Jefferson Lab Weekly Briefs November 17, 2010

Jefferson Lab Weekly Briefs
November 17, 2010

12 GeV Upgrade

The intermediate manufacturing readiness review for the solenoid magnet and the final manufacturing readiness review for the torus magnet for the Hall B CLAS12 spectrometer were held at the vendor, Wang NMR. The wave-shifting fibers for the pre-shower calorimeter (PCAL) are arriving, the extruded scintillator is being cut, and lead sheets and box parts are arriving, all in anticipation of starting assembly of the first PCAL sector in the coming spring. Stringing of the last sense wires is ongoing for the first sector of the region 2 drift chamber for CLAS12, and the second assembly line, at Old Dominion University, is now set up and ready to go. Thirty-eight (of 48) of the five-inch-diameter, quartz-face photomultiplier tubes have arrived for the high threshold Cerenkov counter and are being tested.


The Hall C Moller Polarimeter superconducting solenoid was cooled down, and the polarimeter was recomissioned, measuring beam polarization for the first time since the rebuild of the Hall C beamline. In addition, a paper based on Hall C experiment E02-019 has been published in Physical Review Letters: "Scaling of the F2 Structure Function in Nuclei and Quark Distributions at x>1."

PAC 37 Proposals Due Dec. 1
The Program Advisory Committee (PAC 37) will meet the week of Jan. 10. The PAC will review new proposals for the 12 GeV physics program, which are due no later than Dec. 1. The PAC will also assign scientific priorities and beamtime to already approved proposals and review and assign priority and time to some conditionally approved proposals. The details of the process for PAC 37 are available online.

JSA Postdoctoral Research Prize Nominations Due Dec. 1
JSA Postdoctoral Research Prize winners have a record of accomplishment in physics, promise of further accomplishments in the JLab research fields and an excellent proposal for use of the prize's research grant. All nominees must be within five years of graduation and in a postdoc or equivalent position at the time of nomination. For more information, see the announcement. The prize is funded through the JSA Initiatives Fund.

Outstanding Nuclear Physicist Award
The JSA Outstanding Nuclear Physicist Award recognizes individuals whose work and careers in JLab nuclear physics in experimental or theoretical research, or technical achievements related to this research, have been noted by their peers in the field nationally and internationally. Nominations for individuals who have made outstanding or sustained contributions to JLab research are due Friday, Jan. 14; see the website for nomination details. The award is funded through the JSA Initiatives Fund.


The accelerator has been delivering beam to Halls A and C. Hall B finished its PrimEx-II run on Thursday. About two shifts were spent to optimize the machine optics. The 70 megahertz amplifier in the North Linac faulted twice, which affected the North Linac radiofrequency system. There is some noise (about 10 kilohertz) in the machine, causing double-pick in vertical beam positions, which can be seen in Halls A and C. The experts have been troubleshooting the problem.

Free-Electron Laser

The machine continued to perform well, allowing staff to continue FEL physics and detailed machine performance studies. The team also studied wiggler chamber heating under controlled conditions in preparation for future high power runs and performed radiation control measurements of the floor penetration in lab 1 to prepare for installation of the vacuum ultraviolet transport system.

Theoretical and Computational Physics

What is the velocity (or better, momentum) of a quark inside the proton? How does the motion of quarks depend on spin? Transverse momentum dependent parton distribution functions (TMDs) encode such information and relate it to asymmetries measured, for example, in semi-inclusive deep inelastic scattering. A new paper <arXiv:1011.1213> describes in detail a method to calculate TMDs using lattice QCD and discusses exploratory results obtained with a simplified operator geometry, building on lattice data components provided by the LHP and MILC collaborations.

Facilities Management and Logistics

Planning is underway for a power outage affecting all JLab campus buildings outside the accelerator site, excluding the VARC and ARC, for work on the campus electrical distribution system. The outage is currently scheduled to last for nearly the entire holiday shutdown period, beginning at 5 p.m. on Dec. 23 and ending at 6 p.m. on Jan. 2. There will be no power in these buildings during this period. More details will be announced as plans for the outage are finalized. If you have any immediate questions, contact Rusty Sprouse in FM&L, x7589.

JLab Calendar of Events

Nov. 23: Science Series Public Lecture
Nov. 25-26 Thanksgiving Holiday - JLab closed
Dec. 6: Safety Shoe Vendor onsite
Dec. 24-Dec. 31: Winter holidays/Shutdown days - JLab closed

JLab's Safety Numbers

22 Days since Last Recordable Accident (JLab record: 331)
79 Days since Last Lost Workday Accident (JLab record: 676)




Environment, Health, Safety and Quality

Reminder: Golf Carts Must Use Headlights After Dusk
Good safety practice calls for anyone at JLab using a golf cart between dusk and dawn to drive with the golf cart's headlights on. Golf carts that don't have headlights may not be used from dusk to dawn.

