Minutes of Hall A Group Meeting June 22, 2010
1)	PREX run report: (Juliette Mammei)
a)	For full details see: 
http://www.jlab.org/~crowder/PREx_RC/PREx_Final_R
C_Report.pptx or 
http://www.jlab.org/~crowder/PREx_RC/PREx_Final_R
C_Report.pdf
b)	Gives details of the past week
c)	Friday (6/18) went to 70 micro Amps and stayed 
there for most of the weekend with both arms up 
and running
d)	Shows assorted plots
e)	10.68 C this week! (out of 53 total)
f)	Beamtime:
i)	78.5 ABU
ii)	12.7 BANU
iii)	43.7 BNA
2)	General Announcements: (Kees de Jager)
a)	Introduces Kalyan Allada, the new Hall A post-
doc. Started yesterday
b)	Discusses the important side effect of the 
weekend�s 70 micro Amp running. 
i)	Upon entry into the Hall on Monday morning, the 
whole Hall was declared to be a �High Radiation 
Area� and was promptly closed.
ii)	By 11 AM the High Radiation Area was reduced 
to a significant area around the target. This 
required that a radiation watcher be stationed 
in the Hall whose sole job was to watch the 
boundary of the high radiation area and make 
sure no one crossed into it.
iii)	At ~14:00 Dave Hamlette (RADCON) found the 
watcher asleep. He immediately and 
appropriately evacuated the Hall and closed it, 
ending all activity in the Hall for the rest of 
the day.
iv)	Today the high radiation area is fenced off 
and locked. So, no watcher is needed. (Thanks 
to Ed and company for erecting the fence)
v)	The area will get smaller as the radiation 
levels diminish
vi)	Please obey all the safety rules.
3)	Installation: (Ed Folts)
a)	Supporting APEX installation
b)	For the next couple of days there will be no work 
done around the target.
c)	We must replace the target chamber o-ring
d)	Trying to fix things that are broken
i)	Dipole is working again
ii)	Ready to start on Q1
iii)	Heidi is working on cryogenics.
4)	Jack Segal
a)	VDC on the left arm was not dropped into its 
normal final position for PREX. It�s 
approximately �� high and �� off horizontally. 
Possible ramifications discussed. Decided we 
don�t need to survey. Calibrations with sieves 
are fine.
5)	Engineering/Design: Paul Brindza
a)	Working on:
i)	g2p: beam dump and cooling, checking fit of 
coil 3 against yoke
ii)	SBS TOSCA model
iii)	DVCS: incorporating ne data from France
iv)	Compton beamline
v)	SRC detectors
vi)	Extractor tool for the PREX collimator
6)	Doug Higinbotham
a)	Introduces two new students:
i)	David, Adam Sarty�s student, working on N to 
delta
ii)	Matt, HS student, working on the neutron 
detector in the testlab
b)	Reminds all that you must have anything that was 
in the Hall during beam operations checked by 
RADCON before removing it from the Hall
7)	Alexandre Camsonne
a)	DVCS: 
i)	debugging
ii)	Have all needed HV for the Calorimeter
iii)	Unstacked the Calorimeter to measure blocks
b)	Compton electron detector: shows some signals 
collected
c)	RC this week for APEX installation
8)	Ole Hansen 
a)	Setting up analyzer for the VDC
b)	Creating calibration scripts for APEX
9)	Jixie Zhang
a)	Staring to prepare summer plan for M�ller 
upgrades
10)	Bogdan Wojtsekhowski
a)	Thanks to Ed and Jack for the rapid installation 
of the control fence in the Hall
b)	There will be a temperature sensor on the 
permanent magnet
11)	Kees ends the meeting reminding us all to 
continue to take safety very seriously.
-JJL