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<div id="content">
<h1 class="title">NO BTEAM MEETING TODAY!! Just a status update</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">2009-11-11 Wed
14:00</span></span> </h2>
<div class="outline-text-2" id="text-1">
<p>There will not be a 2:00pm B-team meeting today. We are about to
start (9am nominal start time) a session of compton tuning. I expect
this effort will last most of the day. Today represents a good chance
to learn about the machine, front to end. </p>
<p>
Over the course of the last few days we have had several meetings to
discuss the compton tune and how to approach the problem. In addition
data mining and site visits have been performed to gain a better
understanding of the issues.
</p>
<p>
The present plan consists of:
</p>
<ul>
<li>Nominal Injector checks (bunch length, orbits…) <br>
</li>
<ul>
<li>during these checks the vacuum pumps in the compton region will
be checked in the hall. The vacuum may not be as good as it should
be in this region.
</li>
</ul>
<li>Use the slits in the injector to produce a 10 μ A <b>clean beam</b>.
Where
<b>clean beam</b> refers to a beam with exceptional timing and
bunch length. <br>
</li>
<ul>
<li>If the compton rate improves, then we know the problem is
sourced
upstream of the slits and is probably a bunch length issue.
</li>
</ul>
<li>If compton rate is still bad, check the following:
</li>
<li>5 MeV orbit
</li>
<li>Swing gang phase a bit to see the sensitivity to energy spread
</li>
<li>Separator check, extract the A beam magnetically. Are the rates
sourced at the separation point?
</li>
<li>Put Hall-A at a lower pass? Are the rates sourced from saturating
magnets?
</li>
<li>anything else??? See white board in control room for latest plan.<br>
</li>
</ul>
</div>
</div>
<div id="outline-container-2" class="outline-2">
<h2 id="sec-2"><span class="section-number-2">2</span> <span
class="timestamp-wrapper"> <span class="timestamp">2009-11-04 Wed
14:00</span></span> Agenda–NOTES <span class="tag"><span
class="ATTACH">ATTACH</span></span></h2>
<div class="outline-text-2" id="text-2">
</div>
<div id="outline-container-2.1" class="outline-3">
<h3 id="sec-2.1"><span class="section-number-3">2.1</span> Beam status </h3>
<div class="outline-text-3" id="text-2.1">
<p>Assessment after cathode activation and 6.067 GeV spin up
</p>
<ul>
<li id="sec-2.1.1">PVDIS Beam Requirements <br>
Parity beam requirements for PVDIS are captured in the attached
document from PVDIS.
<ul>
<li id="sec-2.1.1.1">Charge Asymmetry <br>
OK, met during Happex-III, need to continue the good work
</li>
<li id="sec-2.1.1.2">Position Asymmetry <br>
OK, met during Happex-III, need to continue the good work
</li>
<li id="sec-2.1.1.3">Compton Tune <br>
PVDIS would also like to achieve a 1% absolute polarization
measurement. Too achieve this, compton photon rates must be kept
below 100 cnts/μ A. Nothing was discussed about the electron side
of the compton. The implications are that the Hall-A line optics
should be robust. Robust: Matched, understood beam transport in
compton region, acceptable beam size at target and acceptable raster
pattern size.
<p>The electron arm of the compton was not fully
operation/understood by
the end of Happex-III. How much time will be required for this
effort during PVDIS? Is this a priority?
</p>
</li>
<li id="sec-2.1.1.4">Phase advance <br>
Modulation coils will be used to measure the transfer function to the
A target. Present plan is to use the same procedure as Happex-III.
Discussion of going beyond the Happex-III approach of exciting coils
individually took place. Attendees from PVDIS did not object to
the concept of driving a pair of corrections, however the owner of
phase advance monitoring for PVDIS was not present and has objected in
the past to
simultaneously driving modulation coils in pairs. </li>
<li id="sec-2.1.1.5">Beam Matching/transport in the A-line <br>
Attempt to measure the incoming beam parameters Wednesday were
unsuccessful due to a failed harp at IHA1C05. Access will be made on
Thursday to replace the pre-amplifier.
<p><span class="timestamp-wrapper"> <span class="timestamp">2009-11-06
Fri</span></span> harp was repaired on Thursday and good data was
acquired Thursday before the Hall locked up. See the elogs:
<a href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1497094">TWISS/ε
measurements</a>,
<a href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1497121">Beam
transport with current optics and measured input conditions</a>
<a href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1497120">Match
results</a>
</p>
</li>
<li id="sec-2.1.1.6">Vertical Transverse Spin Component <br>
Must be less than 2%. This will be nulled out during a 2hr set of
Mott measurements. We will not be able to monitor this during the
run. </li>
<li id="sec-2.1.1.7">Horizontal Transverse Spin Component <br>
θ<sub>Wien</sub> is set split the polarization equally to A and B. Due
to this running configuration Hall-A has requested and Physics has
approved two shifts of purely transverse spin alignment. During this
setup Hall-B has requested to change from 5-pass to 1-pass for more
low energy calibration. The total time for this test are as follows:
<ul>
<li>2 hours Hall-B pass change
</li>
<li>8 hours injector work to setup purely (horizontal?)
transverse
polarization
</li>
<li>16 hours Hall-A data collection
</li>
<li>4 hours return injector to nominal configuration
</li>
<li>2 hours pass change for Hall-B
</li>
</ul>
<p>Four shifts in total. Scheduling of this is to be discussed
over the
next few weeks. Hall-A is leaning to desiring this run in a few
weeks, Hall-B wants to defer this as far into December as possible
(They want to put some time between the 1-pass running they just
finished and the next round).
