Run Coordinator report: Spring 2017 r3

Dear GlueX members,

I served as a run coordinator for the week Feb 15-22.

Most of the week was devoted to production data taking. We were scheduled to receive only 146 hours of beam time during the week due to 2 scheduled prolonged beam downtimes: on Friday Feb 17 from 7AM to 5PM to bring Hall A to 1-pass running simultaneously with us, and on Tuesday Feb 21 from 9AM to 5PM for beam studies. There were a total of 6 unscheduled instances of beam going down for longer than 30min during the week. The longest such downtime lasted for 2.5 hours. In total, beam was available to us for 115.1 hours, or 78.8% of the scheduled time.

Beam was very stable when available, with mostly consistent current, position and photon transfer ratio, and with significantly reduced frequency of FSD trips. One of the concerns to us was over-focusing of beam in the vertical plane, leading to a somewhat larger beam spot at the collimator. Finally, beam was re-tuned to a more acceptable divergence toward the end of my RC duties.

Out of 115.1 hours of delivered beam we used 100.1 hours (ABU), or 87% of available beam. Such usage was mostly consistent from shift to shift: beam usability was in 80%-90% range for almost all shifts as a plot in the attached file shows. Out of 15 hours lost (BANU), about 9 hours were taken to change the radiator diamond orientation every 1.5 hours. Towards the end of my RC duties we decided that it would be sufficient to change the orientation every 3 hours cutting such lost time in half.

3 hours of BANU were spent on DAQ restarts after crashes or re-initializations between the runs. However, the frequency of such restarts has been reduced significantly during the week. 1.5 hours has been spent on 3 complete harp scans, and small amount of time has been lost on things like non-responsive GUI controls, etc.

Speaking of production, we collected 10.8B production triggers during the week, reaching 25B triggers mark earlier on Wednesday morning. This constitutes about 42% of our 60B goal for the Spring'17 run, and we achieved this after about 42% of the scheduled beam time. Extrapolating the current pace of data taking as shown on another plot in the attached file, we should be able to reach 60B triggers 3-4 days before the March 22 end of the current run.

In addition to production, an empty target run and a run with target being filled were taken on Tuesday. Some time has been spent on trigger and DAQ optimizations (we were running with 30-35kHz event rate and 100% livetime most of the time). A bunch of short parasitic TRD runs were also taken during the week, and TAGM dark rates study was performed.

There were no breakdowns or significant problems with any of the detector systems during the week. Some work has been done to adjust the detector settings for higher intensity (150nA) running during the reign of the next run coordinator.

Alexander Ostrovidov