[Halla_running] [New Logentry] RC Daily Update

[billlee at jlab.org]

Logentry Text:
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Dear all, 
It was a very eventful day yesterday and I am very happy to inform you that the beam could be brought into Hall A again after the 4th pass separator fix! This happened halfway into the swing shift.
See what MCC had to replace for the 4th pass separator: https://logbooks.jlab.org/entry/4144059
The dark part is due to fire.  (not open flare).

The highlight recap of yesterday:
1:00 pm, we might have lost polarization due to a strange incident https://logbooks.jlab.org/entry/4144460 , but soon recovered.
7:00 pm, tune beam into hall A. 
9:00 pm, MCC did a beautiful Harpscan which got us parallel, sigma x=0.43mm, sigma y = 0.30mm, beam  https://logbooks.jlab.org/entry/4144675
10:00 pm, beam check started, but it was strange that MCC could not deliver even 1uA beam to Hall A carbon hole with a 5mm raster on, here, the beam location is set to be 0.7, 0. (center location of our target)
2:00 am, after various checks and attempts, ``` it was found that the only way Hall A could run at CW with the trip is to ramp Hall C to full current and slowly bring hall A online. ''' With this important finding, Hall A went into production mode. Thank Jiwan and Bill Henry for handling this! See log entry from MCC: https://logbooks.jlab.org/entry/4145006 , Bill made a great log entry about the switch mismatch, future target installation should double check this log entry: https://logbooks.jlab.org/entry/4144918
3:00 am, we found a mismatch between the MCC control screen and the target switch, meaning they couldn't set the beam to the He3 cell. This occurs once before! See MCC log: https://logbooks.jlab.org/entry/4144919 .
4:00 am, after consulting with MCC and checking the previous run list, we decided to go to reference cell measurement. Thanks to Bill Henry for setting this up. Took 10uA trippy beam till 9 am.
9:00 am, MCC stopped the beam. Arun and radcon took control access to address the target position switch issue. 
11:45 am, The position switch is fixed/adjusted, but the target interlock refused to engage.  Jesse and tech on-call are looking to fix the issue. 

Overall, we have production beam onsight, MCC day shifters are eager to give Hall A high-quality beam. We should be back online soon.
 
Let's have a RC meeting today at 3:30 pm:

Join ZoomGov Meeting
https://jlab-org.zoomgov.com/j/1619032184?pwd=aWhTVWxya1ZZQzA1K2ZPSTd2ZX...
Meeting ID: 161 903 2184
Passcode: 260715




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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/4145213
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