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<p>Folks,<br>
</p>
<p>Please find the minutes of the last Start Counter meeting below
and at<br>
</p>
<p>
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_May_21,_2015">https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_May_21,_2015</a><br>
</p>
<p> -- Mark<br>
_________________________________________________________________<br>
</p>
<p>GlueX Start Counter Meeting<br>
Minutes</p>
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lang="en"><span class="mw-headline" id="Minutes"></span>
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<p>Present: Mark Ito (chair), Eric Pooser, Simon Taylor,
Beni Zihlmann
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<p><span class="mw-headline"
id="Review_minutes_from_the_April_28_meeting">Review
minutes from the April 28 meeting</span></p>
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</p>
<p>We went over <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_April_28,_2015#Minutes"
title="GlueX Start Counter Meeting, April 28, 2015">the
minutesfrom</a> last time.
</p>
<p>The bias scan was done during the Spring run. <a
rel="nofollow" class="external text"
href="http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2730">Results
were reported</a> by Mahmoud Kamel at the
Collaboration meeting last week.
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<p><span class="mw-headline"
id="Propagation_Time_Calibration">Propagation Time
Calibration</span></p>
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<p>Eric presented <a rel="nofollow" class="external text"
href="https://halldweb.jlab.org/talks/2015/ST_Propagation_Time_Update.pdf">slides</a>
on the status of the propagation time calibration. He
has tried several methods for fitting the dependence of
the time difference between two hit counters vs. the hit
position difference, where hit position is measured
along the counter and is determined by charged tracks.
He sees a few percent variation i the light propagation
velocity depending on the fit method. The values are
also significantly slower that those measured on the
bench at FIU. See his presentation for details.
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<p>We had two suggestions for things to try:
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<ol>
<li>
<p> a cut on minimum energy using the FADC data</p>
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<p> restricting the fit region to positions with high
statistics</p>
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<p><span class="mw-headline" id="Next_Meeting">Next
Meeting</span></p>
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<p>We will meet again in two weeks, on June 4.
</p>
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