[Halla_running] [New Logentry] Hall-A RC Update April 19&20, 2025

[adr at jlab.org]

Logentry Text:
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<p>Dear Collaborators, <br>We are continuing relatively smooth production running over the weekend, other than having to make somewhat regular controlled accesses to fix/restart ECal heaters and AC, and DAQ hang-ups mainly caused by GEM sparks. A more detailed breakdown of the progression of events since Friday swing shift:</p><ul><li>Friday Swing: Major downtimes due to SBS magnet tripping (https://logbooks.jlab.org/entry/4360376) - thanks Ellen and the team for coming and fixing it in Friday evening! ECal group also made an opportunistic (but it was mandatory repair) access to restart to work on ECal heaters (https://logbooks.jlab.org/entry/4360412)(https://logbooks.jlab.org/entry/4360430). Also ECal group changed ECal module HVs (https://logbooks.jlab.org/entry/4360311). After coming back to 12 uA beam current we observed very high ECal singles rate and as a result DAQ live-time dropping to ~20%. Thus, we decided to reduce the beam current to 8 uA to get live time ~90%.</l
 i><li>Sa
 turday Owl: We got beam but the shift was impeded by lots of DAQ issues. Alex worked with shift crew to fix them. Don had to make an access again at around 6:30 AM to restart AC3 (https://logbooks.jlab.org/entry/4360692). </li><li>Saturday Day: Continued taking production data relatively smoothly at 8 uA. Chandan had to make an access around noon reset AC 3 unit for ECal enclosure (https://logbooks.jlab.org/entry/4360832). </li><li>Saturday Swing: Most of the shift we took stable 8 uA beam and continued taking data. At around 10 pm Don had to make an access restart ECal AC1 (https://logbooks.jlab.org/entry/4361116). </li><li>Sunday Owl: GEM group increased FT HV to 3600V in all modules (https://logbooks.jlab.org/entry/4361179). The shift had been impeded quite a bit by DAQ issues. Kip had to make an access for to turn on ECal AC around 4:50 am. Don turned OFF air conditioner cyling process and increase ECal temperature by 5 degrees to get to an average about 2
 15 C&nbs
 p; (https://logbooks.jlab.org/entry/4361354) (https://logbooks.jlab.org/entry/4361367)</li></ul><div>Plan for today is to continue running at 8 uA on LH2. Once ECal experts are ready to alter their HVs / apply coint-match trigger (either later today or tomorrow), we plan to increase beam current hoping for higher elastic rate. </div><p>We will no have a RC meeting today. Apologies about not being able to notify yesterday. We will meet at 1:00 PM tomorrow at the usual place and via the same Zoom link. Have a great Sunday! <br><br>Best regards,<br> Anuruddha Rathnayake<br>Hall-A RC.</p>

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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/4361566
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