Difference between revisions of "September 28, 2007 Calorimetry"
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*** Resolution Function [http://dustbunny.physics.indiana.edu/~emscherr/Simulation%2009-27-07/ResPlot.pdf] | *** Resolution Function [http://dustbunny.physics.indiana.edu/~emscherr/Simulation%2009-27-07/ResPlot.pdf] | ||
* Plans for γp→ηπp toy analysis (Mihajlo/Matt) (time permitting) [http://dustbunny.physics.indiana.edu/~mikornic/GlueX/TwoGammaFit_plots.pdf] | * Plans for γp→ηπp toy analysis (Mihajlo/Matt) (time permitting) [http://dustbunny.physics.indiana.edu/~mikornic/GlueX/TwoGammaFit_plots.pdf] | ||
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| + | == Discussion of Npe in BCAL == | ||
| + | |||
| + | Using the numbers that we have been working with for some time, which come from your group and George has frequently used for estimates, there are about 8000 photons/MeV in scintillator, 12% scintillator energy fraction, 8% fiber capture fraction in each direction, a 10% quantum efficiency for the tube, and about 40MeV/sector for normal incidence muons (should probably be more like 50MeV, taking into account that the incidence angle in the plane of the block axis and the vertical was not restricted by the cuts) the result is more like 300pe. These inputs are somewhat uncertain, but the number is not going to be off by an order of magnitude even taking into account the attenuation factor. True, the 12% scintillator fraction is measured for shower particles, not muons. These are not different by more than 10%, however. | ||
| + | |||
| + | It assumes that only thing producing deviations between the two ends for a given event is the Poisson statistics of the scintillation light detection. This seems like a reasonable starting assumption, but if I am correct, there is either something seriously wrong with our basic design assumptions listed above, or else something we are not taking into account. To get a number like 22pe/end/sector you need fluctuations that dwarf the expectations based on simple pe statistics. I have some ideas on the latter, but I want to hear if other people agree that there is a problem before launching out on that. | ||
Revision as of 14:48, 28 September 2007
Location
JLab: Cebaf Center F226
Dial-in Instructions
To connect by telephone: 1.) dial:
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2.) enter participant code: 39527048# (remember the "#")
Agenda
- Presentation of #PE Analysis (Andrei)(Media:bcal_ampl_070928a.pdf)
- Discussion of radiation hardness of lead glass (postpone)
- Update on FCAL standalone MC Simulations (Elizabeth) (time permitting)
- Plans for γp→ηπp toy analysis (Mihajlo/Matt) (time permitting) [8]
Discussion of Npe in BCAL
Using the numbers that we have been working with for some time, which come from your group and George has frequently used for estimates, there are about 8000 photons/MeV in scintillator, 12% scintillator energy fraction, 8% fiber capture fraction in each direction, a 10% quantum efficiency for the tube, and about 40MeV/sector for normal incidence muons (should probably be more like 50MeV, taking into account that the incidence angle in the plane of the block axis and the vertical was not restricted by the cuts) the result is more like 300pe. These inputs are somewhat uncertain, but the number is not going to be off by an order of magnitude even taking into account the attenuation factor. True, the 12% scintillator fraction is measured for shower particles, not muons. These are not different by more than 10%, however.
It assumes that only thing producing deviations between the two ends for a given event is the Poisson statistics of the scintillation light detection. This seems like a reasonable starting assumption, but if I am correct, there is either something seriously wrong with our basic design assumptions listed above, or else something we are not taking into account. To get a number like 22pe/end/sector you need fluctuations that dwarf the expectations based on simple pe statistics. I have some ideas on the latter, but I want to hear if other people agree that there is a problem before launching out on that.
