Frank L. H. Wolfs
Department of
Physics and Astronomy, University of Rochester
How to get a good time-of-flight?
¥Many corrections need to be applied to go from the raw
TDC channel to a good time-of-flight:
¥TOFraw = raw FB TDC value, converted to
ns, based on FB time calibrations (TPhFBGainCalcMod). Calibrations carried out during the run (once per day), and
corrections made during DV.
¥Toffset = offset correction required to
account for the variations in cable delay (TPhTOFTimeDelayMatchingMod). Calibrations carried out using the DV
trees for each run, and corrections made during processing of PhoHit
files.
¥Tcollision = correction for jitter in the
start of the TDC by using the collision time obtained from the T0
counters. Requires calibrated T0
data, and this correction is made during processing of PhoHit files.
¥Slew = slewing correction. This correction is based on the know
threshold and the measured PMT amplitude.
Slew corrections are made during processing of PhoHit files.
