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<p>Folks,</p>
<p>Please find the minutes <a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_June_3,_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, June 3, 2020, </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
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lang="en">
<p>Present: Paul Eugenio, Mark Ito (chair), Susan
Schadmand, Simon Taylor, Beni Zihlmann
</p>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/KXYRM/">recording of
this meeting</a> on the BlueJeans site. Use your JLab
credentials to gain access.
</p>
<h3><span class="mw-headline" id="Announcements">Announcements</span></h3>
<p>The lab has a plan in place for starting to re-open and
it has been submitted to DOE. No announcement of a date
when things will start happening.
</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,_May_6,_2020#Minutes"
title="GlueX TOF Meeting, May 6, 2020">the minutes
from May 6</a>.
</p>
<ul>
<li> Beni would like to re-do his position study using
the reverse Kalman filter. Simon has given him
examples of how to use it.</li>
<li> Paul reports that the shop at FSU is back working
on fabrication of the six units of
PMT-replacement-glue-joint holders. He was wondering
if we had candidates for swapping out. He reminded us
that we have a cache of new tubes at FSU. Beni has a
candidate that shows strange pulse shape and low
amplitude. Increasing the HV on this channel did not
help much. He is afraid that this may be the PMT that
seemed to have a loose mechanical connection to the
light guide. Beni would like to take raw mode data
during the upcoming run to evaluate other candidates
for replacement via their pulse shape characteristics.
</li>
</ul>
<h3><span class="mw-headline" id="TOF_energy_calibration">TOF
energy calibration</span></h3>
<p>Beni led us through his recent work on the energy
calibration. He is reviewing the current procedure, both
for calibration and the reconstruction algorithm that
uses the calibration, and making improvements. Please
see <a rel="nofollow" class="external text"
href="https://halldweb.jlab.org/talks/2020/tofecal.pdf">his
slides</a> for the details.
</p>
<p>In summary, he is able to find peak values of the
Landau distribution for minimum ionizing particles in
bins of position along the counter for each channel.
Position is determined by end-to-end timing using the
ADCs themselves. He can then extrapolate the pulse area
to that which comes from the middle of the counter (or
the end of the counter for single-ended counters) and
find the conversion constant to energy, where energy is
determined from Monte Carlo.
</p>
<p>He proposes that the TOF reconstruction should report
the energy found in each layer of a TOF point, rather
than the average of the two layers in the case of two
double-ended counters. It turns out the currently, if
the contribution of one of the layers is from a
single-ended counter, that layer is ignored in the
reported energy.
</p>
<p>This is work in progress.
</p>
<h3><span class="mw-headline" id="TOF_NIM_paper">TOF NIM
paper</span></h3>
<ul>
<li> Sasha Ostrovidov has recently added to the section
on testing.</li>
<li> Paul has some changes that he needs to add to
Overleaf.</li>
<li> Beni would like to review the section he wrote on
calibration. He suspects that procedures have improved
since the original draft was written.</li>
</ul>
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