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Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 08 Aug 1996 17:17:37 -0400
Minutes of Hall A Group Meeting 6 August 1996
1 Engineering: (Bill Schneider)
1.1 Concrete fully installed
1.2 Ready for detector lift tomorrow (7 Aug.)
1.3 Electron Arm:
1.3.1 Vacuum all installed except for target chamber (it’s being
aligned)
1.3.2 Collimator box installed and aligned.
1.4 In the process of commissioning the Hadron Arm:
1.4.1 Warm gas from Hadron Arm doesn’t leak into Electron Arm.
The reverse is not true. Will try to repair tomorrow.
1.4.2 Plan to start cooldown the end of next week
1.5 Electrical: (James Proffitt)
1.5.1 Electron Arm Power supplies ready to go. Output contact
problem with Dynapower (dipole) hasn’t reproduced.
1.5.2 Hadron Arm cryo controls almost complete
2 Magnet Measuring and Monitoring: (John LeRose)
2.1 Quadrupole alignments: Addition of QMM (rotating coil) measurements
on Q3 and at exit of Q1 don’t change results reported last week. Leave
Q1 and Q3 aligned according to their geometric centers. Adjust Q2 by
roughly 2 mm. Exact numbers reported to Bill Schneider by memo last
week.
2.2 Dipole maps: very, very preliminary indication is that effective field
boundary location is independent of cycling procedure. Will require
more analysis before this is a firm conclusion.
3 Detectors: (Bogdan Wojtsekhowski)
3.1 Electron stack ready to be reinstalled in the hut. For upcoming runs will
have VDC’s, S1, S2, Pre-shower, Lead Glass, and Gas Cerenkov.
3.2 Showed some recent test results. All looks the same or better than in
May.
3.3 Now have readout for each channel of Pre-shower and Gas Cerenkov
ADC
3.4 Bill Schneider points out that gas fire suppression system is now fully
activated in the hut. To avoid asphyxiation must keep doors open when
working in hut. Also recommends wearing ear protection as the system
is very loud when triggered.
3.5 Al Gavalya is working on shutter for exit window. Suggested trying to
make it reusable with new window.
3.6 Discussed getting Florida International involved in the design and
development of a new thinner window.
3.7 FPP: Ed Brash showed results of recent tests. They’re working on
sorting out assorted small problems.
3.8 Pete Markowitz requests that people be careful when working in the
vicinity of the shower counters, pmt’s are very fragile.
4 Møller Polarimeter and Ops Manual: (Sirish Nanda)
4.1 Dan Dale reports on developments at U.Ky.
4.1.1 Dipole has been refurbished
4.1.2 Testing quadrupole damaged I shipping. Not a big deal we have
spares.
4.1.3 Established fabrication technique for shielding insertion and
identified potential contractors. Expect to start fabrication in
about 2 weeks.
4.1.4 Still collecting power supplies
4.1.5 Detector LED for gain monitoring under fabrication
4.1.6 Dan is looking to borrow a side view pmt for tests. Will contact
Stan Majewski.
4.1.7 Support structure for detectors has some unresolved problems,
looking for engineering guidance.
4.1.8 Working on DAQ and controls. Hope to get CODA running in a
few days.
4.2 Victor Gorbenko presents schematic of electronics for the polarized
target
4.3 Ops Manual: starting to get feedback. Larry urges sending to users for
feedback right away.
5 Controls: (Javier Gomez)
5.1 Working on:
5.1.1 Power supply controls
5.1.2 EPICS problem with gaussmeters
5.2 Trying to do some 6 hour long stability studies of Q2/3 power supplies
this week.
6 DAQ: (Bob Michaels)
6.1 Working on about a dozen small things
6.2 Question: do we want to start working seriously on the fast raster?
6.2.1 Can we make a direct copy of Hall C’s? Bob says probably not.
6.2.2 Eddy maintains that, based on experience at Mainz, raster is not
needed for 16O experiments.
6.2.3 Bob will make a quick study of the capabilities of a direct copy
of the Hall C fast raster in Hall A.
7 Gas Distribution System: (Howard Fenker)
7.1 Cabling and tubing being pulled
7.2 Can begin terminating tomorrow.
7.3 Draft of Ops manual completed.
8 Electronics: (Jack Segal) Getting for detector lift tomorrow (7 Aug.)
9 Cryotarget: (Jian-Ping Chen)
9.1 Joyce Miller:
9.1.1 has finished the mechanical package design
9.1.2 is finishing the cell block design
9.1.3 starting to work on gas handling
9.2 Techs:
9.2.1 have finished leak checking cryocan
9.2.2 will be helping out with the Hadron Arm for the next 3 weeks
9.3 Cryotarget group meeting last week:
9.4 Riad and Gary working on hardware (keeping on schedule)
9.5 Kathy and Fraser working on software with help from Jihnny Tang
(EPICS Group), making progress in spite of some difficulties.
9.6 Technology transfer to Jefferson Lab on cell block etching and plating
with expert (Al Aaron) from U.Md. is going well.
9.7 Still anticipating finished assembly in May ‘97
10 Commissioning: (Eddy Offermann)
10.1 Status of analysis:
10.1.1 Summary table shown: see the postscript version of the minutes on the www
1.1.1 Showed results of various analyses:
1.1.1.1 b determination (need hard information on scintillator
locations)
1.1.1.2 wire vs. TDC time in u-plane (used to determine wire to
wire offsets
1.1.1.3 VDC u12, v12 offsets vs. card #. Systematic offsets can
be result of errors in detector position, still very flat.
1.1.1.4 Angular spectrum on QE data shows angular resolution
on single wires.
1.2 Preliminary Run Plan for 16 August reviewed by Mohammad Khayat:
1.2.1 Two main aspects:
1.2.1.1 Quasi-elastic runs to test detectors
1.2.1.2 Elastic scattering to study spectrometer optics
1.2.2 Plan will be posted on the WWW (see
http://www.cebaf.gov/halla/calibrations/calibration.html)
1.2.3 Anyone (users, this means you!) who has any particular tests
they want done should contact Eddy Offermann
(offerman@cebaf.gov).
1.3 Shift schedule: Eddy asks for student volunteer to coordinate. Riad
Suleiman volunteers. Riad will be contacting people re time preferences
etc.. If you want to participate and don’t hear from him contact him
(Suleiman@cebaf.gov).
-JJL