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Archived Messages for HALLA_MIN_1996@cebaf.gov: Weekly minutes

Weekly minutes

John J. LeRose (LEROSE@CEBAF.GOV)
Thu, 22 Feb 1996 17:13:52 -0500 (EST)

Minutes of Hall A Group Meeting
20 February 1996, 15:00
I. Larry Cardman requests from each Hall A Physicist, over the next two weeks, a
list of user institutions and what they are supposed to deliver along with a
status report for each.
II. Engineering (Bill Schneider)
A. About ready to begin cooldown. Still need to establish communication
between Hall and ESR
B. Rumor re cryoconnections being backwards is only partially true and
operationally not a problem
III. Polarimeters and Cryotargets (Jian-Ping Chen)
A. Møller:
1. all four quadrupoles out of the beamline at Los Alamos
2. quadrupole mapping can begin soon
3. Dipole doesn’t fit through passageway!
a) may have to disassemble
b) S. Nanda going to Los Alamos tomorrow (21 Feb.) Will
investigate
4. Target heating tests underway at Kharkov
a) Observed cooling power not as good as calculated
b) Maybe a vacuum problem. Will try again with better vacuum.
B. Cryotargets
1. Hall C target cooldown planned for later this week
2. Hall C techs are now starting to work for Hall A
3. Dimitri Margaziotis and John Mark are here discussing He targets
a) Questions re space for gas handling and controls. B.
Schneider says yes as long as we’re content to keep the
Hadron arm angle at less than 135 degrees
b) E. Offermann points out that calibrateable backward angle on
both arms limited to 162 degrees by the collimator box
c) Need expressed for 5K cooling for high pressure He target
(more later)
IV. Magnetic field measuring and monitoring (John LeRose)
A. mounting brackets for Hall probes in quadrupoles are ready and will go
in on the electron arm this week.
B. finalizing drawings for fixed NMR probe mounts in dipoles
C. document re situation with respect to the sextupole problem distributed
to the users at the collaboration meeting last week. Copies are
available. Contact LEROSE@CEBAF.GOV
V. Sirish Nanda
A. setting up interviews for post-doc candidates
B. People at Yerevan want to extend their MOU
C. next 4 days at Los Alamos (see Møller above)
VI. Controls (Javier Gomez)
A. Visit last week by engineers and technicians from Saclay
1. concern re changes made by CEBAF voiding warranty
2. Q1 removed from cooldown pending settlement of issues
a) Document on modified protection scheme will be sent to
Saclay
b) Saclay will be asked to propose alternatives if they have
objections
B. Similar concerns for Q2/3 and Dipoles.
1. Review committee recommended changes
2. Documents being prepared to inform manufacturers of changes.
Wording and flavor of documents discussed.
3. Various changes discussed
C. Rewriting paper for operational safety committee
D. Sorting communications problems
1. cooldown won’t start until communications are cleaned up.
2. working on the problem. Bill Schneider doesn’t see convergence.
3. trouble locating source of problem. Problem is apparently in the
driver for the serial link.
4. administrative cage rattling on the refrigerator side might help.
VII. Beamline (Arun Saha)
A. Several meetings last week looking at installation work around the
beamline
1. vacuum is installed up to the shield wall
2. all quadrupoles are in place
3. charge monitors will be installed by the end of February
B. Timeline for beamline installation shown
1. all hardware in by 12 March
2. Tests and verifications after that
C. Target chamber being assemble this week. Vacuum by next week.
D. Exit pipe must be assembled and pumped out. Scheduled for mid-March
E. Overall optimistic will be ready for beam 4 April
F. Working through details of arc and ep beam energy measurements
1. P. Bertin expresses need to plan for installation of Cerenkov
detectors for ep measurement
a) need list of beamline work needed
b) discussion of best time to do precision alignment of ep.
Closer to time when it becomes operational seems better.
c) Re CO2 , can we put bottles in the gas shed? Will have to
add more lines but it can be done. (Not needed until
September)
2. P. Vernin elaborates plans for arc measurement
a) install optics part of system in May
b) modification of shield wall is the outstanding unaddressed
task
3. P. Bertin asks for details re documentation requirements for user
supplied equipment. Larry says to check what was done for Hall C
and copy as much as we can.
VIII. Detectors (Bogdan Wojtsekhowski)
A. Cosmic ray data being taken
B. LeCroy HV system failed this morning, replaced and acting up again..
Jack Segal reports that our problems are very different from Hall B’s
C. Outstanding tasks:
1. Safety documents
2. Remote communications with HV, VME, FSCC and TS, power ON/OFF
3. Geometric survey of the VDC pair
D. Regina completed delivery of all elements
1. Aerogel assembly underway
2. One S3 counter assembled
E. Hadron VDC preparation continues, S2 counters for Hadron arm were
repaired by Saclay tech
F. Design of lifting system not complete
G. Howard Fenker reports that design of straw-man gas system complete. Will
setup meeting to review.
H. Bob Michaels is working with Bogdan on detector checkout.
1. Data quality similar to what we had in October
2. Channel jumping problem noted last week has not recurred. Will
continue to run as much as possible and monitor.
3. T. Smith of UNH will create a database for ESPACE
IX. Waterfall targets:
A. Arun Saha in the process of getting engineering drawings
B. Concern re spacing of heads. Will be sorted out by Arun, Eddy Offermann,
Bill Bertozzi, and the Italian group (Franco Garibaldi et al.)
C. Is heavy water problematic? No!
X. Commissioning (Eddy Offermann)
A. Making files for analyzers and Monte Carlo for distribution to the
users.
B. Eddy expresses concern that users be made aware of what sort of mass
data storage capability will be available on site. Next week Bob
Michaels will make a definitive statement as to what will be available.
C. Mohammad Khayat has successfully read magnetic field maps into COSY.
Working on optics studies.
D. Mike Finn expresses need to begin to setup a serious run plan. Eddy will
start working on an organized plan of attack.
XI. MISSING CERENKOV PARTS! Ed Brash reports that some small parts of the
Cerenkov
counters are missing from EEL 122. (e.g. 5 inch diameter rubber rings...) Ed
will write up and distribute a memo detailing the missing parts.
XII. High Pressure He Target possibilities. (D. Margaziotis)
A. Proposes that CSULA provide 3He, 4He cells (pressure less than or equal
to 20 ATM), and 3He recovery system for use with soon to exist
cryotarget system. Design capability is for 1038 Luminosity and cooling
power of 250 Watts. Could be available at the end of ‘97.
B. Assumes 5K cooling capability will be available.
1. must investigate getting colder gas out of ESR or running parallel
line to CHL
2. need to review with cryo group what the total End Station
refrigeration capability is.
C. Concern expressed by Sirish Nanda that 8 cm diameter may be too small.
8 cm is maximum possible within the confines of existing system.
-JJL