[Clas12_rgb] [EXTERNAL] Re: timelines of v15 available online - and cooking plan for DNP
Raffaella De Vita
Raffaella.Devita at ge.infn.it
Tue Sep 10 09:34:05 EDT 2019
Hi Silvia,
I checked the timelines and I have a few comments:
- for FT, hopefully the new energy calibrations that were loaded after this pass0 will fix the energy dependence; however, there is also a sizable time offset that must have arisen after the latest FTOF calibrations and/or code updates. If there are calibration files available, cooked after the last FTOF calibrations, I could try to quickly redo calibrations.
- for RF, do we still have the previous timelines to compare to? I checked a couple of runs to understand the overall offset and the sector dependence.
— I believe the overall non-zero offsets may be due to the fact that FTOF was recalibrated after RF but RF was not redone: there is an interdependence here that we probably should address modifying the calibration algorithm but that for now would be resolved by redoing RF.
— For the sector dependence, I’m not sure how to explain it with only the information in the timeline but it could probably be cured with FTOF calibration. However, checking specifically one run, 6215 where the RF offsets for sector 4 and 5 are different from the others, I can see the different offset in sector 4 but not in sector 5. Understanding what’s going on would require definitely more investigations and I would simply suggest to avoid these run ranges for now.
Best regards,
Raffaella
> On 10 Sep 2019, at 13:24, Silvia Niccolai <silvia at jlab.org> wrote:
>
> 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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