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Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 05 Sep 1996 17:03:55 -0400
Minutes of Hall A Group Meeting 3 September 1996
1 During Larry Cardman’s absence from the lab (4-19 September) Eddy
Offermann will serve as Hall A Group Leader.
2 Hall A Collaboration meeting scheduled for 11-12 October. Agenda discussed.
3 Engineering: (John Hogan & James Proffitt)
3.1 Hadron Arm:
3.1.1 Still cooling down. Hope to be ready for liquid Helium by the
end of the week.
3.1.2 Installing scattering chamber window for 45 degrees.
3.1.3 Assembling vacuum system.
3.1.4 Dynapower (dipole) power supply checkout proceeding.
3.1.4.1 Anticipating delay because of interruption of LCW for
one week. John Domingo will look into the cause for the
interruption.
3.1.4.2 Larry suggests that people in Accelerator Division be
invited to participate in the checkout since once the
power supplies are fully operational they will inherit
maintenance responsibility.
3.1.5 Q3 readout problem: 5% offset between real and measured
current attributed to method of measurement. Has been
corrected. Explains inconsistencies between 16 and 23 August
runs.
3.2 Question: What configuration do we want for the end of September
runs? Start with both arms at 16 degrees. Will move electron back to 45
degrees later. Engineering can expect 2 weeks tentative notice before a
move and one week definite notice.
3.3 Shield house doors:
3.3.1 Will have to order motors and controllers for mechanized
motion. Not operational until at least the end of October. Parts
are to be ordered.
3.3.2 A handle will be installed in the meantime to facilitate manual
operation.
3.4 Question: Who will have signature authority for large purchases made
during Larry’s and Bill Schneider’s absences? Answer: Eddy Offermann
(temporarily) and John Domingo.
4 Commissioning: (Eddy Offermann)
4.1 Presented summary of measurements made the last 2.5 weekends. (16,
23, & 30 August)
4.1.1 Taking readout problems on Q2/3 into account seems to solve
reproducibility problem
4.1.2 Observed small loss of solid angle attributed to magnetic length
of Q1 being 14 cm longer than design value. Calculations by
John LeRose of acceptance change shown.
4.1.3 Getting focusing at nominal focal plane required large (7%)
reduction in the strength of Q3
4.2 Plans:
4.2.1 Further optics studies
4.2.1.1 with realized quadrupole magnetic lengths.
4.2.1.2 with updated apertures
4.2.1.3 implications of weakened Q3
4.2.1.4 possible options to restore some solid angle.
4.3 Do we install waterfall target the third week in October? Yes!
4.4 Extended target capability needed by 28 September
4.5 Parity Background meeting scheduled for 20-21 September
5 Detectors: (Bogdan Wojtsekhowski)
5.1 Plan to try to install VDC in Hadron Arm Stack this week.
5.2 In general no problems with detectors.
6 Accelerator schedule is being developed. Philosophy and process discussed.
Public meeting re final run schedule planned for 30 September (see
http://www.cebaf.gov/user.index.html)
7 Beamline: (Arun Saha)
7.1 Slanted target for extended target studies being prepared
7.2 Compiling results of current measurement tests
7.3 Question re obtaining help from Accelerator in developing EPICS
drivers for various hardware.
7.3.1 Need to Make a list of exactly what we need.
7.3.2 See what has already been done in Hall C.
8 Controls: (Javier Gomez)
8.1 Finished with EPICS drivers for gaussmeters. Should be in data stream
by the next run.
8.2 Working on EPICS for vacuum gauges.
9 DAQ: (Bob Michaels)
9.1 Making several small improvements to DAQ.
9.2 Question: Should we go ahead and purchase new DAQ computer and
raster hardware? Yes, if we know what we want.
9.3 Bob should contact Steve Wood re Accelerator keeping track of what
target we have in the beamline while running.
10 Magnet Measuring and Monitoring: (John LeRose)
10.1 Been working on optics commissioning
10.2 Septum Magnets Technical review tentatively planned for 3 October.
10.2.1 Have draft document
10.2.2 Franco Garibaldi and Guido Urciuoli will be here next week to
finalize document.
11 Larry asks for volunteer to work with Karen Hokansson on developing a poster
for the DNP meeting re Hall A status. Bogdan volunteers.
-JJL