Minutes of Hall A Group Meeting November 17, 2009
1)
Run
Report: (Seamus Riordan)
a)
For
full details see: http://www.jlab.org/~riordan/20091117_riordan_rcupdate.pdf
b)
Beam
time summary:
i)
ABU:
85.8 hours
ii)
BANU:
36 hours
(1)
Compton
tuning:20 hours
(2)
HRS
detectors and magnets: 4 hours
(3)
DAQ:
3 hours
iii)
BNA:
42.9 hours
c)
Magnets
and cryogenics are better
d)
Compton
signal is problematic
e)
MCC
having difficulty holding 100 micro Amps
f)
Compton
Summary:
i)
Getting
a signal in photon detector difficult - low energy background
ii)
Photon
detector PMT performance degraded in poor beam conditions - replaced PMT and
base
iii)
Suspected
contributors:
(1)
Poor
vacuum - Improved with DP ion pump reactivation
(2)
Poor
injector setup - spent Monday morning working on
iv)
Have
installed shielding to help
v)
Alex
believes we can do a relative measurement with photon detector
vi)
Electron
detector performance still poor
g)
Gives
day to day summary
h)
Progress:
i)
RHRS
- 15.6 C/100 C
ii)
LHRS
- 14.1 C/100 C
i)
Upcoming
week outlook:
i)
HRS
optics runs
ii)
Production
2)
Installation:
(Ed Folts)
a)
Wants
to know what the next angles are and when they will be needed. Seamus will
discuss with spokespeople and get back to him.
b)
Dave
Kausch should be called the next time there is an access
c)
Supporting
the experiment
d)
Staging
for PREX
e)
Last
magnet failure was due to a 15 Volt power supply failure in the ESR
3)
Engineering/Design:
Paul Brindza
a)
PREX:
i)
Working
on magnet assembly
ii)
Designing
bus and controls
iii)
Shutter
mechanism
iv)
Lead
target
v)
Photon
collimator
vi)
Laser
support
b)
Migrating
CAD files to next generation
4)
Dave
Meekins
a)
PREX
target is moving along. Design is essentially complete.
b)
Moving
all target configuration files to Docushare
5)
Bert
Manzlak
a)
Re
2nd floor of the counting house; suggest owners excess equipment
that is no longer useful
6)
Dennis
Skopik announce that John LeRose will take over as safety warden in the
counting house complex when Bill Vulcan retires
7)
Jack
Segal
a)
Having
some issues with cryo right now. Things are repaired but the magnets are not
yet full.
8)
Sirish
Nanda
a)
Re
Compton; suspect that the collimator with the "big hole" is causing
background. Will try reducing the size of the hole.
b)
Ordered
new mirrors
9)
Ole
Hansen
a)
New
version of the analyzer is out on the web.
b)
Working
on back porting to version 1.4
c)
Survey
asking who is using the absoft compiler got 2 positive answers, and they use
their own installation and would switch if automatic conversion tools were
available. Werner Boeglin will modify some of his scripts
d)
2nd
floor of the counting house. There is a cubicle where old computer parts etc.
are stored. 2 years ago it was very neat. Now it's a trash dump. Ole will
excess a lot of that stuff. If there's something there you want claim it now or
it will disappear.
10)
Bogdan
Wojtsekhowski
a)
SBS
proposal submitted last Tuesday
b)
Updating
form factor experiments
i)
John
Annand is doing simulations on improved neutron detection.
c)
GEn:
i)
Jonathan
Miller defended his thesis.
ii)
Results
are final expect draft text of publication in about one week
d)
People
at SLAC are preparing a proposal for a dark matter search using Hall A
equipment. Should give one to two orders of magnitude improvement over existing
data. Hope to submit the proposal for Hall A review.
11)
Alexandre
Camsonne
a)
Been
working with MCC on Compton tuning
b)
Have
good tune for the injector
c)
Low
energy background lead to PMT failure. Replaced the PMT.
d)
Working
on shielding and the collimator
e)
Electron
detector still has lots of background
f)
Relative
measurements are now possible.
-JJL