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Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Mon, 18 Nov 1996 09:39:28 -0500
Minutes of Hall A Group Meeting 13 November 1996
1 Engineering: Bill Schneider
1.1 Hadron Arm:
1.1.1 Quads all checked out last week
1.1.1.1 Special thanks to people from
Saclay who helped with Q1. We
appreciate their support.
1.1.2 Colloidal suspension measurements done on
Q2 and Q3. Thanks to Temple University
group (Jeff Martoff). Corrective measures
being taken.
1.1.3 Dipole down to 240-190 K. Expect to be
fully cold next week.
2 Chamber Gas System: (Howard Fenker)
2.1 System is up and functioning for the Electron
Arm
2.2 Will require short (1 hour) shutdown tomorrow
morning (14 November) to connect Hadron Arm.
3 Detectors: (Bogdan Wojtsekhowski)
3.1 All four FPP chambers installed
3.2 Expect to make the lift 16:30 today. (The lift
went well -JJL)
3.3 Preparations for beam testing going well.
3.4 Shower amplifiers installed by U.Md.
3.5 J. Calarco (UNH) has made a study of S1
counters. Concludes that TOF could be improved
by factor of 1.5 with better pmt’s. (We have
already achieved CDR spec’s)
4 Cryotarget: (Jian-Ping Chen)
4.1 Accelerator has agreed with preinstallation
schedule
4.2 Design
4.2.1 done on gas panel and gas tank
4.2.2 on first iteration with gas platform
4.3 Techs have platform for target loop assembled
4.4 Successfully soldered and leak checked He cell
4.5 Expect pressure test next week
4.6 Wiring from cryo can to loop finished by Riad
Sulieman
4.7 Preparing temperature sensors for calibration
4.8 G. Rutledge has finalized electronics design
for solenoid
4.9 Lars Ewell working on ADIO breakout box
4.10 Software: have had problems with computers.
Things are getting back to normal. Working on
lift mechanism and readouts
5 Beamline: (Arun Saha)
5.1 Pascal Vernin will be here tomorrow. Planning
to meet on Friday to discuss January
installation plans.
5.2 Current monitor report deferred to end of
meeting if there’s time.
6 Controls: (Javier Gomez)
6.1 Still working on code. The end is in sight!
7 Magnet Monitoring and Measuring: (John LeRose)
7.1 Colloidal suspension measurements on Hadron Arm
completed last week (see above)
7.2 Working on installing NMR probes in Hadron
Dipole.
7.3 Observed during colloidal suspension
measurements that there is one inch less space
between Q1 and Q2 on the Hadron arm compared to
the Electron Arm. We knew that errors in z were
not so critical. Quick check using TRANSPORT
indicates no significant change in first order
transfer properties and in fact we get back a
little bit of transverse acceptance. (1 or 2 mr
in phi)
8 DAQ: (Bob Michaels)
8.1 Working on Hadron Arm
8.2 Requests a day long dedicated test after power
is hooked up on the Hadron Detector stack
8.3 As in the Electron Arm, chips in the 1877’s
need to be replaced
8.4 Working on detector map problem while waiting
for power.
9 Waterfall Target: (Meihua Liang)
9.1 Preliminary target thickness studies show
variation of <0.5% over 400 second interval.
10 Ops Manual: (Sirish Nanda) Bad guys list
distributed.
11 Commissioning: (Eddy Offermann)
11.1 y0 reconstruction looking much better. Analysis
of 2.45 GeV data using reconstruction
properties determined from 800 MeV data shows
FWHM about 3 mm. (about what you expect)
Dominated by multiple scattering in the exit
window. Can see foils clearly over full
acceptance.
11.2 Energy resolution not yet fully optimized (All
recent effort went into y0)
11.3 In good shape to look at data on-line.
11.4 Plans for this weekend: (Spectrometer is at 16
degrees with deliberate 2 cm mispointing in the
opposite direction from last time. Beam energy
will be 2.445 GeV. 5 micro amps DC beam. Larry
gave brief explanation of the nature of the
slit problem that is limiting the maximum
current we can take.)
11.4.1 Standard optics study. Sieve and full
aperture for 5 spectrometer central
momentum settings. (3 shifts)
11.4.2 Detector studies:
11.4.2.1 3 hours with deliberate defocus to
fill shower counters. Full solid
angle.
11.4.2.2 200 seconds on thick Fe target
12 Meeting ended with extended report by Branko
Vlahovik on status of current monitoring efforts.
12.1 Many problems outlined.
12.1.1 Fourier analysis of noise, baseline
shifts etc.
12.1.2 Inconsistent performance between our
cavities and accelerator cavities (theirs
seem to work better)
12.1.3 …
12.2 Lots of work to do to get to our goal of 10-3
absolute accuracy
13 -JJL