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<h1 class="firstHeading">Minutes of the August 17 meeting</h1>
<h3 id="siteSub">From Lowqwiki</h3>
<p>Present: Stepan, Bayram, Dave, Carlos, Hovanes
</p>
<p>On the phone: Eric, Yohann, Raphael, Lamiaa
</p>
<p>Notes by Hovanes. </p>
<p><br>
</p>
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<h2>Contents</h2>
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<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_17_meeting#TOF_status">1 TOF status</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_17_meeting#EC_timing">2 EC timing</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_17_meeting#Hodoscope_status">3 Hodoscope status</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_17_meeting#Solenoid_current">4 Solenoid current</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_17_meeting#Other">5 Other</a></li>
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<h2> TOF status </h2>
<ul>
<li> Lamiaa is doing second the third iteration, and it is nearly
complete. </li>
<li> She keep track of the calibrations at <a href="http://www.jlab.org/%7Eelfassi/eg6/calib/tof/check/">JLab TOF page.</a> </li>
<li> She was not able to finish it this week because of the power
outage in Cebaf Center last weekend. </li>
<li> Stepan noticed some inconsistencies in the resolutions for
run 61107. The &sigmas; for electrons from the
"scres_ch7el61107.eps" of the widths and the RF-offset plot did not
agree well. Lamiaa thinks it is because when fitting slices there is
not enough statistics and it yields larger values for the widths from
the fit.
</li>
<li> Lamiaa thinks she will finish this week. But she will need
help identifying the run ranges to which the p2p constants need to
apply.
</li>
</ul>
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<h2> EC timing </h2>
<ul>
<li> Lamiaa cooked run 61107 with the new TOF constants for Bayram.
(EC timing for 61195 has already been done).
</li>
<li> Bayram calibrated 61107 as well. The <a href="http://clasweb.jlab.org/rungroups/lowq/wiki/images/e/e0/EC_TIMING_61107.pdf"> comparison plots</a>
looked good. </li>
<li> Stepan suggested to make summary tables with the relevant
numbers, like resolutions for layers, peak positions, beta position and
widths. </li>
<li> Hovanes suggested to make the plots wider to fill the page more
efficiently. It would make it easier to see.
</li>
</ul>
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<h2> Hodoscope status </h2>
<ul>
<li> Will was not present because his classes started, but Carlos
said that he got the code from M. Yurov and he already extracted the
pedestals from the pedestal runs using Mikhail's package. </li>
<li> Carlos was not sure how to extract the gains. He did not
show plots bu he described the eg6 ADC to be much "cleaner" than what
e1dvcs/eg1dvcs had not exhibiting single or double photoelectron peaks.
</li>
<li> Will will probably be here next week and show some of the plots.
</li>
</ul>
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<h2> Solenoid current </h2>
<ul>
<li> Hovanes <a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Problems_with_solenoid_current_in_Pass0v0_cooking"> looked into
the issue of solenoid current for eg6</a>. </li>
</ul>
<dl>
<dd>
<dl>
<dd> Pass0 v0 cooking was done with essentially solenoid current
set to zero for DC tracking. </dd>
<dd> DC currently tracking uses RUN_CONTROL->currents->ptm
CALDB item which was not set correctly and was not used either.
</dd>
<dd> RTPC uses RUN_CONTROL->currents->solenoid , although
currently it is hardcoded in <i>gem/gem_init_c.c</i>.
</dd>
</dl>
</dd>
</dl>
<ul>
<li> We decided to use RUN_CONTROL->currents->solenoid for both
DC and RTPC tracking. Hovanes will do that. </li>
<li> Hovanes will also correct the current units in the CALDB for
solenoid to mA. </li>
<li> It was also suggested that we need to use the same magnetic
field file for both DC and RTPC tracking. </li>
<li> The normalization issue is still not fully understood. Hovanes
will look into the code more. </li>
<li> We may need to check the sign of the current by cooking the
same set of files with positive and negative fields and check for
instance that the elastic scattering events have back-to-back tracks
(δφ=180<sup>o</sup>). At this point we believe that the positive sign
is the correct one.
</li>
</ul>
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<h2> Other </h2>
<ul>
<li> Yohann showed a plot which he got by cooking a 1.2 GeV run,
but on the electron momentum spectrum he got the quasielastic peak at
1.3 GeV . </li>
<li> One of the possibilities was that he used 2100 Amps for the
torus current instead of 1900 Amps. Yohann will check the Tcl file to
check the setting he used when cooking this run.
</li>
</ul>
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