Jefferson Lab Weekly Briefs August 13, 2008

Jefferson Lab Weekly Briefs

August 13, 2008

12 GeV Upgrade

The horizontal-bend magnet is the first superconducting magnet of Hall C's Super High Momentum Spectrometer. Its location close to the beamline introduces special design constraints, such as small size and heat dissipation. JLab is collaborating with the National Superconducting Cyclotron Lab (NSCL) at Michigan State University on the design development. Recently, collaborators at the NSCL began a trial wind of a magnet coil to demonstrate that the cable can be bent around sharp edges, and the first turn has been successful.


The installation of the polarized 3He target is proceeding smoothly. The three pairs of Helmholtz coils mounted on the pivot are in the process of being field-mapped. The new gas Cherenkov detector for BigBite is being tested with cosmics.


The LN1 transformer was removed by crane and trucked out for repairs. Temporary power has been hooked up until the transformer is re-installed after repairs. In the injector, Gun 3 was high-voltage conditioned, loaded with a new superlattice photocathode and then underwent a bake-out. The planned maintenance of the cooling towers for the North and South Access Buildings has been completed. System checks and cleaning of the RF low conductivity water (LCW) cooling circuits has been finished.

Free-Electron Laser (FEL)

Testing of the high-charge beam is proceeding on the gun test stand, and the FEL gun has been reassembled and is being prepared for installation in the vault. Assembly of the Advanced Energy Systems booster module is proceeding. FEL staff now has the first third of the ultraviolet beamline bolted together and all quad girders but two in the tunnel. Three of four advanced optical transport cans for high-power infrared are installed.

Theory Center

A semi-quantitative estimate of the prehadron production time based on recent preliminary HERMES data on hadron transverse momentum broadening in nuclear deep-inelastic scattering was presented in arXiv:0808.0656 [nucl-th] and confronted with preliminary CLAS data. Prehadrons are an intermediate stage of the struck quark fragmentation into observed hadrons, and their interactions with the target nucleus probe the space-time development of the fragmentation process. The obtained production time can explain the data well except for dependence on the photon virtuality, which remains a theoretical challenge: a few mechanisms that may contribute to its explanation are suggested, along with possible experimental tests.

JLab's Safety Numbers

303 Days since Last Recordable Accident (JLab record: 319)
648 Days since Last Lost Workday Accident (JLab record: 648)

JLab Calendar of Events

Aug. 12-14 Occupational Medicine Cholesterol Screenings
Aug. 12-14: DOE Accelerator Safety Workshop
Aug. 17-19: Lead Radius Experiment (PREX) Workshop
Aug. 22: Christoph W. Leemann Retirement Reception
Aug. 22: United Way Day of Caring signup deadline
Sept. 1: Labor Day holiday: JLab closed
Sept. 5: United Way School Tools Donation Drive ends




Environment, Safety, Health & Quality

Four High-Performance Work Teams (HPWTs) have been formed to address the  findings from the recent HSS Review. These teams are cross-functional in nature and have representatives from across the facility. Facilitated sessions have begun for each, with a primary emphasis on root cause identification and the accompanying corrective action plans. Prevention of future similar issues is critical, thus the improvement plans will focus on site-wide, systemic improvements.

The four noted areas from the review are Material Handling, Assessments, Issues Management and Event Investigation and Reporting. Individual team work sessions will continue throughout the month of August, with each team providing a final plan by Sept. 5. The submissions involve only the plans and milestone dates; implementation dates will vary.

More information on the progress of these teams will be available in the coming months. 

Computing and Networking Infrastructure (CNI)

HelpDesk Hours Are Changing
The HelpDesk will close in the afternoons starting on Monday, Aug. 25. The new HelpDesk hours will be from 8 a.m. until noon, Monday through Friday.


JLab Emergency Backup Website
JLab has created an emergency website that will be used in the event that its website,, is shut down due to an emergency. The emergency website is hosted offsite and can be found at: The website, which is still in the development stages, will be used to post important information for Users and staff during a local or regional emergency. Please save and remember this address.

JLab Adopt-A-Spot Event Needs Volunteers 
The 12 GeV Upgrade Project team is planning an Adopt-A-Spot litter pickup along Jefferson Avenue on Friday, Aug. 22. Participants will meet in the CEBAF Center lobby at 11:15 a.m. for a short safety briefing and then disperse to pick up litter. More information and signup can be found on the Adopt-A-Spot webpage. Volunteers should sign up by Wednesday, Aug. 20. For additional information, contact Steve Suhring, x7670.

Energy Secretary Delivers Address
On Thursday, Aug. 7, Secretary Bodman addressed the entire U.S. Department of Energy to discuss the reality of our energy and national security challenges and highlight the unique ability of the DOE complex to respond to these challenges both today and in the future. The remarks were preceded by a slideshow of images reflecting the wide-ranging work and accomplishments of the Department. To view a recording of the event or read the secretary's remarks, visit the DOE website.

JLab Mourns Death of Henry Whitehead
Longtime JLab staff member Henry Whitehead died Aug. 11.  The funeral service will be held at First Baptist Church, 229 N. King Street in Hampton at 11 a.m. on Saturday, Aug. 16. For more information about Henry's long tenure at JLab, visit this link.

American Red Cross Blood Drive Results
Last week's Red Cross Blood Drive was very successful! A total of 64 people signed up to donate blood surpassing the lab goal of 49. There were three first time donors. Several people were deferred for various reasons; however, the Red Cross still collected 63 pints of whole blood and two donations of red cells using the Double Red process. JLab donors made a significant contribution to the American Red Cross.

Occupational Medicine extends a special thank you to those donors who patiently waited during the drive, as well as those who attempted to donate during the afternoon. There were some problems that caused a delay in the donation process. We apologize for any inconveniences this may have caused. Again, we extend a sincere thank you to everyone that participated and volunteered with this blood drive and to congratulate you for a job well done! Mark your calendars for the next blood drive on Oct. 7.

Christoph Leemann Retirement Reception
An open house celebrating JLab Director Christoph Leemann's retirement will be held Aug. 22 from 3-4:30 p.m. in CEBAF Center. Cake and punch will be served. An electronic guestbook has been created, where staff, Users and others can leave a comment or best wishes for Christoph.



Privacy and Security Notice