[Halla_running] [New Logentry] Status update

[sanghwa at jlab.org]

Logentry Text:
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Yesterday, Moller measurement was done during the DAY shift. The measurement reproduced the previous one, measuring different polarization by ~2% for IHWP IN and OUT. Similar difference was observed from Compton. See details from: https://logbooks.jlab.org/entry/3722119, https://logbooks.jlab.org/entry/3722134
After the Moller measurement, we did detector rate study and Qsq measurements. Had two escorted access at the beginning and end to switch the detector mode and adjusting threshold for ComptonCentralRate. Preliminary plots for the Qsq measurements are posted, from the quick analysis they look stable for different targets. Also took data with Carbon and 40Ca. 

MCC started restoring the beam for the production running around midnight. Comtpon experts took 20min run without target at the beginning. However we observed higher compton background rates (< 3 - 3.5kHz ). We requested MCC to steer the beam a bit around the Compton. It improved a bit, but still higher than before. We will address this when the beam is restored after Wien flip.

Beam has been taken away this morning to prepare the planned Wien flip. A series of work that are planned:
- Yves's benchmark measurement (making snapshot before Wien flip (fopt, Harp scan...))
- Mott measurement 
- MCC access to fix a viewer, Caryn will check IHWP and PC at the injector table
- Wien flip and Mott measurement, PQB check

So... for the whole thing, it will take about a shift. While the injector experts work on the Mott measurement followed by the access, we will have an escorted access to reset Compton laser amp interlock (already arranged with MCC).

We will have a daily experiment meeting at 3:30 (2nd floor CH). Bluejeans connection information is:
Bluejeans Meeting ID: 256 205 934 (Direct link: https://bluejeans.com/256205934


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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/3722382
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