[BTeam] injector energy change this morning affected BCD

[Matthew Bickley]

Jay,
   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.

Matt

________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Jay Benesch <benesch at jlab.org>
Sent: Tuesday, September 8, 2020 3:22 PM
To: BTeam <bteam at jlab.org>
Subject: [BTeam] injector energy change this morning affected BCD

Colleagues,

https://logbooks.jlab.org/entry/3843753 Yan phased 0L04 cavities in 0L06
spectrometer
https://logbooks.jlab.org/entry/3843858 7 degree phase change needed for
A Compton counts

after phone calls from Brad:
https://logbooks.jlab.org/entry/3843974  Terry
https://logbooks.jlab.org/entry/3843977   me
https://logbooks.jlab.org/entry/3843984   me

Examining the archiver, I found that INJ:p changed by 0.87 MeV across
the injector work necessitated by the 0L04-4 problem.  This caused the
ARC1 energy lock to lower the NL by the same amount.  Hall A energy
locked by SL so it's fine.  Halls B and C lose 4*0.87 MeV and Hall D
loses 5*0.87 MeV.  This is not good for polarization in either B or C.
spinDoctor is broken on both RHEL 6 and 7 (see below) so I can't say how
bad it is.  Dave Gaskell created a graph which wmhenry posted in the
CLOG a week or so ago that showed about 1% drop per MeV.

It would seem that the only way to fix this is to go back into the
injector and adjust BL dipoles and horizontal correctors to reduce the
injector energy to where it was on owl shift.  Not something I want to
do late swing shift.  I expect I'll hear from run coordinators about my
elog and their druthers.

Jay


spinDoctor errors on RHEL6, RHEL7 roughly the same:

ACC RHEL i686 6.10 (rhel-6-ia32)
[51] benesch at opsl12 > spinDoctor&
[1] 10065
[52] benesch at opsl12 > Can't load
'/a/certified/apps/swig/cedlib/6.4/perl/5.10.1/lib/rhel-7-x86_64/cedlib.so'
for module cedlib:
/a/certified/apps/swig/cedlib/6.4/perl/5.10.1/lib/rhel-7-x86_64/cedlib.so:
wrong ELF class: ELFCLASS64 at
/usr/csite/pubtools/perl/5.10.1/lib/5.10.1/i686-linux-thread-multi/DynaLoader.pm
line 200.
  at
/a/certified/apps/swig/cedlib/6.4/perl/5.10.1/lib/rhel-7-x86_64/cedlib.pm
line 11.
Compilation failed in require at /cs/prohome/bin/spinDoctor line 25.
BEGIN failed--compilation aborted at /cs/prohome/bin/spinDoctor line 25.

[1]    Exit 2                        spinDoctor
[
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