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Archived Messages for HALLA_MIN_1996@cebaf.gov: Minutes
Minutes
John LeRose (lerose@CEBAF.GOV)
Thu, 25 Jul 1996 09:08:16 -0400
Minutes of Hall A Group Meeting 23 July 1996
1 Larry discussed priority setting for Hall A for the coming year. As part of the
laboratory's planning for the upcoming fiscal year (starting this Oct 1) Hall A
has been asked to define its goals. They are divided into "must," "should," and
"like." The "must" items are ones that we are proposing as top level lab goals,
where if we are failing to meet them we have rights to request additional help
from the lab as necessary (in the form of resource shifts from other projects).
The "should" items are those we deem important, and likely to be done within
the nominal resource allocation provided. However, they may be sacrificed to
other things if crunches develop. The "like" items are those that we would
hope to accomplish if things broke our way consistently (murphy takes a
holiday, the accelerator and experimental equipment runs almost perfectly,
etc.). The first meeting to discuss these goals (along with equivalent ones from
other activities in physics and the accelerator) will take place in the near future
(about a week and a half). User comments and suggestions on the goals are
welcome. Larry will be at the Photonuclear Gordon Conference all of next
week, but can be contacted by e-mail during that time. Larry also noted that
there is one key thought that is implicit in the listed goals - namely that we are
going to be giving the FPP our "best shot" but we will not hold up the program
(first major experiment) if we can't sort it out and understand it quickly.
1.1 The Goals are as follows:
1.1.1 Must:
1.1.1.1 Completion and Commissioning of the HRS
Spectrometer Pair and their Detector Packages.
1.1.1.2 Installation and Commissioning of the Spectrometer
Positioning System and Beamline Instrumentation
(position and charge measurement, and raster)
1.1.1.3 The 16O(e,e’p) Commissioning Experiment (1st half)
1.1.1.4 Completion , Installation, and Commissioning of the Hall
A Cryotarget
1.1.1.5 The First Complete Hall A Experiment
1.1.1.6 Completion, Installation, and Commissioning of the HRS
Alignment System.
1.1.2 Should:
1.1.2.1 Complete O16(e(polarized),e’p(polarized)) or, at least
O16(e,e’p(polarized))(2nd half of commissioning
experiment with polarization: at least with FPP working,
preferably with electron polarization as well)
1.1.2.2 Møller Polarimeter Operational
1.1.2.3 Parity Beam tests Completed
1.1.2.4 ARC and (e,p) Energy Measurement Systems
Commissioned
1.1.2.5 Second Major Experiment Completed Successfully
1.1.3 Like:
1.1.3.1 Third Major Experiment Completed Successfully
1.2 All Hall A users should have received an e-mail from Roy Whitney
explaining the process for scheduling experiments at the lab
(see: http://www.cebaf.gov/general/visit/experiments/exp_sched.html)
all are urged to read and make comments quickly.
1.3 Spokesmen for experiments that want to be scheduled for 1997 calendar
year are reminded that they must go through all the steps outlined to be
considered for scheduling.
2 Engineering: (Bill Schneider)
2.1 Alignment group have aligned the Target Chamber.
2.1.1 Dick Lindgren to install wiring etc.
2.1.2 Discussion of target position system and problems (home
position, limit switches, encoders, etc.)
2.2 Shield Houses:
2.2.1 Golden Eagle has completed concrete and steel installation on
the Beamline side of both houses.
2.2.2 Hadron arm moved to allow installation on the utility side (in the
course of moving had to replace CPU board and discovered
loose bolts in gantry foot)
2.2.3 Tested gas fire suppression systems in both houses
2.3 Hadron Arm:
2.3.1 LCW complete
2.3.2 All Q1Q2 piping complete
2.3.2.1 pump and purge next week
2.3.2.2 attempt cooldown in 2 weeks
2.4 Electron Arm:
2.4.1 Vacuum installation underway
2.4.2 M3/M4 contact overheating on Dynapower power supply
(electron dipole) being looked into.
2.4.3 Looking into problems with cryogenic valve drivers.
2.4.4 Q1 quench problem solved by raising He level sensor 2 cm
2.5 Roll filters to be installed by plant engineering before 9 August run
3 Magnet Measuring and Mapping: (John LeRose)
3.1 QMM mechanical hardware stored in Blue Crab warehouse.
3.2 Analysis continues on dipole map data.
3.3 Electron Arm fixed field monitoring probes (Hall probes in quads, NMR
in Dipole) being reinstalled in coordination with vacuum system
installation.
3.4 Still awaiting final word from surveyors re comparison magnetic axis as
determined by QMM and colloidal suspension with geometric axis.
Larry would like to know before the end of the week. JJL will try to
hurry them along.
4 Commissioning: (Eddy Offermann)
4.1 Italians (Franco Garibaldi and Co.) have arrived:
4.1.1 Are setting up the waterfall target in the EEL as originally
planned.
4.1.2 Continuing discussions on Septum magnet
4.1.2.1 Technical review scheduled tentatively for 22 August (J.
LeRose will not be able to attend)
4.1.2.2 Eddy will do some simulations for them if he can fit them
in. Larry insists that spectrometers get first priority.
4.2 Have observed instabilities in the trigger timing that need further
investigation. Leads to discussion of these instabilities. Bob Michaels
and John Calarco (UNH) are looking into it.
5 Cryotarget: (Jian-Ping Chen)
5.1 Joyce Miller working on Cell Block design.
5.2 Techs mounting diodes in cryocan and continuing with platform
assembly.
5.3 Gary Rutledge (W&M) finished winding coils for tachometer, checking
out readout units for pressure transducer
5.4 Riad Sulieman is working on wiring and installation of diodes.
5.5 EPICS work progressing
5.6 Larry Weinstein (ODU) working on tests of lifting mechanism.
6 Controls: (Javier Gomez)
6.1 Set up IOC controllers for beam charge monitors
6.2 Debugging EPICS drivers
6.3 Ongoing meetings between Javier, Eddy Offermann, and Will Oren re
positioning system. Will Oren will write up a proposal.
6.4 Meeting this afternoon (23 July) on positioning system
7 DAQ: (Bob Michaels)
7.1 Reiterates trigger problem, shows plots of self timing peak jitter.
8 Jack Segal reports that Cerenkov is halfway in.
9 Detectors: (Bogdan Wojtsekhowski)
9.1 Re trigger jitter: tested by installing passive delays. Got better but still
not perfect.
9.2 VDC set B
9.2.1 had problem with leakage current. Backfired etc. Leakage
current still not great but signals and spectra look fine.
9.3 Expect to be ready to lift Electron Arm detectors back onto
spectrometer next week.
9.4 Aerogels: pmt problem noted. 2 pmts have broken (cracked glass).
Would like to understand. Suspect problem is socket design is not
optimal.
9.5 Question: When do we need Aerogels from Franco Garibaldi? Not till
the end of the year.
10 Møller Polarimeter and Operations Manual: (Sirish Nanda)
10.1 Møller:
10.1.1 EPICS: selecting VME and hardware drivers.
10.1.2 Dan Dale (U.Ky.) trying to get power supplies.
10.1.3 Victor Gorbenko working on interface between power supplies
and coils.
10.2 Ops manual: Memo coming out shortly
11 User Report: Kathy McCormick (ODU)
11.1 Developed EPICS control of LeCroy HV distribution.
11.2 Now working on EPICS controls for the Cryotarget.
Erratum: In the minutes of the 18 July meeting it was mistakenly reported that Sophie
Kerhoas gave a report on progress on the ARC beam energy measurements. The report
was in fact given by Dominique Marchand.
-JJL