Minutes of Hall A Group Meeting June 30, 2009

1)    Bert Manzlak:

a)    Things are looking nice in the Hall

b)    Work observations are being done routinely

i)     Anyone who would like to tag along is welcome (a different perspective could be useful)

c)    Protocol for undergraduates at the lab:

i)     For the 1st 90 days:

(1)  Get all needed training

(2)  Must always have a trained escort when in the Hall

(3)  After 90 days will be reevaluated and the escort requirement may be lifted.

d)    Sirish, having collaborators coming in who will need to work with lead, asks what training is needed/available. Bert says there is training. Contact Bert to schedule it.

2)    Sirish Nanda:

a)    Compton Polarimeter:

i)     Spoke with Brian Quinn last week re the photon detector

(1)  Going to enlarge the beam pipe

(2)  Brian talked to the designers

(3)  Hope to get it done during the down

ii)    Cavity:

(1)  Dismantled the cavity last week for ultrasonic cleaning

(2)  Reassembling this week

(3)  Getting ready to make plans to install it. Talking with Al re the installation design

iii)   Introduces ODU post-doc helping with the Compton.

3)    Javier Gomez:

a)    Ed is trying to cooldown the Møller magnet again

b)    All parts for the Møller target holder are in the machine shop, test fits underway

c)    Møller target thicknesses fixed:

i)     Two: 1 micron

ii)    One: 5 microns

iii)   One: 10 microns

4)    Doug Higinbotham

a)    Thanks to Vince for getting things cleaned up in the Hall

b)    Working on installation plans for 2012

5)    Alexandre Camsonne:

a)    Working with Michel Brossard:

i)     Checked the Trigger logic

ii)    Efficiency is low at the logic level, tested with an oscilloscope.

iii)   Doing more tests with a source

6)    J-P Chen:

a)    Transversity and Coulomb Sum Rule analyses are making progress

b)    Most things taken down in the Hall

c)    Review paper on Spin for Progress in Particle and Nuclear Physics is ready

d)    10-year chapter on spin is finished

e)    Working on Proceedings for Intersections

7)    Ole Hansen:

a)    Counting house computers were upgraded to Giga-bit this morning

b)    Getting bug reports re the analyzer

i)     Encourages all users of the Analyzer to report bug info to Ole

8)    Bogdan Wojtsekhowski

a)    Preparation of VDC6 continues

i)     Chamber is working

ii)    Debugging gas leakage

(1)  Mostly from thin windows

(2)  Refining gluing technique and repairing

b)    Starting to repair VDC5

c)    S1m was constructed a few months ago. Now we need to design a frame for it. There's a student working on that.

d)    SBS: CERN making good progress on GEM technology. Have manufactured 1 x 0.4 m2 foils and have plans to make 2 x 0.4 m2 foils

e)    Introduces Delano Wilson, U. Va. Student working on SBS layout.

i)     Delano shows assorted 3-D views of SBS magnet, target chamber, and detectors as assembled in his 3-D model.

9)    John LeRose

a)    Looking at ways to get larger acceptance out of HRS without going to the extreme of moving Q1/Q2 or the low momentum limit it imposes

i)     Adding a quad in front of Q1(suggested by Doug) gives an increase in acceptance with less loss of maximum momentum (3.7 GeV/c and 23% increase in acceptance)

ii)    Simply retuning HRS works almost as well (~3.2 GeV/c and  ~18% more acceptance)

b)    Looking at 3-D magneto statics for SBS magnet and the problem of bending the primary beam due to field caused by the combination of the field clamp and holes in the clamp and yoke. Last week managed to make it worse. So, hopefully have a handle on making it better.

-JJL