[Prex] [New Logentry] RC Update 2/26/2020

[adaq at jlab.org]

Logentry Text:
--
Dear Collaborators,<br>
<br>
We will have our usual meeting upstairs in the counting house at 3:15 PM today. Bluejeans link for remote participants: https://bluejeans.com/256205934<br>
<br>
Last night beam was restored to production at 20:20. Around 23:18 FFB issues began. When we attempted dithering with RF on an autocalibration engaged causing ion chambers to trip. While FFB issues were ongoing we were limited to 130 uA for a few hours. Eventually we returned to running with FFB off at 150 uA. Crew Chief is aware and has spoken with Caryn about a solution when we're back up. Overall, little data gathered over Swing and Owl.<br>
<br>
This morning RadCon began a survey of the hall around 8:00 to take us to restricted access which we entered at 8:55. We will remain in restricted until after the accelerator safety downtime and then through the Hall A site visit for some contractors beginning around 13:30. This process may be finished around 15:00-16:00 at which time we wil ask to return to controlled and restore production beam. During this time Jack will perform some mantainence on the magnets as well as some other hall work including covering the HV lines on the GEMs (which has been completed). <br>
<br>
Outstanding Issues:<br>
<br>
1. FFB auto calibration issue when dithering with RF on (this odyssey can be followed in logs 3792135, 3792148, 3792188, 3792192, 3792199, 3792226, 3792245,  3792416, 3792422, 3792462).<br>
2. Magnet work ongoing during downtime. <br>
<br>
Resolved Issues:<br>
<br>
1. GEM HV circuit covered (log 3792432).<br>
<br>
Best,<br>
<br>
Scott Barcus <br>
(current Hall A Run Coordinator signing off)<br>


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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/3792491
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