[Lad_hallc] [New Logentry] RC Report 25 May 2025

[schmidta at jlab.org]

Logentry Text:
--
Yesterday, we resumed data taking. Not everything was running perfectly yet. The SHMS drift chamber 1 was unable to hold high voltage initially, likely because it needed more time to flush with Ar+CH3. Over time, the chamber recovered and by the middle of owl shift, it was up to full nominal HV again. (https://logbooks.jlab.org/entry/4383151). 

Unfortunately, we also found a problem with the forward-angle half of the far GEM, for which it appears that one trace has been severered, possibly during the GEM work conducted while we were down. (https://logbooks.jlab.org/entry/4382709). Because of this problem, we decided to postpone any optics calibration with the carbon multi-foil target, since the entire purpose was to establish good GEM tracks. Fixing this will require and access, and the work is high-hazard. This will be done on Tuesday at the earliest. 

GEM woes didn't end there. During swing shift, the GEMs started to cause problems for the DAQ. Initially, rebooting the MPD crate seemed to fix the issue (https://logbooks.jlab.org/entry/4382817), but after further problems (https://logbooks.jlab.org/entry/4382867), the far GEM was removed from the DAQ (https://logbooks.jlab.org/entry/4382963), and then the GEMs were removed from the DAQ entirely (https://logbooks.jlab.org/entry/4382987). 

Without the GEMs, running overnight has been very smooth. 

The question for the day is what can be done to bring the GEMs back online. For this reason, I would like to hold a short RC meeting at the usual time to make a plan.


SHIFT SUMMARIES:
DAY -> https://logbooks.jlab.org/entry/4382511
SWING -> https://logbooks.jlab.org/entry/4382760
OWL -> https://logbooks.jlab.org/entry/4383229


RUN PLAN:
We will continue production with D2, with single arm measurements once per day. Until we can do work to improve the GEMs, they will remain out of the trigger.

NOTES FOR SHIFT TAKERS:
Don't forget to enter runs on the run list google sheet.


-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
We will have our regular RC meeting today at 2:30. I will be in person at the CH conference room, but feel free to join remotely. 

Online information here -> https://logbooks.jlab.org/entry/4346862

More information will be filled on the wiki:

https://hallcweb.jlab.org/wiki/index.php?title=May_25,_2025
-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-

RUN LIST
22720 - C-hole calibration
22721 - Optics calibration (LAD was off) -  32 k events
22722 - Production (partial GEMs, SHMS DC at low HV) - 3.7M events
22723 - Production (partial GEMs, SHMS DC at low HV) - 4.7M events
22724 - Production (partial GEMs, SHMS DC at low HV) - 3.5M events
22725 - Production (partial GEMs, SHMS DC at low HV) - 3.0M events
22726 - HMS single arm (3/4 trigger) - 1.2M events
22727 - HMS single arm (Ereal) - 0.7M events
22728 - Production (partial GEMs, SHMS DC at low HV) - 27K events
22730 - Production (partial GEMs, SHMS DC at low HV) - 0.6M events
22732 - Production (partial GEMs, SHMS DC at low HV) - 0.5M events
22733 - Production (partial GEMs, SHMS DC at low HV) - 0.6M events
22735 - Production (partial GEMs, SHMS DC at low HV) - 3.8M events
22737 - Production (partial GEMs, SHMS DC at low HV) - 3.6M events
22739 - Production (partial GEMs, SHMS DC at low HV) - 0.4M events
22740 - Production (partial GEMs, SHMS DC at low HV) - 1.3M events
22741 - Production (partial GEMs, SHMS DC at low HV) - 0.6M events
22742 - Production (partial GEMs, SHMS DC at low HV) - 0.3M events
22743 - Production (no GEMs, SHMS DC at low HV) - 3.8M events
22744 - Production (no GEMs, SHMS DC at low HV) - 3.7M events
22745 - Production (no GEMs, SHMS DC at low HV) - 3.8M events
22746 - Production (no GEMs, SHMS DC at low HV) - 3.8M events
22747 - Production (no GEMs) - 3.7M events
22748 - Production (no GEMs) - 3.8M events
22750 - Production (no GEMs) - 3.3M events
22751 - Production (no GEMs) - 3.6M events
22752 - Production (no GEMs) - 3.6M events
22753 - SHMS Single Arm (3/4) - 0.5M events

---

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/4383268
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/lad_hallc/attachments/20250525/ac36fe55/attachment.htm>