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<p>Please find the minutes below and on the <a
moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_May_30,_2017#Minutes">meeting
page</a>.</p>
<p>_________________________</p>
<p>Agenda<br>
</p>
<p>3. Calibration Status
</p>
<ol>
<li> first run calibration done</li>
<li> investigate calibration procedure identify potential
improvements (Brad)<br>
<a
href="https://halldweb.jlab.org/wiki/index.php/File:DeltaTVsPaddleNum.png"
class="image"><img alt="DeltaTVsPaddleNum.png"
src="https://halldweb.jlab.org/wiki/images/thumb/e/ea/DeltaTVsPaddleNum.png/200px-DeltaTVsPaddleNum.png"
width="200" height="121"></a> <a
href="https://halldweb.jlab.org/wiki/index.php/File:Paddle40.png"
class="image"><img alt="Paddle40.png"
src="https://halldweb.jlab.org/wiki/images/thumb/5/50/Paddle40.png/200px-Paddle40.png"
width="200" height="136"></a> <a
href="https://halldweb.jlab.org/wiki/index.php/File:Paddle18.png"
class="image"><img alt="Paddle18.png"
src="https://halldweb.jlab.org/wiki/images/thumb/5/5c/Paddle18.png/200px-Paddle18.png"
width="200" height="136"></a></li>
<li> Track position vs tof hit position very linear<br>
However, left and right side do not necessarily point to zero or
same value. <br>
<a
href="https://halldweb.jlab.org/wiki/index.php/File:Tof_trackpos_vs_tofpos_p8.jpg"
class="image"><img alt="Tof trackpos vs tofpos p8.jpg"
src="https://halldweb.jlab.org/wiki/images/thumb/e/eb/Tof_trackpos_vs_tofpos_p8.jpg/200px-Tof_trackpos_vs_tofpos_p8.jpg"
width="200" height="141"></a> <a
href="https://halldweb.jlab.org/wiki/index.php/File:Left_fit_p8.jpg"
class="image"><img alt="Left fit p8.jpg"
src="https://halldweb.jlab.org/wiki/images/thumb/1/1e/Left_fit_p8.jpg/200px-Left_fit_p8.jpg"
width="200" height="141"></a> <a
href="https://halldweb.jlab.org/wiki/index.php/File:Right_fit_p8.jpg"
class="image"><img alt="Right fit p8.jpg"
src="https://halldweb.jlab.org/wiki/images/thumb/6/6c/Right_fit_p8.jpg/200px-Right_fit_p8.jpg"
width="200" height="141"></a></li>
</ol>
<div id="mw-content-text" dir="ltr" class="mw-content-ltr" lang="en">
<h2><span class="mw-headline" id="Minutes">Minutes</span></h2>
<p>Present:
</p>
<ul>
<li> <b>FSU</b>: Sasha Ostrovidov</li>
<li> <b>JLab</b>: Thomas Britton, Brad Cannon, Mark Ito
(chair), Simon Taylor, Beni Zihlmann</li>
</ul>
<h3><span class="mw-headline" id="Calibration_Status">Calibration
Status</span></h3>
<ul>
<li> Beni reports that the first calibration pass through all
runs from Spring 17 is done. He got around the previously
reported wall-time problem by running the analyses of mean
time and time difference in parallel.</li>
<li> Brad is studying some systematics of the current
calibration procedure. He has looked at the difference between
a single-Gaussian fit (as is done presently) and and a
double-Gaussian fit to the time difference histograms. See
plots in section 3.2 of the agenda above. The difference is
only about 30 ps in the case shown, which was judged
acceptably small.
<ul>
<li> There appear to be shoulders on both sides of the
accidental peak at Δt=0 in all counters. We discussed
their origin, but did not come to firm conclusions.</li>
</ul>
</li>
<li> Beni has looked at whether there is any systematic position
dependence in the position measured in the TOF via end-to-end
timing. He compared the difference in position between charged
track projection and the TOF-determined position separately
for opposite sides of the beamline. See plots in section 3.3
of the agenda above. He sees good agreement, although there
are a few counters which show offsets, relative to charged
particle projections, of several tens of picoseconds (position
measured in units of Δt, end-to-end).</li>
</ul>
<h3><span class="mw-headline" id="Active_Dividers">Active Dividers</span></h3>
<p>The test counter is still in the Hall. Nothing new to report on
this project.
</p>
</div>
<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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