Privacy and Security Notice
Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 15 Aug 1996 09:38:10 -0400
Minutes of Hall A Group Meeting, 13 August 1996
1 Sirish announces that everyone should have received, via e-mail, a formal call
for input to the Operations Manual. Deadline for submissions is 6 September.
2 Tutorial sessions on magnet and target ladder controls will be held Friday at
13:00 in the counting house.
3 Engineering: (Bill Schneider)
3.1 Almost ready for beam Friday PM. Final preparations pose no problem.
3.2 Planning to start up magnets for checkout Thursday afternoon (13:30)
3.3 Hadron Arm:
3.3.1 expect to start gas cleanup sometime next week
3.3.2 problem of valve cross talk has been corrected
4 Magnetic measuring and monitoring: (John LeRose)
4.1 Still working on whether it is necessary to cycle the dipole or not. At
1500 (4 GeV/c) and 1200 Amps it looks as though, on the 1-2 mm level
the locations of the effective field boundaries are not influenced by
cycling. At 900 and 600 Amps the situation is less clear and may simply
be due to the fact that the signal to noise ratio is less favorable at lower
excitations of the magnet. Recommendation for this weekend is to
perform a simple cycle. Go up to 1750 amps with the power supply
limited to 5 Volts. Wait there 30 minutes. Got down to the desired
current. Wait 45-50 minutes for the field to stabilize (watch NMR
readouts). Then go for it!
4.2 James Proffitt points out that the M3/M4 overtemp warning light came
on again during recent tests of the NMR probes. Investigation suggests
that there is no serious problem. The sensor is just a little too sensitive.
5 Beamline: (Arun Saha)
5.1 Had beam in the Hall last Friday for about 1 hour while Hall C was
down.
5.2 Failed to achieve 2 beam operation. Need to work on injector.
5.3 Test plan for beam in the Hall reviewed (1-2 shifts per weekend)
5.4 Survey systematic errors discussed
5.5 Radiation monitoring plans reviewed.
5.6 Arun’s proposal for adoption of more formalized run sheets as is done
in Hall C leads to discussion of the relative merits of electronic vs. paper
logbooks. Arun will make up run sheets for next weekend.
6 Commissioning: (Eddy Offermann)
6.1 Everyone should have heard from Riad re shift schedule.
6.2 Visitor from Italy, Roberto Peroni, is introduced. (Software specialist
for gas Cerenkov )
6.3 Run Plan is posted on the WWW
6.4 Need to update programs and command files for data analysis.
7 Cryotarget: (Jian-Ping Chen)
7.1 Still working on target cell and cell block design.
7.2 Now have finished drawings of He cell and cell block.
7.3 Dummy cells discussed. Will have thickness with the same radiation
length as the full target.. Experiments with special needs should contact
Jian-Ping.
7.4 Software: Kathy is making good progress. All software has been ported
to Hall A.
7.5 Pressure transducers and gauges being tested
7.6 Tachometer almost finished
7.7 Christoph Jutier has returned from France.
7.8 Target meeting planned for Friday morning (16 August)
8 Detectors:
8.1 Jack Segal reports that we are unable to locate all our CCD cameras and
our portable oscilloscope. He’s buying locks for the cabinets.
8.1.1 Ives Roblin says he has the O-scope.
8.2 Jack and Bogdan both say there’s a lot of reconnecting to do to get
ready for Friday.
8.3 Bogdan Wojtsekhowski reports:
8.3.1 Operational Safety Manual for the VDC’s has been completed
by Kevin Fissum.
8.3.2 Plan to install VDC under Hadron Arm detector frame next
week. Will help with FPP studies
8.3.3 Gas Cerenkov ready for run.
8.3.4 Shower counters still require some cabling. Help is solicited.
8.3.5 FPP:
8.3.5.1 Ed Brash has achieved 0.4 mm resolution on first try.
8.3.5.2 Trying to develop operating parameters for gas.
8.3.5.3 Carbon analyzer requires repair of bearing on one light
door
8.3.6 U. Regina group:
8.3.6.1 Prepared design of the frame for the aerogel counter
8.3.6.2 Assembled 4 S3 counters, PMT’s installed, HV tested.
8.3.6.3 Concept for S3 frame design is completed.
-JJL