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<article id="node-1447900" class="node node-logentry article ia-n clearfix" role="article">
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<a href="https://logbooks.jlab.org/entry/4374840" rel="bookmark">Follow-up Re: Escorted Access: GEM FT XW L1 work : Turning on GEM FT XWL1 after gas leakage fix</a>
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<p class="author-datetime">
Lognumber <a href="https://logbooks.jlab.org/entry/4374840" class="lognumber" data-lognumber="4374840">4374840</a>. Submitted by <a href="https://logbooks.jlab.org/user/vidura">vidura</a> on <time datetime="2025-05-14T01:11:59-0400" pubdate="pubdate"><a href="https://logbooks.jlab.org/entries?start_date=1747195919&end_date=1747203119&book=HAGEM&book=HALOG">Wed, 05/14/2025 - 01:11</a></time>. </p>
<p class="last-update">
Last updated on <time datetime="2025-05-14T01:13:35-0400" pubdate="pubdate">Wed, 05/14/2025 - 01:13</time> </p>
<table class="field-vitals">
<tr><th>Logbooks: </th><td><a href="https://logbooks.jlab.org/book/hagem">HAGEM</a> <a href="https://logbooks.jlab.org/book/halog">HALOG</a></td></tr>
<tr><th>References: </th><td><a href="https://logbooks.jlab.org/entry/4374600">4374600 - Escorted Access: GEM FT XW L1 work</a></td></tr>
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<p>We turned off GEM XW L1 after suspecting a possible gas leakage during the early swing shift on 05/12/2025. (See the log entry made by Jacob for a detailed explanation: <a href="https://logbooks.jlab.org/entry/4373976">https://logbooks.jlab.org/entry/4373976</a>). Yesterday, 05/13/2025, in an escorted access to the hall, we found out that one of the gas inputs to a valve on this layer was loose, which was causing the gas leakage and fixed it (See here: <a href="https://logbooks.jlab.org/entry/4374600">https://logbooks.jlab.org/entry/4374600</a>). Today, during the early owl shift, after about 7 hours of gas flow, Asar requested me to turn on only XWL1. Initially, we had no beam, so I ramped it up to 500V, then 1000V, 2000V, 3000V, and 3600V. Then increased to 3625V and finally to 3650V in 10uA beam. During the ramp up I did not see any discharges or instability. The latest channel currents of this layer at 3650V with XWL0 are also comparable now. Issues seem to be fixe
d.</p>
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<div class="image-wrapper"><img view_mode="elog_email" class="image-style-plentybig" src="https://logbooks.jlab.org/files/styles/plentybig/public/2025/05/4374840/Screenshot from 2025-05-14 00-37-59.png" width="960" height="516" alt="" title="Initial step wise HV ramping-up" /></div> <div class="image-wrapper"><img view_mode="elog_email" class="image-style-plentybig" src="https://logbooks.jlab.org/files/styles/plentybig/public/2025/05/4374840/Screenshot from 2025-05-14 00-39-52.png" width="960" height="484" alt="" title="Channel currents at 3650V in 10uA beam" /></div> <div class="image-wrapper"><img view_mode="elog_email" class="image-style-plentybig" src="https://logbooks.jlab.org/files/styles/plentybig/public/2025/05/4374840/Screenshot from 2025-05-14 00-44-08.png" width="960" height="554" alt="" title="Channel currents on XWL0 in 10uA beam for comparison" /></div> </div>
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