[Halla_running] [New Logentry] RC daily update April 20 2024

[jcaylor at jlab.org]

Logentry Text:
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Yesterday morning the techs were able to quickly insert the steel analyzer and we were able to go back to beam permit sooner than expected. 

Jiwan also made some adjustments to the HCal coincidence window. - https://logbooks.jlab.org/entry/4283343

Alex did some work on the GRINCH VETROCs - https://logbooks.jlab.org/entry/4283398

We starting taking beam again around 10:30 am

Shortly after this it was noted by the GEM experts that there were some issues with the GEM gas mixture that could potentially compromise the GEM - https://logbooks.jlab.org/entry/4283433

GEM experts requested the GEMs be turned off until this issue could be addressed. During the afternoon the gas mixture was adjusted and extra protections were added to the alarm handler. - https://logbooks.jlab.org/entry/4283701, https://logbooks.jlab.org/entry/4283854 , https://logbooks.jlab.org/entry/4283853

While GEMs were off during the afternoon and evening some threshold scans were done and some IC calibrations were completed. - https://logbooks.jlab.org/entry/4283821 , https://logbooks.jlab.org/entry/4283689

GEMs experts began the process of very carefully setting trip point and HVs around 11 pm and we stated taking beam around 1:30 am

GEM gains were set very conservatively overnight and we took some data with productions settings. During this time GEM efficiently was nearly zero. 

There was a meeting of GEM experts and other this morning and a plan to go back to normal running efficiencies. Currently the gas mixture ratio is about to be changed and then low current data will be taken to check efficiency. It may take a couple hours for the new gas mixture to stabilize. 

Lets have a quick RC meeting this afternoon at 3:30 to discuss progress with the GEMs. 

Sorry about the multiple emails from previous days, I was editing them and it resent the emails. 

We will meet at 3:30 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/4284396
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