Privacy and Security Notice
Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Fri, 04 Apr 1997 15:07:09 -0500
Minutes of Hall A Group Meeting 1 April 1997
1 Report an Access incident in Hall A on last Thursday
morning (27 March): (Kees deJager)
1.1 Hall was in controlled access mode and someone
was able to get into the hall via the truck
ramp because a door was not latched properly.
Appropriate alarms did go off.
1.2 Plant engineering was contacted and the door
was repaired so this could not happen again.
1.3 Two addition actions will be taken:
1.3.1 Second lock will be put on the door.
1.3.2 Third status control using an independent
technology will be put on the door.
2 Run Report: (Paul Rutt)
2.1 Tom Hassler gave the shift summaries an A.
2.2 Only got about one third of scheduled beamtime.
2.3 Down most of the day Thursday (27 March) with
cryo problems in the spectrometer magnets.
2.4 Lost 2.5-3 shifts tuning the Hall C line for
tests in Hall C.
2.5 Dump ion chambers cost almost 1 full shift.
2.6 Got 20 hours of data with 6” analyzer
2.7 Got 13 hours with 9” analyzer (wanted 20)
2.8 Working on replay.
2.9 Progress also made on: Parity tests, 3He gas
cell tests, and Hall C Møller studies.
2.10 Krishni Wijesooriya reports on results of FPP
chamber offset studies.
2.11 Richard Holmes reports on Parity tests:
2.11.1 First time use of integrating 16 bit
ADC’s. Data analysis underway. More next
week.
2.11.2 Looked for cross talk in electronics.
Very small.
2.11.3 Looked for helicity correlated
differences in:
2.11.3.1 Beam intensity. Saw none.
2.11.3.2 Beam position. Saw none.
2.11.4 Looking for stupid mistakes. Haven’t
found any yet.
2.11.5 Width of the beam intensity distribution
was 5 to 10 times larger than with the
thermionic gun.
2.11.6 If results hold up parity experiments may
be easier than we ever dared to dream.
2.12 Jian-Ping Chen reports on He cell tests.
2.12.1 Saturday and Sunday saw almost no beam.
2.12.2 3.5 hours on Monday (31 March)
2.12.3 Subjected cell to varying levels of
intensity and raster size. Could not break
the cell even when exceeding anticipated
operating conditions.
2.12.4 Got no information on long term
durability. Beam switched off every 5-10
minutes.
2.12.5 Expressed desire to expose test cell to
continuous beam for a full day to get
better idea of long term capabilities.
Prompted discussion of how well we can
extrapolate experience with this test cell
to cells used in the experiment.
2.12.5.1 We will be running for 2 months
with this target.
2.12.5.2 SLAC experience is that cell life
is proportional to window thickness.
This cell has thinner windows than
the ones we plan to use in
production.
3 Installation: (Mark Stevens)
3.1 Modifications to Q3 Electron are 50% complete.
3.2 Q2 Hadron He leak repair is in design stage.
3.3 Møller magnet stands going in today (1 April)
3.4 Møller dipole should be in the Hall by Friday
(4 April)
3.5 Working on Bench for (e,p)
3.6 Vacuum pipe modifications for raster underway.
3.7 Italians arrive tomorrow to begin installation
of the new waterfall target.
3.8 Hadron collimator successfully operated with
software control. Software is crude. Still
needs some development.
3.9 Cryo-controls: Fix to get spectrometers up
last week was to remove all cryo-controls from
the Q1’s and feed them He at a constant rate.
Paul Brindza reiterates that cryo-control loops
need to be better tuned.
3.10 Hope to have all Q2/3 quadrupoles under EPICS
control by May. Trying to do Q3 Electron first to
see how it goes.
4 Magnet Measuring and Monitoring and Optics: (John
LeRose)
4.1 Delighted to report that no one called over the
weekend to report that the NMR’s won’t lock.
4.2 Trying to get started using ESPACE. Getting
started is slow going.
4.3 Planning to take calibration data on Hadron
Dipole tomorrow (2 April)
5 Beamline: (Arun Saha)
5.1 Be foil plating: have incurred a 2 day delay.
Need these foils for the new waterfall. Expect
them here by Friday (4 April), Monday for sure.
5.2 Preparing run plans for 16O experiment.
5.3 Meeting tomorrow for 16O experiment.
5.4 Refrigerator, microwave, and coffee maker are
now in the counting house. All are urged to
keep things clean.
6 DAQ: (Bob Michaels)
6.1 DAQ will be down this week. Installing more
memory and fast ethernet. Should be back up by
Saturday.
6.2 Fast Raster: Alexander is making progress.
6.2.1 Low power tests completed
6.2.2 Getting ready for high power tests
6.2.3 Control program written
6.3 Making various improvements in ESPACE.
7 Cryo Target: (Jian-Ping Chen)
7.1 Riad has finished installing heat sensors on
the heat exchanger.
7.2 JT valve control electronics box completed.
7.3 Starting gas panel installation this week.
8 Detectors: (Bogdan Wojtsekhowski)
8.1 Lead Glass:
8.1.1 Laments having gotten no beam tests.
8.1.2 Using Cosmic ray tests to prepare Electron
Arm lead glass.
8.1.3 Surik Mehrabyan working on shower counter
aspects of ESPACE.
8.2 New High Voltage power supply installed. Jack
Segal warns about lack of over current
protection during ramp up.
9 Møller Polarimeter and Ops Manual: (Sirish Nanda)
9.1 Draft of Ops manual is in Kees’ hands.
Completed package should be ready by the end of
the week.
9.2 16O FPP experiment readiness meeting planned
for evening of 11 April, during the
collaboration meeting. No agenda yet.
9.3 Møller:
9.3.1 After one full day installation is still
on schedule.
9.3.2 Expect the dipole to be here at 14:00 on
Friday (4 April)
10 Announcement: Parity collaboration will be having a
bi-weekly meeting every second Friday at 13:30 in
room 84 of Trailer City. Starting this Friday.
-JJL