27 Jun 2005S. Kahn -- Tof/Ckov Status1 Status of TOF and Ckov Sub- packages in G4Mice Steve Kahn 27 June 2005

27 Jun 2005S. Kahn -- Tof/Ckov Status2 TOF Geometry Parameters The TOF geometry is mostly up to date. The only current discrepancy is that the segmentation of the TOF0 station is still 8  8 not 12  12 of the current design.

27 Jun 2005S. Kahn -- Tof/Ckov Status3 TOF Digitization Response Parameters The parameters of the Tof0 scintillation plastic correspond to BC-420 instead of BC-404 that the current design uses. These numbers are only slightly different but they should be updated. Tof1,2 have always used BC- 404 plastic. The number of bits used to describe the ADC and TDC counts have not been seriously set. Now that we have some idea of the electronics we can choose something realistic.

27 Jun 2005S. Kahn -- Tof/Ckov Status4 TOF Digitization Response Algorithm Signal amplitude at PMTs: These responses are converted to digits (adc counts) Signal time at PMTs: t track is the time of the track through the scintillator t decay is an exponentially distributed scintillator decay time t PMT jitter is a gaussian distributed PMT resolution time. These responses are converted to digits (tdc counts) transit time No attempt yet to track scintillator photons

27 Jun 2005S. Kahn -- Tof/Ckov Status5 Cherenkov Systems Geometry Should be up-to-date Upstream Ckov C 6 F 14 radiator with n= PMTs 2 on top, 2 on bottom. Threshold cherenkov: 0.7 MeV for electrons 140 MeV for muons 190 MeV for pions Downstream Ckov Aerogel with n=1.03 (Should use 1.04) 12 PMTs on 12-sided polygon. Typically on electrons visible since pion threshold is > 500 MeV. Requires TOF coincidence.

27 Jun 2005S. Kahn -- Tof/Ckov Status6 Cherenkov Threshold Effect The number of Č photons generated by the passage of a charged particle through the radiator is The digitization process does where  phys includes R mirror, PMT efficiencies, etc

27 Jun 2005S. Kahn -- Tof/Ckov Status7 Photon Generation in the Cherenkov Detectors For each track that crosses the radiator with a velocity above threshold a number of photons are generated proportional to the deposited energy. We currently do not use the Cherenkov photon facility in Geant4. There is some question as to how well it works with reflective surfaces. Imaginary photons are generated in a cone (at the č angle) around the particle direction. Since all mirrors are at 45º w.r.t. the beam direction, we can position the PMTs on an imaginary plane. The č photons that intercept the PMT circles are “seen”. Note that Ckov1 has an angle of 53°. The circles should be ellipses. This has not yet been taken into account Note that Ckov2 has 12 PMTs whereas Ckov 1 has only 4 PMTS.

27 Jun 2005S. Kahn -- Tof/Ckov Status8 Tracking of Cherenkov Photons I have made changes in the Ckov DetModel to accommodate the generation and tracking of  c. I can see that they are generated, but I cannot see them tracked outside of the radiator. I am looking at this problem currently.