</p>
</li>
<li id="sec-2.1.1.8">Raster size <br>
This will be an issue for PVDIS. No requirement presented at the
meeting. </li>
<li id="sec-2.1.1.9">Bob Micheals summary <br>
PVDIS parity requirements achieved during the Happex-III running.
Energy measurement of 150nm at 1C12 appears to be some noise source in
the machine. Large spread might be due to interception at the
injector. Noise is speculated to be amplified when running with a
closed slit for the Hall-A.
<p>The commissioning plan for PVDIS can found <a
href="http://hallaweb.jlab.org/experiment/E05-007/documents/runplan/draft.html">here</a>.
General PVDIS
information can be found <a
href="http://hallaweb.jlab.org/experiment/E05-007/">here</a>.
</p>
</li>
</ul>
</li>
<li id="sec-2.1.2">Bonus Beam Requirements <br>
<ul>
<li id="sec-2.1.2.1">Any issues with Hall-B beam? <br>
Beam size and halo requires as usual for Hall-B σ<sub>x</sub>, σ<sub>y</sub>
<
150 μ m. Bonus will run a unusually high beam current (up to 200nA)
for Hall-B. This has the benefit of allowing the typical SEE BPMs to
work so we will be able to monitor Hall-B orbit during most of the
run.
<p><span class="timestamp-wrapper"> <span class="timestamp">2009-11-06
Fri</span></span><br>
The Hall-B beam size has not be repeatable across accelerator
activities (Injector work, control accesses). A good beam spot can
be achieved, but it is disconcerting to loose time establishing a good
tune every time something changes in the machine.
</p>
</li>
</ul>
</li>
<li id="sec-2.1.3">Spin dance <br>
Hall-A is measuring 83% Hall-B is measuring 81%. This suggests that
θ<sub>Wien</sub> is set very close to the optimum point. Typically
Hall-A M{\o}ller measures slightly higher polarization than the Hall-B
M{\o}ller. More M{\o}ller runs are planned over the next few days
which will provide more information as to the present configuration
and the need for the spin dance.
<p>Both
A & B are at 5-pass, so the machine configuration options are
limited
to adjusting θ<sub>Wien</sub> so that P<sub>A</sub> = P<sub>B</sub>. </p>
<ul>
<li id="sec-2.1.3.1"><span class="todo TODO"> TODO</span> Make a
decision about Spin Dance before Monday morning <span class="tag"><span
class="HallB">HallB</span> <span class="HallA">HallA</span></span><br>
<span class="timestamp-wrapper"><span class="timestamp-kwd">DEADLINE:
</span> <span class="timestamp">2009-11-09 Mon</span></span><br>
</li>
</ul>
</li>
</ul>
</div>
</div>
<div id="outline-container-2.2" class="outline-3">
<h3 id="sec-2.2"><span class="section-number-3">2.2</span> General
Discussion </h3>
<div class="outline-text-3" id="text-2.2">
<ul>
<li>Parity requirements achieved for Happex-III and PVDIS
</li>
<li>energy spread achieved for HKS, HKS completed with a large
fraction
of the expected data. </li>
<li>Bonus is fully commissioned
</li>
</ul>
<p>These accomplishments were difficult and have strained the staff.
What can we do better? Things I'd like to discuss include:
</p>
<ul>
<li id="sec-2.2.1">B-team <br>
<ul>
<li>more involvement from Physics?
Yes, everyone agrees that more communication is better. Arun
(Hall-A), Stepan (Hall-B) and Gaskell (Hall-C) will be added to the
bteam mailing list.
<p>We will also try to organize the B-team meetings such that
Hall
specific items are during the first portion of the meeting.
</p>
</li>
<li>less Wednesday meetings, more daily 8:15 meetings
No and yes.
</li>
<li>B-team content
</li>
<li>Goals for FY10?
– 12 GeV commissioning plan
– PREX parity quality
– QWeak parity quality
– Information transfer/cross training
– TWISS/ε measurement and matching routine
– raytrace data collection and analysis routine for beam physicists </li>
</ul>
</li>
<li id="sec-2.2.2">1:30 scheduling meetings <br>
<ul>
<li>Low attendance
</li>
<li>Little information transfer
</li>
<li id="sec-2.2.2.1">Summary <br>
The 1:30 scheduling meeting serves a different purpose than the 8am
meetings. However the 1:30 meeting has become too static. Need to
figure out how to make the meeting a bit more animated.
</li>
</ul>
</li>
<li id="sec-2.2.3">Beam Studies <br>
<ul>
<li>C50 commissioning has resulted in almost no beam studies
being
performed. </li>
<li>No more C50 commissioning during physics operation
</li>
<li>Double Wien commissioning during physics operation (Spring10)
looks
to be just as disruptive.
– working with Whitney to see if Homeland security run can be move
to July2010.
</li>
</ul>
</li>
</ul>
</div>
</div>
<div id="outline-container-2.3" class="outline-3">
<h3 id="sec-2.3"><span class="section-number-3">2.3</span>
Optics-On-Call </h3>
<div class="outline-text-3" id="text-2.3">
<ul>
<li>Outgoing Byunn Yung
</li>
<li>Incoming Yuhong Zhang
</li>
</ul>
</div>
</div>
</div>
<div id="postamble">
<p class="date"> Date: 2009-11-11 08:44:15 EST</p>
<p class="creator">HTML generated by org-mode 6.32trans in emacs 23</p>
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<br>
<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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