Run Coordinator report: fall 2022 w6
RC report for week (9/28-10/5):
The liquid helium target was filled at the start of this week (Wednesday, 9/28 at 1PM), and we began collecting production data. On Thursday there was a long maintenance day dedicated primarily to restoring RF cavities and the injector setup in preparation for Hall A coming online. When MCC attempted to restore beam to the halls after the maintenance, there was an issue with one magnet in the south linac tripping due to an overtemperature fault. The beam was down from Thursday night through Saturday morning at 10:30AM because of this incident. The beam was down for another 1.5hrs on Saturday due to an issue with one RF zone dropping out of HV. However, we were able to resume production on the LHe target on Saturday at 1PM. The beam stability was decent throughout the weekend, with trip rates staying just above the average value of 15 trips/hr. There were about 2 hours over the weekend of BANU due to two separate instances of DAQ problems (Sergey was called for both). However, at 4:20AM on Monday morning, a new magnet in the same zone of the SL as the previous problematic magnet (RSEP8) had similar issues (overtemperature fault causing the magnet to trip). Because of this issue the beam was down most of the day Monday, and was restored around midnight, Tuesday morning, after which we performed the routine harp scans and continued taking production data on the LHe target. Unfortunately, the same overtemperature issues in both of these problematic magnets reoccurred on Tuesday morning at 11AM. The relevant expert groups from the accelerator side spent most of the day Tuesday troubleshooting this problem, but were not able to diagnose the problem. MCC instead focused on sending first pass beam to Hall A only over night Tuesday, as the magnet issue only impacts fourth pass beam. The issue with the magnets was not resolved by the end of the week.
In summary, we collected 8.3B total triggers this week, all on the full LHe target. The accelerator efficiency was only about 36% due primarily to issues with magnets in the SL, and there were an additional 3.4 hours of BANU due mostly to DAQ issues and overhead from changing runs.
