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Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Mon, 03 Mar 1997 09:11:41 -0500
Minutes of Hall A Group Meeting 25 February 1997
1 General announcements:(Kees de Jager)
1.1 Observations on last weekend’s run:
1.1.1 It was educational.
1.1.2 Things we could improve on:
1.1.2.1 Better communication between shift
leader and run coordinator
1.1.2.2 Checks of systems before start of
run could be improved.
1.1.3 Overall people made a great effort to get
things to work.
1.2 Next collaboration meeting tentatively
scheduled for 11-12 April.
1.3 Abstracts will be submitted for the
presentation of papers at the intersections
meeting in Montana. The deadline for abstract
submission is this Saturday.
1.3.1 Topics include:
1.3.1.1 Spectrometer Commissioning Results:
Bob Michaels
1.3.1.2 FPP Commissioning Results: Paul
Rutt
1.3.1.3 Calibration Results: Mohammad
Khayat
1.3.2 Kees wants to see the abstracts before
they go out
1.3.3 Protocol for submission of abstracts and
making presentations will be a subject for
discussion at the collaboration meeting
1.4 John LeRose will be run coordinator for the
upcoming commissioning runs. Direct requests
and ideas for use of beam time to John.
2 Installation: (Ed Folts)
2.1 Mainly taking care of safety write-ups
2.1.1 Guards on power supplies
2.1.2 Shield hut doors
2.1.3 Installation of new stairs on the
spectrometers.
2.2 Requests that everyone take a look around the
hall and bring any safety issues to Ed’s
attention.
2.3 Trying to reinstall parts that were borrowed
from the Electron arm Q3 to repair the Hadron
Q3 over the weekend. Waiting for parts
delivery.
3 Commissioning: (Eddy Offermann)
3.1 Preliminary results on the Hadron arm look very
promising. Hadron arm appears to be essentially
identical to the Electron Arm..
3.1.1 Got 4E-04 momentum resolution with only a
minor adjustment of the first order focus
term.
3.1.2 Angle reconstruction looks very good just
using Electron arm parameters.
3.1.2.1 It appears that the sieve is
upside down compared to Electron arm.
(Ed Folts says it was never checked)
3.1.3 Acceptance appears to be about the same.
3.1.4 Had no NMR readout so must be careful
about quantitative results.
3.2 Beta spectra indicate that we need to check the
scintillator positions
3.3 Careful inspection of PID information confirms
that initial dipole field was reversed.
3.4 Kees announces plan to ask Accelerator to close
the Hall on midnight Wednesday.
4 Magnet Monitoring and Measuring: (John LeRose)
4.1 Problems getting NMR’s to lock after the
polarity change last weekend traced to failure
to reverse polarity of gradient compensating
coils. Reversed coils and tested yesterday.
Everything works.
5 Cryotarget: (Jian-Ping Chen)
5.1 Almost finished plumbing top of cryocan
5.2 Working on variable frequency controller.
5.3 Riad Suleiman presents results of cold tests
5.3.1 Reviewed operating parameters and layout
5.3.2 Gave specs on temperature readout units.
5.3.3 Purpose of test: Check cabling, software,
controls, and calibrate and or cross
calibrate temperature sensors.
5.3.4 Results look good
6 Detectors: (Bogdan Wojtsekhowski)
6.1 Hadron arm looks OK.
6.1.1 still need to position frame.
6.2 Starting to work on Cerenkovs. Number of
photoelectrons is low.
6.3 Measured magnetic field in vicinity of
detectors is very low.
6.4 FPP report from Paul Rutt
6.4.1 showed preliminary raw spectra
6.4.1.1 Front chamber missing about 20 out
of 2000 wires. Some are repairable.
6.4.1.2 Rear chamber had problems caused by
conductive epoxy. Have been repaired.
6.4.2 Carbon door remote control good
6.4.3 Controls in general look good
6.5 Remote reset of Fastbus crates not a priority
for this weekend (Kees deJager)
6.6 Eddy Offermann points out that detector map
appears to have errors. Should be corrected.
Eddy will talk with Bogdan.
7 Safety: (Bert Manzlak)
7.1 Reviewed recent safety issues in the Hall
7.1.1 Shielding hut doors
7.1.2 Guards for energized electrical equipment
7.1.3 Egress. Keep paths and stairways clear.
7.1.4 General housekeeping and artistic
expression
7.2 Urges communication with safety personnel.
8 Polarization Issues: (Sirish Nanda)
8.1 Report on discussions of helicity signals in
Data Acquisition at 16O meeting last week .
8.2 Møller Polarimeter:
8.2.1 Mechanical support design almost
completed. Slight snag in that designer
working on it quit last week.
8.2.2 Further discussions of vacuum needs. Ed
Folts points out that some hi tech modern
turbo pumps may not work well in the
radiation environment. Ed also requests
detailed drawings as soon as they are
available.
8.2.3 Work underway at U.Ky. to increase dipole
gap by one inch.
8.3 Hope to have a draft ops manual ready by the
end of the month.
9 Beamline: (Arun Saha)
9.1 High power beam test was unsuccessful (didn’t
reach 200 microamps). Reasons for failure are
believed to be understood. Planning to try
again next week.
9.2 Franco Garibaldi to arrive Thursday
(27 February)
10 Waterfall Target: (Meihua “Meme” Liang)
10.1 Italian engineer is here working on restoring
rotational motion. Problem believed to be a
broken angular encoder.
10.2 Complaint that during the power failure last
weekend the target was turned off but nobody
informed Meme. This prompted the expression of
a need for checklist for what to do when
recovering from a power failure.
11 Electrical Systems: (James Proffitt)
11.1 Q3 Hadron: had to steal parts from Q3 Electron
to repair damage this weekend. Working to get
Electron back up (waiting for parts).
Speculates that problem was triggered by people
running the current up to 2000 Amps, which
should NEVER be done. Requests that people
operating the magnets pay closer attention to
what they’re doing and verify that commands
issued in the controls are executed correctly.
Watch the current go to and settle in at the
desired value.
11.2 Hadron Dipole field regulation software works.
Could be improved.
11.3 Q1 Hadron controller problem requiring reset in
the hall being worked on. At least trying to
setup a remote reset.
11.4 Working with Italians to setup an FSD interrupt
for Waterfall target motion.
11.5 Working on remote operation of spectrometer
collimator.
12 Coincidence commissioning planned for the weekend
after this coming weekend (6 March and following
days). Will set Hadron arm at 63 degrees and stay
there till April.
13 Party: Friday 28 February at 15:00 in the residence
facility to bid farewell to Eddy Offermann
-JJL