Jefferson Lab Weekly Briefs February 20, 2008
Jefferson Lab Weekly Briefs
February 20, 2008
12 GeV Upgrade
The 12 GeV Accelerator Team continues to make good progress on Project Engineering and Design (PED). A review was held of the proposed procurement strategy for the beamline magnets, and a decision was made to shift from JLab buying the materials and supplying them to the magnet vendors to one which has the vendors buy the materials; the new plan yields more schedule flexibility with no technical risk and roughly the same cost risk as the previous baseline plan. A Change Request to reflect this altered strategy is under development. Ten of the 12 Advanced Procurement Plans for FY09 accelerator-related major procurements have been approved, with the final two expected to be complete in the next week. Progress also continues on the R&D effort to prototype the beamline quadrupoles. Feedback has been provided to the vendor of the laminations, and fixtures for winding the coils at JLab have been completed.
The Scheduled Accelerator Down started on the first day of this reporting period. Injector studies were started, which included a load-lock gun study, a 71 Mhz (Megahertz) beat frequency measurement and a surface charge limit test. Additional tests included a high-current lifetime study at 150 microamps, bunch timing vs. Wein angle and a Wein quad test. A bakeout of Gun 3 was completed over the holiday weekend. Among the multitude of scheduled maintenance activities for this SAD period, one of the first jobs to be completed was replacing a reducing gear in the South Access Water Cooling Tower. After Superconducting Radiofrequency group staff finished the necessary preparations, the C50-4 cryomodule for North Linac RF zone 6 was lowered into the tunnel.
Free-Electron Laser (FEL)
FEL staff successfully tested and verified operation of the FEL quadrupole and trim magnet systems in preparation for operations. The FEL gun is being assembled for that effort and is being prepared for high-voltage conditioning. Meanwhile, the gun test stand is preparing for production of its first beam with alignment and testing of the drive laser and Quantum Efficiency (QE) measurements system. The sextupoles are now ready for power-up tests in a test stand in the FEL vault. Michelle Shinn, Steve Benson, and Dave Douglas participated in a Technology Area Working Group (TAWG) meeting in Nashville and presented a status update and a tutorial on power recovery in FELs.
A major goal of nuclear physics and the JLab scientific program is to obtain an understanding of the nuclear force. A recent paper, arXiv:0802.1552 [nucl-th], provides all the details supporting an earlier, brief report that showed (contrary to conventional wisdom) that a simple covariant one-boson-exchange model gives the best high precision fit to the NN scattering data and hence provides the best phenomenological description of the nuclear force to date. This theoretically simple description is now being used to interpret few-body measurements at JLab.
JLab's Safety Numbers
154 Days since Last Recordable Accident (JLab record: 319)
JLab Calendar of Events
Feb. 20: JLab Physics Colloquium: Stefano Miscetti, INFN
Environment, Safety, Health & Quality
The National Safety Council (NSC) estimates that off-the-job injuries and fatalities cost U.S. businesses over $220 billion annually in lost productivity. NSC research shows that nine out of 10 fatalities and more than two thirds of disabling injuries to workers each year occur off the job. The impact on deaths and injuries in U.S. homes and communities include the following:
Oak Ridge Temporary Lighting "Near Miss" Lesson Learned
Computing and Networking Infrastructure
E-mail System Improvements
Volunteers Needed for Middle School Science Bowl
Property Validation Season Nears
2008 Benefits Open Enrollment Ends Monday
JAG Dog Sports Training Club Informational Meeting