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Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 08 May 1997 11:56:02 -0400
Minutes of Hall A Group Meeting 6 May 1997
1 Field Measuring and Monitoring: (John LeRose)
1.1 Have completed field gradient measurements
around the pivot for polarized 3He.
1.1.1 Preliminary indication is that gradients
are very small, making them difficult to
measure. Probably not bigger than
0.030 Gauss/cm with error bars about as
big. Still analyzing data.
2 Beamline: (Arun Saha)
2.1 Spent two days last week getting survey
training
2.2 Reviewed plans for on OTR monitor to give beam
profile and position measurements in the Hall A
Beamline.
2.3 Re questions about current monitoring during
the last run requests that interested parties
meet to discuss.
3 Detectors: (Howard Fenker)
3.1 Putting together some wire chambers for use in
the Møller Cave. Has potential as a low Q2
spectrometer and useful for Møller
commissioning.
4 Cryotarget: (Jian-Ping Chen)
4.1 Gas line installation and leak checking going
well.
4.2 Gas panel wiring started
4.3 Design:
4.3.1 Collimator for Deuterium loop finished.
4.3.2 Dummy target and solid target ladder
almost finished.
4.3.3 Tests of variable frequency power supplies
went well. Still need further testing.
4.3.4 Winding 6 low power heaters.
4.3.5 Working on JT and Solenoid valve controls.
5 Waterfall Targets and Surveying: (Meihua “Meme”
Liang)
5.1 Waterfall:
5.1.1 Italians arriving this Friday (9 May) to
start repairs.
5.2 Survey:
5.2.1 team training underway
5.2.2 Survey crew will be available to help us
during daytime hours in the first 16O run,
but not after that.
5.2.3 Discussion of pointing tolerances. Issues
raised will be resolved outside the
meeting. (How good is good enough?)
6 Installation and Engineering:
6.1 James Proffitt reports:
6.1.1 Electron Q2 is now under EPICS.
6.1.2 Conversion of Hadron Q2/3 is underway.
6.1.3 Working on bogies. Want independent
control of both spectrometers. Should be
completed by the end of this week.
6.1.4 Visitor: Jerry Toole of the magnet review
committee is coming next week (Monday-
Wednesday) to finalize the magnet review.
6.2 Ed Folts reports:
6.2.1 Post is welded on the flange. Will reweld
to pivot tomorrow (7 May).
6.2.2 Plan to remount target chamber tomorrow.
To be surveyed on Thursday (8 May)
6.2.3 Assembling the new diffuser.
6.2.4 0.6 msr collimator installed on Electron
arm. Now have 5 msr, 0.6 msr, and sieve.
6.2.5 Beamline between Møller and girder is in
place.
6.2.6 Still need to switch polarity on Hadron
Dipole.
6.2.7 Plan to start reestablishing vacuum on
Friday (9 May)
7 Controls: (Javier Gomez)
7.1 Investigating NMR lockup problem.
7.1.1 Ran Electron arm for 1 week. Saw no
problem.
7.1.2 Put Hadron arm on GPIB interface and ran
for 1 week also saw no problem.
7.1.3 Don’t know why it locks up during runs.
Something to do with the beam?
8 Møller Polarimeter and Ops Manual: (Sirish Nanda)
8.1 Showed results of field measurements in the
Dipole. Residual field in shielding insertion
is good to about 5 GeV/c.
8.2 Installation is going on schedule.
8.3 Should be ready for next tests during the next
run.
8.4 Ops manual: still no green light. Expect
progress next week.
-JJL