[Hallc_running] [New Logentry] Hall C RC Summary - October 16, 2022 - SWING and OWL Shift Leader shifts cancelled

[tjhague at jlab.org]

Logentry Text:
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<p>Ask not for whom the <s><i>bell</i></s> alarm tolls, it tolls for <s><i>thee</i></s> the SHMS Q1 magnet insulated vacuum.</p>

<p>Yesterday around 20:00, the North Linac 2K cold box tripped. During this down time, Bob Michaels continued his work on the HMS DAQ with some work to make CODA easier to start after he rebuilt it for us on Friday. It has been running smoothly since the rebuild.</p>

<p>Some misunderstandings in communication on estimated beam restoration led to OWL and DAY shift leaders being put on standby errantly. Beam was restored at 03:30 and the SL shifts were reinstated.</p>

<p>Around 06:45 it was noticed that the SHMS Q1 vacuum insulated vacuum was being lost. Shortly after, the alarms began. Magnet on-call was contacted and the situation was monitored. Around 08:30, the decision was made that a pump needed to be put on the magnet as self-restoration of the vacuum did not seem likely. A radcon survey was completed so that work could begin. The pump was attached at 10:30.</p>

<p>The problem is taking longer than anticipated to resolve. There appears to be an issue with the LN2 dropping. Around 16:30, it was decided that the magnet must be pumped overnight as the current state of the magnet indicates that there is no chance of restoration imminent. A tech will come to the hall around 07:30 tomorrow to assess the current state. Hopefully there will be improvement and we can make a more informed decision on the path forward at that point.</p>

<p>As the pump will be going overnight, Shift Leader shifts for SWING and OWL are <u><b>cancelled</b></u>. The situation will not be reassessed until DAY shift tomorrow, so there will not be beam in the hall during SWING or OWL shifts. Currently, DAY shift Shift Leader should still plan to report at 08:00 as we hope that the situation can be resolved. I will update further as we learn more.</p>

<p>Target Operators <u><b>must</b></u> still report. The target is cold and must be watched. As always, call me if you have questions or need anything.</p>

<p>Patiently(?) waiting for the vacuum,</p>
<p>Tyler (Hall C RC Oct. 12-19, 2022)</p>

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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/4060495
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