Search for TOF bad channels¶

Related to Suspicious channel in TOF1 and 2017 TOF Low Level Plots.

While investigating how to improve Time Walk calibration for TOFs, a suspicious channel was found (see here). This prompted need of quality check of all channels. In the first step, a representative run was chosen, #10248. ADC distributions for each channel were examined.

The following files contain figures with 2 plots for each channel. One represent electron event sample and the other muon event sample. For each event, exactly 1 space point reconstructed in each TOF was required. Electrons and muons were identified based on TOF1 - TOF0 time difference. Electrons were selected from [25 ns, 26 ns] and muons from [29.25 ns, 31.25 ns]. Charge ADC data were extracted from DAQ digits corresponding to the given selected event. No check or requirement was used for number of digits in each channel.

The Landau distribution convoluted with Gauss distribution (see ROOT's langaus example) was fit to the data. Only fits of histograms with more than 100 entries were attempted. Even then, many fits were not successful due to low statistics in the particle charge peak.

• individual_hists_tof0.pdf
• individual_hists_tof1.pdf
• individual_hists_tof2.pdf