[Halla_running] [Revised Logentry] RC daily update April 18 2024

[jcaylor at jlab.org]

Logentry Text:
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Tuning was complete and we started to get beam middle of swing to start beam check out. There was an issue with the Compton IC and I contacted Dave Gaskell to approve bypassing this IC. After this the functional test of the IC was completed. We started centering on the carbon hole targets but there was a 2 pass beam separator issue and beam was down for an hour and half or so. 

During the beam down time Kate was able to take some cosmic data with the Magnets on to check HV settings. They looked pretty good but she made some small changes. - https://logbooks.jlab.org/entry/4281787

Around midnight beam was restored and we were able to procede with the beam checkout. We were able to see what we thought was the carbon hole and center it well with the beam spot. Raster size was 3x3 mm and this is on the 2 mm hole - https://logbooks.jlab.org/entry/4281909

The Issues arose we went to the two different sized carbon holes and the solid carbon foil and saw the same hole as in the above log entry. Long story short, we verified the size of the holes was consistent with what is one the target screen with unrastered beam but we were not able to verify the size of the raster. Without knowing the size of the raster I was not comfortable moving forward with the run plan. Beam checkout was aborted and we right into a Moller measurement at about 4 am. This was completed by about 9 am. - https://logbooks.jlab.org/entry/4282071

After talking with experts and thinking about it more during the night it seemed like the raster size was much larger than the input 3x3mm, this was confirmed this morning. - https://logbooks.jlab.org/entry/4282190

We are currently shrinking the raster empirically and centering the carbon hole with the smaller raster. - https://logbooks.jlab.org/files/2024/04/4282250/summaryPlots_62_SBS_critical_noSBSGEMs.pdf

We will meet a 3:30 pm on the second floor of the counting house and also via zoom:

https://jlab-org.zoomgov.com/j/1616220064
Meeting ID: 161 622 0064
Passcode: 314159

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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/4282323
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