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<h1 class="title">BTeam 2010-12-15</h1>
<div class="outline-2">
<h2 id="sec-1">1 2010-12-22 Wed 14:00 BTeam Meeting Agenda</h2>
<div class="outline-3">
<h3 id="sec-2">1.1 Optics-on-Call Report: Tief/Yuhong Zhang</h3>
</div>
<div class="outline-3">
<h3 id="sec-3">1.2 Beam Studies Report</h3>
<div class="outline-4">
<h4 id="sec-4">1.2.1 Prebuncher module swap, injector retune</h4>
<p>To reduce 9.5 kHz noise when running prebuncher above 2.
Was planned for 12/16.
</p>
</div>
<div class="outline-4">
<h4 id="sec-5">1.2.2 RF Recovery: Ron</h4>
</div>
<div class="outline-4">
<h4 id="sec-6">1.2.3 Accelerator/Engineering Holiday Party
Report</h4>
</div>
<div class="outline-4">
<h4 id="sec-7">1.2.4 Take multiharp data in arcs 1 and 2:
Benesch</h4>
<p>Don't need more data at present before further offline
analysis.
</p>
</div>
<div class="outline-4">
<h4 id="sec-8">1.2.5 NL Pathlength: All</h4>
</div>
</div>
<div class="outline-3">
<h3 id="sec-9">1.3 Beam Studies Planning</h3>
<div class="outline-4">
<h4 id="sec-10">1.3.1 Arc9 Transport: Roblin</h4>
<p><a
href="http://devweb.acc.jlab.org/CSUEApps/atlis/task/10511">ATLis
10511</a>: Planned for 12/21, deferred to 12/23 first
thing in morning.
</p>
</div>
<div class="outline-4">
<h4 id="sec-11">1.3.2 Mott Measurements: Grames</h4>
<p><a
href="http://devweb.acc.jlab.org/CSUEApps/atlis/task/10588">ATLis
10588</a>: Planned for 12/21, deferred to 12/23 first
thing in morning.
Planned for 12/23 daytime after shutdown of rest of facility
except
for NL.
</p>
</div>
<div class="outline-4">
<h4 id="sec-12">1.3.3 Adjust FFB/FF gains to minimize noise in
hall C: Benesch/Suleiman</h4>
<p><a
href="http://opsweb.acc.jlab.org/CSUEAppsatlis/task/10532">ATLis
10532</a>: But noise presently seems acceptable. Perhaps
last week's comments exclude this: optimize FFB FF system,
what
are the requirements?
If asymmetries look ok do we really need to improve the FFB
FF system? Roger Carlini: "I would not mess with it"
Discussion of further comments from Jay Mon 2010-12-20 in
email.
</p>
</div>
</div>
<div class="outline-3">
<h3 id="sec-13">1.4 BSY Diagnostics: Benesch</h3>
<div class="outline-4">
<h4 id="sec-14">1.4.1 <span class="todo">TODO</span> Analyze
raw harp profile data and write up recommendations.</h4>
</div>
</div>
<div class="outline-3">
<h3 id="sec-15">1.5 12GeV Pathlength Requirements Status:
Tiefenback</h3>
<div class="outline-4">
<h4 id="sec-16">1.5.1 <span class="todo">TODO</span> Need
conclusions before end of calendar year.</h4>
</div>
</div>
<div class="outline-3">
<h3 id="sec-17">1.6 Restart planning: All</h3>
<p>Includes optics days, baseline measurements before and after
new model
optics from Arne.
</p>
</div>
<div class="outline-3">
<h3 id="sec-18">1.7 US Particle Accelerator School Tour:
Todd/Arne</h3>
<div class="outline-4">
<h4 id="sec-19">1.7.1 <span class="todo">TODO</span> Need
volunteers for Sat 2011-01-22 USPAS afternoon tours</h4>
</div>
</div>
<div class="outline-3">
<h3 id="sec-20">1.8 AOB?</h3>
<p>
======================================================================
</p>
</div>
</div>
<div class="outline-2">
<h2 id="sec-21">2 2010-12-15 Wed 14:00 BTeam Meeting Notes</h2>
<div class="outline-3">
<h3 id="sec-22">2.1 Optics-on-Call Report: Krafft</h3>
<p>No received calls! Worked with Reza during Tue beam studies.
