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<title>NO BTEAM MEETING TODAY!! Just a status update</title>
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<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">2009-09-30 Wed
14:00</span></span> No meeting today </h2>
<div class="outline-text-2" id="text-1">
<p>There will not be a Bteam meeting today. </p>
<ul>
<li id="sec-1.1">Tuesday's activities <br>
The machine was down for 2 shifts of C50 commmissioning on NL04
Tuesday. During that time the following activities were performed:
<ul>
<li>Fixed the laser power meter
</li>
<li>Measure QE, value was about
<a href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1489558">0.18%
for A laser</a>
</li>
<li>spot move
</li>
<li>search for source of 35kHz current fluctuations, source
traced to
the <a href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1489552">Gun
HV. No plans to remove the noise. - </a>Measure QE at new spot, <a
href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1489598">QE now
1.2% for A laser</a>
</li>
<li>Install beat frequency module to support 31MHz operation,
found some
problems with the hardware, hope to fix and install today. 31MHz
beam to Hall-C moved to Thursday. People involved in making 31MHz
beam <b>will</b> meet after the 1:30 meeting to discuss the status and
make
final preparation plans.
</li>
<li><a
href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1489619?PHPSESSID=8434b04d77b6e49c87bccc06a1b681c2">Operational</a>
Emaxes for 3 of the 4 remaining NL04 cavities set and
now 7 of the eight cavities are in <b>operation!!!!</b>
</li>
<li>NL04-3 has a cabling issue and an access will be needed to
get this
cavity online. This work will be deferred to next CHL trip or
winter down? Up for discussion.
</li>
<li>Hall-C dump pump repaired, installed and returned to
operation
</li>
<li>HKS magnet limits adjusted to support upcoming energy shifts.
</li>
</ul>
<p>Machine restored reasonably quickly from the down activity and
the
program to send beam to HKS with small energy shifts is on schedule.
</p>
</li>
<li id="sec-1.2">Program for the upcoming week <br>
<ul>
<li id="sec-1.2.1">HKS special energy runs <br>
We are presently, 7:30am Wednesday, delivering beam at -1MeV from the
nominal energy. HKS expects to finish data at about 8:30am at this
energy. From there the program is as follows:
<ul>
<li>Configure the machine +20MeV above nominal energy (4hrs)
</li>
<li>Two shifts of HKS data taking (16hrs)
</li>
<li>Restore machine to nominal energy (4hrs)
</li>
<li>31 MHz run to HKS (2hrs?)
</li>
<li>Back for nominal program, 100μ A to Hall-A (3-pass), 30μ
A to
Hall-C (2-pass)
</li>
</ul>
</li>
<li id="sec-1.2.2">The return of Hall-B <br>
Hall-B will return to 5-pass operation sometime in the next few days,
earliest date is Thursday swing, but we will hear more definitive
times at today's 1:30 scheduling meeting.
</li>
<li id="sec-1.2.3">Happex-III Phase advance <br>
Conversation with Kent yesterday about phase advance in the line. The
last <a href="http://opweb.acc.jlab.org/CSUEApps/elog/entry/1489207">quad
change</a> improved the situation and "it might be good
enough". I conveyed our plan to take data, quad scan at 1C05 and
raytrace through the A line, in order to have some data to chew on
while they decide if the phase advance is adequate. Kent wasn't too
keen on the idea of taking the data right away and suggested that we
wait until 100μ A CW production has been established for a few
shifts. I disagree, most of the work in establishing CW operation
has been orbit steering, not quad tweaking. So the optics are not
changing and we should take the data as soon as possible.
<p>Presently it looks like Hall-A will be getting beam back
about noon on
Thursday. After the 31 MHz run to HKS.
</p>
<p>
Kent expressed his view that since the optics are linear it makes no
difference if one or two correctors are used. This is true, accept
that aperture issues are non-linear and it may be that by using two
correctors one can better utilize the available aperture to achieve
the required phase advance. This is one more reason to put apertures
in the elegant decks, so that we can explore these issues.
</p>
<p>
Riad was present and also suggest that perhaps bigger kicks should be
tried and Kent thought this was a reasonable suggestion.
</p>
<p>
So the phase advance is still an open issue, developing
tools/techniques to easily and deterministically setup the desired
phase advance in the A and C line need to developed. We will be
dealing with parity experiments until the end of 6 GeV operations and
they will be a large part of the 12 GeV program as well.
