<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p>Folks,</p>
<p>Please find the minutes below and at
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_26,_2016#Minutes">https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_26,_2016#Minutes</a>
.</p>
<p> -- Mark</p>
<p>_____________________________</p>
<div id="globalWrapper">
<div id="column-content">
<div id="content" class="mw-body" role="main">
<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX TOF Meeting, July 26, 2016, </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
<div id="bodyContent" class="mw-body-content">
<div id="mw-content-text" dir="ltr" class="mw-content-ltr"
lang="en">
<p>Present:
</p>
<ul>
<li> <b>FSU</b>: Sasha Ostrovidov</li>
<li> <b>JLab</b>: Eugene Chudakov, Mark Ito (chair),
Simon Taylor, Beni Zihlmann</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/a2@C/">recording of this
meeting</a> on the BlueJeans site.
</p>
<h3><span class="mw-headline"
id="Review_of_minutes_from_the_previous_meeting">Review
of minutes from the previous meeting</span></h3>
<p>We went over <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_July_19,_2016#Minutes"
title="GlueX TOF Meeting, July 19, 2016">the minutes
from July 19</a>. No significant comments.
</p>
<h3><span class="mw-headline" id="PMT_order">PMT order</span></h3>
<p>Ardavan Ghassemi of Hamamatsu sent us <a
rel="nofollow" class="external text"
href="http://www.jlab.org/Hall-D/gluex_secure/procurements/TOF_PMT/ardavan_2016-07-22.pdf">an
email</a> cautioning us that the current PMT model
used in the TOF will be discontinued as some point soon.
He proposes a replacement model and sent along <a
rel="nofollow" class="external text"
href="http://www.jlab.org/Hall-D/gluex_secure/procurements/TOF_PMT/R13435%20Tentative%20Data%20Sheet%2020150527.pdf">a
data sheet for the R13435</a>. The new tube has a
diameter about 1 mm greater than the old.
</p>
<h3><span class="mw-headline" id="Cosmic_data">Cosmic data</span></h3>
<p>Beni led us through his plots:
</p>
<ul>
<li> looking at signal amplitude vs time difference for
1350V <a
href="https://halldweb.jlab.org/wiki/index.php/File:Amp_vs_dt_1350V_paddle11_plane2.jpg"
class="image"><img alt="Amp vs dt 1350V paddle11
plane2.jpg"
src="cid:part5.4CE906FF.7ACA5E1F@jlab.org"
srcset="/wiki/images/thumb/f/fe/Amp_vs_dt_1350V_paddle11_plane2.jpg/450px-Amp_vs_dt_1350V_paddle11_plane2.jpg
1.5x,
/wiki/images/thumb/f/fe/Amp_vs_dt_1350V_paddle11_plane2.jpg/600px-Amp_vs_dt_1350V_paddle11_plane2.jpg
2x" height="212" width="300"></a> <a
href="https://halldweb.jlab.org/wiki/index.php/File:Amp_vs_dt_1350V_paddle11_plane2_zoom.jpg"
class="image"><img alt="Amp vs dt 1350V paddle11
plane2 zoom.jpg"
src="cid:part7.6C32B0BD.B2A41155@jlab.org"
srcset="/wiki/images/thumb/f/fa/Amp_vs_dt_1350V_paddle11_plane2_zoom.jpg/450px-Amp_vs_dt_1350V_paddle11_plane2_zoom.jpg
1.5x,
/wiki/images/thumb/f/fa/Amp_vs_dt_1350V_paddle11_plane2_zoom.jpg/600px-Amp_vs_dt_1350V_paddle11_plane2_zoom.jpg
2x" height="212" width="300"></a></li>
<li> The flash250 ADC op-amp signal inverting input
causes a baseline shift that feeds back to the input
