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<p>Collaborators,</p>
<p>Please find the minutes <a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_October_7,_2020#Minutes">here</a>
and below.</p>
<p> -- Mark</p>
<p>_____________________________________________________</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX TOF Meeting, October 7, 2020, </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
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lang="en">
<p>Present: Mark Ito (chair), Sasha Ostrovidov, Susan
Schadmand, Simon Taylor, Tim Whitlatch, Beni Zihlmann
</p>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/XShAv015Zfb/">recording
of this meeting</a> on the BlueJeans site. Login with
your JLab credentials starting from <a rel="nofollow"
class="external free"
href="https://jlab.bluejeans.com">https://jlab.bluejeans.com</a>
to gain access.
</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_TOF_Meeting,_September_23,_2020#Minutes"
title="GlueX TOF Meeting, September 23, 2020">the
minutes from September 23</a>.
</p>
<ul>
<li> Tim reported that there were not issues with
Hot-Check Out at the end of the Summer run.</li>
<li> We reminded ourselves that the PrimEx group needs
to be aware of the need for tracking if they would
like to calibrate the TOF.</li>
</ul>
<h3><span class="mw-headline" id="Hardware_Assessment">Hardware
Assessment</span></h3>
<p>Beni led us through two of his recent entries in the
TOF log.
</p>
<ol>
<li> <a rel="nofollow" class="external text"
href="https://logbooks.jlab.org/entry/3853854">TOF
PMT signal checks</a>
<ul>
<li> Beni noted that in the table, the
next-to-next-to-last column is the set HV, the
next-to-last column is the position of the MIP
peak in the ADC integral in beam data, and the
last column is the peak voltage he saw with a
scope in the Hall after the run. Vertical 25 BOT
23B is the channel that shows up as weak in the
beam data but it looks fine on the scope. </li>
</ul>
</li>
<li> <a rel="nofollow" class="external text"
href="https://logbooks.jlab.org/entry/3854094">Follow-up
Re: TOF PMT signal checks</a>
<ul>
<li> Here the PMT current is plotted versus electron
beam current during the run. The PMT currents do
not change much from beam on to beam off as
expected, including the "weak" channel, shown in
the top line in the plot in blue. So no huge rate
sensitivity for that PMT.</li>
</ul>
</li>
</ol>
<p>The problem with the weak channel remains a mystery.
</p>
<p>Beni's next step is to look at beam data taken in raw
mode to see if that gives insight into the ratio of peak
voltage and integrated pulse area.
</p>
<p>He also noted that any channel with a high set voltage
and low ADC response is a candidate for replacement in
situ. But given what we know now, there is not a
compelling reason to dismount the TOF from the forward
carriage.
</p>
<p>And by the way, the large scope he normally uses in the
Hall is broken. He had to borrow one to do this work.
</p>
<h3><span class="mw-headline" id="Calibration">Calibration</span></h3>
<p>Beni has redone the calibration for the summer run,
including the runs taken at the end, with the fixes to
the program that he described in the last meeting. After
consulting with Sean Dobbs, all new constants have been
entered into the CCDB.
</p>
<h3><span class="mw-headline" id="TOF_NIM_paper">TOF NIM
paper</span></h3>
<p>Nothing new.
</p>
<h3><span class="mw-headline" id="Action_Item_Recap">Action
Item Recap</span></h3>
<ol>
<li> Decide on when to ship PMTs to JLab from FSU (Mark,
Paul Eugenio)</li>
<li> Prepare a complete draft of the TOF NIM paper.
(all)</li>
<li> Make a plan for TOF repair during the SAD,
including Paul in the discussion. (all)</li>
<li> Send TOF calibration skim email discussion to Beni.
(Mark)</li>
<li> Remind PrimEx folks that they need tracking if they
want to calibrate the TOF. (Mark)</li>
</ol>
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