[Rgc] [New Logentry] Daily RC Summary

[kuhn at jlab.org]

Logentry Text:
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Summary 3/6-7

Overall very little beam, maybe 3-4 hours of ABU total. Changed to NH3 target.

Day Shift: Accelerator down for "impromptu" maintenance day. We remove the ND3 target and install the NH3 target (15 mm dia. cell filled with the ammonia beads we used in 2022). Take a TE which is quite noisy and yields a rather small calibration constant (maybe 2/3 of what it was before; suspicion it could be ice on the bath). Preparatory work in the Hall by Yury and Sergey. Valery is doing DAQ tests.

Swing Shift: Still waiting for beam - accelerator folks are trying to phase the 4-pass separator cavities after repairing cable. Abandoned around 7:45 and start tuning for beam. Meanwhile target polarization goes up to 40% which we believe is probably closer to 60%. Beam finally comes around 9. We tune on the tagger dump and take harp scans. (See log entries). Afterwards, we take a Moller run - nearly 80% +/- 1.5% polarization. Tune beam to FC. When we are finally ready to resume data taking (11ish), adcpcal1 develops a problem. Controlled access requiring RadCon since beacon is flashing.

Owl Shift: Crate repaired (fan stack) around 1 a.m. Ask for beam - struggling with beam instabilities until about 3:45. DAQ problems until 4:10. After that data taking on NH3 starts.

Continued data taking during Day Tuesday until 9:50 - then beam goes down again for several hours to continue Separator cavity phasing work. Tornado Drill.

PLAN: Continue data taking on NH3 once beam is back. Monitor target performance (trigger bit asymmetry = consistent with 60% right now) to decide when to anneal / reverse target polarization.
Daily RC meeting at 2 -> https://clasweb.jlab.org/wiki/index.php/RGC_RC

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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/4144433
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