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Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Wed, 16 Jul 1997 16:52:53 -0400
Minutes of Hall A Group Meeting 15 July 1997
1 General Announcements: (Javier Gomez)
1.1 Decision has been made deliver beam to only 2
hall at a time for the near future. Schedules
will be adjusted accordingly.
1.2 All users and staff are urged to not park in
the designated 10 minute parking area in front
of CEBAF Center for more than 10 minutes.
1.3 Roy Whitney will serve as acting head of the
Administration Division until the vacancy
created by the departure of Jim Coleman is
filled.
2 Installation/Engineering:
2.1 Ed Folts reports that 80% of scheduled activity
for this shutdown is done.
2.1.1 Raster did not get started.
2.1.2 Requests that no one start anything new
after 800 tomorrow (Wednesday 16 July) and
that everyone be out of the Hall by noon
so that he can commence cleanup activities
and be ready to close the Hall for swing
shift.
2.1.3 Installation of Møller shielding
discussed.
2.1.4 Raster target discussed.
2.1.5 French are reassembling ep system.
2.1.6 Møller target cooler now has automatic
fill. Dan Dale will get together with Ed
to get familiarized with the system.
2.2 James Proffitt reports:
2.2.1 Have standardized magnet controls so that
all magnet power supplies look and feel as
much alike as possible.
2.2.2 Run coordinators for 89-033 have been
checked out on controls and spectrometer
movement.
2.2.3 Collimator motor on the Hadron arm has
been replaced. Updating error handling in
controls software.
2.3 Al Gavalya reports that he’s coming close to a
finished design on the reference cylinder for
the alignment system.
2.4 Status of measurements of sieve and its
location discussed.
2.4.1 Rutgers says all original drawings were
sent to JLab in care of Eddy Offermann.
Will resend what they have but don’t have
a complete set.
2.4.2 John LeRose has been appointed
clearinghouse for sieve information. Give
him anything you have.
3 Run Plan: (Paul Rutt: run coordinator)
3.1 After cosmic tests tonight requests that
detectors be left alone.
3.2 See the Web page for information about run
plans
(http://www.cebaf.gov/~malov/fpp_home/e89033men
u.html)
3.3 All shift workers must read the COO (Conduct Of
Operations; see the web page) for 89-033 before
taking shifts and inform Paul via e-mail
(rutt@jlab.org) that they have.
4 Detectors: (Bogdan Wojtsekhowski)
4.1 Need to check on noise on electron arm VDC’s
4.2 Gas Cerenkov:
4.2.1 Did not replace PMT’s
4.2.2 Bases have been reinstalled and High
Voltages are being adjusted.
4.2.3 Discussed sliding out of stack.
4.3 Measured detector geometry of Electron arm last
week.
4.4 500 lb. detector installed on the floor for
Dick Lindgren on Electron arm side of the
Beamline.
5 Optics and magnetic field monitoring: (John LeRose)
5.1 Working on TRANSPORT based model of
spectrometer for Deuterium experiment. Have a
version of TRANSPORT that takes into account
quadrupole fringe fields. Getting better
agreement with RAYTRACE than before.
5.2 Reminds people that just because there is an
“L” in the yellow field next to the field
display on the control panels for the NMR
Gaussmeters that doesn’t mean there is a good
“Lock” established. Only when the oscilloscope
shows a locked resonant signal is there truly a
lock.
6 Beamline: (Arun Saha)
6.1 OTR (Optical Transition Radiation) monitor is
now installed in the Hall A line. Requires
insertion of a 250 nm target in the beam.
Question is what effect will this have on
experiments if the target is left in? Propose
some tests during upcoming run. Compare Emissing
resolution and backgrounds with and without OTR
target in.
6.1.1 Also some concern for effect on
Polarization. Test of that will have to
wait until the Møller Polarimeter is fully
operational.
6.2 89-003 run summary completed (more than 600
individual runs!).
6.3 Reminds Javier and Ed that Accelerator Ops
wants a list of all Beamline related activities
in the Hall during the shutdown.
6.4 Reports that computerized shift summary reports
are now available. Bob Michaels will have to
install the software on the DAQ computers.
7 Waterfall Target: (Meihua “Meme” Liang)
7.1 Encoder replaced and calibrated. Calibration
information has been distributed.
7.2 Cable for computer in the Hall turned out to be
too short. (Ordered 350 feet got 250 feet)
Computer connections will stay as they are.
8 Cryotarget: (Jian-Ping Chen)
8.1 The transport fixture design is completed. The
fixture is being fabricated and should be ready
by early August.
8.2 The design of the dummy solid target ladder is
in its last iteration. It should be ready in a
few more days.
8.3 The loop plumbing is almost done.
8.4 The upstream window blocks are being plated.
8.5 Joule-Thomson valve controller work is almost
completed.
8.6 The high power heater control box is being
assembled and should be ready this week.
8.7 Have ordered 2 more variable frequency power
supplies. We currently have 3 in house and one
of those has problems.
8.8 Still on schedule for 12 August.
9 Møller Polarimeter Commissioning: (Dan Dale)
9.1 Reviewed layout of Polarimeter.
9.2 Showed results of tests of residual field on
beam position.
9.3 Showed various plots illustrating detector
performance. Detectors look OK.
9.4 Discussed backgrounds and the need for more
shielding
9.5 Discussed problems apparently associated with
charge monitoring.
9.6 Jian-Ping suggests looking into beam heating
effects.
9.7 Outline of goals for upcoming run:
9.7.1 Debug hodoscope
9.7.2 Investigate charge calibration and
monitoring.
9.7.3 Check shielding improvements.
9.7.4 Cross check with Mott and Hall C
9.7.5 Vary injection angle.
-JJL