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.

Theory Center

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)
473 Days since Last Lost Workday Accident (JLab record: 473)

JLab Calendar of Events

Feb. 20: JLab Physics Colloquium: Stefano Miscetti, INFN
March 1: Virginia Regional Middle School Science Bowl
March 6-8: Photon-Hadron Physics with the GlueX Detector
March 25: Science Series Lecture: The Civil War Unplugged


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:

  • About one out of 16 people experience an unintentional injury each year.
  • About 39 percent of the deaths and 55 percent of the disabling injuries involve workers off the job.
  • A fatal injury occurs in the home every 14 minutes and a disabling injury occurs every four seconds.
  • The five leading causes of fatal injury are falls, poisoning, choking, drowning and fires/flames.
  • Smoke inhalation accounts for a majority of deaths in home fires.
  • The four leading causes of death in public places are falls, poisoning, choking and drowning.


Oak Ridge Temporary Lighting "Near Miss" Lesson Learned
A DOE Oak Ridge facility (the East Tennessee Technology Park) recently experienced an electrical "near miss" grounding problem with a temporary power cart. A magnetic-base light arced when workers attempted to attach it to an out-of-service lighting panel. The arc resulted from a loosely connected ground lead within a 480-Volt disconnect. When using temporary power, care must be exercised to ensure that the power source is fully functional. The event followup discovered an electrical fault when the ground connection failed in the 480-volt receptacle feeding the power distribution cart to which the light was connected. Fortunately, there were no injuries as the result of this event, but the potential for either electric shock and/or arc flash burns existed. In addition, subsequent power distribution cart disassembly revealed numerous non-code-compliant issues. Based on the number of issues identified, all power carts were removed from service, inspected and brought into code compliance.

Computing and Networking Infrastructure

Helpdesk Changes
Starting on Monday, Feb. 25, the Helpdesk will be open from 8 a.m - noon, Monday-Friday. Phone calls to the helpdesk, or helpdesk personnel, after helpdesk hours will be answered on a best effort only basis. This change is a result of the current budget and a retasking of personnel to higher-priority projects for the Lab.

E-mail System Improvements
Over the past several months, our e-mail system has been experiencing higher and higher loads. This higher load is a direct result of users' large inboxes and the inefficient file format used for storing e-mail. Last week in particular, the loads spiked to the point where even the central file server was adversely affected. The CNI group had been working on a project to implement an e-mail system that utilized a storage format with indexes. Using indexes reduces the performance impacts associated with the size of users' inboxes. The group had been making steady progress towards implementing this new system in March. At the end of last week, it was clear it could not wait any longer. The previous e-mail system was disabled, and the new system that was being tested at the time was enabled. The results were immediate and astounding. E-mail responsiveness and availability has increased dramatically. Users of the web-based e-mail ( have particularly noticed an increase in performance. The CNI group appreciates everyone's patience as these issues were worked through last week.


Volunteers Needed for Middle School Science Bowl
About a dozen more volunteers – JLab employees, family members, users, and students – are still needed to help with the Virginia Regional Middle School Science Bowl on Saturday, March 1. Volunteers will serve as competition moderators, rules judges, timekeepers and scorekeepers. All volunteers receive a 2008 Science Bowl T-shirt, and those working all day will receive a sack lunch. A volunteer practice/training session will be held on Thursday, Feb. 28, beginning at 10 a.m. in CEBAF Center, room F113. Anyone interested in more information or in volunteering may contact Jan Tyler at or x7164.

Property Validation Season Nears
Nearly every employee at JLab is a property custodian, responsible for proper use, control, physical protection and disposition of assigned property. The annual property custodian validation process will run from March 1-15. During this period, each custodian must "validate" all of the items on his or her inventory list and take the Property Custodian Refresher GEN 150 training (about 5 minutes).

2008 Benefits Open Enrollment Ends Monday
JLab’s 2008 Benefits Open Enrollment will be offered Feb. 11- 25, via the Employee Self Service System. All regular and term employees are eligible for medical, dental, health and dependent care flexible spending accounts, short-term disability and supplemental life insurance. For complete information on benefits options, visit the Human Resources Benefits webpage.

JAG Dog Sports Training Club Informational Meeting
If you are interested in training your dog in basic obedience, agility skills or freestyle dog dancing, you're invited to Come, Sit, Stay at an informational meeting! Those interested in forming a JAG Dog Sports Training Club will hold an hour-long brownbag lunch in VARC room 72 at noon, Thursday, Feb. 28. For more information, contact Joyce Miller at x7163 or or Brian Kross at x7022 or


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