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<h1 class="title">B-team Meeting Notes</h1>
<div id="outline-container-1" class="outline-2">
<h2 id="sec-1"><span class="section-number-2">1</span> <span
class="timestamp-wrapper"> <span class="timestamp">2009-11-18 Wed
14:00</span></span> Agenda–Notes </h2>
<div class="outline-text-2" id="text-1">
<p>Realtime notes, no post-mortem editing or spin applied.
</p>
</div>
<div id="outline-container-1.1" class="outline-3">
<h3 id="sec-1.1"><span class="section-number-3">1.1</span> Hall-A
Compton and Accelerator issues <span class="tag"><span class="ALL">ALL</span></span></h3>
<div class="outline-text-3" id="text-1.1">
<p>Status report/discussion from Alex on Compton polarimeter and from
Optics/Inj
team on present status of the machine. </p>
<ul>
<li>present signal to noise
</li>
<li>discriminating between beam quality issues and physics issues
</li>
<li>Open discussion of path forward
</li>
<li id="sec-1.1.1">Summary <br>
Presently there is a low energy background. Hypothesis it is from
synchrotron radiation.
<p>Photon detector collimator has been changed for PREX, so a
compton at
6GeV with this collimator has never been previously established. </p>
<p>
Might be better to commission compton at lower energy.
</p>
<p>
Compton works reasonably well at low current, but at high current the
PMT cannot handle the low energy background.
</p>
<p>
No real way to discriminate between physics related background
(synchrotron radiation) and beam quality issues.
</p>
<p>
There is a DAQ issue, something about old DAQ (which has a 3% error)
but can operate at high current. The new DAQ was designed to
achieve 1% error, but does not work at high current.
</p>
<p>
Shielding and its effectiveness.
</p>
<p>
New collimator will arrive next week, 2inches of Pb same aperture as
previous collimator used for 5.9 GeV run.
</p>
<p>
There has not been any optics tuning in the A line proper. </p>
<p>
Is the vacuum the source? No progress in improving the vacuum.
Should the vacuum be purposefully degraded to see if the background
gets worse.
</p>
<p>
Dithering coils and modulation system is working.
</p>
</li>
</ul>
</div>
</div>
<div id="outline-container-1.2" class="outline-3">
<h3 id="sec-1.2"><span class="section-number-3">1.2</span> Hall-B beam
size issues <span class="tag"><span class="ALL">ALL</span></span></h3>
<div class="outline-text-3" id="text-1.2">
<p>There has been some loss time due to establishing the required beam
size σ<sub>x</sub>,σ<sub>y</sub> < 150 μ m at the B target.
Discussion and
development of a trouble shooting guide for OPS
</p>
<ul>
<li id="sec-1.2.1">Summary <br>
Two different analysis routines, Halls and Accelerator, give different
results.
<p>What is the source of the double hump? Would like to explore the
source of the double hump by varying injector parameters.
</p>
<p>
Double peaking should appear in all PMTs. Can this be programmed into
the GUI to display all the data.
</p>
<p>
Operations would like to see improvements to the harp analyzer, so
that what OPS sees is the same as what the Halls are using. </p>
<p>
Operations needs more guidance on how to resolve this problem.
</p>
<p>
Use an EPICS RECORD to pick the PMT that is used for the harp
analysis.
</p>
<p>
Perform scans at lower current.
</p>
</li>
</ul>
</div>
</div>
<div id="outline-container-1.3" class="outline-3">
<h3 id="sec-1.3"><span class="section-number-3">1.3</span> Viewer
limited BPMs <span class="tag"><span class="Tief">Tief</span></span></h3>
<div class="outline-text-3" id="text-1.3">
<p>Proposal to adjust the timing of the viewer limited beam pulse so
that the
BPMs work during viewer limited mode. </p>
<ul>
<li id="sec-1.3.1">Summary <br>
Viewer limited pulse is 10 μ s
<p>This will require better timing on BPMs?
</p>
<p>
Delay viewer limited pulse.
</p>
<p>
Take it up next week.
</p>
</li>
</ul>
</div>
</div>
<div id="outline-container-1.4" class="outline-3">
<h3 id="sec-1.4"><span class="section-number-3">1.4</span> FY10
projects <span class="tag"><span class="ALL">ALL</span></span></h3>
<div class="outline-text-3" id="text-1.4">
<p>Any thoughts on what Bteam wants to accomplish in FY10. There are
two
downs in FY10, Jan/Feb Winter down and the July/Aug Summer down. </p>
<ul>
<li id="sec-1.4.1">Continue/complete BSY diagnostic suite? <br>
<ul>
<li>viewers in front of dumplettes
</li>
<li>move more harps?
</li>
</ul>
</li>
<li id="sec-1.4.2">Open to ideas <br>
<ul>
<li>halo detector in BSY
</li>
<li>finish the matching algorithm. Prove that our present
diagnostics
and software provide a good match which is verified by downstream
harps. </li>
<li>Continue/finish ODR R&D in Hall-A
</li>
<li>get undulator from Darsburry and put in a chicane. Can tune
to
different energies, so in the linac one can measure beam size of all
five passes. Need a meter at the end of linac in 12 GeV and a new
vacuum chamber in the BCOM.
</li>
<li>Replace 5 MeV dipole. Retain -12.5, -30 degree ports, and
+12.5 or
+30 degree ports. Magnet, vacuum chamber, power supplies.
Horizontal gap is XXX? Does ISU have such a magnet? What are the
field requirements? What are the space limitations?
</li>
</ul>
</li>
</ul>
</div>
</div>
<div id="outline-container-1.5" class="outline-3">
<h3 id="sec-1.5"><span class="section-number-3">1.5</span>
Optics-on-call </h3>
<div class="outline-text-3" id="text-1.5">
<dl>
<dt>Outgoing</dt>
<dd>Mike Spata, Geoff Krafft
</dd>
<dt>Incoming</dt>
<dd>Alex Bogacz
</dd>
</dl>
<ul>
<li id="sec-1.5.1">Program <br>
<ul>
<li>Production running in A and B
</li>
<li>Possible Compton optimization
</li>
<li>Thaw the turkey
</li>
</ul>
</li>
</ul>
</div>
</div>
</div>
<div id="postamble">
<p class="date"> Date: 2009-11-18 15:45:00 EST</p>
<p class="creator">HTML generated by org-mode 6.32trans in emacs 23</p>
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<pre class="moz-signature" cols="72">--
Arne Freyberger
Director Operations Department
Jefferson Lab Phone: (757) 269-6268
12000 Jefferson Avenue Pager: (757) 584-6268
Newport News, VA 23606 Email: <a class="moz-txt-link-abbreviated" href="mailto:freyberg@jlab.org">freyberg@jlab.org</a>
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