Jefferson Lab Weekly Briefs August 27, 2008

Jefferson Lab Weekly Briefs

August 27, 2008

12 GeV Upgrade

The Beam Transport team continues measurements of both prototype beamline quadrupole magnets with the goal of optimizing certain design features such as the end-chamfer. The end-chamfers are small bevels on the ends of each of the magnet’s four poles and are used to minimize the amount of magnetic field errors not associated with fabrication or assembly errors. Determination of the end-chamfers for the "QP" style magnet is underway and is nearly complete for the "QR" style magnet. The Request For Proposals (RFP) was released for the 4-meter arc dipole contract.


The installation of the polarized 3He target in Hall A is proceeding smoothly. The field mapping of the three pairs of Helmholtz coils mounted on the pivot and of the BigBite magnet has been successfully completed. Cosmics tests of the new gas Cherenkov detector for BigBite have demonstrated that it is operating to specifications. The installation of the new electron detector for the Compton polarimeter, designed by the University of Clermont-Ferrand, is underway with technical support from Clermont-Ferrand.

Preparation of Hall B for the next DVCS (deeply virtual Compton scattering) run is in progress, repairs to CLAS have been completed; electronics for the DVCS inner calorimeter are under installation. The new SiPM hodoscope is in final tests before installation of amplifier boards. Repair work on Cherenkov sector 1 is almost complete.


Injector: The 500ua (microamps) test run was successfully concluded. A combined peak current of 930ua was achieved. A mirror for remote gun switching has also been installed.


Connections to the C50-6 cryomodule at NL11 are progressing at an efficient rate, including hooking up the waveguides. Painting of the electrical substations on the accelerator site has been finished.

Free-Electron Laser (FEL)

The FEL gun vacuum bake is well underway and proceeding smoothly. All sextupoles are now installed in the infrared beamline. Installation of the ultraviolet beamline has been proceeding well; all dipoles, quads and sextupoles are in and the system is getting ready for pump down. FEL staff held a Kickoff Review for its Joint Technology Office efforts in Energy Efficiency and Ring Resonators.

Theory Center

A relativistic quark model of the nucleon and Δ (1232), where only the lowest orbital angular momentum states (L=0) are considered in the quark-quark pair, was recently used to estimate the electric and magnetic distributions of the Δ (arXiv:0807.2922 [hep-ph]). Since the Δ is the first excited state of the nucleon, knowledge of its electromagnetic structure is very important in nuclear physics; however, its physical proprieties are largely unknown due to its unstable character. It lives for a very short time before decaying to other hadrons. The results of the model are consistent with the scarce experimental information available, and with the magnetic dipole distribution estimates based on lattice QCD (quantum chromodynamics), although it predicts a higher charge concentration than that in lattice QCD.

JLab's Safety Numbers

317 Days since Last Recordable Accident (JLab record: 319)
662 Days since Last Lost Workday Accident (JLab record: 662)

JLab Calendar of Events

Aug. 27: 3 p.m. Colloquium: Fermilab Plan with an Intensity Frontier Accelerator; Young-Kee Kim, Deputy Director, Fermilab
Sept. 1: Labor Day holiday; JLab closed
Sept. 5: United Way School Tools Donation Drive ends
Sept. 10: JLab welcome picnic for new Director Hugh Montgomery
Sept. 12: United Way Day of Caring




Environment, Safety, Health & Quality

JLab implemented a web-based Lessons Learned Program ( in early June. The site is similar to others throughout the Department of Energy complex, allowing each lab or facility a central location for researching safety topics while conducting work planning or task hazard analysis.
JLab's Lessons Learned Center contains information on a broad range of topics, including Chemical Management, Personnel Protective Equipment, Radiological Control and Pressurized Systems. This information is gathered from sources both internal and external to the DOE complex, with the overall goal of providing valuable information that JLab can use to plan and conduct safer, more efficient work.

The Lessons Learned Center is administered by ESH&Q; many useful inputs come from across the JLab campus. Divisional Lessons Learned Coordinators solicit and distribute relevant information. Once a lesson is put into the system, they and the designated Subject Matter Experts (SME's) receive automatic emails distributing the information throughout the lab.

For questions, information or improvement recommendations on the COE Program, contact your divisional Lessons Learned Coordinator ( or Stephen Smith, x7007.


School Back in Session Soon: Be Safe Around Buses
For 23 million students nationwide, the school day begins and ends with a trip on a school bus. The greatest risk is not riding the bus, but approaching or leaving the bus. Before children go back to school or start school for the first time, it is essential that adults and children know traffic safety rules. Visit this webpage for general safety information for both drivers and students, courtesy of the U.S. Dept. of Transportation.


Tee'em up for the JLab 2008 Fall Golf Tournament!
The tournament will be held on Wednesday, Oct. 8, at the Williamsburg Country Club in Williamsburg. The event will begin at 1 p.m. with a shotgun start. The tournament will be a four-person Captain's Choice. All teams will be handicapped. There must be at least two JLab employees per team. The cost for JLab employees is $45 each. A JLab employee is anyone receiving a paycheck from Jefferson Science Associates. The cost for non-JLab employees is $60. The fee includes range balls, green fees, cart, food (afterwards) and the prize fund.


Directions to the course from JLab: When leaving JLab, turn right on Jefferson Avenue and go 14.2 miles. Williamsburg Country Club is on the right.
See Danny Machie (ARC 402/09) to sign up. When signing up, golfers must list their average score for 18 holes.


Please make checks payable to Danny Machie. The entry deadline is Friday, Oct. 3. Contact Machie, x7501, for more info.


JLab welcome picnic for new Director Hugh Montgomery
The picnic will be held from 11:30 a.m. - 1:30 p.m. on Wednesday, Sept. 10 at the SURA Residence Facility Field (adjacent to CEBAF Center on the Jefferson Lab campus in Newport News, Va).

All JLab staff and On-Site Users are invited to attend the event, which is sponsored by JSA Associates, LLC. Come out and meet and welcome JLab's new director. Quark Cafe is catering the picnic lunch so the cafeteria won't be open for lunch that day. In case of inclement weather, a rain date of Sept. 11 has been set.

An RSVP request will be distributed by e-mail later this week.


TIAA-CREF Retirement Counseling Sessions
The September and October dates for individual counseling sessions are now posted. This is an opportunity to discuss the current status of your account, investment strategy and retirement goals. The dates are Friday, Sept. 12 and Friday, Oct. 10 in VARC room 42. To sign up for an appointment, click on Meetings & Counseling and follow the menu on the TIAA-CREF website.


United Way School Tools Drive Ends Sept. 5
The annual United Way School Tools Drive is underway. JLab participates in this community outreach program to assist disadvantaged youth in Hampton Roads public schools as they return to school. Collection boxes for donations of new school supplies have been placed in Building 85, CEBAF Center and the VARC and ARC lobbies. School supplies for students of any grade level may be placed in the boxes and will be collected until close-of-business Friday, Sept. 5. For more information, call Joshua Cameron, Human Resources, x7628, or click here for the complete announcement.

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