Jefferson Lab Weekly Briefs February 22, 2012

Jefferson Lab Weekly Briefs
February 22, 2012


The Hall D complex beamline and infrastructure installation is continuing. All 48 Barrel Calorimeter (BCAL) modules, built at the University of Regina, Saskatchewan, Canada, have now arrived at Jefferson Lab. More than 2,200 of the 3,840 Silicon Photomultipliers for the BCAL have been received, and the first full prototype of a readout module is being assembled. The second full six-layer package (of four total needed) has been built for the Forward Drift Chamber. The manufacturing contract has been placed for several hundred Flash ADC-250 modules to be used in pipelined electronics and triggers in all halls.


In Hall A, the refurbished magnet for the target was tested at full field (5 Tesla). This was a major milestone. The work was done by the target group. Hall A staffers are in the midst of the last week of installation and alignment before starting the g2p experiment on Monday (Feb. 27).

After the resolution of issues with the Hall C dump, beam with transverse polarization was delivered to the Q-weak experiment. A series of measurements was taken with vertically and horizontally polarized beam on hydrogen, aluminum and carbon targets at elastic and inelastic QTOR magnet settings. These measurements, as well as providing a correction factor needed in the analysis of production Q-weak data, have a physics interest of their own. After the transverse polarization measurements, data taking continued with longitudinally polarized beam on the hydrogen target.

JSA/JLab Graduate Fellowship Program
JSA, LLC, is now accepting applications for the 2012-2013 JSA/JLab Graduate Fellowship Program. More information and an application can be found on the JSA, LLC website. The application deadline is March 9.

JSA/JLab Sabbatical Support Program
JSA is now accepting applications for the 2012-2013 academic year JSA/JLab Sabbatical Support Program. More information and an application can be found on the JSA, LLC website. The application deadline is March 9.


The beginning of the week saw no beam to any hall as Hall A continued to reconfigure for a new experiment. Hall B began Monday reconfiguring for the upcoming electron run, and Hall C was down for the investigation of its dump issue. Accelerator time was put to good use with several opportunistic maintenance items completed, along with studies on the new C100 superconducting radiofrequency cavities conducted in the South Linac, installation of various PEPPo equipment in the injector and the resurrection of the 2A synchrotron light monitor in the West Arc. Five-pass beam was set up in preparation of the March run to Hall B. Beam delivery was resumed to Hall C on Thursday. Problems with the Hall B fast shutdown system and vacuum valve controls, and other items including the impending bad weather, prevented delivery to Hall B over the weekend. This allowed Hall C to be the sole receiver of beam over a quiet weekend.

Free-Electron Laser

The gun was prepared for operation with a newly installed wafer. First, a high-quantum efficiency surface was prepared, and then the whole gun was conditioned for high-voltage operation. Cryomodule FEL03 was cooled down without incident, and RF conditioning commenced. The FEL vault was re-posted as a radiologically controlled area in preparation for running electron beam.

Center for Theoretical and Computational Physics

The orbital motion of quarks and gluons is expected to play an essential role in accounting for the proton spin and many of its other observable properties. Quantifying orbital angular momentum in the context of the fundamental theory of Quantum Chromodynamics and detecting it in high-energy scattering processes have so far proved extremely challenging. To coordinate the various approaches, researchers held a two-week workshop this month at the Institute of Nuclear Theory at the University of Washington. The results of this meeting will provide guidance for the planning and interpretation of nucleon structure experiments with JLab at 12 GeV, including elastic form factors, deep-inelastic structure functions at large x, and semi-inclusive and exclusive processes.


The machine shop has completed manufacturing all components for the second and third SPX Cryomodule Cavity Assemblies, CRM Crab Cavities (defecting mode crab cavity) for Argonne. The shop also completed all final machining, after electron beam welding, of these components. For Hall A's g2p experiment, the shop completed the manufacture and assembly of the girders up-stream and down-stream of the second FZ magnet. The accompanying mounting components were also completed. The magnet pole extensions for the g2p target magnet were completed. For the FEL, the shop manufactured custom flanges and machined the chamber ends to repair the vacuum leak in the wiggler chamber.
The Machine Shop is presently manufacturing or continuing to manufacture:
  • CLAS12 high-threshold Cerenkov counter mold mirror facet block 4 assembly for HALL B and the associated mirror assembly fixture;
  • Two beam transport insertable dumps for the 12 GeV Upgrade are presently being vacuum welded;
  • One BL OR02 synchrotron light monitor vacuum chamber and a dipole vacuum chamber for the 12 GeV Upgrade are being vacuum welded;
  • 68 dipole vacuum chambers for the 12 GeV Upgrade;
  • 170 each dipole-lengthening shims for the 12 GeV Upgrade.

Environment, Safety, Health and Quality

Integrated Safety Management at JLab
The Occupational Safety & Health Administration notes that 4,547 workers died on the job in 2010. As a visible sign of its commitment to making America's workplaces safer, OSHA keeps a running tally of worker fatalities on the front page of its website. Many of the scrolling descriptions serve as a stark reminder of the dangers of taking on a task without putting you and your fellow employees' safety first.

 At Jefferson Lab, we apply the steps of the Integrated Safety Management System in the planning and execution of work. These include defining the scope of work, analyzing the hazards, developing and implementing hazard controls, performing work within controls, monitoring the work and re-evaluating the task if conditions change, and providing feedback and continuous improvement.


2012 Benefits Open Enrollment Ends Feb. 29
The Benefits Open Enrollment is offered via the Employee Self Service System (ESS) to all Regular and Term staff employees through Feb. 29. Visit the Human Resources Benefits page for a wealth of information on the 2012 benefits offerings for open enrollment, including comparison charts, summaries and full program descriptions. Important details about changes to medical benefits can be found here. Don't forget: You must access the ESS before Feb. 29 to select another medical option outside of the medical plan default; to make changes to your current benefit elections; to participate for the first time in a Medical Care or Dependent Care Flexible Spending Account Plan or to continue your enrollment in a Medical Care or Dependent Care Flexible Spending Account.

Annual Property and Key Validation Set for March
Jefferson Lab's annual Property and Key Validation period is set for March 1-30. During the validation period, everyone with Jefferson Lab property inventory must take the JLab Property Custodian Refresher training (GEN150). The training takes about five minutes. After completing the refresher training, log into your Property Inventory and account for and validate each item on your property list. Be sure to click on the Submit Form button when you've completed the validation process. In addition, every person who has one or more Jefferson Lab keys must also validate each key issued to them. More information about this process can be found on the Insight page and at this link.

Tracking Thomas at JLab
Little Thomas is visiting all corners of the JLab campus. If you can identify his location this week, email Kandice Carter with your guess. Guesses are accepted through Friday.

Congratulations this week go to Jason Willoughby, Harry Fanning, Percy Harrell, Michelle Shinn and Jim Follkie, who were the first to correctly identify the Feb. 15 location. Honorable mentions go to Sasa Radovic, Ryan Bodenstein, Johnny Leung, John Fischer, Pete Kushnick, Stephen Smith and Doug Higinbotham. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.

JLab Calendar of Events

Feb. 27: Safety Shoe vendor onsite
Feb. 28: Advanced Materials Forum, CC auditorium
March 3: Virginia Regional Middle School Science Bowl
March 5-9: International ICFA Workshop on Future Light Sources