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</style>BTeam --<br>
<br>
Here are the notes from last week and the moderately long agenda for
this week. As usual, please bring your ideas and priorities to the
meeting this afternoon, and/or send them to me, and we'll develop
our plans for BTeam for the remainder of this run. See you there,
and thanks!<br>
<br>
-Todd<br>
<h1 class="title">BTeam-2011-02-16</h1>
<div class="outline-2">
<h2 id="sec-1">1 2011-02-16 Wed 14:00 BTeam Meeting Agenda</h2>
<div class="outline-3">
<h3 id="sec-2">1.1 Optics-on-Call Report: Shahid/Geoff =>
Todd/Jay</h3>
<p>At last at least a moderately quiet week, though with some
position
parity issues to be worked out for Hall C/Qweak. This included
an
investigation of injector match through the injector chicane
into
NL, which seems to still be questionable.
</p>
<div class="outline-4">
<h4 id="sec-3">1.1.1 <span class="done">DONE</span> Check
quad ranges/procedure for injector match multiharp</h4>
<p>Arne questioned last week: Does multiharp have good quad
ranges
for match? Need to collect multiharp data and return to
injector
match procedure. This includes getting hardware for harps
back in
working order. RonL notes that harp repair wants an injector
access. This was checked and adjusted during below Tue
2011-02-15
studies by Jay.
</p>
</div>
<div class="outline-4">
<h4 id="sec-4">1.1.2 <span class="done">DONE</span> Check
injector skew quad scaling and setup</h4>
<p>Yves noted last week that we should check skew quads,
particularly
whether they were scaled properly for 6.3 MeV and lemi work.
This
was likely done as part of check and measurement to 100 keV
during
2011-02-15 Tue beam studies by Yves.
</p>
</div>
</div>
<div class="outline-3">
<h3 id="sec-5">1.2 Beam Studies Report</h3>
<div class="outline-4">
<h4 id="sec-6">1.2.1 <span class="done">DONE</span>
Multiharp, injector optics match into NL: Jay</h4>
<p>Data and attempt at rematch acquired 2011-02-15 Tue, but
rematch
seemed to make conditions worse.
</p>
</div>
<div class="outline-4">
<h4 id="sec-7">1.2.2 <span class="done">DONE</span> Measure
injector transport across capture, 1/4: Yves</h4>
<p><a href="http://cebaf.jlab.org/atlis/task/9622">ATLis 9622</a>:
Some data acquired 2011-02-15 Tue. Do we need more
data for the downstream section of the injector?
</p>
</div>
<div class="outline-4">
<h4 id="sec-8">1.2.3 New injector optics review: Alex</h4>
<p>Alex will briefly review the high points (including
dispersion
through the chicane, and modified optics for diagnostics) of
the
injector optics installed 2011-02-03 Thu.
</p>
</div>
<div class="outline-4">
<h4 id="sec-9">1.2.4 <span class="done">DONE</span> Injector
model: Arne</h4>
<p>Elegant baseline should now match machine settings. Jay:
Are
these values consistent with those used by matchElengant?
</p>
<ul>
<li><span class="todo">TODO</span> Check consistency. If
not, make consistent and achieve consensus.<br>
</li>
</ul>
</div>
</div>
<div class="outline-3">
<h3 id="sec-10">1.3 APEL Hall Liason Comments</h3>
</div>
<div class="outline-3">
<h3 id="sec-11">1.4 Beam Studies Planning and Discussion</h3>
<div class="outline-4">
<h4 id="sec-12">1.4.1 <span class="todo">TODO</span>
Raytrace/Multiharp in HallC/Qweak: Jay/Ryan/MikeT</h4>
<p>Investigate optics/transport of response to modulation
coils at
3C08/10 and FFB coils at 3C04/06/07. Requires beam to hall C
and may disrupt beam to other halls depending on where the
the measurement is launched.
</p>
</div>
<div class="outline-4">
<h4 id="sec-13">1.4.2 <span class="todo">TODO</span> Bunch
length measurement: Alicia/Reza</h4>
<p>Need to check harp status before measurement. Both 130 kV
normal
and backphase bunch length measurements should be performed
before 6 month SAD. 4D00 spectrometer PS was reinstalled
2011-02-10 Thu.
</p>
</div>
<div class="outline-4">
<h4 id="sec-14">1.4.3 <span class="todo">TODO</span> Parity
quality improvements from injector coupling: Yves</h4>
<p><a href="http://cebaf.jlab.org/atlis/task/8346">ATLis 8346</a>:
Some concern that parity quality is marginal for
Qweak. A measurement and retune, such as this ATLis from
Yves, is
fairly invasive. Can be checked in ~10min with 30Hz PZT;
this is
a backup plan in case PZT/other injector measurements are
inconclusive.
</p>
</div>
<div class="outline-4">
<h4 id="sec-15">1.4.4 <span class="todo">TODO</span> LOCO
Model Calibration Tests: Yves/Ryan/MikeT (~2h)</h4>
<p><a href="http://cebaf.jlab.org/atlis/task/10700">ATLis
10700</a>: Measured, but BPM problems in center of arc.
