trg_p03, part of CPT and ECS
• Produces tables of FLE, FHE setting v. thresh ADC
  bin
• FLEMeV linearized(ADC bin) x MeVperDAC x
  FleScaleFactor
• Whats this FleScaleFactor?
• Response of fast shaper is not the same for
  chg-inj pulses as for scintillation signals
• FleScaleFactor derived from muon check of FLE
• On-line script calf_trg_mu, part of MuC suite
• Produces table of FLE, FHE setting v. thresh MeV
• FleScaleFactor 1.7

9
Modes of muon operation

• Flight mode We have to do this
• Ground test of flight operations
• Flight trigger
• TKR trigger enabled (i.e. flight trigger)
• CAL trigger thresholds set high (i.e. flight
  trigger)
• FLE 100 MeV but disabled
• FHE 1 GeV, enabled
• Flight gain
• LE rails at 1.6 GeV (i.e. flight gain)
• HE rails at 100 GeV (i.e. flight gain)
• Minimize data volume
• Auto-range, one-range readout (i.e. flight
  readout)
• Zero-suppression enabled (i.e. flight readout)
• LAC threshold 2 MeV or below

?
10
Modes of muon operations

• Ground test with muons visible in HE ranges
• Energy calibration with muons
• Flight trigger
• TKR trigger enabled (i.e. flight trigger)
• CAL trigger thresholds set high (i.e. flight
  trigger)
• FLE 100 MeV, but disabled
• FHE 1 GeV, enabled
• Muon gain
• LE rails at 1.6 GeV (i.e. flight gain)
• HE rails at 4 GeV (i.e. muon test gain)
• Intermediate data volume
• Auto-range, four-range readout (i.e. see all
  ranges)
• Zero-suppression enabled (i.e. flight setting)
• LAC threshold 2 MeV or below

?
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Testing and calibration to date

• CAL Module FM101 ( FMA)
• Initial reference CPT and MuC completed
  successfully
• Post-EMC/EMI-test CPT completed successfully
• Post-Vibration-test CPT completed successfully
  today
• Post-Vibration-test MuC should be completed
  Wednesday
• CAL Module FM102 ( FMB)
• Initial reference CPT and ECS should be completed
  tomorrow
• Initial reference MuC should be completed
  Thursday

CAL FM101 ready for test and calibration