</p>
</li>
</ul>
</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">2009-09-28 Mon
13:30</span></span> Two things </h2>
<div class="outline-text-2" id="text-2">
<p>I'd like to have a meeting <b>today</b> at 13:30 to discuss the HKS
energy
changes and the Happex-III phase advance. </p>
<ul>
<li id="sec-2.1">HKS energy changes <br>
<ul>
<li id="sec-2.1.1">Physics consensus on the allotted amount of
time <span class="tag"><span class="Arne">Arne</span></span><br>
Still no word from Dennis on the agreed upon time allotment.
<span class="timestamp-wrapper"> <span class="timestamp">2009-09-28
Mon 14:48</span></span><br>
This just in from Dennis
<pre class="example">Dennis:
I talked to Nue some more. He would be willing to go down to one
major energy change (+20MeV), but get more statistics. It doesn't
save much time , but reduces risk because of fewer energy changes.
So the request looks like
Pulsed beam 2hr (spacing between micropulses to do Time of flight studies.)
+1 MeV 4hr (including tuning)
-1 Mev 4hr (including tuning)
+20Mev Tune 4hr
+20MeV data 16hr
Restore 4hr
So about 4.25 shifts.
Steve
</pre>
</li>
<li id="sec-2.1.2">HKS desired energy shifts <span class="tag"><span
class="Spata">Spata</span></span><br>
<ul>
<li id="sec-2.1.2.1">± 1 MeV shifts <br>
Small ± 1 MeV energy shifts, with the energy acceptance of the
machine. Hall-C does not need high currents for these energy shifts.
four hours of data taking per point.
<p>Hall-A beam during this part of the test?
one-hour to perform these shifts. </p>
<ul>
<li>dial in the shift into the energy lock.
</li>
<li>adjust Hall-C arc dipole to accomodate this change?
No leave dipole
strings alone. </li>
<li>Adjust Hall-A string? Might need to do this since
Hall-A is running
at 100μ\text{A}.
</li>
<li>FFB in relative mode in C due to the energy offset.
</li>
<li>DW1, DW2 small adjustments to keep beam on dump
viewers.
</li>
</ul>
</li>
<li id="sec-2.1.2.2">+20 MeV shift <br>
This will require a tune of the entire machine (after it is scaled).
It will go faster if we leave Hall-A out of the mix.
<ul>
<li>splitter stays unchanged
</li>
<li>DW1 goes down
</li>
<li>DW2 goes up
</li>
<li>change dipoles, quads, correctors.
</li>
<li>Raise DZ HMAX, HOPR need more headroom. Needs to goto
320 Amps.
</li>
<li id="sec-2.1.2.2.1">Steps <br>
<ul>
<li>load scaled allsave, in the special file area
</li>
<li>relem at the new energy
</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
<li id="sec-2.1.3">Schedule <br>
<ul>
<li id="sec-2.1.3.1">Dump pump issues <span class="tag"><span
class="Arne">Arne</span></span><br>
Presently Hall-C dump pump is broken and Hall-C is limited to
3.5μ\text{A}. The pump will be repaired sometime on Wednesday.
<p>When the pump is repaired and ready to be installed,
there will be a
2hour interruption to beam delivery to Hall-C during this period.
</p>
<p>
The pump will have to fixed before the 20 MeV shift since HKS wants to
run at full current for this portion of the test.
</p>
</li>
</ul>
</li>
<li id="sec-2.1.4">Plans <br>
<ul>
<li>Yan to develop ATLIS
</li>
<li>Benesch to scale the file
</li>
</ul>
</li>
<li id="sec-2.1.5">Owner <br>
<ul>
<li>Spata to own the process, review the ATlis, and review
the scaled allsave file </li>
</ul>
</li>
</ul>
</li>
<li id="sec-2.2">Happex-III phase advance <br>
<ul>
<li id="sec-2.2.1">Happex-III requirement <span class="tag"><span
class="Alex">Alex</span> <span class="Jay">Jay</span></span><br>
<ul>
<li>Position at 1H04A, 1H04B
</li>
<li>angle at 1H04A, 1H04B
</li>
<li>Energy shifts
</li>
</ul>
</li>
<li id="sec-2.2.2">Present status <span class="tag"><span
class="Alex">Alex</span> <span class="Jay">Jay</span></span><br>
Using various settings of the quadrupoles after the Compton
polarimeter Jay has altered the phase advance for Hall-A. It has
improved, but we are waiting for word if it is good enough.