Have
some analysis upstream and downstream of affected mux, but
should
restore good BPM behavior and remeasure. Being worked on,
will
not ask for more time until sorted out. Noisy BPMs were
vertical?
Tief investigating, noted horizontal noise.
</p>
</div>
<div class="outline-4">
<h4 id="sec-16">1.4.5 <span class="todo">TODO</span> RayTrace
in ARC3: Ryan/MikeT (~30min)</h4>
<p><a href="http://cebaf.jlab.org/atlis/task/10708">ATLis
10708</a>: See above, should redo with LOCO model
remeasurement.
</p>
</div>
</div>
<div class="outline-3">
<h3 id="sec-17">1.5 AOB?</h3>
<div class="outline-4">
<h4 id="sec-18">1.5.1 <span class="todo">TODO</span> Injector
configuration documentation: Reza</h4>
<p>Document proper operational injector configuration (6.3 MeV
energy,
crested within 5 degrees, etc): Reza et al
</p>
</div>
<div class="outline-4">
<h4 id="sec-19">1.5.2 <span class="todo">TODO</span> Plan
1-pass A/C split, B offline (probably) for Feb 25 (Yves/Jay)</h4>
<p>What resources/beam time do we need to be prepared?
</p>
<p>
======================================================================
</p>
</div>
</div>
</div>
<div class="outline-2">
<h2 id="sec-20">2 2011-02-09 Wed 14:00 BTeam Meeting Agenda</h2>
<div class="outline-3">
<h3 id="sec-21">2.1 Optics-on-Call Report: Balsa/Alex =>
Shahid/Geoff</h3>
<p>Yet another eventful week with a lot of operations diagnosis
concentrating on the injector. On Friday we fixed the recent
machine
woes with a reduction of GSET on the 0L03-2 cavity in the
injector
to reduce fluttering PASKR (phase loop effort RMS). We have
since
been able to return to stable running conditions for Halls
B/C, and
with the addition of Hall A this week, we should be able to
return
to beam studies that do not involve immediate firefighting to
keep
the operational program on track.
</p>
<p>
Alex: Thursday optics was particularly productive (see below).
2h into optics work, spots improved/reproduced. Also modified
model
for existing 6.3 MeV injector rather than old 5 MeV, and Jay
prepped
new GSETs for cavities to include end-field effects. Geoff: Do
we
have good procedures? Alex believes we're in good shape there.
</p>
<div class="outline-4">
<h4 id="sec-22">2.1.1 <span class="todo">TODO</span> Arne:
Does multiharp have good quad ranges for match? Need to</h4>
<p>collect multiharp data and return to injector match
procedure.
This includes getting hardware for harps back in working
order.
RonL notes that harp repair wants an injector access.
</p>
</div>
<div class="outline-4">
<h4 id="sec-23">2.1.2 <span class="todo">TODO</span> Yves:
notes that we should check skew quads, particularly</h4>
<p>whether they were scaled properly for 6.3 MeV and lemi
work.
</p>
</div>
</div>
<div class="outline-3">
<h3 id="sec-24">2.2 Beam Studies Report</h3>
<div class="outline-4">
<h4 id="sec-25">2.2.1 <span class="done">DONE</span> Injector
optics: Bogacz</h4>
<p>Alex implemented a different injector optics last week,
which
also improved injector performance and reduced some trips in
the middle of the injector chicane where beam sizes had
previously
been high. These optics should now be much closer to the
design
optics, as we also put these optics into the elegant design
baseline.
</p>
</div>
<div class="outline-4">
<h4 id="sec-26">2.2.2 <span class="done">DONE</span> Injector
model: Freyberger</h4>
<p>See above: elegant baseline should now match machine
settings.
Jay: Are these values consistent with those used by
matchElengant?
</p>
<ul>
<li><span class="todo">TODO</span> Check consistency. If
not, achieve consensus.<br>
</li>
</ul>
</div>
</div>
<div class="outline-3">
<h3 id="sec-27">2.3 Beam Studies Planning and Discussion</h3>
<div class="outline-4">
<h4 id="sec-28">2.3.1 <span class="todo">TODO</span> Bunch
length measurement: Hofler/Kazimi</h4>
<p>Lack of reliable bunch length measurements seemed to be a
challenge
during the diagnosis of the 0L03-2 problem. The most recent
measurements did not seem correct. Perhaps we should make
sure that this measurement is now reliable and understood.
There is still a beam tail on the 1A SLM but there is no
strong drive to change the injector or try to fix this based
on experiment feedback and Compton/halo backgrounds.
</p>
<p>
Do we expect bunch length measurement to work at 130 kV?
Reza
says yes, but this requires desk time and some operations
time.
This is a priority to get working before the 6 month SAD
since
we also return with the gun at 130kV. Temperature
stabilization
may also have helped stabilize this effort, but picture and
procedure – it was the beam and stability that were bad.
