1. SimCalorimetry CMSSW Calorimetry Digi Simulation SimCalorimetry CMSSW Calorimetry Digi Simulation EcalSimProducers HcalSimAlgos EcalSimAlgos HcalSimProducers CaloSimAlgos Doesn’t need full geometry. Only a list of active cells. Needs to access calibration interface, to get gains, baselines, & noises Main class: CaloTDigitizer  Contains a CaloHitResponse  Creates analog signal from Sim Hits, cell parameters  Templated on an ElectronicsSim class  Adds baseline & noise, creates subdetector-specific digi

2. CaloHitResponse CaloHitResponse: Adds up analog signals from Hits è è Input: r r Calo Sim Hits r r List of Active DetIds è è Subdetector-specific parameters: r r Shaping function è è Readout-cell-specific parameters stored in a CaloVSimParameterMap r r Photomultiplier gain: u u converts SimHit units to avg. # of photolectrons r r Amp gain: u u from photoelectrons to units of analog signal u u Haven’t hooked this up to real calibrations yet è è Output: r r Analog signals (CaloSamples)

3. Electronics Sim u Templated in the CaloTDigitizer, because it needs to produce a subdetector-specific type of digi u Should use: è CaloVNoisifier: r Adds baseline, noise, gain variations r Creates digis è A Coder u HCAL implementation è Uses interface for calibration database, so it can use real gain variations, baselines, and noises, on a cell- by-cell and capacitor-by-capacitor basis è Test program makes digis from single Hits for all HCAL subdetectors

4. To-do u Profile HCAL code to find bottleneck u Add a standalone ECAL simulation è Have a Shaper & a SimParameterMap u Use real calibrations in ECAL sim u Extend to use Producers u Get cells from a real geometry u Use actual SimHits