Up to 180 uA beam current with 88%(?) transmission.
Hall A Compton: running off crest creating low backgrounds?
Not well-understood? Hall C Compton may also be impacted.
Handoff of energy lock during A/C Compton measurements
may need to be addressed in future. Presently switching
energy lock does not seem to incur large overhead, but
both want continuous measurements; will need to revisit
after, e.g., path length retune.
Should we be rethinking path length innovations in light of
program requirements? We'll evaluate experiment schedule
but this is a strategic rather than tactical need.
</p>
</div>
<div class="outline-3">
<h3 id="sec-23">2.2 Beam Studies Report</h3>
<div class="outline-4">
<h4 id="sec-24">2.2.1 Take multiharp data in arcs 1 and 2:
Benesch</h4>
<p><a
href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1558178?PHPSESSID=d05ad0a06eb2b3e5df32ea0182c72eb4">Large
noise observed</a>: poor signal quality? Seems to be an
algorithm problem rather than intrinsic data quality
problem.
Could analyze at least some arc 2 data by hand. Arc 1 data
looks okay, 2 quads varied; will evaluate with 1 quad
varying.
TODO Further analysis required to come to S10/E03
comparison.
</p>
</div>
<div class="outline-4">
<h4 id="sec-25">2.2.2 Arc9 Transport: Roblin</h4>
<p><a
href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1558199?PHPSESSID=d05ad0a06eb2b3e5df32ea0182c72eb4">Run
aborted</a> due to problem saving data?
problem taking data rather than saving data. Iron core
correctors
in arc9 defaulted to hysteresis cycles with beam on,
creating
significant losses. Altering test plan to condition
correctors
without beam then take measurements off loop, then
recondition
back to operational settings. This should avoid hysteresis
cycles
on correctors during measurement. Yves has a test plan in
that
will work. Yves should be present for this measurement to
make
sure that things are working and alter test plan as
necessary.
Fopt has some undesired behaviors with iron core correctors.
12/21?
</p>
</div>
<div class="outline-4">
<h4 id="sec-26">2.2.3 RF Recovery: Ron</h4>
<p>Shimmed rack, quieted down noise on 1L08, so some success.
Some cavities could be brought back online. We're in good
shape
and should make it to winter shutdown without more work.
</p>
</div>
<div class="outline-4">
<h4 id="sec-27">2.2.4 High Current (180 uA) Injector setup for
QWeak</h4>
<p>Great successes last week getting up to 180 uA.
Can't get prebuncher above 2 without 10kHz noise on beam.
Would rather run at 2.8 for Qtor; should form group to
investigate.
Only prebuncher module has noise, 100 kHz sidebands "all
over".
There is a spare that can be used and investigated.
Should we do this on the 3rd when we come back up?
TODO Evaluate impact of module swap, injector retune on
12/16
</p>
</div>
<div class="outline-4">
<h4 id="sec-28">2.2.5 Mott Measurements</h4>
</div>
</div>
<div class="outline-3">
<h3 id="sec-29">2.3 Beam Studies Planning</h3>
<div class="outline-4">
<h4 id="sec-30">2.3.1 Prebuncher module swap, injector retune</h4>
<p>To reduce 9.5 kHz noise when running prebuncher above 2.
Planned for 12/16.
</p>
</div>
<div class="outline-4">
<h4 id="sec-31">2.3.2 Arc9 Transport: Roblin</h4>
<p>Planned for 12/21.
</p>
</div>
<div class="outline-4">
<h4 id="sec-32">2.3.3 Take multiharp data in arcs 1 and 2:
Benesch</h4>
<p>Don't need more data at present before further offline
analysis.
