Run Coordinator report: fall 2022 w3

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During this week we were scheduled for 158 hours of beam, of which 78%, or 123.3 hours were used (ABU). The accelerator efficiency was particularly good this week, perhaps in thanks to only Halls B and D taking beam for most of the week (Hall A was offline all week, and Hall C went offline on Friday). During the maintenance day on Wednesday (Sep. 7), the target was changed from Beryllium to the liquid He-4 target (the primary physics target for PrimEx-eta). In addition, 2 FCAL bases and 1 PMT were replaced, and a new FCAL HV scan was performed for calibration. We lost about 1.5 hours of available beam time after the maintenance day had ended while an issue with a connector cable for the start counter was being fixed. Once that work was done, we moved the Hall to beam permit, began ramping up the solenoid current, and began filling the helium target. At 2:42am on Thursday morning, the first production run at the nominal solenoid current and full target was started. Later on Thursday morning, Sasha implemented a new, low-energy threshold trigger for the FCAL and a second FCAL HV scan was performed (a new scan was needed with the solenoid turned on). We continued with these settings, taking 2 hour runs until Monday morning when the target was emptied. There were a few short beam down-times, most notably a 5 hour period in the early hours of Monday morning where a CPS breaker had to be replaced. We collected raw-cosmic data whenever there was no beam for more than 1 hour. In total we collected 13B triggers on the filled helium target. After the target was emptied on Monday morning, we took a 7-hour long TAC run to measure the PS acceptance. It was important to do this TAC run while Hall C was down and there was no bleedthrough. Sasha performed an initial analysis of the data and found the PS acceptance to be consistent with the previous PrimEx run in Fall 2021. After the TAC run was completed, we took production data at 200nA on the empty target to use for background subtraction until Wednesday morning when the beam was turned off for another maintenance day. In total we collected 1.8B triggers on the empty target, and based on the number of PS triggers collected, about 28% of the photon flux used for production data for the week was spent on the empty target (72% for full target).