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<p>Colleagues,</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,_September_6,_2016#Minutes">https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_September_6,_2016#Minutes</a>
.</p>
<p> -- Mark<br>
</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX TOF Meeting, September 6, 2016, </span><span
class="mw-headline" id="Minutes">Minutes</span></h2>
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<p>Present:
</p>
<ul>
<li> <b>JLab</b>: Eugene Chudakov, Mark Ito (chair),
David Lawrence, Simon Taylor, Beni Zihlmann</li>
</ul>
<h3><span class="mw-headline"
id="High_Intensity_Running_Issues_with_the_TOF">High
Intensity Running Issues with the TOF</span></h3>
<p>David showed <a
href="https://halldweb.jlab.org/wiki/images/0/08/20160906_simulation.pdf"
class="internal" title="20160906 simulation.pdf">slides</a>
illustrating the need to reduce the data volume from the
TOF at high rate. The slides were from the Level 3
review.
</p>
<p>The per crate limit is 1 Gbit/s as presently
configured. We could upgrade the NIC to give 10 Gbit/s,
but the VME backplane would limit us at about 1.5
Gbit/s. Crates TOF1 (with FADCs) and TOF2 (with TDCs)
are two of the big contributors relative to other crates
in the system. The amount of data can be reduced by
tightening timing windows, enough to operate at high
rates from a bandwidth perspective. For the TDCs the
window is currently several microseconds wide. The
reduction possible for the FADCs from time window
tightening is not as great. Beni is afraid that raising
the sparsification threshold may not do to much good; a
lot of the hits are real particles. To get to high rate,
we may have to upgrade the NIC for the flashes.
</p>
<p>Eugene pointed out that the central part of the TOF may
not be usable at high rate anyway. That needs to be
studied, and alternative approaches explored.
</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 briefly looked at <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_August_23,_2016#Minutes"
title="GlueX TOF Meeting, August 23, 2016">the minutes
from August 23</a>. Brad Cannon is meeting with Mark
and Beni weekly now, with the exception of this week; he
is away on travel.
</p>
<h3><span class="mw-headline"
id="TOF_Analysis_Status_and_Run_Plan">TOF Analysis
Status and Run Plan</span></h3>
<p>Beni reviewed progress and plans for developing new
high voltage set-points.
</p>
<ul>
<li> The analysis of HV scan runs, 10838-10845, 10646,
and 10648 is now complete. The outer counters look to
be efficient at 1200 V or perhaps a bit less. The
picture from the inner counters is not as clear, but
the low voltage points in the scan show voltage
settings comparable to those of the outer counters.</li>
<li> The four hours of data used by the HV scan provided
sufficient data for gain calibration and determining
HV set points. We have asked for six hours for this
run. We should run at nominal beam intensity to see if
any problems with rate are still present at lower
voltage.</li>
<li> Beni plans to run at a variety of fixed voltages
for all tubes to simplify operations. Recall that with
the Spring 2016 scan, voltages were adjusted with
reference to their nominal value.</li>
</ul>
<h3><span class="mw-headline" id="CAEN_TDC_calibration">CAEN
TDC calibration</span></h3>
<p>Beni reminded us that we have not heard any recent news
about the calibration to correct for the CAEN TDC system
clock running at 41.7 MHz rather than 40 MHz. We need to
look into what the plans are for this activity and
schedule it.
</p>
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