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Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 27 Mar 1997 13:22:30 -0500
Minutes of Hall A Group Meeting 25 March 1997
1 Run Summary: (Bob Michaels)
1.1 Review list of accomplishments (almost all of
the plan)
1.2 Problems:
1.2.1 Trigger setup errors
1.2.2 Poor beam availability
1.2.3 NMR troubles
1.2.4 Magnet trips
1.2.5 Fields sometimes not recorded accurately.
1.2.5.1 Kees adds that logbook should
indicate all problems AND their
solutions. Shift summaries should
reiterate.
1.2.6 Too few volunteers for shifts. (Riad took
3 shifts including 16 hours straight. This
shouldn’t happen)
1.3 Discussions of ways to encourage run
participation.
1.4 Discussion of acceptable deadtimes and
distinction between Data Acquisition deadtime
and others.
2 Installation/Engineering: (Ed Folts)
2.1 Q2 Hadron liquid level problem fixed (was causing
trips during run)
2.2 Working on cause for Q1 Electron trips.
2.3 Hall to close tonight at 19:00 for high current
beam tests. (Meme will make sure target is out
of beam)
2.4 Have begun staging for the shutdown next week.
If you have anything to add to the work list
it’s too late. List already includes:
2.4.1 New waterfall target
2.4.2 Møller quadrupoles and stands, target
chamber, and dipole stand
2.4.3 Raster
2.4.4 (e,p) chamber
2.4.5 LCW for Compton and Møller
2.5 Target FSD is installed and tested. Still must
call MCC before moving target.
2.6 Checking out cryogenics problems with
diagnostic strip chart tool provided by J.
Proffitt.
2.7 Problem of running Q2/3’s at high currents
discussed. It appears that lead flows are
inadequate for high current applications. Any
plans involving high quadrupole fields should
be discussed with James Proffitt beforehand.
3 Run plan for 27 March: (Paul Rutt - run coordinator)
3.1 Main objective is FPP spin tests. Single magnet
settings O(e,e’p) very high statistics. If
significant progress toward this goal is not
made by Saturday evening the Møller run in Hall
C may be scratched.
3.2 lots of other test plans
3.3 Trying to close the hall at 19:00 Wednesday
(26 March) and have beam on target by 8:00
Thursday (27 March)
3.4 Will have 3 FPP people on each shift along with
1 or 2 general Hall A experts.
4 Møller Polarimeter and Ops Manual: (Sirish Nanda)
4.1 Ops Manual almost ready
4.2 Møller:
4.2.1 Dipole should be delivered 8 April (moved
6 days forward)
4.2.2 Reviewed plans and schedules for shutdowns
4.2.2.1 April: Quadrupoles and stands
4.2.2.2 May: Dipole and Target
4.2.3 Danfysik says first power supply will be
shipped 15 April. (The second 20 May.)
5 Controls: (Javier Gomez)
5.1 Learning analysis codes
5.2 Discussed need for high luminosity test run
before Deuterium experiment.
6 Beamline: (Arun Saha)
6.1 Working on Ops Manual contributions
6.2 Have Located vendor for Be window plating.
6.3 Points out that grants are available for
teachers over the summer.
7 Detectors: (Bogdan Wojtsekhowski)
7.1 VDC’s:
7.1.1 Remote control of High Voltage now
available (notes calibration problem)
7.1.2 Juncai Gao confirms that Electron arm VDC
is in the correct position. Will weld
permanent stop in place today.
7.1.3 Hadron arm database is not complete.
7.2 Gas Cerenkov’s:
7.2.1 High Voltage scan is completed.
7.2.2 French team will be here in April to test.
Plan to open and check mirror positioning.
7.3 Lead glass counters were not ready for last
weekend. Preshowers are now taking cosmic ray
data. Expect full array ready by tomorrow
(26 March)
7.4 Javier Gomez warns that the High Voltage
supplies will be going back for upgrades during
the first week in April.
7.5 High Voltage Trip time test report by Howard
Fenker.
7.5.1 New LeCroy supplies trip very fast. This
is good.
7.5.2 They trip so fast that the trip must be
disabled during power up. This is not
good.
8 Magnet measuring and Monitoring and Optics: (John
LeRose)
8.1 Trying to get up to speed on ESPACE to analyze
some of the commissioning.
8.2 Outlines problem encountered in September
commissioning run data pointed out by Meme. Two
“identical” runs, one with sieve in and one
with open collimator displaying apparently
different momentum focusing properties. Traced
problem to bad or at least ambiguous field
setting in Q2. Current readings the same within
0.01%, but field readings differ by 4.5%.
Points to need for good record keeping.
8.3 Trying to catalogue optics commissioning runs
with an eye toward checking consistency of
field settings.
9 Electrical Engineering: (James Proffitt)
9.1 Recalibrated Q2 Hadron ADC. Someone accidentally
destroyed calibration during the weekend run.
Points to need to be careful with magnet
controls. Q2/3 controls are far from foolproof.
9.2 Collimator interlock circuits are finished.
Software still needs work.
10 Cryogenics Controls: (Paul Brindza)
10.1 Discussion of need to turn over cryogenics
controls to Accelerator.
10.2 Paul demonstrates that cryo control loops need
to be carefully tuned and haven’t been.
11 Waterfall Target and Hadron Arm Commissioning:
(Meihua “Meme” Liang)
11.1 Waterfall:
11.1.1 New parts to be shipped from Italy
tomorrow (26 March)
11.1.2 Franco Garibaldi will be here 2-9 April
to install new waterfall target.
11.1.3 Broken encoder has been sent to Italy for
vendor evaluation. (Had small problem with
import duty. We just paid.)
11.1.4 Spectrometers being surveyed today and
tomorrow (25-26 March) Volunteers lined up
to take lessons.
11.2 Hadron arm optics study encountered a problem
with ESPACE. Trying older versions to see if
the problem goes away.
12 Electronics: (Jack Segal) Working on terminating
fibers in the Hall.
13 Cryotarget: (Jian-Ping Chen)
13.1 Working on modification of the cell block
adjustment.
13.2 Design work continues on the loop layout and
target ladder.
13.3 Installing temperature sensors on the heat
exchanger.
13.4 Solenoid valve control prototype tested and OK.
13.5 Polarized He cell test:
13.5.1 Partially setup in Hall C last Friday.
13.5.2 Had safety review.
13.5.3 Will finish this Friday (28 March)
13.5.4 ready to run Saturday through Tuesday
(29 March - 1 April)
-JJL