Hi all,
I spot a shift in TOF tdc in run 1703 to 1713 against other runs from 1642
to 1799. please see the atatched figure. it plots ttl with ntl==0
and qwl ==-1 (average TOF tdc channel numbers after offset subtraction, in
left paddle 0, generated mostly by electrons).
the lower peak at left are runs 1703-1713, the higher peak at right are
the rest of the runs in the range quoted above.
these are all unpol deuterium runs taken during a few days running.
It could be a real shift in electronics or due to a temporary change in
offset file. No way to tell at this moment. It may be useful to save
offset values with our data ntuple. it takes just another 200 float
numbers at most into our root file.
I believe all paddles on both sector are shifted together but need to
look at TDC spectra in other paddles to confirm.
Just want to let you know this and consider possible effects.
Chi
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