In these plots, I show the raw ADC spectra for all Veto pmts. The black line is with no cuts, and the red line is when the counter has a hit in both top and bottom pmts.
During production data runs, the counters which straddle the beamline have more noise in them than the other counters. In the histgram of the TDC difference between top and bottom pmts, there are non-gaussian tails. I looked at a run at the end of the experiment when we ran the snake-scan to recalibrate HYCAL. There a low-intensity photon beam was incident on each HYCAL element. Here are four plots of the Veto TDC difference to show this noise.
I started making plots of the raw TDC and ADC position and sigma. To retrieve these values, I fit the peaks for the ADC after the first 6000 events in the A00 and for the TDC at the end of the A00 file. Currently, the study extends to run number 4901 which is toward the beginning of the experiment. Here are the plots.
All of the plots below where from an analysis of run 5353 which was taken during the HYCAL scan at the end of the experiment. The HYCAL detector was on the elevator and was moved with a low-intensity photon beam incident on it.
Hits in Veto ADC and TDC channels - see plots. The files contained 669704 events. The ADC occupancy histogram has ~16M entries which is about 666k hits per Veto pmt. The Veto TDC histogram contains 186662 hits. If I divide this number by 2 to estimate the number of top/bottom coincidences, it is 93331. The number of coincidences I find in the thrid histogram is 73824 which is 79% of my estimate.
The x,y positions from HYCAL and Veto - see plots. The plot on the right is the TDC difference vs HYCAL y-position for counter 2.
Raw ADC and TDC spectra for Veto pmts 2 and 12 - see plots.
TDC difference plots for Veto counter 2 (pmts 2 and 12 coincidences) - see plots.
TDC vs ADC plots for Veto counter 2 where I zoomed in on the region of in-time events - see plots.
