Difference between revisions of "Run Coordinator report: fall 2022 w15"

Revision as of 09:09, 8 December 2022

The week from Oct. 30th-Dec. 7th 2022 went well. Most of the time was spent running on filled 4He and empty targets with in all a total 120.5h of ABU, or 72% of the time scheduled for this week. The beam was quite good, with the only long downtime being about 7h lost on Dec. 6th to separator and RF problems, and 10h of RF recovery on the 7th. On our side, the only significant problem was Saturday Dec. 4th around 10:15am, when we had a power supply failure for a tagger hodoscope mainframe. This compromised 120 channels on the photon high energy side of the tagger hodoscope. (The crate also services the beam halo monitor in the tagger hall beam line, so we lost those too.) Because we have no off-work-hours electronic support and we did not know initially what was wrong with the crate, fixing the problem was difficult. Many people were called (sometime not immediately successfully owing to the week-end), Richard Jones, Alex Somov, Boris Grube, Benedict Zihlmann, Eugene Chudakov, Tim Whitlatch, Hovanes and Lubomir) but non of them had a contact number for electronic support or, with the exception of A. Somov and Beni, the expertise/availability to help with the problem. This cost us about 6h of ABU. A. Somov was able to come in around noon and accessed the tagger area. However, he could not reset the crate. This was a problem since the knowledge of good crate spares and expertise to replace crates is with the electronics group. Meanwhile, Beni had come to JLab and looked for a spare in the EEL building. He diagnosed that the problem was only with the crate power supplies and had found some spare in the EEL. At 15:45, Beni went in the tagger hall to swap the power supplies. Boris was by then appraised of the problem and went in to help Beni do the replacement. After that, we could restart data taking around 17:00. Beside this major issue, we had the regular usual minor problems such as the need to restart the DAQ from time to time, changes FCal bases regularly, beam/transmission instabilities because the position/energy locks are disabled without us being informed.

Friday Dec. 2nd Last 24h Thursday was spent mostly with production on full target. It was an efficient day, with 17.8h of ABU (7am-7am). A. Somov did a low beam current test of the Active Colim. high gain in anticipation of a future TAC run. It looks good. Hall C was supposed to get back to running in mid-swing shift, which would be followed by us doing Harp scans (last ones done: Oct. 21st), but it did not happen (Hall C vacuum issue). Reports FCAL Base lockup reset Issues The FDC fadc installed Wednesday by Naomi and Lubomir needed baseline calibration. Done during swing shift (Sergei/Lubomir). cdc p_diff alarms are becoming rarer: 1 (day shift) + 1 (swing shift) + 0 reported in owl shift + 1 early riser. Short term run plan Hall C is expected to be back to running ??at some point??. Harp scan after Hall C beam is tuned (last harps done on Nov. 21st, but Transmission is fine.) FDC fadc: 20 min raw mode run with beam. Beni will analyse it and determine if the fadc needs to be replaced If beam is off, we have opportunistic work: Beam off for more than 1h: rapid access for A. Somov and Vlad for ?? Beam off for more than 2h: rapid access for Lubomir or Beni IF FDC fadc needs to be changed Beam off for more than 2h and RadCon is available, need to survey fadc to removed them from the Hall (Lubomir/Codi) Tentative longer term run plan Possible RF recovery Wednesday Dec. 7th. TAC run Luminosity study Thursday Dec. 1st Last 24h Wednesday started with production on empty target. It was an efficient day, with 17.1h of ABU (7am-7am). 9:10am-11:30 Rapid access to change fadc for FCal and FDC, and fill the target. Filled the target, from 10am-1pm. It took 3h to reach nominal density, and the first production runs are done while it was still filling. Target status indicated that it was full&ready by 11:30am. Hall A re-started running at 17:48. A consequence is that the Hall D beam energy was quite instable from 6pm (Wed.) to 1am (Thursd.), with total drift of about 14 MeV. Reports PrimEx Analysis progress (Drew) Issues The new FDC fadc is worst than the one replaced (Naomi/Lubomir). The problem is only for raw mode run. Many cdc p_diff alarms (e.g. 0.8 alarm/hour during swing and owl shifts) leading to runs often shorter than 2h (this has already been discussed several time. This is just a report). Run plan Hall C is expected to be back to running during swing shift today. 20 min test at low beam current/high Active Colim. gain to see if adjustment are needed (A. Somov)? Last harp scan was done on Nov. 21st. Should we do a new one? (Transmission is fine.)