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<h1 class="firstHeading">Minutes of the August 10 meeting</h1>
<h3 id="siteSub">From Lowqwiki</h3>
<p>Present: Stepan, Will, Bayram, Hovanes
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<p>On the phone: Yohann, Lamiaa
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<p>Notes by Hovanes. </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_10_meeting#TOF_update">1 TOF update</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_10_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_10_meeting#DC_calibrations">3 DC calibrations</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_10_meeting#Solenoid_current">4 Solenoid current</a></li>
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<h2> TOF update </h2>
<ul>
<li> Lamiaa did multiple iterations on run 61107 for paddle-to-paddle
calibrations. </li>
<li> She is going to apply these constants to all 5.7 GeV runs. </li>
<li> Hovanes pointed out that one needs to be careful when
calibrating TOF p2p run-by-run so that in the calibration process you
are subtracting/adding the same constants which were used during
cooking. </li>
<li> Lamiaa will cook ~15 files from 61107 for Bayram to perform
EC-timing calibrations.
</li>
<li> Everyone wished a Lamiaa good recovery.
</li>
</ul>
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<h2> EC-timing </h2>
<ul>
<li> Bayram completed EC-timing calibration for 61107 and one of the
runs from e1dvcs2.
</li>
<li> Bayram showed a <a href="http://clasweb.jlab.org/rungroups/lowq/wiki/images/b/b8/EC_TIMING_EG6_DVCS.pdf"> comparison of the eg6
EC-timing to e1dvcs2 EC-timing</a> which he did.
</li>
<li> The results are compatible, with e1dvcs2 having slightly larger
width.
</li>
<li> The INNER timing predicted by the code is on the order ~200
ps, the OUTER is ~250 ps. Stepan commented that it is a little worse
after actual cooking is done. </li>
<li> The beta peak for neutral is 2% for INNER, ~3% for outer. </li>
<li> The shift in OUTER timing for neutrals is still not understood.
Stepan is looking into this. </li>
<li> Stepan may change the code such that the EC timing comes from
INNER when there is a "good" INNER timing information. This should
improve the TOTAL timing resolution from EC.
</li>
</ul>
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<h2> DC calibrations </h2>
<ul>
<li> Seema is working oin DC calibrations from India. </li>
<li> She expects that she will be in US sometime in the end of
August. </li>
<li> Seema e-mailed the first results from DC calibration for the
first iterations. They looked reasonable. </li>
<li> The residual widths for 61107 seem to be larger that for the
other runs.
</li>
</ul>
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<h2> Solenoid current </h2>
<ul>
<li> Stepan found out that the solenoid current is read into the
cooking code from CalDB (as polarized target magnet) for a narrow run
range. For other runs it is using either the default or the value from
the TCL file. </li>
<li> This is done by hardcoding run numbers in the code.
Removing this if may affect runs which do not have valid solenoid
current values. Therefore we will simply add our run range to the range
hardcoded in the source which will not make it any worse. Hovanes will
look into this. </li>
<li> Eric, who actually could not attend the meeting, sent an
e-mail where he mentioned that there might be issues with maximum
solenoid magnet current. Apparently while we use solenoid current 534 A
during CLAS runs, the table is correct if calculated for current of
536.22 A. Therefore we might need to specify that this table is
calculated for max. current of 536.22 A when running the code. Here is
the quote from Eric's e-mail:
</li>
</ul>
<pre>According to the GEM package, the reference current is 534 A while in order to reconcile our
map with Jacques'one we would need a current of 536.22 A. This is the first difference (4 per 1000)</pre>
<ul>
<li> This needs to be investigated, either the code or the magnetic
field file needs to be modified to correctly normalize the B-field.
Also this may be a negligible effect.
</li>
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