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Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Wed, 29 Jan 1997 17:29:36 -0500
Minutes of Hall A Group Meeting 28 January 1997
1 Kees de Jager reviews the Hall A schedule for the
coming year. Highlights include:
1.1 1st beam weekend 15 February for ARC tests.
1.2 Hadron Arm commissioning starts around
20 February with assorted short runs. Will need
to formulate detailed plans.
1.3 Coincidence commissioning begins in early March
1.4 16O experiments run from May through August
1.5 Cryotarget operational by late September.
2 Hadron Dipole Status:
2.1 Have successfully ramped up to 900 Amps
(0.15 Amps/sec) without any problems.
2.2 Small “quenches” on ramp down from 1000 and
1100. Will try slower (0.1 Amp/sec) ramp down
tomorrow (29 January) to see if it goes away.
3 Engineering: (Ed Folts)
3.1 Working through list of safety items.
3.2 TACL to EPICS conversion still not complete
3.3 Started installing automatic lead flow control
3.4 Working on manual vertical positioning system
(temporary solution)
3.5 Trying to get all extraneous things out of the
Hall. Recall that things in the hall while
there was beam have to be surveyed before they
can be removed. If you have something that can
go talk to Ed.
3.6 Drawings being made for fixtures needed to make
holes in the large Kapton window.
4 Beamline: (Arun Saha)
4.1 Pascal Vernin reports that the super harp is
installed and its software is working. Ready
for beam as soon as downstream vacuum is
established
4.2 Pierre Bertin reports on status of ep beam
energy measurements:
4.2.1 Planning electronics test with detectors
in place later this week.
4.2.2 Have solution to 3D measurement problem.
4.3 Reviewed new waterfall target layout allowing
14 degree minimum angle (add 2 to 3 to allow
for acceptance etc.). Expect to have target
here by 2nd week of March.
5 DAQ: (Bob Michaels)
5.1 Upgrading DAQ computers to CUE environment. Can
expect shutdown of HP’s for switchover later
this week.
5.2 New scratch is available. e-mail has been
circulated re access.
5.3 Work disk is the same as before only twice as
large. Plan to clean disk every day if more
than 95% full. (Delete largest and oldest files
until only 90% full)
5.4 Fast Raster: will require some space in the
EEL.
6 Commissioning: (Eddy Offermann)
6.1 Nilange Liyanage reports on acceptance studies
using commissioning data.
6.1.1 outlined procedure
6.1.2 Extracted water foil thickness’ by
comparison to BeO data. Observes that not
all foils are the same thickness. Arun
explains that this is as expected.
6.1.3 Results seem to agree rather well with
simulations (with a few caveats)
6.2 Juncai Gao reports on Beam and Focal Plane
energy calibrations using systematic study of
elastic peaks at 16 and 45 degrees. Gets
agreement to a few parts in 10E-03 with
expected values.
7 Cryo Target: (Jian-Ping Chen)
7.1 Installing platform this week
7.2 expect to install gas tank next week
7.3 warm return line design completed
7.4 Techs working on U-tubes
7.5 Gas panel frame completed
7.6 All cells now plated (8 long and 4 short)
7.7 Lars Ewell has been looking into the Vapor
Pressure Transducer radiation damage problem.
Solution may be to put the transducers behind
the shield wall attached to the target by a
long tube.
8 Controls: (Javier Gomez)
8.1 Working on alignment system. Expect to start
making sketches this week.
9 Waterfall Target and Detector Electronics: (Meihua
“Meme” Liang)
9.1 Working on optimization of three foil
positions.
9.2 Testing change in MLU mode to get rid of
sporadic time shifts.
10 Møller Polarimeter: (Sirish Nanda)
10.1 Good news and Bad news:
10.1.1 Bad news: Shielding insertion did not
pass acceptance. Steel quality was not
adequate.
10.1.2 Good news: Vacuum system is OK.
10.2 Meeting tentatively planned for 6 February.
10.3 Hardware for target has been completed by Kevin
Jordan and handed over to the software people.
Target looks to be in good shape.
10.4 Dannphysik is asking for a two week delay in
the delivery of the first power supply. (Moves
to mid March). Second power supply (Compton)
will be shipped on 1 April but will not arrive
in France until 1 May. Pascal Vernin will check
if this is OK with the French.
10.5 Dipole designs are going well.
10.6 Sirish remind us that he would like feedback on
the shift checklist that he circulated.
11 Detectors:
11.1 Pascal Vernin reports that gas Cerenkov in the
Hadron arm will be tested this week.
11.2 Pascal would like to get field measurements at
the PMT’s in the electron arm with dipole and
Q3 at 4 GeV power. Speculation is that Bogdan
already made the measurements. If not they can
be done fairly easily. Main obstacle is the
Dynapower control card being borrowed for the
Hadron arm dipole.
-JJL