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<p>Folks,</p>
<p>Please find the minutes below and at</p>
<p>
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_May_31,_2018#Minutes">https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_May_31,_2018#Minutes</a></p>
<p> -- Mark</p>
<p>______________________</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX Start Counter Meeting, May 31, 2018, </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
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lang="en">
<p>Present:
</p>
<ul>
<li> <b> FIU: </b> Werner Boeglin, Mahmoud Kamel</li>
<li> <b> FSU: </b> Sean Dobbs</li>
<li> <b> JLab: </b> Thomas Britton, Mark Ito (chair),
Simon Taylor, Beni Zihlmann</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/xCY6G/%E2%80%8E">recording
of this meeting</a> on the <a rel="nofollow"
class="external text"
href="https://jlab.bluejeans.com/">BlueJeans site</a>.
Use your JLab credentials to authenticate.
</p>
<h3><span class="mw-headline"
id="Review_of_Minutes_from_the_Previous_Meeting">Review
of Minutes from the Previous Meeting</span></h3>
<p>We went over the <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_March_8,_2018#Minutes"
title="GlueX Start Counter Meeting, March 8, 2018">minutes
from the meeting on March 8</a> without significant
comment.
</p>
<h3><span class="mw-headline"
id="Calibration_and_Efficiency">Calibration and
Efficiency</span></h3>
<p>Sean went over the state of things. See <a
rel="nofollow" class="external text"
href="https://halldweb.jlab.org/wiki/images/4/40/Sdobbs_SC_May2018.pdf">his
slides</a>] for plots and details.
</p>
<p>We should nail down z-dependence of efficiency and
resolution and complete the alignment studies we
planned. Alignment parameters can be put into the
geometry as perturbations to the nominal geometry. So
far, only the CDC has done this. Sean showed a proposal
for a parametrization of the perturbations. It was
endorsed by the group.
</p>
<p>Once the resolution is settled, he would also like to
see the reconstruction report the errors on timing
measurements.
</p>
<p>He showed results from a prototype approach to getting
time resolution as a function of z. He also showed
results from the propagation time correction; there
appears to be some systematic in the calibration scheme
at the far end of the nose.
</p>
<p>Lately there was <a rel="nofollow" class="external
text"
href="https://halldweb.jlab.org/talks/2018/sc_prop_time_email_sdobbs.pdf">some
confusion about where the propagation time correction
should go in the CCDB</a>. That has been resolved now.
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