Presently they have 20 μ radians in horizontal, 8 μ radians in the
vertical plane. Changes are coupled to changes in the rastered beam
size. These two requirements are often in conflict.
</li>
<li id="sec-2.2.3">Hardware <br>
Qweak is moving towards powering two coils simultaneously with
different amplitudes. Hall-A has the same hardware installed but are
not using the coils in this manner. Why not? Need to write a letter
to Kees and Kent. We want to use the coils as designed for PVDIS and
Prex and possibly for Happex-III. </li>
<li id="sec-2.2.4">Plans if present status is unacceptable <br>
Upon resumption of beam delivery to Hall-A, after C50 work and HKS
energy shifts, we will take a couple of hours to perform:
<ul>
<li>Ray-trace data through the hall-A line
</li>
<li>New set of harp data at 1C05
</li>
<li>???? </li>
</ul>
</li>
<li id="sec-2.2.5">Owner <br>
Jay and Alex will work on this problem. Ryan will help by collecting
the ray-trace data and assisting the analysis.
</li>
</ul>
</li>
</ul>
</div>
</div>
<div id="outline-container-3" class="outline-2">
<h2 id="sec-3"><span class="section-number-2">3</span> <span
class="timestamp-wrapper"> <span class="timestamp">2009-09-23 Wed
14:00</span></span> No meeting </h2>
<div class="outline-text-2" id="text-3">
<p>There will not be a B-Team meeting today. </p>
<ul>
<li id="sec-3.1">Brief status Report <br>
Machine is running well since last Wednesday transport clean up. It
is unclear if the Compton rate reduction was due to shifting the
doglegs "out of the mud" and fixing the separator, or the thorough
cleaning up of separation and transport lines by MikeS and Yan. The
reason we are confused is due to the fact that the Compton detector
was in a non-standard configuration all day Wednesday. Nevertheless
the machine is in a "good place" due to all these efforts.
<p>The Beam Loss Accounting system is still has a large amount of
noise,
but the transport appears to be clean if one looks at the Beam Loss
Monitors, Beam Scraping monitors, Hall-B harp scans, Hall-A compton
rates. Yesterday the 500KeV kicker sensor was jumpered out to remove a
80Hz
intensity fluctuations in order to minimize the issues with BLA
system. With the this sensor jumpered out the 80 Hz noise was
removed, but the BLA still fluctuates between 0 and 1.7 μ A of loss.
</p>
<p>
The main issue this week have been establishing robust FFB
configuration
to both A and C. Sometime Monday morning, things drifted such that
disabling/enabling FFB in the A line caused ep ion chamber trips.
By carefully calibrating the FFB response matrix using low 5 to 10
μ A beam current, the FFB system appears to be more stable. Scott
Higgins, Pete Francis and Yan worked out the FFB subtleties yesterday.
</p>
<p>
There was a spurious, unexplained vacuum event in Arc1 earlier this
week. The excursion was not significant enough to close valves, but
three
ion pumps reported elated vacuum levels.
</p>
<ul>
<li id="sec-3.1.1">Parity Quality-Happex <br>
Happex is not reported any information on parity quality so we don't
know where we stand on this issue, only that the user claims there are
more pressing issues. The most pressing issue to Happex is the phase
advance at the last two BPMS, Alex and Jay have some plans to address
this at Happex's request.
</li>
<li id="sec-3.1.2">Energy Spread-HKS <br>
Energy spread appears to be reasonably under control. The OPS crews
need to keep running KREST and chase down pathlength errors as much as
possible to keep the energy spread under control. Without knowing the
η, ε and β and the 3C12 dipole the exact value
for the energy spread is unknown. The Synchrotron Light
Interferometer measures 3.5× 10<sup>-5</sup>, which is an upper limit
as
long as the η is near the design value of 4m.
<p>Beam transport to HKS has been routine over the week, no
issues other
than FFB.
</p>
</li>
<li id="sec-3.1.3">Hall-B <br>
Hall-B finished their experiment this morning and will down for the
next nine days to reconfigure. This experiment started in the Winter
run this year.
For this Fall09 run period Hall-B did not achieve its goals. </li>
</ul>
</li>
<li id="sec-3.2">On Call <br>
Reza was on-call last week. This week it is Geoff Krafft. </li>
</ul>
</div>
</div>
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<p class="date"> Date: 2009-09-30 08:51:43 EDT</p>
<p class="creator">HTML generated by org-mode 6.30trans 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>
</pre>
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