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<p>Please find the minutes below and on the web in the <a
moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_June_1,_2017#Minutes">usual
location</a>.</p>
<p>____________<br>
</p>
<span class="mw-headline" id="Minutes"></span>
<h2><span class="mw-headline" id="Minutes">Minutes</span></h2>
<p>Present:
</p>
<ul>
<li> <b>FIU</b>: Werner Boeglin, Mahmoud Kamel</li>
<li> <b>JLab</b>: Thomas Britton, Mark Ito (chair), Eric Pooser,
Simon Taylor</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/sXjGC/">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="Announcements">Announcements</span></h3>
<p>Thomas mentioned that he and Dmitry have started developing a new
3D event display programs. He encouraged us to start thinking
about how we would like to visually represent the start counter
and its hits.
</p>
<h3><span class="mw-headline"
id="Review_minutes_from_the_last_meeting">Review minutes from
the last meeting</span></h3>
<p>We went over the <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_April_20,_2017#Minutes"
title="GlueX Start Counter Meeting, April 20, 2017">minutes from
the meeting on April 20</a>.
</p>
<p>Most of the discussion was on geometry.
</p>
<ul>
<li> The current geometry is based on an idealized geometry from
before construction was completed. It is does not reflect the
details of the support structure as built.</li>
<li> There are small rotations and translations done in the HDDS
XML file to make the adjustments suggested by surveys.</li>
<li> There are accurate engineering drawings that we can use to
bring the geometry closer to reality.</li>
<li> Werner pointed out that if we want to do studies of
acceptance, we will need to do studies of efficiency as a
function of non-ideal displacements/rotations. It would be great
to have a parametric way of achieving this.</li>
</ul>
<h3><span class="mw-headline" id="NIM.2FTDR">NIM/TDR</span></h3>
<p>A complete draft of the NIM paper is done. The folks at FIU are
reviewing the text and creating new figures for it based on Spring
2016 data.
</p>
<h3><span class="mw-headline" id="Calibration">Calibration</span></h3>
<p>Mahmoud has been working on measuring attenuation as function of
position using data. The constants we have been using for
reconstruction thus far are based on bench measurements at FIU.
See <a rel="nofollow" class="external text"
href="https://halldweb.jlab.org/talks/2017/SC_Meeting_6_1_2017.pdf">his
slides</a> for details and plots.
</p>
<p>He measures the position of the minimum ionizing peak as a
function of z in the start counter as predicted by charged
particle tracks. The overall behavior is consistent with what we
expect from the bench measurements. There were suggestions for
improvements including for example, using finer bins in z.
</p>
<pre class="moz-signature" cols="72">--
Mark Ito, <a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org">marki@jlab.org</a>, (757)269-5295
</pre>
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