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Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 22 May 1997 12:08:47 -0400
Minutes of Hall A Group Meeting 20 May 1997
1 General Announcements: (Kees deJager)
1.1 Thanks to all for the hard work in getting the
Hall up and running over the past week.
2 Installation: (Ed Folts)
2.1 Hall is now closed
2.2 Target protection windows being added to the
Hall Closure checklist.
2.3 Electron arm is at 100.7 degrees, Hadron arm is
at 23.2 degrees
2.4 0.001” stainless steel window is installed on
the waterfall
2.5 New Kapton window is installed on the
scattering chamber. Should be good for 6
months. People asked to BE CAREFUL around the
window.
2.6 Having problem with plated Be windows. Ni is
delaminating (peeling) away from the Be.
2.7 New diffuser is installed.
2.8 Jack Segal report two outstanding items on his
list:
2.8.1 Need to install flammable gas stickers on
the Electron Arm cable trays.
2.8.2 Cameras not fully installed.
2.9 James Proffitt reports:
2.9.1 All quadrupoles are now under EPICS
control.
2.9.2 Bogie controls are in place. Meme is
trained in their use.
2.9.3 Bob Michaels requests an updated list of
EPICS variables
2.9.4 New better field regulator for the Hadron
Dipole is completed but not yet tested.
We’re still using the old one.
3 Run Plan and Status: (Meihua “Meme” Liang)
3.1 Reviews runplan:
3.1.1 Target thickness tests
3.1.2 Dipole reproducibility tests (some
discussion of usefulness of planned tests)
3.1.3 Normalization
3.1.4 Data taking: reviewed planned
measurements.
3.2 Status:
3.2.1 Special thanks to survey group for coming
in over the weekend and surveying the
target.
3.2.2 Closed Hall Sunday 2200
3.2.3 Saw first beam around 0300 Monday
3.2.4 Discovered today that protective window
hadn’t been removed from scattering
chamber. Must redo what little was done
yesterday.
3.2.5 As of 1330 today (Tuesday 20 May) have
seen no beam since noon Monday (19 May)
3.2.6 We will have beam until noon on Friday
(23 May)
3.3 Results of first survey of Electron Arm
position by Hall A Physicists (Meme, Paul Rutt,
and John LeRose) agree very well with results
from survey group.
3.4 Discussion of variations in beam position.
4 Output from latest scheduling committee meeting
(Kees deJager)
4.1 Tuesday (27 May) is a maintenance day. We will
try to move Electron Arm to 16 degrees. Hall to
be closed in the evening for polarized source
commissioning
4.2 Starting swing shift Wednesday we have 5 shifts
for PID studies and parity detector tests.
4.3 On Friday (30 May) Electron Arm goes back to
100.7 and is surveyed. 16O (845 MeV) comes back
on-line with the swing shift and continues
until Thursday 5 June.
4.4 16O at 1.6 GeV will start on 6 June
5 Møller Polarimeter: (Sirish Nanda)
5.1 All heavy equipment installed and checked out.
5.2 Detectors partially installed. One plane of
Scintillators to go (not necessary except at
high energies and currents)
5.3 Electronics are all setup
5.4 Ready for first measurement of asymmetry. Needs
to make formal request for beamtime.
5.5 Target cooling is still somewhat down the road.
Can handle 2-5 microamps without it.
5.6 Howard Fenker reports on test chamber tests.
(Small wire chamber in front of Møller
detectors)
5.6.1 Cosmic ray data consistent with uniform
response.
5.6.2 Preliminary indication is that everything
is working fine.
5.6.3 Still no data with beam.
6 Larry Cardman compliments the group on timely and
efficient completion of OSP and related documents.
7 Cryo-Target: (Jian-Ping Chen)
7.1 All planned installation for this access period
was completed.
7.2 Wiring for the gas panel is halfway completed.
7.3 Have started assembly of the main target loop.
7.4 Variable frequency power supply has been tested
by Riad Sulieman.
7.5 Work continues on control electronics and
software
7.6 Meeting: 23-24 May for polarized 3He. Friday AM
will meet in residence facility, Friday PM in
A110, Saturday in L104.
7.7 Question re safety of various components when
used with H2 discussed.
8 DAQ: (Bob Michaels)
8.1 New version of ESPACE has been assembled and is
now available on the web.
8.1.1 Warns that one must use the new version of
the database with the new version of
ESPACE and appropriate old versions of the
database with old versions of ESPACE.
8.2 Planning to do some CODA development work over
the holiday weekend.
8.3 Bob will not be here next week. Dave Abbott is
on call to address DAQ problems.
8.4 Raster status:
8.4.1 Power supply tested
8.4.2 Accidentally burned out a coil. New one
being made.
8.4.3 Still must setup up mounting for the power
supply.
8.4.4 Could be installed in July.
9 Beamline and 16O experiment: (Arun Saha)
9.1 Thanks to all for getting the experiment
running.
9.2 Remaining issue: re VESDA fire suppression
system, when can it be installed? During
11 August to 17 September shutdown.
10 Magnet Measuring and monitoring: (John LeRose)
10.1 Reviewed results of measurements of magnetic
field gradients in the target area. With Q1
Electron energized for 4 GeV/c electrons saw
nothing greater than 30 milliGauss/cm.
11 Detectors: (Bogdan Wojtsekhowski)
11.1 Gas Cerenkov: tube bases on electron arm
modified. Spectra look better but still have
too few photoelectrons
11.2 Showed shower vs. preshower counter pulse
height spectra showing some electron-pion
differentiation. Need more calibration data.
11.3 Shower detector meeting was held on 9 May
11.3.1 package is now available for shower
detector analysis in ESPACE.
11.4 Will need to build various detector components
(Frames etc.) Requests services of Al Gavalya.
12 Reminder Monday 9 June is John Domingo day.
-JJL