Privacy and Security Notice
Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 25 Apr 1996 15:32:37 -0400
Minutes of Hall A Group Meeting 23 April 1996
I. Congratulations to Accelerator Division and Hall A Staff for getting beam on target in
Hall A
II. Budget difficulties still not resolved. Decision expected by the end of this week.
III. Post-Doc Search: Planning to make a formal offer early next week.
IV. Engineering: (Bill Schneider)
A. Beam delivered into Hall A last Thursday (18 April). Congratulations to all
involved.
B. Setting up hydraulics to point electron arm at target.
C. Working on remote controls of magnet power supplies for electron arm
D. Power on to Hadron arm gantry/cradle/shielding hut
E. Pushing cryogenics to Hadron arm
F. Assembling vacuum system for electron arm
G. List of tasks to get detectors ready for beam in May.
H. Concrete delivery this Friday (26 April)
I. Still need to commission dump for high power operation
V. Beamline: (Arun Saha)
A. Reviewed last weeks successes:
1. 18 April: One pass beam in Hall (845 MeV 2%df)
2. 20 April: Two pass beam in Hall
3. 21 April: Two pass beam in Hall with RF separator
4. Optics studies Sunday evening (21 April)
a) showed preliminary results
b) 1st approximation everything looks OK
c) data being analyzed
B. outstanding work:
1. certify dump for high power operation
2. punch list being assembled for target chamber
3. Target control program working remotely via stand alone PC. Need to
hook up to EPICS.
4. Unser and BCM’s need to be hooked up.
VI. Commissioning: (Eddy Offermann)
A. Question for Bill Schneider from Rutgers: Should they bring the first collimator
box this Friday or wait two weeks and bring both boxes together? Answer: Send
the first one ASAP!
B. Work on data analysis code completed.
C. Now 100% occupied by commissioning plan.
D. Franco Garibaldi will be here in May with waterfall target.
E. French Collaborators (QMM and Arc measurement) will be here in May also.
VII. DAQ: (Bob Michaels)
A. Dave Abbott has replaced chips in the VDC TDC’s. This should prevent further
lockup problems.
B. Problem noted last week of occasional loss of synchronicity is now understood to
be the result of rare missing or extra gates on the Fastbus crate and has been
corrected.
C. Nilange has made better on-line diagnostics.
D. Ed brash has identified a new timing problem that has hopefully been solved.
E. Mark Jones has made an electronic logbook. Looks good and is working already.
VIII. Chamber Gas System: (Howard Fenker)
A. Making good progress on plumbing.
B. Possible problem with mixing valves being checked out.
IX. Magnet Measuring and Monitoring: (John LeRose)
A. Colloidal suspension measurements of magnetic center of Q2 electron completed
last Thursday (18 April). Measurements were made of the location of the
magnetic axis relative to the geometric axis at three points along the bore of the
magnet inside the Effective Field Boundaries. Overall accuracy is estimated to be
about +-0.2 mm. Results as follows:
1. Horizontal: Magnetic axis is shifted 0.5 to 1.1 mm to the left facing
downstream. Shift increases from 0.5 to 1.1 as you go from front to back
(just inside EFB’s)
2. Vertical: Magnetic axis is shifted 1.6 to 2.3 mm vertically. Shift decreases
from 2.3 to 1.6 as you go from front to back.
B. Preliminary schedule for Quadrupole field measurements on the electron arm
presented and discussed. Will continue working on with following
considerations:
1. Add Dipole field measurements and Colloidal suspension measurements
to schedule.
2. Discuss with Bill Schneider off-line and try to maximize parallel
operations in order to streamline schedule.
X. Cryotargets: (Jian-Ping Chen)
A. Design is going well. We have the length of the bellows and can place an order.
Bellows is a potential long lead item. Bill Schneider suggests good vendors to
contact for reliable fast service.
B. Both Techs working full time this and last week on the Hall C target. Last month
timesheets indicate that Techs worked half for Hall A and Half for Hall C.
C. Tentatively planning preliminary mechanical design review for next week.
D. Møller:
1. Report from Karkhov with results of magnetization tests on the target.
Annealed targets are getting better and better.
2. Question re format to send drawing files. Answer DXF.
3. U.Ky. tested Al vacuum window. Looked OK. Planning to test Kapton.
4. Magnet Power Supplies: Have located two power supplies among SSC
surplus. One for dipole and one for quadrupole. They have been reserved
by John O’Meara. We’re negotiating. If we get these will still need one
more for quadrupoles.
5. Dipole:
a) Sirish reports that he has been in contact with Los Alamos. They
are willing to cooperate to accomplish the dipole move ASAP.
b) Also contacted 2 private contractors in the Los Alamos area for
estimates. Should have answers within the week.
c) Looking into possibilities for getting other surplus magnets with
similar specs.
XI. Controls: (Javier Gomez)
A. Power Supplies:
1. Q3 electron is now operational (with some small glitches)
2. Q2 electron was run up to 700 Amps for Colloidal Suspension
measurements.
3. James Proffitt is working on isolation amplifiers and buffers for controls
of Q2/3 and the Dipole (electron arm)
B. User Jobs:
1. NMR readouts are done.
2. Yves Roblant has taken on the Hall Probe readout task.
XII. Detectors: (Bogdan Wojtsekhowski)
A. Lift is now scheduled for 1 May
B. Various small problems discussed (TDC scales, unexplained time jitter, etc.)
C. Re rumor that detector stack may not fit in the hut. Jack Segal says that it should
fit but may be a little tighter than planned front to back.
D. Electronics rack map shown.
1. Need to make sure everything is accounted for.
2. Users who anticipate needing rack space either in the hall or in the
counting house should contact their CEBAF liaison
XIII. User Report: Mark Jones (W&M)
A. Working on straw chambers. Ready to transport from W&M to CEBAF
B. Developed electronic run sheet. Sample shown and discussed.
XIV. Using space in detector tent to test FPP chambers discussed.
XV. Waterfall Target tests will be in the EEL.
-JJL