Leaves of Three, Let It Be
The beautiful colors of autumn are out in full force throughout Hampton Roads, presaging the annual raking that many of us will undertake in the coming weeks. In addition to the usual dangers of yard work, fall presents additional dangers from native poison plants. According to the Centers for Disease Control website, poison ivy, poison oak and poison sumac release an oil, urushiol, when the leaf or other plant parts are bruised, damaged or burned. Skin exposure to urushiol in amounts equaling less than a grain of table salt can cause an allergic reaction, resulting in an itchy red rash with bumps or blisters in 80 to 90 percent of adults. Although over-the-counter topical medications may relieve symptoms for most people, immediate medical attention may be required for severe reactions, particularly when exposed to the smoke from burning these poisonous plants (never burn these plants). When working in areas harboring poisonous plants, the CDC recommends avoiding the plants when possible, covering all exposed areas with clothing or barrier skin creams and thoroughly cleaning items that may have come into contact with poisonous plants. For more information, including pictures of the plants, visit the CDC's website.

Beware Glowing Eyes in the Headlights
Lab staff members have recently expressed concern about the number of deer sighted around the JLab campus. The following are basic safety tips for driving near deer from the Insurance Information Institute:

  • Be especially attentive from sunset to midnight and during the hours shortly before and after sunrise, the high-risk times for deer-vehicle collisions.
  • Deer seldom run alone. If you see one deer, others may be nearby.
  • When driving at night, use high-beam headlights when there is no oncoming traffic. The high beams will better illuminate the eyes of deer on or near the roadway.
  • Slow down and blow your horn with one long blast to frighten the deer away.
  • Always wear your seat belt. Most people injured in car/deer crashes were not wearing a seat belt.
  • If your vehicle strikes a deer, do not touch the animal. A frightened and wounded deer can hurt you or further injure itself.


Today's Colloquium to Feature Graphene
Diamonds may be a girl's best friend, but many scientists prefer graphene. Like diamond, graphene is a form of carbon. It is a thin flake of ordinary carbon that's just one atom thick. This flat form embues graphene with exceptional properties from the remarkable world of quantum physics. Graphene is the thinnest material ever, the strongest and the best known conductor of heat. It is almost completely transparent, yet so dense that not even helium gas can pass through it. Peter Abbamonte, an associate professor at the University of Illinois, Urbana-Champaign, will discuss his research into this remarkable form of carbon and the implications of his recent results. The colloquium begins at 4 p.m. in the CEBAF Center auditorium.

Order Quark Cafe Desserts for Thanksgiving
Selections include apple, pumpkin, pecan and sweet potato pies and pumpkin cheesecake. The deadline for orders is 2 p.m. on Friday, Nov. 19. Order forms and a full list of desserts are available in the cafeteria. Orders must be picked up and paid for on Nov. 23, 11:30 a.m. – 2 p.m., or Nov. 24, 8 a.m. – 1:30 p.m.

JLab Children Invited to Winter Wonderland Party
The Jefferson Activities Group is hosting a children's Winter Wonderland Holiday Party on Saturday, Dec. 11, 10 a.m. -1 p.m., in the CEBAF Center lobby. All children of JLab employees, contractors and users are invited. Kids may share their Christmas lists and be photographed with Santa, play games and make crafts. Light snacks and drinks will be provided. All children must be accompanied by an adult. Each family is asked to bring a new, unopened toy donation for the Toys For Tots toy drive.
Volunteers Needed to Help With Children’s Party
A number of volunteers are needed to help with the children's holiday party, mostly as crafts-table and game helpers. All crafts and supplies will be provided. Volunteers are needed to assist younger children with basic cutting, gluing or tying. Volunteers are also needed for the snack area and as Santa's Helpers. Sign up will soon be available online.
Toys For Tots Toy Drive Dec. 1-10
JLab is participating in the U.S. Marine Corps' annual Toys For Tots toy drive. Bring in your donation of new, unopened toys for children ages 1-12 and deposit them in the collection boxes. Marked drop boxes will be located near the main entrances of CEBAF Center, VARC, ARC, Test Lab and the MCC from Wednesday, Dec. 1 through Friday Dec. 10.
Holiday Decoration Contest
Unleash your inner decorator in the Holiday Office Door/Cubicle Decorating Contest. Prizes will be awarded for the Best Decorated, Most Original Decoration, and the Silliest. All employees, users and contractors with an office or cubicle at JLab may enter the contest (individuals and groups). To enter, e-mail Bridget Paul by COB, Dec. 15. Include your name(s), building number and office/cube location. Judging will take place Dec. 17. Decorations may go up as early as Dec. 1. Decorating materials should be fire resistant, and only UL-approved lighting/electronics may be used. No opened food items allowed.

JLab Jackets Available for Purchase
JLab 25th Anniversary Jackets may be purchased for $38.12 per jacket at the CEBAF Center reception desk. Sizes available for purchase include small, large, extra large, XXL and XXXL. Payment can be made by cash or personal check addressed to Jefferson Science Associates, LLC. Exact change is appreciated.