<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head>
<body>
<p>Folks,</p>
<p>Please find the minutes <a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_July_23,_2020#Minutes">here</a>
and below.</p>
<p> -- Mark</p>
<p>
</p>
<div id="globalWrapper">
<div id="column-content">
<div id="content" class="mw-body" role="main">
<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX Start Counter Meeting, July 23, 2020, </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
<div id="bodyContent" class="mw-body-content">
<div id="mw-content-text" dir="ltr" class="mw-content-ltr"
lang="en">
<p>Present: Rupesh Dotel, Mark Ito (chair), Simon Taylor,
Beni Zihlmann
</p>
<p>There is <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/5jg6WswNhsO/">a
recording of this meeting</a> on the BlueJeans site.
Use your JLab credentials to gain access.
</p>
<h3><span class="mw-headline" id="Announcements">Announcements</span></h3>
<p>The start of the run has been delayed. All shifts are
canceled until August 3rd.
</p>
<h3><span class="mw-headline"
id="Review_of_minutes_from_the_last_meeting">Review of
minutes from the last meeting</span></h3>
<p>We went over <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_July_9,_2020#Minutes"
title="GlueX Start Counter Meeting, July 9, 2020">the
minutes from July 9</a>.
</p>
<h4><span class="mw-headline" id="Run_Readiness">Run
Readiness</span></h4>
<p>Beni reported the start counter is ready to go, all
channels look good electronically. The only thing left
to check is that the data appears properly in the events
output by the DAQ. The start counter has been moved to
Ready in the Hot Check-Out list.
</p>
<h4><span class="mw-headline"
id="Pulse-Height_Data_quality">Pulse-Height Data
quality</span></h4>
<p>Rupesh performed fits for individual channels of the
start counter to the distribution of peak amplitude of
the ADC hits. He fit to a Landau distribution in a
limited region of the distribution to avoid noise hits
at threshold. Data came from a single run. He did this
for several runs. Here are the fits from channel 30:
</p>
<table>
<tbody>
<tr>
<td><a
href="https://halldweb.jlab.org/wiki/index.php/File:Sc_fit_30274.png"
class="image"><img alt="Sc fit 30274.png"
src="https://halldweb.jlab.org/wiki/images/thumb/9/9a/Sc_fit_30274.png/400px-Sc_fit_30274.png"
width="400" height="232"></a>
</td>
<td><a
href="https://halldweb.jlab.org/wiki/index.php/File:Sc_fit_31057.png"
class="image"><img alt="Sc fit 31057.png"
src="https://halldweb.jlab.org/wiki/images/thumb/0/06/Sc_fit_31057.png/400px-Sc_fit_31057.png"
width="400" height="234"></a>
</td>
</tr>
<tr>
<td><a
href="https://halldweb.jlab.org/wiki/index.php/File:Sc_fit_40856.png"
class="image"><img alt="Sc fit 40856.png"
src="https://halldweb.jlab.org/wiki/images/thumb/3/3d/Sc_fit_40856.png/400px-Sc_fit_40856.png"
width="400" height="244"></a>
</td>
<td><a
href="https://halldweb.jlab.org/wiki/index.php/File:Sc_fit_42559.png"
class="image"><img alt="Sc fit 42559.png"
src="https://halldweb.jlab.org/wiki/images/thumb/4/43/Sc_fit_42559.png/400px-Sc_fit_42559.png"
width="400" height="247"></a>
</td>
</tr>
<tr>
<td><a
href="https://halldweb.jlab.org/wiki/index.php/File:Sc_fit_71350.png"
class="image"><img alt="Sc fit 71350.png"
src="https://halldweb.jlab.org/wiki/images/thumb/5/5d/Sc_fit_71350.png/400px-Sc_fit_71350.png"
width="400" height="246"></a>
</td>
<td><a
href="https://halldweb.jlab.org/wiki/index.php/File:Sc_fit_71839.png"
class="image"><img alt="Sc fit 71839.png"
src="https://halldweb.jlab.org/wiki/images/thumb/b/b2/Sc_fit_71839.png/400px-Sc_fit_71839.png"
width="400" height="269"></a>
</td>
</tr>
</tbody>
</table>
<p>From the fit parameters, he formed the ratio of the
"width" to the most-probable value of the Landau
distribution, for each channel and for each of these
runs, and plotted them:
</p>
<p><a
href="https://halldweb.jlab.org/wiki/index.php/File:Sc_ratios.png"
class="image"><img alt="Sc ratios.png"
src="https://halldweb.jlab.org/wiki/images/thumb/d/d0/Sc_ratios.png/800px-Sc_ratios.png"
width="800" height="455"></a>
</p>
<p>There is no clear trend. We asked if he could plot the
level found in each run, averaged in some way over all
channels, as a function of beam intensity and as a
function of time so see if any trends emerge.
</p>
<h4><span class="mw-headline"
id="Copying_input_files_to_the_local_disk_on_the_farm">Copying
input files to the local disk on the farm</span></h4>
<p>Mark sent a question to Ying Chen on the subject. Here
is the email exchange:
</p>
<hr>
<p>Ying,
</p>
<p>What is the current idea for how to analyzing data from
cache in a farm job, in particular for raw data? Should
one copy the file from cache to the local disk and
analyze it from there, or should one analyze the data
directly from cache? My memory is that the advice on
this has changed in years past and I don't know which is
the current best practice.
</p>
<p>-- Mark
</p>
<hr>
<p>Mark,
</p>
<p>I think this depends on how the job access the file. If
it just read once, it should be good to read from /cache
directly.
</p>
<p>If there are many small read, we suggest user to copy
the file to local disk.</div>
</p>
<p>By default, Auger will not copy the files to local disk
when the input files from /mss (only make a link), and
files from other location (/volatile, /work, /home etc.)
will be copied to local disk. The reason behind this
design is that the files stored on /cache are larger
file, on /home, /work and /volatile are small files. But
in later 2018, I add a new attribution (copyOption =
link or copy) so user can specified copy to link the
file.
</p>
<p><a rel="nofollow" class="external free"
href="https://scicomp.jlab.org/docs/node/92">https://scicomp.jlab.org/docs/node/92</a>
</p>
<p>But I don't know whether Swif implements this option
yet. If not, user still can use the old way to copy the
file to local disk.
</p>
<p>Ying
</p>
<h3><span class="mw-headline" id="Action_Item_Review">Action
Item Review</span></h3>
<ol>
<li> Document calibration procedure (Rupesh)</li>
<li> Reproduce Beni's dark current results. (Tolga)</li>
<li> Revisit Yi's study of SiPM annealing. (Mark, Beni)</li>
<li> Look up type of SiPMs used in start counter. (Mark)</li>
</ol>
</div>
<div class="printfooter">
Retrieved from "<a dir="ltr"
href="https://halldweb.jlab.org/wiki/index.php?title=GlueX_Start_Counter_Meeting,_July_23,_2020&oldid=100608">https://halldweb.jlab.org/wiki/index.php?title=GlueX_Start_Counter_Meeting,_July_23,_2020&oldid=100608</a>"</div>
</div>
</div>
</div>
<div id="footer" role="contentinfo">
<ul id="f-list">
<li id="lastmod"> This page was last modified on 23 July 2020,
at 13:06.</li>
</ul>
</div>
</div>
</body>
</html>