[Clas12_rgb] timelines of v15 available online - and cooking plan for DNP

Silvia Niccolai silvia at jlab.org
Tue Sep 10 07:24:00 EDT 2019


Dear all,
thanks to Zhiwen, Yordanka, and Sangbaek, we have now timelines online for 
the pass0/v15 cooking (ten files/run). The link is:
https://clas12mon.jlab.org/rgb/pass0/v15/tlsummary/
I encourage all detector-responsible people to please give a look at them.

Keep in mind that the latest FT calibrations from Raffaella were not yet 
included in this cooking pass.

We have spotted a problem in CND calibration, that has already been fixed, 
constants re-uploaded in ccdb.

There are still some problems in the rftime electron mean distribution:
1) the runs 6189-6222 and 6351-6399 show that weird "sector dependence" we 
had previously observed. I am not sure if the cause of this was ever full 
understood. The effect is not so big, as the maximum shift is below 100 
ps, but still, for now I prefer to exclude these two run ranges from the 
cooking for DNP.
2) there is a 25-ps "step" between the first set of runs and run 6329, 
then it goes back down for 6346, to finally go permanently back up by 25 
ps from 6420 onwards.
3) the last set of runs (6546 onward) seem to show again some sector 
dependence, albeit even smaller than for the two other sets of runs.
Raffaella and/or Daniel, do you have any suggestions/ideas? I think that 
on the RF calibration side all should be ok now, so maybe the problem is 
at the level of ftof?

I have prepared, and sent to Zhiwen, a run list for DNP including only 
"stable" regions, from the point of view of number of triggers and timing 
alignment (thus excluding the weird ranges of point 1) above).

Unless any detector expert sees the need to calibrate runs in the rest of 
the run period, and please let me and Zhiwen know before this evening if 
it's the case, I'd say we could move on with the DNP cooking.

Best regards,
Silvia



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