[clas_members] [Revised Logentry] RC Daily Summary August 22, 2022

avakian at jlab.org avakian at jlab.org
Tue Aug 23 13:45:01 EDT 2022

Logentry Text:
8/22 (Mon) 5-Pass Beam on NH3 Target (~50% polarization)
Smooth data taking, starting from swing shift ~5PM
Overall ABU ~10h, BANU ~0.5h Total number of events accumulated ~180M
The trigger rates  and the downstream halo rates  increased by (~13%) compared to last night for the same beam current
Comparison of monitoring plots seem to indicate that the change most likely is related to either beam or target. Possible improvements of the beam quality to mitigate the hall current spikes  with some adjustments are listed in https://logbooks.jlab.org/entry/4032501
In a longer term activities there is a plan to  shield one of the viewers in the injector which may help to solve the problem completely, but it will take more down time, and current plan is to try that in the next SAD, or during/right after the winter break.
If the increase of electrons is real, and not related to additional dilution from target, we should be able to measure the same asymmetries as before. We can check the beam quality when we come back after some downtime.

Plans for today: Continue with NH3 at 4nA. Change the HWP during the Swing shift, or any predictable beam down time.

We will have the daily RC meeting today at 2:00 PM:

RC Meeting Coordinates:
Meeting ID: 160 867 4253
Passcode: 786506


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/4032789
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