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Minutes of Hall A Group Meeting 16 September=20
1997
1 General Announcements: (Kees de Jager)
1.1 Manpower is needed:
1.1.1 Sign-ups for commissioning=20
shifts have been very poor.=20
Physicists on site should sign=20
up for shifts.
1.1.2 All users expecting to use=20
cryotargets in the next 2 years=20
are encouraged to apply.
1.2 Late requests for odd jobs will be=20
ignored.=20
1.3 Don=92t approach techs directly. only=20
go through their supervisors.
1.4 Requests for supportive manpower:
1.4.1 Ed Folts requests that anybody=20
with anything in the Hall that=20
can be taken out please remove=20
it.
1.4.1.1 Discussion of 1KW=20
Cryotarget loop parts and=20
where to store them. Jack=20
Segal and J-P Chen will=20
look into possibilities.
1.4.2 Things that should be removed=20
include:
1.4.2.1 FPP frame
1.4.2.2 Lockers
1.4.2.3 Wire Chamber parts
1.4.3 John LeRose, Bob Michaels, Arun=20
Saha, and Michael Kuss volunteer=20
to meet down in the Hall=20
tomorrow (17 September) at 1000=20
to help move things.
2 Installation: (Ed Folts)
2.1 Has some questions re Ion chamber=20
mounting. Arun Saha will supply=20
necessary information.
2.2 Jobs around target area becoming=20
critical. Hope to be under vacuum by=20
the weekend.
2.3 Tested turbo pumps today.
2.4 Hadron arm is now at 12.5 degrees.
2.5 Expect to have electron at 12.5 by=20
the weekend. (Not both=20
simultaneously. That will wait so as=20
not to interfere with Bob Michaels=20
work on the trigger setup)
2.6 Welded plate was finished today.
2.7 AC is done
2.8 Inergen test this Monday=20
(22 September) Should take about 2=20
hours.
2.9 Diffuser status? Unknown. Accelerator=20
hasn=92t been in the dump tunnel to=20
check.
3 Design/engineering: (Paul Brindza)
3.1 Wire pot system pivot ring bids are=20
in
3.2 Can with cable interface for Q2-
Dipole connection will go out for=20
bids momentarily.
3.3 Hall C radiator design will fit in=20
the Hall A Beamline.=20
3.3.1 Drawing shown
3.3.2 Some discussion of details
3.3.3 Collecting piece part drawings=20
and procurement history
3.3.4 Questions:
3.3.4.1 Superharp interference?
3.3.4.2 Seal with target chamber?=20
Indium
3.3.4.3 Need for Pb shielding? To=20
be explored with Hall C=20
people by Ron Gilman.
4 Detectors: (Bogdan Wojtsekhowski)
4.1 Electron Arm gas Cerenkovs almost=20
completed
4.2 Starting on Hadron gas Cerenkov
4.3 Aerogel prototype still awaiting HV=20
conversion. Techs are very busy.
5 Data Analysis: (Meme Liang)
5.1 Working on Oxygen data
5.2 Asked if she has any new information=20
from surveyors on collimator=20
positions. John LeRose has latest=20
report, just got it this week, will=20
give Meme a copy.
6 Cryotarget: (Jian-Ping Chen)
6.1 Transfer line U-tubes installed and=20
pumped down.
6.2 JT valves installed
6.3 Lifter limit switch changed to=20
mechanical switch.
6.4 Final survey started this morning.=20
Positions finalized. Waiting for=20
final numbers.
6.5 Cryo lines are pumping down.
6.6 Gas panel still needs leak checking.
6.7 Controls:
6.7.1 Solenoid valve tested
6.7.2 JT valve testing in progress.
6.7.3 Temperature monitors tested and=20
OK.
6.7.4 Variable frequency power supply=20
controller tested and OK.
6.7.5 Software changeover completed.=20
Initial problems all overcome.
6.8 Hope to start pumping down the target=20
this weekend. With cooldown early=20
next week.
6.9 Is target motion interlocked with FSD=20
system? Yes.
6.10 John Mark is here today checking=20
procedures and inspecting the target.
6.11 First draft of the run plan is=20
available and being distributed to=20
staff. Comments and suggestions are=20
welcome. Need magnet settings from J.=20
LeRose.
6.12 Kees comments that there is still no=20
runplan for VCS or Parity.
7 Michael Kuss reports that testing=20
continues on gas Cerenkov PMT=92s. They fall=20
into three distinct groups. Those that are=20
coated and appear clear (these are the=20
best), those that are coated and appear=20
cloudy (these are the worst), and those=20
that are uncoated (these are mediocre)
8 DAQ: (Bob Michaels)
8.1 Checking on memory lookup files.
8.2 Checking scaler gating. charge=20
integration should be better than 1=20
microsecond (overkill)
8.3 Raster is being run by itself today.=20
Making progress on controls.
8.4 Looking over modifications to ESPACE.=20
Expect a new release by next weekend.
9 Beamline: (Arun Saha)
9.1 Working on procedure for beam tuning=20
into the Hall. Meeting with=20
Accelerator people.
9.2 Points out that radiator will need an=20
official name.
9.3 Reports on new communication facility=20
between counting house and MCC.=20
Computer of submission of =93Beam Event=20
Requests=94. There is also an intercom=20
which should be used and its=20
malfunctions reported.
9.4 Ninth dipole shed drawings will be=20
ready tomorrow. After review will go=20
out for bids.
9.5 OTR results show no background=20
increase in the spectrometers and no=20
observable effect on resolution. No=20
data yet on background in eP energy=20
measurement device. Installing ion=20
chamber to check background at eP.=20
Jean-Claude is given the go ahead to=20
implement OTR.
10 Magnets and Optics: (John LeRose)
10.1 Reports on latest developments in=20
effort to make an absolute=20
calibration of the central momentum=20
of the Hadron arm based on field=20
measurements and alignment=20
information.
10.1.1 Total error =B12x10-3
10.1.2 Changes since last presentation=20
include:
10.1.2.1 Correction for known=20
misalignment of Q3
10.1.2.2 Increased uncertainty in=20
location of Q3
10.1.2.3 Better determination of=20
central field with improved=20
analysis of uncertainties=20
in the field
10.1.3 VERY, VERY preliminary analysis=20
suggests that beam energy at=20
nominal 845 MeV was actually=20
5 =B1 2 MeV lower. Meme says this=20
agrees with her analysis of=20
H(e,e=92p) data.
10.2 Finishing off ARM training
10.3 Putting acceptance studies for=20
y0 > 5 cm on WWW. Information is in=20
hand just needs to be worked into=20
existing acceptance studies web page.
10.4 Re cables suspected of being in the=20
trajectory path in the Electron arm:=20
Good news and bad news.
10.4.1 Good news: They=92re not in the=20
way anymore.
10.4.2 Bad news: In moving them out of=20
the way the Hall probes in Q1=20
and Q2 came unseated and are now=20
lying in the bottom of the=20
quads. Feeling is that since the=20
hall probe readings aren=92t=20
necessary to operations putting=20
the probes back in their proper=20
places can wait until January=20
when we open up the vacuum=20
system to replace the whole=20
feedthrough and cabling setup.
11 Controls: (Javier Gomez)
11.1.1 Working on spectrometer=20
alignment:(Leveling, Position,=20
Pitch, and roll)
11.1.2 Preparing for Deuterium=20
experiment.
12 Ed Folts questions timing of Hadron arm=20
polarity change: Negative (electron)=20
polarity now, switch back to Positive=20
(proton) after six days of commissioning.
-JJL
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