[Clas12_rgb] [EXTERNAL] RC meeting and run summary

[Gilfoyle, Jerry]

Hi Folks,

We're running smoothly now with the DC occupancies the outstanding issue that still needs to be be resolved. There are a couple of efforts onging to understand it and I believe we can handle the communication for that discussion via email. I don't see a compelling reason to meet face-to-face today. Let me know if you think otherwise.

Below is the summary for the last day or so.

jerry

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Summary of last day (or so) (1/11/20)

Continued production running at 35 nA to keep Region 1 DC occupancies to a minimum.

DC occupancies - Work continues to understand why the DC occupancies are higher 
   	       	 than the RGB runs in spring, 2019 and Dec, 2019. The lead suspect
		 now is still the DC gas mixture. 
	       - The staff are changing the DC gas composition to the one used in 
	         the previous RGB runs, but this process takes a while because of
		 the large volume of the buffer tanks used to hold the gas.
	       - Last night we did a run with the spring, 2019 trigger file to
	         see if that was culprit. The trigger file is innocent.
	       - Zhiwen is cooking low- and high-luminosity runs taken this week 
	         so Stepan can study the track reconstruction efficiency and 
		 compare with past results.

trigger-timing - This week we saw large oscillations in the trigger time 
	         distribution caused by 100 kHz noise associated with the injector
		 laser phase.
	       - The lead suspect here is the chopper. 
	       - The problem  was fixed by the injector group by resetting the 
	         injector parameters to their defaults. 
	       - On Friday, To get the injector working for Halls A and B 
	         simultaneously required about 6-7 hours of work. After this work
		 was completed we still saw the expected trigger-time distribution
		 and livetimes and continued production running.

MVT trips - The high voltage on some of the MVT channels tripped. We called Yuri and
     	    he fixed it remotely.

Bluejeans - New address for RC meetings: bluejeans.com/8928008153.

Upcoming
     Hall C: As mentioned above we will do a Moeller after the Wien angle change
     	     for Hall C. Will likely do the Moeller during Sunday day shift.


-----
Dr. Gerard P. Gilfoyle
Physics Department
University of Richmond, VA 23173  USA
e-mail: ggilfoyl at richmond.edu
phone:  804-289-8255