[Hallc_running] [Revised Logentry] RC daily update May 10, 2025

[ole at jlab.org]

Logentry Text:
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Update: Sorry, I forgot to send this to the mailing list this morning.

===>>> NO RC MEETING TODAY <<<====

Original post:

We finished checkout of the hall systems during the day yesterday. Almost everything (see below) went well. The target was cooled down and condensed, and was ready at the start of swing shift. We locked up the hall at that time.

Unfortunately, the HMS Q2 power supply has kept interlocking ever since we came back from the power outage due to an issue with the quench protection sensors. Techs advised not to use the HMS over the weekend so that further troubleshooting could be done on Monday. See https://logbooks.jlab.org/entry/4372199. So, for the weekend, the HMS will stay off, and we will run with only the SHMS.

Since we closed the hall, we have been waiting for beam. We've received a little intermittent tune beam, but little else. When we did have tune beam late in the swing shift, the positions were way off, and high ion chamber rates were seen: https://logbooks.jlab.org/entry/4372432. At the morning PD meeting just now, we learned that a box power supply for part of the Hall C beamline was accidentally left off, explaining the abnormalities we saw last night. That was corrected in the morning.

Accelerator has been having great trouble delivering beam simultaneously to all halls. The problem is currently not understood, and various checks are being planned on the accelerator side for today's day shift. Additionally there is a suspected water leak in the SL which may take some time to repair. Realistically, we'll likely not get much usable beam in Hall C until late tonight. Fingers crossed.

In light of the delay with the beam, I suggest we skip today's RC meeting and meet tomorrow, depending on progress. Notes for the weekend shifts can be found here: https://logbooks.jlab.org/entry/4372233. The current run plan, which remains unchanged, is here: https://hallcweb.jlab.org/wiki/images/9/96/LAD_Runplan.pdf. We are on Section 9 in the plan.

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This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/4372704
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