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It is not yet clear to me why this is in play. Absent changes to the injection chicane BL magnets, there should have been no change in injector momentum. The injection chicane is no longer set up in an adequately calibrated fashion (strong interferences from
local dipoles in the main machine) and steering corrections are not bucked out appropriately. If the energy in the halls fell on multi-pass beam, then it must be that the energy gain per pass fell. With first pass energy being held constant, this must be
due to a rise (not decrease) in injector energy. I am confused by what is being stated. Perhaps I am misinterpreting what is happening. But it looks confused to me, although perhaps the confusion lies in a different quarter.<br>
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Michael Tiefenback<br>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> BTeam <bteam-bounces@jlab.org> on behalf of Matthew Bickley <bickley@jlab.org><br>
<b>Sent:</b> Tuesday, September 8, 2020 15:33<br>
<b>To:</b> Jay Benesch <benesch@jlab.org>; BTeam <bteam@jlab.org><br>
<b>Subject:</b> Re: [BTeam] injector energy change this morning affected BCD</font>
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Jay,</div>
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Your decision is the right one...Hall A will have to live with the higher Compton counts in the interest of maintaining the other endstations' (in particular Hall C's) polarization.</div>
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Matt</div>
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<div id="x_divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> BTeam <bteam-bounces@jlab.org> on behalf of Jay Benesch <benesch@jlab.org><br>
<b>Sent:</b> Tuesday, September 8, 2020 3:22 PM<br>
<b>To:</b> BTeam <bteam@jlab.org><br>
<b>Subject:</b> [BTeam] injector energy change this morning affected BCD</font>
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<div class="x_PlainText">Colleagues,<br>
<br>
<a href="https://logbooks.jlab.org/entry/3843753">https://logbooks.jlab.org/entry/3843753</a> Yan phased 0L04 cavities in 0L06
<br>
spectrometer<br>
<a href="https://logbooks.jlab.org/entry/3843858">https://logbooks.jlab.org/entry/3843858</a> 7 degree phase change needed for
<br>
A Compton counts<br>
<br>
after phone calls from Brad:<br>
<a href="https://logbooks.jlab.org/entry/3843974">https://logbooks.jlab.org/entry/3843974</a> Terry<br>
<a href="https://logbooks.jlab.org/entry/3843977">https://logbooks.jlab.org/entry/3843977</a> me<br>
<a href="https://logbooks.jlab.org/entry/3843984">https://logbooks.jlab.org/entry/3843984</a> me<br>
<br>
Examining the archiver, I found that INJ:p changed by 0.87 MeV across <br>
the injector work necessitated by the 0L04-4 problem. This caused the <br>
ARC1 energy lock to lower the NL by the same amount. Hall A energy <br>
locked by SL so it's fine. Halls B and C lose 4*0.87 MeV and Hall D <br>
loses 5*0.87 MeV. This is not good for polarization in either B or C. <br>
spinDoctor is broken on both RHEL 6 and 7 (see below) so I can't say how <br>
bad it is. Dave Gaskell created a graph which wmhenry posted in the <br>
CLOG a week or so ago that showed about 1% drop per MeV.<br>
<br>
It would seem that the only way to fix this is to go back into the <br>
injector and adjust BL dipoles and horizontal correctors to reduce the <br>
injector energy to where it was on owl shift. Not something I want to <br>
do late swing shift. I expect I'll hear from run coordinators about my <br>
elog and their druthers.<br>
<br>
Jay<br>
<br>
<br>
spinDoctor errors on RHEL6, RHEL7 roughly the same:<br>
<br>
ACC RHEL i686 6.10 (rhel-6-ia32)<br>
[51] benesch@opsl12 > spinDoctor&<br>
[1] 10065<br>
[52] benesch@opsl12 > Can't load <br>
'/a/certified/apps/swig/cedlib/6.4/perl/5.10.1/lib/rhel-7-x86_64/cedlib.so' <br>
for module cedlib: <br>
/a/certified/apps/swig/cedlib/6.4/perl/5.10.1/lib/rhel-7-x86_64/cedlib.so: <br>
wrong ELF class: ELFCLASS64 at <br>
/usr/csite/pubtools/perl/5.10.1/lib/5.10.1/i686-linux-thread-multi/DynaLoader.pm <br>
line 200.<br>
at <br>
/a/certified/apps/swig/cedlib/6.4/perl/5.10.1/lib/rhel-7-x86_64/cedlib.pm <br>
line 11.<br>
Compilation failed in require at /cs/prohome/bin/spinDoctor line 25.<br>
BEGIN failed--compilation aborted at /cs/prohome/bin/spinDoctor line 25.<br>
<br>
[1] Exit 2 spinDoctor<br>
[<br>
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