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<p>Please find the minutes <a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_October_23,_2019#Minutes">here</a>
and below.</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX TOF Meeting, October 23, 2019, </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
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lang="en">
<p>Present:
</p>
<ul>
<li> <b> FSU: </b> Jason Barlow, Edmundo Barriga, Sean
Dobbs, Paul Eugenio</li>
<li> <b> JLab: </b> Mark Ito (chair), Tim Whitlatch,
Beni Zihlmann</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/yDpbg/">recording of
this meeting</a> on the BlueJeans site. Use your JLab
credentials to access it.
</p>
<h3><span class="mw-headline" id="Announcements">Announcements</span></h3>
<p>Tim announced that the Hall will close for the upcoming
run in 4.5 weeks.
</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 reviewed the <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_October_9,_2019#Minutes"
title="GlueX TOF Meeting, October 9, 2019">minutes
from the meeting on October 9</a>.
</p>
<ul>
<li> Yesterday Sean showed some plots at the HDGeant4
meeting showing an anomaly in the monitoring
histograms. He reported that he has found the cause
and corrected it. The wrong propagation speed was
being used for Monte Carlo. Now bggen simulations for
HDG3 and HDG4 look consistent.</li>
<li> Mark issued an erratum on his statement from last
time that the cable numbering goes increases going
from positive x to negative x. The numbers do indeed
increase from negative x to positive x as Beni
asserted.</li>
</ul>
<h3><span class="mw-headline" id="Upgrade_Status">Upgrade
Status</span></h3>
<ul>
<li> Tim reported that the <b>TOF is installed and
surveyed</b>. It sits a bit high, 4 or 5 mm higher
than the previous survey.
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</li>
<li> Beni went into the Hall and <b>measured the TOF
with a tape measure</b>. from counter #3 to counter
#25 on the upstream layer he sees only an additional 3
mm from the ideal sum of the widths of unwrapped
scintillator, a testament to how well the modules were
packed into the frame. Using tracking with TOF I, he
saw a bigger effect, perhaps due to the tracking
itself. Kelly Tremblay is going to give Beni some
stickers that can be placed on the array itself as
targets for another survey. Unfortunately, this can
only be done with the upstream (horizontal) layer of
the TOF.</li>
<li> Beni told us that as of last night <b>half of the
TOF is cabled up</b>.</li>
<li> <b>PMT Mounter</b>. Paul showed <a rel="nofollow"
class="external text"
href="http://hadron.physics.fsu.edu/~eugenio/gluex/TOF-PMT-Mounter-Oct2019.pdf">pictures
of the fixture</a>, designed by Ian Winger, that can
be used to glue PMTs to light guides in situ on the
mounted TOF. Paul wants to do a test fit in the Hall
and then make 4 or 6 of these so than multiple PMT
replacement operations can be done at the same time.</li>
<li> Paul asked Mark to check on the order of more new
PMTs.</li>
<li> Beni would like to look at changing the resister
values on the voltage divider to get more voltage drop
between the photocathode and first dynode in order to
reduce the current load on the anode without
compromising timing resolution. There are some spare
PMTs in the Hall that he can use for tests.</li>
<li> <b>Halo Shield</b>. Paul showed <a rel="nofollow"
class="external text"
href="http://hadron.physics.fsu.edu/~eugenio/gluex/TOF-HaloShield2-Oct2019.pdf">a
slide with a sketch of his idea</a> for a new halo
shield in front of the TOF. He proposes a Lucite
square, 30×30 cm. After some discussion in the
meeting, he may increase this to 34.5×34.5 cm. There
is an inner wall, inside the beam hole support, to
shield the inner edges of the inner counters. The
shield needs to be installed by November 19, the date
when the carriage will be pushed up against the DIRC.</li>
</ul>
<h3><span class="mw-headline" id="Software_Issues">Software
Issues</span></h3>
<ul>
<li> Mark spoke with Hovanes Egiyan about the labeling
for the Slow Control channels, both high voltage and
discriminator scalers. Hovanes will follow the old
scheme of using the cable labels to label channels in
the GUI, but arrange them in the true geometric
relation when appropriate.</li>
<li> Mark needs to talk to David Lawrence about the
translation tables for TOF II.</li>
<li> Beni reported that the calibration software is
ready for the upgraded TOF. All changes needed for the
geometry have been made and the code can now handle
TOF I and TOF II as appropriate.</li>
</ul>
<h3><span class="mw-headline" id="TOF_NIM_paper">TOF NIM
paper</span></h3>
<p>Sasha Ostrovidov is working a draft of the testing
section of the paper in consultation with Paul.
</p>
<h3><span class="mw-headline" id="Action_Item_Recap">Action
Item Recap</span></h3>
<ol>
<li> Build a halo shield (Paul)</li>
<li> Check on PMT order (Mark)</li>
<li> Write the testing section for the NIM paper (Sasha)</li>
<li> Do a new build of the offline software when all
pull requests from Sean have been merged (Mark)</li>
<li> Figure out a backup scheme for the TOF NIM paper
(Beni, Mark)</li>
</ol>
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