[Rgc] [Revised Logentry] RC Daily Summary July 2, 2022

[bueltman at jlab.org]

Logentry Text:
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The NH3 target material change went very well. 
Because of tune beam during the day we took a long TE calibration and started polarizing positively at 5:30.
(The proton polarization throughout the night with beam was hovering about 0.7.)

The beam was at the tagger dump at 6:30. 
We found that the nominal 2H01 beam position led to the beam hitting the bottom of the target cell.
We changed the raster y-offset from -0.1 to +0.5 (about +3 mm shift in vertical y).
This might be due to either the target cell being higher compared to before or the 2H01 re-calibration giving a different result.

Data taking throughout the night with semi-stable beam at 4.0 nA.
The event rate is higher compared to previous NH3 runs, from about 5 kHz to a little above 6 kHz. 
The luminosity increase might be in part due to the slightly higher beam current (usually 4.25 nA on the accelerator overview), but also because of the more densely packed target cell.

I don't think we need to have a RC meeting today.
Please let me know if we need to meet and we will schedule a zoom meeting. 




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