to the leading edge discriminator resulting in a miss
match between threshold setting and actual threshold.</li>
<li> other examples of amplitude vs dt paddle 18 plane
1: <a
href="https://halldweb.jlab.org/wiki/index.php/File:Amp_vs_dt_1350V_paddle18_plane1.jpg"
class="image"><img alt="Amp vs dt 1350V paddle18
plane1.jpg"
src="cid:part9.7B2468EC.5ED652BD@jlab.org"
srcset="/wiki/images/thumb/3/3a/Amp_vs_dt_1350V_paddle18_plane1.jpg/450px-Amp_vs_dt_1350V_paddle18_plane1.jpg
1.5x,
/wiki/images/thumb/3/3a/Amp_vs_dt_1350V_paddle18_plane1.jpg/600px-Amp_vs_dt_1350V_paddle18_plane1.jpg
2x" height="212" width="300"></a></li>
<li> or paddle 20 plane 1: <a
href="https://halldweb.jlab.org/wiki/index.php/File:Amp_vs_dt_1350V_paddle20_plane1.jpg"
class="image"><img alt="Amp vs dt 1350V paddle20
plane1.jpg"
src="cid:part11.DDF1C590.E7FFABBC@jlab.org"
srcset="/wiki/images/thumb/4/4f/Amp_vs_dt_1350V_paddle20_plane1.jpg/450px-Amp_vs_dt_1350V_paddle20_plane1.jpg
1.5x,
/wiki/images/thumb/4/4f/Amp_vs_dt_1350V_paddle20_plane1.jpg/600px-Amp_vs_dt_1350V_paddle20_plane1.jpg
2x" height="212" width="300"></a></li>
<li> or paddle 20 plane 2: <a
href="https://halldweb.jlab.org/wiki/index.php/File:Amp_vs_dt_1350V_paddle20_plane2.jpg"
class="image"><img alt="Amp vs dt 1350V paddle20
plane2.jpg"
src="cid:part13.D9AACDF4.83CDD6E4@jlab.org"
srcset="/wiki/images/thumb/3/3b/Amp_vs_dt_1350V_paddle20_plane2.jpg/450px-Amp_vs_dt_1350V_paddle20_plane2.jpg
1.5x,
/wiki/images/thumb/3/3b/Amp_vs_dt_1350V_paddle20_plane2.jpg/600px-Amp_vs_dt_1350V_paddle20_plane2.jpg
2x" height="212" width="300"></a></li>
<li> and the same PMT but 100V higher at 1450V: <a
href="https://halldweb.jlab.org/wiki/index.php/File:Amp_vs_dt_1450V_paddle20_plane2.jpg"
class="image"><img alt="Amp vs dt 1450V paddle20
plane2.jpg"
src="cid:part15.D80149D7.365FE002@jlab.org"
srcset="/wiki/images/thumb/f/f9/Amp_vs_dt_1450V_paddle20_plane2.jpg/450px-Amp_vs_dt_1450V_paddle20_plane2.jpg
1.5x,
/wiki/images/thumb/f/f9/Amp_vs_dt_1450V_paddle20_plane2.jpg/600px-Amp_vs_dt_1450V_paddle20_plane2.jpg
2x" height="212" width="300"></a></li>
</ul>
<p>The DC shift in the baseline at the discriminator from
the FADC can be as much as 35 mV and depends on the FADC
channel. We will need to have channel-by-channel
discriminator settings, especially when running the
tubes at lower gain.
</p>
<p>The next step is to try and look at time resolution at
new reduced voltages.
</p>
<h3><span class="mw-headline" id="Next_Meeting">Next
Meeting</span></h3>
<p>We will meet again in a week.
</p>
</div>
<div class="printfooter">
Retrieved from "<a dir="ltr"
href="https://halldweb.jlab.org/wiki/index.php?title=GlueX_TOF_Meeting,_July_26,_2016&oldid=76574">https://halldweb.jlab.org/wiki/index.php?title=GlueX_TOF_Meeting,_July_26,_2016&oldid=76574</a>"</div>
</div>
</div>
</div>
<div id="footer" role="contentinfo">
<ul id="f-list">
<li id="lastmod"> This page was last modified on 28 July 2016,
at 16:42.</li>
</ul>
</div>
</div>
<pre class="moz-signature" cols="72">--
<a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org">marki@jlab.org</a>, (757)269-5295
</pre>
</body>
</html>