</p>
<p>
Backphase bunch length measurement at 130kV is also a
priority
before the 6 month SAD. We have not yet checked the harps
necessary for this measurement, should check those at first
opportunity. This at 4D00, requires spectrometer PS back in,
which should be done 2011-02-10 Thu AM along with change
back
to longitudinal polarization for Qweak.
</p>
</div>
<div class="outline-4">
<h4 id="sec-29">2.3.2 <span class="todo">TODO</span> ? Parity
quality improvements from injector coupling: Roblin</h4>
<p><a href="http://cebaf.jlab.org/atlis/task/8346">ATLis 8346</a>:
Some concern that parity quality is marginal for
Qweak. We should check that the injector skew correctors
were
scaled properly for the gun HV/energy changes during our
optics
fixes on 2011-02-03, and, if not, perhaps scaling them will
improve Qweak parity quality with little impact. A
measurement
and retune, such as this ATLis from Yves, is fairly
invasive.
Can be checked in ~10min with 30Hz PZT, should still work.
</p>
</div>
<div class="outline-4">
<h4 id="sec-30">2.3.3 <span class="todo">TODO</span> ? LOCO
Model Calibration Tests: Roblin (~2h)</h4>
<p><a href="http://cebaf.jlab.org/atlis/task/10700">ATLis
10700</a>: Measured, but BPM problems in center of arc.
Yves reported last week. Have some analysis upstream and
downstream
of affected mux, but should restore good BPM behavior and
remeasure.
Being worked on, will not ask for more time until sorted
out.
Noisy BPMs were vertical? Tief investigating, noted
horizontal noise.
</p>
</div>
<div class="outline-4">
<h4 id="sec-31">2.3.4 <span class="todo">TODO</span> ?
RayTrace in ARC3: Bodenstein (~30min)</h4>
<p><a href="http://cebaf.jlab.org/atlis/task/10708">ATLis
10708</a>: See above, should redo with LOCO model
remeasurement.
</p>
</div>
</div>
<div class="outline-3">
<h3 id="sec-32">2.4 AOB?</h3>
<div class="outline-4">
<h4 id="sec-33">2.4.1 <span class="todo">TODO</span>:
Document proper operational injector configuration (6.3 MeV</h4>
<p>energy, crested within 5 degrees, etc): Reza et al
</p>
</div>
<div class="outline-4">
<h4 id="sec-34">2.4.2 Jay: C Compton scintillator adjacent to
beamline noise spikes,</h4>
<p>per elog entry. 100s intervals, per elog entry last night.
Compton photon detector also modified, so comparisons to
previous
expectations difficult. Hall C will perform access to switch
back to old detector electronics.
</p>
</div>
<div class="outline-4">
<h4 id="sec-35">2.4.3 <span class="todo">TODO</span> Add hall
liason reports to BTeam agenda (Todd)</h4>
</div>
<div class="outline-4">
<h4 id="sec-36">2.4.4 <span class="todo">TODO</span> Add
MikeS to list (BSY/Recombiner measurements) (Todd)</h4>
</div>
<div class="outline-4">
<h4 id="sec-37">2.4.5 <span class="todo">TODO</span> Plan
1-pass A/C split, B offline (probably) for Feb 25 (Yves/Jay)</h4>
</div>
<div class="outline-4">
<h4 id="sec-38">2.4.6 Update on path length (Tief): annual
thermal cycle, machine bigger</h4>
<p>in summer, smaller in winter, so doglegs take up slack more
in
winter than summer. 12 GeV heat loading will dominate arcs,
about
half of total machine length. Concrete has dirt/water
outside,
and will have heating resistors on walls. Calculations for
1C temp
change is about 3.5 degrees of RF phase. (3.5deg/C)
Surrogate meas
was to raise water temperature, saw about 2F~1C temp rise at
surface
of concrete; pathlength changed about 6deg cumulative around
machine.
After dogleg compensation, they got a number closer to
5.5deg, all
from east arc (minus arc 9), or about 1.5deg/C/arc. This
about half
of what one would expect from the naive/simple thermal
argument.
Questions about whether we saturated the temperature rise;
also
only did half the planned temp rise because of caution about
hoses.
Measurement was same order of magnitude, hence concrete
heating
contribution to pathlength is a plausible mechanism.
Observation
of pathlength change is also consistent with similar
pathlength
change in all east arcs.
</p>
<p>
Multiyear pathlength drift drives possible need for
additional
pathlength compensation. We've exhausted previous
capabilities,
which is why we need to take up slack now in arc orbit
pathlength
changes.
</p>
<p>
Consensus seems to be that we should increase dogleg
capability
by momentum change for 12 GeV plus taking up arc slack –
nearly.
The open question is whether the upper bound of the cooling
water
heating test is the additional dogleg capability that is
needed.
</p>
</div>
</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: 2011/02/16 10:24:41</p>
</div>
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