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Archived Messages for HALLA_MIN_1997@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 28 Aug 1997 16:17:07 -0400
Minutes of Hall A Group Meeting 26 August 1997
1 General Announcements: (Kees de Jager)
1.1 Spokesman for experiments are reminded that
beam time requests for the second half of 1998
are due in on 15 September. Attendant
observations include:
1.1.1 It is useful to get your beamtime request
into the system early
1.1.2 The schedule is already tight because of
polarized 3He and Parity.
1.2 There was a meeting yesterday with Accelerator
re oversights in implementation of the Machine
Protection System (MPS). Decisions taken:
1.2.1 Checking of position and status of
ionization chambers will be added to the
Hall A beam readiness checklist.
1.2.2 All restrictions on tuning into Hall A
(trip levels, etc.) should be clearly
communicated to MCC through Arun Saha.
1.3 Run report from 89-003: At 845 MeV at the time
of last week’s meeting were having lots of
problems with intermittent high radiation level
trips. At about 1530 the problems abruptly
disappeared and the experiment got 2 shifts of
good beam, doubling the statistics for that
kinematics.
1.4 Re waterfall target: request that the target be
given a full internal visual inspection after
it cools off and before it is stored. Target
will be stored such that it can be used again.
2 Engineering/installation:
2.1 Ed Folts presents a very long list outlining
installation tasks completed, in progress, and
awaiting execution.
2.2 James Proffitt reports:
2.2.1 working on reprogramming chips for motor
drives
2.2.2 working on dipole power supply
modifications (being reviewed by Bill
Vulcan)
2.2.3 chasing IP addresses
2.2.4 expresses concern re trip levels for
radiation levels downstream of the target.
Will see Arun Saha.
2.3 Paul Brindza reports:
2.3.1 Working on alignment system:
2.3.1.1 wire pot system
2.3.1.2 mounts for Q1 wire pots in design
2.3.2 Meeting with cryo group re transfer of
responsibility to them. Getting drawings
and documentation up to date for them.
2.3.3 Solid modeling around the pivot for the
polarized 3He target is underway.
2.4 Jack Segal reports:
2.4.1 Working on removing Aerogels
2.4.2 Needs more nimbins (Bob Michaels suggests
getting more X-terminals too. Yes for 3
more)
2.4.3 Working through his list.
3 Detectors: (Bogdan Wojtsekhowski)
3.1 Discusses aerogel removal
3.2 Working on S1S2 phototube replacement.
3.3 Gas Cerenkov: replacing phototubes and wave
shifters may be more work than expected.
Worried that some of the new wave shifters are
cloudy. May need to test every phototube. Must
discuss with Franco and Pascal.
3.4 Discusses concerns re gas usage in the
Aerogels.
3.5 Space is available in the Hadron arm for the
prototype Aerogel Cerenkov.
4 Cryotarget and Compton Polarimeter: (Jian-Ping Chen)
4.1 Cryotarget:
4.1.1 Target is in the Hall and setup on a stand
4.1.2 Target Cell and cell blocks installed
4.1.3 Preliminary survey done. Looks OK.
4.1.4 Solid target ladder not finished
4.1.5 Gas line between gas panel and bottles
installed
4.1.6 VPT purge panel installed.
4.1.7 Tech’s are installing valves for switching
between D and He
4.1.8 UPS being installed
4.1.9 Running tests on control system. Seeing
some small problems.
4.1.10 Will need viewports on scattering chamber
to see target.
4.2 Compton Polarimeter:
4.2.1 Power supplies will be here in early
October
4.2.2 Dipoles will be here in late October
4.2.3 Expect full installation in January-
February shutdown
4.2.4 Power supplies and magnets have been
tested in Saclay
4.2.5 Discussed commissioning of the chicane:
4.2.5.1 How to tune beam without destroying
mirror?
4.2.6 Discussed storage of dipoles and power
supplies.
4.2.6.1 Upon arrival they go to the Test
Lab for testing
4.2.6.2 Then into the Hall. (Ed Folts
observes that the Hall is a round
room with no corners to hide things
in.)
4.2.7 We are reminded that all additions and
modifications to the Beamline must go
through Arun Saha. Jian-Ping will give
Arun an itemized list of planned changes
and additions.
5 DAQ: (Bob Michaels)
5.1 Trigger:
5.1.1 John Calarco was here last week.
5.1.2 Diagram of setup for Deuterium was
developed and presented to Deuterium
collaboration.
5.1.3 Working on implementation
5.1.4 John will return for final tests.
5.2 Raster:
5.2.1 Setting up for tests in a few weeks.
5.2.2 Will have chapter in the Ops Manual by the
end of September.
5.3 Reported on internet break-in and recovery. No
real harm done, just some nerd hackers looking
for a trophy they can show to their nerd
friends.
6 Beamline: (Arun Saha)
6.1 Energy Arc review tomorrow (27 August) L104
900-1200, close-out on Friday at 1500.
6.2 Re Radiation levels in the Hall and putting ion
chambers into the MPS:
6.2.1 Rad levels must be defined for each
experiment
6.2.2 Contact Arun for permission to move any
ion chamber.
6.3 Experimenters on shift should be very careful
to only declare beam that is really acceptable
as acceptable.
7 Controls: (Javier Gomez)
7.1 Checking on things for the next experiment
(Deuterium)
7.2 Discussed ways to monitor background in the
room.
7.2.1 Would like ion chamber raw signals in the
counting house.
7.3 Debugging code
7.4 Re target boiling tests: Question was asked,
When will we have instrumentation for beam
profile monitoring in the Hall A line? Answer:
January-February
7.5 Spectrometer positioning: will not require
surveys for Deuterium. Marks on the floor for
angles and encoders at the front of the
spectrometer for pointing will be adequate.
8 General Information: (Kees de Jager)
8.1 All REQ’s using money for this fiscal year
should be submitted before 1 September.
8.2 Agreement between MCC and the Halls re fire
alarms. In the event of a fire alarm:
8.2.1 Everybody leave the building
8.2.2 Trained people on a designated list may go
into the Hall with accompaniment to check
the source of the alarm
8.2.3 MCC will call 911 for ANY fire alarm
-JJL