Calorimeter calibration data.

A.Chekhtman.

May,10,2002

There is Eric Grove’s presentation on calorimeter calibration at GLAST software meeting January, 2001

Data used by actual calorimeter reconstruction code for BFEM and BTEM.

• Muon calibration: muon peak position (in ADC units) for each crystal face (2*8*12=192 float values per tower)
• Charge injection calibration:
• peak positions (in ADC units) for different injected charge (up to 50 different DAC settings, 0<DAC<2000).
• For each crystal face and each range calibration gives a table of 50 pairs (DAC, ADC) => total data volume 2*50*4*2*12*8=76800 float values per tower.
• Pedestals: peak position (in ADC units) corresponding to 0 energy deposition in a crystal. This information is in fact included in charge injection calibration as data for DAC=0. Actually, pedestals are used by cal reconstruction only for zero suppression purposes.
• Mu slopes: coefficient converting light asymmetry into longitudinal position. One float value for each crystal and each diode size. Total volume: 2*12*8=192 float values per tower.

Future modifications:

· Muon calibration will be replaced by cosmic ray calibration

o Calibration using ~10 different nuclei (H, He, C,N,O,Si,Ne,Fe) =>there will be 10 peak positions for each crystal face (1920 float values per tower)

· One mu slope per crystal (and diode size) will be replaced by complete calibration table (light asymmetry vs position) containing 12 pairs of float values => total data volume 12*192=2304 float values.