BCAL Readout Segmentation Task group Meeting: Oct. 3, 2011
Contents
Meeting Info
Time:
- 1:30 JLab
- 11:30 Regina
Location:
- CC F326-327
Vid-con:
- ESNet 8542553
Agenda
Review action items from previous meeting
- Clarify the total gain of the preamp board and whether or not it is included in the existing simulation
- Identify source of large floor terms in Energy resolution plots
- Review Elton's method for choosing a value of R for a summed cell and implement it in current simulation.
New Agenda items
- BCAL Energy Resolutions (David L.)
Minutes
Participants
David L., Elton S., Beni Z., Curtis M., Zisis P., Andrei S.
BCAL Energy Resolutions
David presented slides that followed up on the energy resolution plots he showed at the previous meeting. The major concern to be addressed was the unexpectedly large floor term encountered during the first attempt to extract energy resolutions from the custom simulation he has been working on. Floor terms of around 3%-4% were seen.
A second (partial) set of simulations were done with the major stochastic effects turned off. The resulting residual energy spectra became very asymmetric (with stochastic effects turned on, distributions were symmetric). The distributions were fit to asymmetric Gaussians and the variance+uncertainty extracted from those fit parameters. The threshold was varied from 10mV to 100mV and the resolutions extracted for each. The parameters were plotted as a function of threshold and indicated a floor term still around 3-4% and flat w.r.t. threshold. The 1/E term was most strongly correlated with the threshold. It was noted that the large floor terms seemed inconsistent with previous simulations and beam test results. It was speculated that this floor term was arising from fluctuations in the leakage of energy out of the BCAL. Zisis volunteered to review the documentation to try and identify differences in those methods and the current study. David volunteered to do the same.
Also shown were some plots indicating missing energy from the current simulation. Energy missed from the BCAL (~5% at 12o) was considered roughly consistent with previous simulations. Plots were also shown indicating about 1%-1.5% of the energy was missing from the gustep/DESTEP altogether. After a brief discussion, it was agreed that this is most likely due to the particles leaving the mother volume and so their energy does not appear in DESTEP. Several suggestions were made on how to test this and David agreed to verify that this is the case.
Action Items
- Review existing documents on leakage and methods of resolution extraction to try and identify source of discrepancy between those and the current simulation study. (Zisis, David)
- Verify that the missing energy from gustep/DESTEP is due to particles leaving the mother volume (David)
- Clarify the total gain of the preamp board and whether or not it is included in the existing simulation (David)
