[Halla_min] Minutes of Hall A Group Meeting: September 4, 2018

[Stephanie Tysor]

 Minutes of Hall A Group Meeting: September 4, 2018

1. Thia Keppel
   a. No Senior Staff meeting
   b. Hall Leaders meeting
     i. Planning for Software Review
   c. Lab Agenda preparations, needed:
     i. 12 GeV publications
     ii. Milestone achievements for MOLLER and SoLID
     iii. Preparation milestone for SBS
   d. Currently no beam, possible by 9/19/18

2. Dave Meekins
   a. Close hall 9/11 to re-install Tritium cell 

3. Robin Wines
   a. SBS
     i. Submitted lead wall frame for procurement
     ii.  Continue revising drawings of vertical supports to make affordable
   b. PREX/CREX
     i. Preparing package for procurement submittal of concrete shielding
     ii. Completed engineering documents on vacuum chambers and collimator enclosure
   c. APEX
     i. Visited septum support vendor
     ii. Installation fixture near complete but no sign of support legs at vendor’s subcontractor facility
     iii. Procurement investigating. 
     iv. Waiting on these pieces then all APEX items will be ready

4. Jessie Butler
   a. Please remove things from Radcon shelf
   b. Continued to work on getting the hall ready to receive beam
   c. Were able to troubleshoot an repair the helium liquid level probe in the right dipole
   d. The probe is now back online and reading the correct liquid level
   e. Continued working on improving the LHRS vacuum
   f. Replaced the seal between the dipole and LQ3 and began pumping own over the holiday weekend
   g. Spectrometer is already showing improvement with the vacuum reaching the -5 range
   h. Will do the final leak check on Tuesday
   i. Began moving equipment out of the hall to Physics Storage and building 98, this will continue throughout 
            next week
   j. Tritium cell was packaged and shipped
   k. LHRS was moved to starting angle and pointing survey was complete
   l. Dump beam pipe work continued

5. Jack Segal
   a. HRS bogie motors and controllers
     i. Removal of motors from LHRS to be used on RHRS 
     ii. Staged on floor for preliminary testing before mounting
     iii. Preparation of bogie drive shafts on RHRS for motor mounting
   b. HRS Fiber Patch Panels
     i. Channels from back of detector stack LHRS and RHRS tested by John Musson’s group
     ii. Signal good from both HRS to floor level fiber patch panel
     iii. Fiber cable from patch panel to BCM receiver in labyrinth connected 
     iv. BCM receiver connected to detector stack
     v. Need one more 50 ft. fiber cable from back of detector stack to 2nd level of each HRS
   c. Trigger Cable Between Spectrometers
     i. Existing cable length measurement with TDR
     ii. Measured 355 ft.
     iii. Determination of Vp of jacketed ribbon cable to be used using measured length of 65 ft., velocity of 
               propagation = 53 to 54
     iv. Ordered more BNC connectors, reviewed RG-58 cables to be installed
   d. Hall A Compton Polarimeter – Electron Detector
     i. Cut back and replaced SHV connectors on 3 HV cables, made4 ft. extensions and attached & labeled
     ii. Supported Carnegie Mellon group with scintillator crystal testing
   e. Beamline HV Crate Replacement
     i. Replacement of LeCroy crate with bad fans, provides HV for Compton Electron Detector and Moeller
     ii. Crate removed to be repaired along with the one other from DVCS to be stored as spares
   f. Cherenkov Extension  Painting
     i.Additional coating of ultra flat black paint 


-- 
Stephanie Tysor
Hall A Administrative Assistant
Thomas Jefferson National Accelerator Facility
(office)757-269-6005 (fax)757-269-5235