User name R. Michaels
Log entry time 17:54:57 on April25,2007
Entry number 200027
keyword=stability of timing offset T0
There was some concern that the timing is shifted when we
run at very high Qsq, leading to shifts in coinc. time D.ctimel.
The most straightforward diagnostic is the T0 of the VDCs.
See fig 1. I plot one of the chamber raw TDCs for a recent
cosmics run and for a Qsq=29 He-4 run 2645 for T5 and T6.
Ideally the T0 should be independent of trigger type and of
kinematics. If not, it's a long explanation. Anyway, there
might be shifts of order 40 channels (20 nsec) in these plots,
it's a little hard to tell. Well, at least its not crazy big.
So this is a variable to watch. I notice all the root files
have L.vdc.*.rawtime and R.vdc.*.rawtime.