Transcript ppt

GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
Instrument Analysis meeting, January, 20, 2006
Status of calorimeter calibration.
Alexandre Chekhtman
NRL/GMU
A.Chekhtman
1
GLAST LAT Project
Instrument Analysis meeting, January, 20, 2006
Tresholds calibration
• calibDAC (run 135005271)
– pedestals, relgain, fle2adc, fhe2adc, lac2adc, uld2adc
• muTrg (runs 135005296, 135005297, 135005298)
– Bias between FLE/FHE thresholds for charge injection and muons
• Additional input – adc2nrg tables
– We used data from 8-towers configuration + preship data for
recently added towers.
• Output:
– Xml files for FLE, FHE, LAC and ULD for all required configuration
• Difficulties:
– Bug in the algorithm for smoothing sparsed characterisation tables
• caused some LAC and FHE to be too low producing high trigger rate and
occupancy – has been fixed
– For some channels required FLE thershold could not be set – the
algorithm incorrectly returned FLEDAC=7f in this case
• Fixed
A.Chekhtman
2
GLAST LAT Project
Instrument Analysis meeting, January, 20, 2006
Energy scale calibration
• Inputs:
– calibGen (runs 135005279 and 135005280)
• Nonlinearity calibration
– B13 (run 135005337)
• Pedestals
– B30 , runs 135005404 – 135005524, excluding 135005406(file
missing) and 135005494 (bad)
• 26 M events
• Separate batch job for each tower
– CPU time ~3 hours per tower
– All towers processed in parallel
• Outputs:
ci_intnonlin.digitization-v3r4p4_135005279_digi_DIGI.xml
mc_peds.digitization-v3r4p4_135005337_digi_DIGI.xml
mc_asym.digitization-v3r4p4_135005404_digi_DIGI.xml
mc_mpd.digitization-v3r4p4_135005404_digi_DIGI.xml
A.Chekhtman
3