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Archived Messages for HALLA_MIN_1996@cebaf.gov: Hall A Minutes
Hall A Minutes
John LeRose (lerose@CEBAF.GOV)
Mon, 08 Apr 1996 14:30:35 -0400
Minutes of Hall A Group Meeting 2 April 1996
I. Beam Schedule, Summary Version, Not formally issued yet.
A. 4/3-4 PSS Certification
B. 4/15-21 First beam to Hall A
C. 5/1-12 Parasitic beam available for tests (if no serious problems with RF separators and
we are ready for it)
D. 5/14-23 First Beam to e-spectrometer (Hall A has first priority)
E. 5/28-7/9 Shutdown
1. A-line Al. vacuum chambers installed
2. Begin Hadron Arm mapping
F. 7/10-8/30 Parasitic beam available
G. 9/4-16 Shutdown:
1. Hall B beamline
2. superharp installed
H. 9/19-11/21 Beam available for commissioning
I. 12/5-24
1. commissioning continues
2. 89-003/033 begin (commissioning experiments)
J. 12/25-2/4/97 Shutdown (Hall A Møller installation completed (if not done earlier)
K. 2/5-3/17
1. Møller commissioning
2. 89-003/033 continue
L. 3/20-4/30 Hall A Cryotarget installation
M. 5/1 Normal Physics program begins following EXPINT plan.
II. Critical dates or observations re the above schedule:
A. 4/15 basic beamline ready
B. 5/1 and after: Strong User presence useful and desirable.
C. 5/14 electron spectrometer ready
D. until 11/21/96 can run on TOSP’s (Temporary Operating Safety Procedures) after that all
safety reviews of all aspects of the equipment must have been met.
E. 12/5 both spectrometers and coincidence operation commissioned
F. 2/5/97 Møller ready
G. 3/15 cryotarget ready for installation
III. Engineering (Larry Cardman reports in Bill Schneider’s absence)
A. cooldown of magnets: having hiccups fits and starts but no major problems
B. checking out electrical/protection circuits for power supplies
C. final girder just about assembled and ready to go in.
D. Scattering chamber is on the pivot post
IV. Commissioning: (Eddy Offermann)
A. Discussed anticipated count rates for early sieve slit measurements
B. TDC/ADC bug in ESPACE fixed
C. Sieve Slit Box is still not here
D. Working on commissioning plan
V. Beamline: (Arun Saha)
A. Reviewed checklist of tasks and assigned people
1. fair fraction already completed
2. list will be reviewed in meeting on Thursday (4 April)
3. everything looks to be under control
B. Wobbling of solid target post has been measured to be +-250 microns and is reproducible.
The problem is understood but repair attempts will wait until the June shutdown.
VI. Magnet Monitoring and measuring: (John LeRose)
A. First (of two) fixed NMR probe rack for the electron dipole is fully assembled and ready
for installation in the magnet. Second will be ready shortly.
B. Jeff Martoff (Temple U.) has been informed of the schedule and should be prepared to
make colloidal suspension measurements on 10 April. Will double-check with him.
C. Further studies of the how to determine roll angles of the quads based on sieve slit
measurements of nonmidplane symmetric transfer elements show that it is important in
such an analysis to know that y0 is actually equal to zero. y0=1mm is equivalent to a roll
of Q3 of just less than 1mr. Trying to extract y0 and the roll angles should work in
principle but so far is giving ambiguous results.
VII. Chamber gas system: (Howard Fenker)
A. Mixing system ready for leak checking
B. Expecting major delivery of parts tomorrow
VIII. Controls: (Javier Gomez)
A. Working on several parallel tasks
1. Alignment of bench
2. Decoding Fug controls
3. EPICS driver for NMR gaussmeter
B. Re help from Chip Watson, nothing yet.
IX. Cryotargets and Polarimeters: (Jian-Ping Chen)
A. Cryotarget
1. Have received various tools and parts from SLAC
2. Larry Philips has agreed to provide help in making cells. He provides access to
shop equipment. We provide manpower.
3. Have received first heat exchanger.
4. Problems with second will cause a six week delay.
5. Working on sensor readout
6. Loop Pump package ready to go out for machining except need paperwork from
SLAC releasing drawings
7. Joyce Miller officially started working on design yesterday (1 April NO
FOOLING!)
B. Hall C Target:
1. Running with one loop
2. Recovery system works well (one hour recovery time)
C. Møller: no progress on dipole at Los Alamos.
X. Detectors: (Bogdan Wojtsekhowski)
A. Data taking stable
B. 2 triggers in place
C. Retuning timing for S1/S2
D. Level Translator save 60 ns on trigger
E. Shower counter test OK.
F. There is a need to analyze data taken with different triggers. Bogdan does not have time to
do it himself.
G. E. Offermann expresses concern over use of complicated triggers during optics studies.
H. Showed puzzling TDC spectra taken with high rate source. Discussed but unresolved.
(“Don’t leave the high rate source on the scintillator when we take data.” - E. Brash)
I. Drift time spectra shown and discussed. Tails attributed to bad gas. Should go away with
new gas system.
J. Scintillator ADC spectra shown indicating need for some retuning of PMT gains.
K. Also displayed were:
1. Preshower ADC spectra
2. efficiency of VDC planes
3. 6 cluster resolution vs. wire number
L. Test lift next week
XI. DAQ: (Bob Michaels)
A. Agreed with Bogdan re need for more people to analyze data. (User community take
note!)
B. Has list of things that need to be done in the counting house. List will be reviewed in a
separate meeting with Bob, B. Schneider, J. Segal, and L. Cardman.
C. Larry Cardman points out that Dave Heddle has developed an event display for Hall B and
was wondering if we have interest.
D. Weekly progress meeting on DAQ being held every Wednesday at 10 in the counting
house.
XII. RE getting SSC surplus:
A. contact Dale Ouimette.
B. What is supposed to happen:
1. Most of what comes in is preassigned
2. It all goes to a warehouse. Where Dale and someone from accelerator direct its
disposition.
XIII. In the future guest workers will be asked, one at a time, to present a ten minute summary at the
end of the Tuesday meeting of what they have been working on. Mohammad Khayat will
organize.
XIV. Long discussion re Bill Bertozzi’s request to add neutron parasitic experiment to oxygen
experiment. General feeling seems to be that fielding a parasitic experiment may be taking on too
much in the early running.
XV. Ed Brash points out 2 problems in Hall C:
A. That the pivot has become sufficiently contaminated by the beam that people have to have
level 2 radiation training to work there.
B. There are problem with the protocol for communication between accelerator operations
and the experiment on-line. Being ironed out in Hall C but we should be aware of the
problem.
-JJL