</p>
</div>
<div class="outline-4">
<h4 id="sec-33">2.3.4 NL Pathlength: All</h4>
<p>NL pathlength system was <a
href="https://cebaf.jlab.org/elog/elog_item.php?elog_id=1558253">repaired
Tue 2010-12-14</a> after diagnosis
determined that some components were damaged by
misconfigured 10V
instead of 5V. After repair, pathlength is not correct, and
the
MoMod/pathlength systems have not agreed. Recommend that we
fix pathlength, compare against MoMod, and remove 1.7
degrees of
existing gang phase offset in both linacs.
</p>
<p>
Appears based on MoMod that path length error, third pass
stretched.
MoMod could be used to nurse system back during operations.
Haven't verified that NL pathlength system works now after
repairs.
Better to run CW with MoMod to maintain low Hall A Compton
rates,
then go to tune mode and check with pathlength system.
Tief: Estimate is about 3h to nurse system back to health,
Weds
night 12/15 or very early Thursday 12/16. Current plan is to
do
in evening 12/15 with hall C available, hall A concurrence.
Then will verify NL pathlength with tune mode before holiday
shutdown.
</p>
</div>
<div class="outline-4">
<h4 id="sec-34">2.3.5 Adjust FFB/FF gains to minimize noise in
hall C: Benesch/Suleiman</h4>
<p><a
href="http://opsweb.acc.jlab.org/CSUEAppsatlis/task/10532">ATLis
10532</a>: But noise presently seems acceptable. Perhaps
last week's comments exclude this: optimize FFB FF system,
what
are the requirements?
If asymmetries look ok do we really need to improve the FFB
FF system? Roger Carlini: "I would not mess with it"
</p>
</div>
<div class="outline-4">
<h4 id="sec-35">2.3.6 Hall A BCM recalibration: ?</h4>
<p>Likely next week rather than this week. Still open.
Not really a beam study, but should be coordinated with
other halls.
</p>
</div>
</div>
<div class="outline-3">
<h3 id="sec-36">2.4 BSY Diagnostics: Benesch</h3>
<p>Present updated table and comment based on results (or lack
thereof) of multiharp arc 1/2 test on 2010-12-14. See above;
further analysis required and recommendation to be written.
</p>
</div>
<div class="outline-3">
<h3 id="sec-37">2.5 12GeV Pathlength Requirements Status:
Tiefenback</h3>
<p>Will revisit in future, need before end of calendar year.
</p>
</div>
<div class="outline-3">
<h3 id="sec-38">2.6 ARC1 model: Arne</h3>
<p>First MBE dipole has different body gradient than rest; quads
were
okay, but this restores arc symmetry with respect to focusing.
This
was based on some guidance from Michele. Arne shows some data
from
ARC1.pdf including 2010-12-13 Mon Table match. Nothing to get
alarmed about in the match. Solution also has nice minimum at
center
of arc as originally designed.
Are doglegs in the model? Edge focusing set to zero?
Jay/Michele: Has nominal settings.
Will check for this problem in other arcs.
12 GeV propogates the outlier throughout, while Arne's
analysis
corrects the outlier. We'll decide this in measurements and
comparing to Tosca.
Jay: 2005 decks say that this was measured in 2004, changed
sign!
</p>
</div>
<div class="outline-3">
<h3 id="sec-39">2.7 AOB?</h3>
<p>Heating/reactivating gun 2, replacing detectors on Mott
polarimeter.
Need about 2h of beam on Mott for a baseline. Can Joe do his
time
on 12/21, locking up NL?
</p>
<p>
Arne: need volunteers for Sat Jan 22 PM USPAS
</p>
</div>
</div>
<div id="postamble">
<p class="author"> Author: Todd Satogata
<a href="mailto:satogata@Todd-Satogatas-MacBook-Pro.local"><satogata@Todd-Satogatas-MacBook-Pro.local></a>
</p>
<p class="date"> Date: 2010/12/20 16:14:33</p>
</div>
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