Run Coordinator report: Fall 2021 w4

RC summary, 09/29/2021 - 10/06/2021, Keigo Mizutani

This week, we accumulated PrimEx production data with several target configurations. The target works were successfully carried out twice, on Monday and Tuesday. Aside from production runs, we took special 40-min runs with hall D laser OFF for bleedthrough study twice.

We started production on Be target with chambers turned ON and with a 50 nA beam at 2:40 am on Friday, 1 October 2021. We had no beam on Wednesday and Thursday (29, 30 September) due to machine maintenance and subsequent accelerator troubles. After beam came back, we spent 3 hours for the debugging of trigger issue (a problematic FCAL FADC was replaced).

On weekend, we collected sufficient amount of data with 100 nA and 200 nA beams with chambers OFF. On Monday, we removed Be target and collected empty target data with 200 nA, 100 nA and 50 nA beams. On Tuesday, we installed LHe4 target system during the planned beam studies, and took production runs with a 200 nA beam after that. On Wednesday (October 6), we started to cool down the target cell without filling with the helium. During this cooling down, we were taking data with a 100 nA beam.

In general, data taking of this week was smooth without major issues except for the bleedthrough issue, and we successfully moved on to the final target configuration (LHe4).

Finally, I would like to thank target group members, shift crews and detector/DAQ/beamline experts.