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 2^nd 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) 2^nd 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