<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
<!--
html{color:#555555;}body{line-height:1.5;font-family:'Trebuchet MS','Helvetica Neue',Arial,Helvetica,sans-serif;font-size:87.5%;}h1{font-size:1.6em;}h2.field-label{display:inline-block;font-size:1em;padding-right:5px;min-width:10em;margin:0.3em;}.problem_report{line-height:1.5;max-width:60em;}fieldset.problem_report.resolved
legend{background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVQ4jWP8//8/AyWAiZACd3f3/xYWFrht+f//P1a84t3e/0obff4rbfT5D1GGXR0LuoEr3+/7X3W4n2gvwA0gVSOKAcqbfPGGpImJCU45JgYGBoa7fpsZ22wLSbadgYGBgRE9GrF55Vf2BYbHjx8zYjWB0ljAcAGGExkZ/0MtwuoCggmJEBh4AzBS4pMnT/7fuXOH4dKlSwwnT56EiwcGBv43MDBgMDExYdDX12eQkZGBhAlyiC5YsOA/AwMDUXjLli3/iYoFQgAA+pSxZrXofD0AAAAASUVORK5CYII=);background-repeat:no-repeat;padding-left:18px;}fieldset.problem_report.needs_attention
legend{background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABmJLR0QA/wD/AP+gvaeTAAAA9ElEQVR42sWTvUoDQRSFv9wMKWxSBVmzdhZJIwTWv9pyLWxTpbE1kBeJPoLxBazzBgGFKNqlHXAhsITUw1y7sMpmjER0YJrDPWcO556BPzhjYPJjlhfT82LUpxcK6Lo5U0JMgcu56tXy7BQajeBDpkAcAEdz1W6uyrLdYieK2DMmKCArcqczpH/ddc0msy+OkyQJC4h3N0ynx+Q5ALtUNs5q5U+8e+R+VPFi4kjk3NZqd++qUK+TZVnYwSfAOyvejeLXt/2qVG/dYoG1dqseBNco27bs/wXKWhIDB8AhcFLAH4Bn4Al4AUqT7RVC++6mv/JVPwDi3VGzomYvyAAAAABJRU5ErkJggg==);background-repeat:no-repeat;padding-left:18px;}.problem_report div.field-items{display:inline-block;}div.date-vitals p{font-size:87.5%;}a{text-decoration:none;}.Readme a:link,.Readme a:visited,.Readme
a:active{color:red;}
-->
</style>
</head>
<body id="mimemail-body" class="elog-logentry-notify">
<div id="center">
<div id="main">
<style>
<!--/*--><![CDATA[/* ><!--*/
div.field-vitals{
margin: 0.5em 0;
}
div.field-vitals .field-type-taxonomy-term-reference {
margin: 0.1em 0;
}
article.comment {
padding-left: 10px;
}
article.comment.odd {
background-color: #EEEEEE;
}
article.comment.even {
background-color: #DDDDDD;
}
div.node-content.logentry table{
width: auto;
border-collapse: collapse;
border-spacing: 0;
border-width: 1px;
}
div.node-content.logentry th{
border: inherit;
}
div.node-content.logentry blockquote{
background-color: #FFFFFF;
}
div.node-content.logentry caption{
font-size: 1em;
font-weight: normal;
}
table.field-vitals{
margin-top: 1em;
margin-bottom: 1em;
font-size: 87.5%;
}
table.field-vitals th{
vertical-align: middle;
text-align: left;
width: 15%;
padding: 0.1em;
}
table.field-vitals td{
vertical-align: middle;
text-align: left;
width: auto;
padding: 0.1em;
}
table.field-vitals td li {
margin-left: 0;
list-style-type: none;
list-style-image: none;
}
table.downtime {
width: 30em;
margin-bottom: 1em;
border: 1px black dotted;
}
table.downtime th {
text-align: center;
}
table.downtime td {
text-align: center;
}
tr.caption th {
border-bottom: none;
}
table.downtime tfoot{
background-color:#EEEEEE;
}
div.field-name-body{
margin: 1em 0;
font-size: 110%;
}
div.date-vitals p{
margin: .1em 0;
}
article div.ctools-collapsible-container{
margin-left: -5px;
clear: both;
}
#comment-form{
margin-left: 5px;
border: graytext outset medium;
-moz-border-radius: 15px;
border-radius: 15px;
padding: 1em;
}
div.comments-form-box {
margin-top: 2em;
margin-bottom: 5em;
}
h3.comment-title {
/* display: none; */
}
p.author-datetime{
font-weight: bold;
}
/*--><!]]>*/
</style><article id="node-1367466" class="node node-logentry contextual-links-region article ia-n clearfix" role="article"><header class="node-header"><h1 class="node-title">
<a href="https://logbooks.jlab.org/entry/4294418" rel="bookmark">Plan to increase Argon in SBS GEM gas mix</a>
</h1>
</header><div class="contextual-links-wrapper"><ul class="contextual-links"><li><a href="https://logbooks.jlab.org/entry/4294418/edit?destination=email/send">Edit</a></li><li><a href="https://logbooks.jlab.org/entry/4294418/delete?destination=email/send">Delete</a></li></ul></div>
<div class="date-vitals">
<p class="author-datetime">
Lognumber <a href="https://logbooks.jlab.org/entry/4294418" class="lognumber" data-lognumber="4294418">4294418</a>. Submitted by <a href="https://logbooks.jlab.org/user/hszumila">hszumila</a> on <time datetime="2024-05-02T09:58:31-0400" pubdate="pubdate"><a href="https://logbooks.jlab.org/entries?start_date=1714654711&end_date=1714661911&book=HALOG">Thu, 05/02/2024 - 09:58</a></time>. </p>
<p class="last-update">
Last updated on <time datetime="2024-05-02T10:03:21-0400" pubdate="pubdate">Thu, 05/02/2024 - 10:03</time></p>
<table class="field-vitals"><tr><th>Logbooks: </th><td><a href="https://logbooks.jlab.org/book/halog">HALOG</a></td></tr></table></div>
<div class="logentry node-content">
<p>After studying the gas system yesterday, we have seen that the read back on the premix cylinder for the SBS GEM gas system is about 77-78% when the cylinder is 75%. This is consistent with how we had set the SBS GEM gas mix for the past year. We are currently sitting at a read back value of 73% assuming that we are at approximately 70/30 gas mix. </p>
<p>Here is our plan for this morning:<br />
1. We are turning off the SBS GEMs now.<br />
2. We will increase the SBS GEM gas mix by 2% to get something still less than the 75/25 premix (or 77% readback). This should put us around 73/27 gas mix with a readback of 75% (still less than previously).<br />
3. We are reducing the GEM HV to 3500V in the SBS GEMs. </p>
<p>After watching the gas mix ratio change for a bit (toward stability), we will turn on the GEM HV at a reduced beam current to study the ADC distributions and occupancy. We will also compare the read back currents from the previous runs at 3600V at the 70/30 mixture.</p>
</div>
<div class="attachment-box">
</div>
</article> </div>
</div>
</body>
</html>