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ECAL and HCAL Simulation Status. Rick Wilkinson Fabio Cossutti. Simulation. Sim Hit : One ns of energy deposit in an active volume Done by GEANT4 ( Sunanda Banerjee ) Depends strongly on geometry modeling ECAL ( Paolo Meridiani ) HCAL ( Jeremy Mans ). Digitization.
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ECAL and HCAL Simulation Status Rick Wilkinson Fabio Cossutti
Simulation • Sim Hit: One ns of energy deposit in an active volume • Done by GEANT4 (Sunanda Banerjee) • Depends strongly on geometry modeling • ECAL (Paolo Meridiani) • HCAL (Jeremy Mans)
Digitization • Digitization includes: pulse shape, pileup, amplification, noise, ADC encoding, trig prims, zero suppression • CMSSW Digitization has details not in ORCA • Common framework for all systems (Wilkinson) • ECAL (Cossutti, P. Govoni, Wilkinson) • HCAL (Fedor Ratnikov, Wilkinson) • Preshower (Chia-Ming Kuo)
Digitization using Calibration? • Allows added realism • Make hot channels hot, noisy channels noisy • Allows blind test of calibration techniques • Simulate the data with one set of constants • Use derived calibration for reconstruction
ECAL Digitization: Details(Fabio Cossutti) • Gain Switching (including hysteresis) • Calibration Interface (Shahram Rahatlou) • No database access yet, just interface • Uses gain ratios, pedestals, & widths • Correlated Noise • Implemented with a global correlation matrix • Currently a unit matrix
HCAL Digitization: Details • Layer 0: Weighting done by GEANT4 (Banerjee) • Calibration Interface (FedorRatnikov) • Fetch pedestals, gains, & noise • For each of four capacitors in channel • Time Slew (JeremyMans) • Small signals delayed by ~10 ns • Correlated Noise • Effect is big in HCAL (Michal Szleper) • Not simulated, but infrastructure exists
Trig Prims • ECAL Trig Prims (Ursula Berthon) • HCAL Trig Prims (Jeremy Mans)
Zero Suppression • ECAL Selective Readout (Philippe Gras) • Trig prim > 5 GeV: read all 25x25 crystals • Trig prim > 2.5 GeV: read 5x5 crystals • Otherwise • 90 MeV threshold in barrel • 450 MeV in endcap • HCAL Zero Suppression (Jeremy Mans) • Pedestal-subtracted amplitudes • Can store both suppressed & unsuppressed digis
Validation ECAL • Hits (Xingtao Huang) • Digis (F.Cossutti) • RecHits (ChiaraRovelli) • 30 GeV photons • 400 GeV photons • 60 GeV pions • Neutrinos (for noise) • HCAL • Hits (Salavat Abdullin) • Digis (Dmitri Konstantinov) • 100 GeV Pions
ECAL Simulation Plans • New Geometry (Brian Heltsley) • Handles material behind the crystals better • Important for HCAL • Study shower shape • ~1% discrepancy, maybe Cerenkov • Energy deposit inside APD