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Rick Wilkinson. HCAL Digitization. Program Flow. Energy 0.855 GeV Tof 6.783 ns Geant track #0. SimHits. DetId=1107320961, 10samples 0:0 1: 4.97957 2: 10.5976 3: 2.68312 4: 814.103 5: 657.711 6: 185.86 7: 73.7753 8: 31.0982 9: 13.2264. CaloHitResponse.
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Rick Wilkinson HCAL Digitization
Program Flow Energy 0.855 GeV Tof 6.783 ns Geant track #0 SimHits DetId=1107320961, 10samples 0:0 1: 4.97957 2: 10.5976 3: 2.68312 4: 814.103 5: 657.711 6: 185.86 7: 73.7753 8: 31.0982 9: 13.2264 CaloHitResponse (HB 1,1,1) 10 samples 4 presamples ADC=4, capid=1, DV ADC=6, capid=2, DV ADC=8, capid=3, DV ADC=5, capid=0, DV ADC=58, capid=1, DV ADC=54, capid=2, DV ADC=33, capid=3, DV ADC=21, capid=0, DV ADC=14, capid=1, DV ADC=9, capid=2, DV CaloSamples (analog signal) HcalElectronicsSim HBHEDataFrame (or HF, or HO)
SimHits • One SimHit is created for each: • Generator particle • Detector Unit • Nanosecond of shower development • A typical 100 GeV charged pion will have: • 30 detector cells • 75 SimHits (~1/4 with long time of flight)
CaloHitResponse FOR EACH HIT: Delay 3 ns for big hits, up to 10 ns for small hits HcalHitCorrection • Do Time Slew • Photostatistics • Shaping • Superimpose 17 photoelectrons per incoming GeV (HF hits already in p.e.) CaloSimParameterMap 14 ns peak in HB, HE, HO 2 ns peak in HF CaloVShape
Time Slew • Observed effect: small signals arrive later than large ones • Implementation: Delay is applied to each SimHit, based on expectedsignal charge • Exaggerates the effect: real signal can be a sum of many SimHits • Tuning may be needed HCAL: ~6 fC/GeV HF: ~2 fC/GeV HO uses “Slow” Others use “medium”
Calibration Databases • Digitization is designed to use calibration & condition interfaces • Gains & gain widths • Pedestals & pedestal widths • Digi encoding • Trigger primitive encoding & compression • For now, I just get hardcoded numbers, through the DB interface • Datasets will always know what conditions were used to make them • Allows a more realistic simulation of the real detector • Hot channels will be hot, & noisy channels will be noisy. • Each simulated event could be assigned to an actual run. • Allows a more realistic simulation of calibrations • Can simulate with one set of constants • Blindly try to determine calibrations • Reconstruct with derived calibrations
HcalElectronicsSim FOR EACH Analog signal: • Convert from photoelectrons to fC • Calculate from Fedor's calibrations: • 0.177 +/- 0 GeV/fC (HB, HE, HO) • 0.48 +/- 0 GeV/fC (HF) • Result is 0.32 fC/pe (HB, HE, HO) • Amplification of 2000x. • HF: 1 fC/pe for short fibers, 0.72 fC/pe for long • ORCA uses 2.3 pe/fC • Apply pedestals & pedestal noise • Again, retrieved from DB interface • 0.75 +/- 0.10 fC (HB,HE,HO) • 0.75 +/- 0.14 fC (HF) • Use Fedor's encoding Service
Trigger Primitives • TowerMapping done through geometry service • One-to-one in barrel • Energy split between two trigger towers in double-wide f endcap regions • 6 cells to one tower in HF • Energy summed by TPGCoder conditions object • 125 MeV per ADC • Output is HcalTriggerPrimitiveDigi • compressed using a HcalTPGTranscoder conditions object
Still Missing: • Zero suppression