Kaon_LT Experiment

Hello Mark and Carlos,

   I submitted the pull request.  You can see the type of diagnostic histograms the code produces here:

https://hallcweb.jlab.org/xem2/tmp/plot_tmp.htm

The only thing I am not totally sure about is the COIN DAQ Reference times for pT2 and hT1

If you load "coin_reftimes.root" in the link above (enter CUE username and password) and load you will see c6_pT and c6_hT.  

For T.coin.pT2 tdcTimeRaw and T.coin.hT1 tdcTimeRaw I am drawing the refence time as t_coin_trig_tdcrefcut.  

Do you know if that is the correct reftime cut for those channels in the COIN DAQ?  I haven't used it much. 

Cheers,

Casey Morean

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Casey,

      Carlos can double check me, but the pT1 is the reference time for slot 19 tdc

and the pT2 is for slot 20 tdc. The slot 20 has the channels like pTRIG1_ROC2 

which are used for coincidence.

      We should really define te HMS trig detector and the SHMS trig detector

for coincidence instead of this joint COIN trig detector.

Then we could set the reference time separate for the HMS channels and

SHMS. But we have been only using the SHMS channels for the coincidence.

Cheers,

          Mark

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Hi Casey,

I think pT1,pT2 (SHMS) and hT1,hT2 (HMS), are just copies we use of the reference time, but only one from each arm 

in set as the reference time in HCANA

Here is a link to a DEF-file for 50k replay I have for CaFe, were I added the reference times directly to the 50k replay ONLINE GUI

so I could monitor the reference times directly.

For SHMS:

https://github.com/Yero1990/cafe_online_replay/blob/master/DEF-files/cafe_shms50k.def#L393

For HMS:

https://github.com/Yero1990/cafe_online_replay/blob/master/DEF-files/cafe_hms50k.def#L358

I don't  remember which one is actually used, but pT1 and pT2 should not really be that different. You can plot both pT1,pT2

and check.  Same for hT1 and hT2, for HMS hodoscope reference times

** Something I noticed when plotting reference times in the online GUI is that in the 50k replay, if you have both singles and coin. triggers

enabled in the DAQ, you actually will see the reference time repeated for both singles and coincidence, and shifted by a time deltaT. 

Then you can put a cut to require the event type to be either only singles or a coin. event,  and that way you can figure out which one

you should put in the tcoin.param. Anyways, I only tried this recently, so you can also check using recent pionLT data.

Also, like Mark said, we have always been using the tcoin.param to set the t_coin_trig_tdcrefcut

from ONLY pT1.  And we should really probably add a parameter like:  t_coin_hms_trig_tdcrefcut, t_coin_shms_trig_tdcrefcut

to set an HMS and SHMS ref. time cut independently, rather than only setting.  But I wonder if that means we have to change

something in HCANA to allow these separate reference times to be applied.

Thanks,

Carlos