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Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Fri, 06 Dec 1996 11:32:37 -0500
Minutes of Hall A Group Meeting 3 December 1996
1 Announcements: (Larry Cardman)
1.1 Hall Leader’s Office (C114) is to be vacated by
15 December. Occupants should see Mike Syptak
or Janet Prater for alternate arrangements.
1.2 New accounts have been setup for Cryotarget and
Compton Polarimeter expenses. Jian-Ping needs
to get signature authority.
1.3 Staff reminded of last weeks request for
information for the 17 December meeting. Memo
has been circulated.
1.3.1 Draft agenda reviewed
1.3.2 Need one page summaries of work needed,
general layout, etc. no later than Monday
(9 December)
1.4 Re Accelerator Fast Feedback team.
1.4.1 “Team” was disbanded, as reported by Arun
Saha last week, but all pieces are being
pursued. Expect to implement the fast
feedback system in the next 6 months.
1.4.2 Warning that implementation as now seen
may not be effective for ARC energy
measurement purposes.
1.4.3 V. Lebedev is the person to talk to.
2 Engineering: (Bill Schneider)
2.1 Hadron Arm:
2.1.1 James Proffitt reports that dipole has
been run at 100 Amps. Measured inductance
is 3.2 H (what we expect)
2.1.2 Controls are almost complete
2.1.3 Ed Folts reports:
2.1.3.1 Vacuum is in 1E-04 range.
2.1.3.2 Modifying exit beam pipe to get
better vacuum.
2.1.3.3 Planning to change diffuser
2.2 Present layout for Møller doesn’t interfere
with truck access. (It was feared that it
would)
2.3 Drawings for fast raster have been updated.
Location is just in front of ep scattering.
3 DAQ: (Bob Michaels) Everything seems to be in
working order.
4 Magnet Measuring and monitoring: (John LeRose)
4.1 Hadron Arm NMR installation is almost
operational. Just some external cabling left.
4.2 Trying to resolve Pascal Vernin’s need for
information on Quadrupole locations for use
with his field measurements.
5 Commissioning: (Eddy Offermann)
5.1 Finishing last calibrations at 845 MeV
5.2 Working on detailed plan for next year.
5.3 For upcoming run:
5.3.1 Is transducer readout for sieve position
on Hadron arm available? Yes.
5.3.2 Target: same as last time.
5.3.3 Scattering chamber window is 5 mils
kapton. Spectrometer vacuum window at
entrance is 7 mils kapton. Exit is 4 mil
Ti.
5.4 Working on calculation of effect of adding
8 mils of kevlar to scattering chamber window.
(Arun Saha recommends talking to Cynthia Keppel
re kevlar reinforced windows.)
6 Beamline: (Arun Saha)
6.1 Report next week on field measurements of
standard arc dipole.
6.2 Reorganizing web page three main categories:
6.2.1 General information
6.2.2 Equipment documentation
6.2.3 Experiments.
7 Controls: (Javier Gomez)
7.1 Writing and testing Hadron arm controls.
7.2 Report on beam readout meeting:
7.2.1 Preliminary plans allows us to compensate
event by event for beam position.
7.2.2 Discussion of various ways to handle the
combined raster and beam position readout
problem.
8 Waterfall target and Hadron arm electronics: (Meihua
Liang)
8.1 Hadron Arm:
8.1.1 ADC cabling checked out with help from
Maja.
8.1.1.1 request that no one change any
cabling without contacting either
Meme or Maja. (Apparently Bogdan is
at it again! He explained the tests
he was making.)
8.1.2 Hadron arm is ready for electrons
8.1.3 Detector map is in place.
8.1.4 Need for three cables from Hadron arm to
counting house discussed. Won’t need until
February.
8.2 Waterfall target:
8.2.1 Have made optical fiber connection and
have run for 5 days without a problem.
8.2.2 Franco Garibaldi coming next week with a
technician.
9 Cryotarget: (Jian-Ping Chen)
9.1 Platform went out for bids. Still hoping to
fabricate by mid January and install the 2nd
half of January.
9.2 Techs now have 10 “beer cans” with
approximately 4 mil windows. Getting setup to
make precise measurement of cell thickness.
9.3 Techs have started working on plating
procedure.
9.4 Dimitri is bringing more He cells.
9.5 Students and post-docs continuing as last week.
10 Detectors: (Bogdan Wojtsekhowski)
10.1 Electron arm is operational
10.2 Hadron arm:
10.2.1 Trigger is working
10.2.2 Cables checked out
10.2.3 VDC’s are working. HV is on. Resolution
and efficiency are not yet tested.
10.2.4 Will be running cosmics continuously
starting today. (3 December)
10.2.5 Access problem for FPP. Paul Rutt will
talk to Bert Manzlak re safe solution.
10.2.6 Exit window flange has 2 inch alignment
error.
10.2.6.1 Caused by boxbeam misalignment.
Hard to fix.
10.2.6.2 OK as is for December run (only
need point target acceptance)
10.2.6.3 will rework window to center on
optic axis for February.
10.2.6.4 implications re upgrade to thin
window discussed.
10.2.6.5 concern also expressed re possible
sources of assymetric background.
-JJL