TOF performance in Run 995

Run 995 is claimed to be the best:
beam up to 220nA, FCAL trigger rate 500Hz
Average number of TOF hits per event: 7.5

Per-pulse energy of the TOF hits has an expected Landau shape for all channels. Absolute scale of the energy is arbitrary at the moment. No correction for light attenuation is done yet but most of the hits come from the middle of a few central bars. This fact together with balanced PMT gains leads to the similar Landau distributions in all channels.

Position of the hits on the TOF surface has a round distribution around the incoming beam as expected. White stripes in the center are due to the fact that half-length one-side modules are not handled properly in the reconstruction yet.

TDC and ADC occupancies also have similar shapes as expected from the hits distribution around the beam. No dead or inefficient channels are seen in the occupancies. The abundance of ADC hits over the TDC hits (factor of 2.5) tells us that ADC readout threhshold of 210 ADC counts is apparently smaller then the 30 mV discriminator threshold for TDC. We may need to adjust them at some point.

Overwhelming majority of TOF hits are in time with the trigger (i.e., within a ~50ns range around the trigger time). Such 50ns makes sense due to expected variations in the particles' time of flight and light propagations along the modules together with some unknown jitter of the trigger time itself. Percentage of out-of-time background hits is quite small.

There seems to be a problem with pedestal calibration of FADC250. Baseline for all channels is supposed to be very stable at 200+-1.5 counts. Perhaps, general DAQ is not using the same calibration file as TOF standalone DAQ was using. We need to check that. Also, proper values of NSB/NSA parameters (10/45) need to be verified for general DAQ config.