Transcript ECAL and HCAL Simulation Status

ECAL and HCAL Simulation
Status
Rick Wilkinson
Fabio Cossutti
Simulation
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Sim Hit: One ns of energy deposit in an
active volume
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Done by GEANT4 (Sunanda Banerjee)
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Depends strongly on geometry modeling
ECAL (Paolo Meridiani)
 HCAL (Jeremy Mans)
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Digitization
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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?
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Allows added realism
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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
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Noises
Pedestal
ECAL
Barrel
200 ADC
ECAL
Endcap
200 ADC
HCAL
HF
Pedestal
width
1.26 ADC
(40 MeV)
Gain Width
0.3 %
Rear non-uniformity
Front done in OSCAR
2.87 ADC 0.3 %
(150 MeV)
5 ADC
0.56 ADC 0
(0.75 GeV) (0.1 GeV)
2 ADC
0.3 ADC
0
(0.75 GeV) (0.14 GeV)
Photostatistics
Photoelectrons / GeV
1 / sqrt(N)
ECAL Barrel
2250
2.1% / sqrt(E)
ECAL Endcap
1800
2.4% / sqrt(E)
Photoelectrons / GeV
Sampling Frac.
HCAL (HB)
17
117
HCAL (HE)
17
117
HCAL (HO)
18.4
217
HCAL (HF1)
2.84
1
HCAL (HF2)
2.09
1
178
ECAL Digitization: Details
(Fabio Cossutti)
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Gain Switching (including hysteresis)
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Calibration Interface (Shahram Rahatlou)
No database access yet, just interface
 Uses gain ratios, pedestals, & widths
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Correlated Noise
Implemented with a global correlation matrix
 Currently a unit matrix
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HCAL Digitization: Details
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Layer 0: Weighting done by GEANT4 (Banerjee)
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Calibration Interface (Fedor Ratnikov)
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Time Slew (Jeremy Mans)
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Fetch pedestals, gains, & noise
For each of four capacitors in channel
Small signals delayed by ~10 ns
Correlated Noise
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Effect is big in HCAL (Michal Szleper)
Not simulated, but infrastructure exists
Trig Prims
ECAL Trig Prims (Ursula Berthon)
 HCAL Trig Prims (Jeremy Mans)
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Zero Suppression
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ECAL Selective Readout (Philippe Gras)
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Trig prim > 5 GeV: read all 25x25 crystals
Trig prim > 2.5 GeV: read 5x5 crystals
Otherwise
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HCAL Zero Suppression (Jeremy Mans)
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90 MeV threshold in barrel
450 MeV in endcap
Pedestal-subtracted amplitudes
Can store both suppressed & unsuppressed digis
Validation
ECAL
 Hits (Xingtao Huang)
 Digis (F. Cossutti)
 RecHits (Chiara Rovelli)
•30 GeV photons
•400 GeV photons
•60 GeV pions
•Neutrinos (for noise)
HCAL
•100 GeV Pions
•Hits (Salavat Abdullin)
•Digis (Dmitri Konstantinov)
ECAL Simulation Plans
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New Geometry (Brian Heltsley)
Handles material behind the crystals better
 Important for HCAL
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Study shower shape
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~1% discrepancy, maybe Cerenkov
Energy deposit inside APD