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Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Mon, 02 Dec 1996 09:42:14 -0500
Minutes of Hall A Group Meeting 26 November 1996
1 Announcements: (Larry Cardman)
1.1 Quarterly in lab status reports are needed by
16 December. Larry reviewed present report and
plan (available on www). Asks that present plan
be reviewed and suggestions forwarded to him by
next week (1st week December)
1.2 Accelerator division is starting to take
responsibility for various things (Beamline
etc.). They have asked that we have a meeting
with them to layout what we will expect of them
in the foreseeable future. Tentatively
scheduled to happen at our regular weekly
meeting on 17 December. People should be
provide Larry before then with:
1.2.1 Plan views
1.2.2 Time scale
1.2.3 Resources required.
1.3 Reviewed ‘97 budget. Copies available (see
Larry)
2 Engineering: (Bill Schneider)
2.1 Hadron Arm:
2.1.1 Dipole is filling. Checkout begins
tomorrow (27 November)
2.1.2 Vacuum chamber is fully assembled. Chasing
down leaks.
2.1.3 Detector stop has been installed. Detector
stack can move into hut anytime.
2.1.4 Set at 16 degrees with no mispointing.
(We’re leaving electron arm as is with
deliberate mispoint)
3 Commissioning: (Eddy Offermann)
3.1 Momentum resolution at 845 MeV is 3E-04 FWHM
over full acceptance with sixth order
corrections (expect 2E-04 at delta=0 from exit
window)
3.2 Bill Schneider asks if it is possible to put
thicker window with Kevlar reinforcement on
scattering chamber (safety concerns). People on
Oxygen experiments charged with evaluating the
possibility.
3.3 Bill also points out that we should expect to
interleave running with maintenance and
installation in the hall even after 1 February.
4 Detectors: ( Bogdan Wojtsekhowski)
4.1 Hadron arm DAQ is working
4.2 Shows TDC spectrum (#events vs. time) from
electron arm VDC’s with strange bump in what
should be flat accidentals background. Several
theories put forward and discussed to no
conclusion.
4.3 Pre-shower and shower counters are looking
good.
4.4 Aerogel shipment (Federal Express) from Regina
had $12K worth of damage (was insured).
Pictures shown by Maja of smashed aerogel
tiles.
4.5 Surik ??? from Yerevan has arrived on site.
Will be working with Bob Michaels.
5 Cryotarget: (Jian-Ping Chen)
5.1 Showed plans for platform. Worried time period
available for installation in hall (2nd half of
January) too short. Bill Schneider reiterates
his observation that we will need to interleave
periods of beam with periods of maintenance and
installation.
5.2 Techs getting parts together for tank fittings
and upstream target window.
5.3 Students and post-docs continuing as before.
6 Controls: (Javier Gomez)
6.1 Working on getting controls in order for Hadron
arm.
6.2 Sees no major obstacles to being ready for
12 December.
7 Møller Polarimeter: (Sirish Nanda)
7.1 Expressed concern re quadrupole installation.
7.1.1 Support structure still in design
7.1.2 Meeting either Monday or Thursday next
week (1st week December) to review
planning.
7.2 Action item: Quads should be moved into the
hall. Bill Schneider says they will go in
tomorrow (27 November)
7.3 Expresses need to have signals from polarized
source down in the Hall (not just in the
counting house as in Hall C. Larry suggest that
we set up for both.
8 Waterfall Target and Hadron Arm Electronics: (Meihua
Liang)
8.1 New (English) operating system installed on
Mac’s with help from E. Offermann. System seems
more stable now.
8.2 Problems with motion control discussed.
8.3 Ethernet connection: Steve Wells suggested
using fiber optic ethernet connection. Not
clear that this is the problem, but probably
worth trying.
8.4 Working together with Maja and Bob, Hadron Arm
trigger looks to be in good shape now. Showed
S1 S2 ADC and TDC spectra from cosmics data.
Some miscablings have been found, still working
on it.
9 Magnet Measuring and Monitoring: (John LeRose)
9.1 Hadron arm NMR’s are installed. Special thanks
to Ed Folts for crawling inside the magnet to
make the actual physical installation.
9.2 Discussed problems with probe 5 on Electron
Dipole not locking. Needs further
investigation.
10 Beamline: (Arun Saha)
10.1 Report on tests of Arc Scanner by Pascal Vernin
10.1.1 Observed 60 Hz instability in beam
position.
10.1.1.1 We knew it was there.
10.1.1.2 Must get rid of it to make the
desired energy measurements
10.1.1.3 Arun Saha points out that team to
install fast feedback system in
accelerator has been disbanded. It
will have to be reactivated.
10.1.2 Signal to noise ration much less
favorable with C wire as compared to
results with W wire in superharp. (C can
take higher current) Possible solutions
include:
10.1.2.1 Bremsstrahlung measuring
10.1.2.2 Filtering
11 DAQ: (Bob Michaels)
11.1 Working on Hadron Arm
11.2 Reports on computer center meeting re data
analysis farm.
11.2.1 See Bob for transparencies
11.2.2 Suggests we invite speaker to one of our
data analysis meetings to make
presentation.
11.3 Fast raster: reports that presentation was made
at accelerator planning meeting regarding our
plans for the raster.
-JJL