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<p>Folks,</p>
<p>Please find the minutes below and at
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_April_20,_2017#Minutes">https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_April_20,_2017#Minutes</a>
.</p>
<p> -- Mark</p>
<p>_________________________<br>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX Start Counter Meeting, April 20, 2017; </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
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lang="en">
<p>Present:
</p>
<ul>
<li> <b>FIU</b>: Mahmoud Kamel</li>
<li> <b>JLab</b>: Thomas Britton, Mark Ito (chair),
Eric Pooser, Simon Taylor, Beni Zihlmann</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/iuZBV/">recording of
this meeting</a> on the <a rel="nofollow"
class="external text"
href="https://jlab.bluejeans.com/">BlueJeans site</a>.
</p>
<h3><span class="mw-headline"
id="Review_minutes_from_the_last_meeting">Review
minutes from the last meeting</span></h3>
<p>We looked at <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_March_23,_2017#Minutes"
title="GlueX Start Counter Meeting, March 23, 2017">the
minutes from March 23</a>.
</p>
<h4><span class="mw-headline"
id="Time-dependent_geometry_adjustments">Time-dependent
geometry adjustments</span></h4>
<p>Simon has received the latest survey spreadsheet from
Tim. The next step is to encode the data into an HDDS
file. Because of the large shifts we are seeing from run
to run, Simon will simply create a new global offset for
each run period. Shifts as large a centimeter seem to
occur; it is not understood why. The pitch of the
counter also seems to change, though a systematic study
of the shifts has not been done.
</p>
<p>Mahmoud has tried out Simon's recent changes to
matching of charged particles to the start counter. He
does not see improvement. Simon reports crashes in this
part of the code after recent tracking changes were
checked in. The precise cause is still under
investigation.
</p>
<h3><span class="mw-headline" id="NIM.2FTDR">NIM/TDR</span></h3>
<p>Eric has a draft of the NIM paper. Currently, the files
are stored in <a rel="nofollow" class="external text"
href="https://github.com/pooser/st-nim-article">his
private GitHub repository</a>. There is a <a
rel="nofollow" class="external text"
href="https://github.com/pooser/st-nim-article/blob/master/st_nim_article.pdf">PDF
file on the site</a>. At some point the paper will
migrate to the <a rel="nofollow" class="external text"
href="https://github.com/JeffersonLab/gluex_documents">gluex_documents
repository</a>.
</p>
<p>Eric is getting help with the mechanical drawings from
Stephanie Worthington. She has translated several of his
original drawings into her CAD system. Also Mahmoud has
agreed to contribute plots illustrating the calibration
procedure.
</p>
<h3><span class="mw-headline" id="Collaboration_Meeting">Collaboration
Meeting</span></h3>
<p>Mahmoud proposed not having a Start Counter talk this
time; not enough has changed to justify a dedicated
talk. He will provide slides to either Sean
(calibration) or Paul M. (analysis) for inclusion in one
of their talks.
</p>
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<pre class="moz-signature" cols="72">--
<a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org">marki@jlab.org</a>, (757)269-5295
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