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