[Halla_running] [New Logentry] Present experiment status

[jones at jlab.org]

Logentry Text:
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Yesterday was spent with a test plan to understand the 6 quads in the Moller beam line region. The OTR
viewer was essential to accomplish this. See entry https://logbooks.jlab.org/entry/3326311 with pictures from the
test plan.  The end result was that MCC found that the last quad , MQA1H04, had the wrong polarity . See
entries https://logbooks.jlab.org/entry/3326313 and https://logbooks.jlab.org/entry/3326314.

During an hall entry to look into a problem with cycling a Moller quad, MQO1H03A, ( this ended up to
be a problem with the wrong value in the database for cycling the magnet which was trying to make the
power supply go above its limit) , a water leak was found in the HRSR Q1. The water flow was closed to
Q1 and the power turned off. Probably Monday there will be an opportunity to fix this problem. I will
update people when I learn more.

The swing shift was spent centering the carbon hole target. The end result was that the target ladder needed to
be shifted by 6.5mm vertical and the beam put at 2.5mm in the horizontal. next the "raster target" or long cylinder
was put in the been and various raster sizes were tried and the T3 scaler rate was  monitored. At raster sizes of
"1x1" and "2x2" the T3 rate was a little more than cosmic rate.
It was found that at raster of "3x3" the T3 rate jumped to 4 Khz.  See entry for summary
https://logbooks.jlab.org/entry/3326454 . Efforts were made to vary the incoming beam angle but no setting was better than
others , though setting the 4AY and 4DY positions both to zero gave a 3 fold increase in the rate. So it was
decided to have the 4AY = - .5 and 4DY = +.5 and use the "2x2" raster.

 For owl shift the "optics"  target was put in place and the optics looked good.  The LH2 target
was put in place and the target reconstruction looked good with no long tails.



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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/3326557
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