Single-paddle Delta(t) from cosmics at different HVSetup
EfficiencyThe efficiency is measured by counting the number of triggered events with a TDC hit in a proper time window for left and right PMTs independently and for both of them simultaneously.
Delta(t) resolutionDelta(t) = (tleft - tright)/2. No timing correction is done for time-walks or anything else.After HV reduction from 1500V to 1200V, Delta(t) resolution has changed by 26ps in sigma (from 161ps to 187ps), or by 17ps in RMS (from 214ps to 231ps). There was also a shift in the mean value by about 110ps. The reason for a non-Gaussian shape is unclear. Old measurement from 2009Measurements of the same paddle with the same PMTs in 2009 gave a resolution of 124ps. Note the proper Gaussian shape. The differences are:
|