Jefferson Lab Weekly Briefs November 5, 2014

Jefferson Lab Weekly Briefs
November 5, 2014

12 GeV Upgrade

Shielding for the Hall D tagger building was completed and approved by the Radiation Control Department. After some start-up difficulties with cryogenics and setting up the accelerator, Hall D commissioning is slated to begin this week. The plan is to deliver photons to Hall D for approximately four days, starting Monday, Nov. 3. In Hall B, the support spit for the CLAS12 Torus magnet was installed.


Jefferson Lab Published Journal Articles Oct. 26 - Nov. 1

  • Yingjie Li, Lanfa Wang, Fanglei Lin. "Landau damping effects and evolutions of energy spread in small isochronous ring." Nucl. Instrum. Meth. A 763, 674 (2014).
  • Jozef J. Dudek et al. “Resonances in Coupled πK−ηK Scattering from Quantum Chromodynamics.” Phys. Rev. Lett. 113, 182001 (2014).
  • O. Hen et al. “Momentum sharing in imbalanced Fermi systems.” Science 346, 614 (2014).

Remember to submit your papers for approval to the Jefferson Lab Publications database.

Center for Theoretical and Computational Physics

A new paper provides an updated determination of the nucleon's tensor charge, using a next-to-leading logarithmic order fit of semi-inclusive deep-inelastic scattering and electron-positron scattering data. The contributions to the tensor charge from the experimentally accessible region of nucleon momentum fractions x between 0.0065 and 0.35 are found to be δu = +0.30+0.12-0.11 for up quarks and δd = -0.20-0.13+0.35 for down quarks at the 90 percent confidence level, at a scale of 10 GeV2. A complete determination of the total tensor charge, covering all momentum fractions, will be possible by extending transversity distribution measurements to the small x and large x regions at future experimental facilities.


The Machine Shop is presently manufacturing or continuing to manufacture:

  • a 1 nanoAmp beam position monitor and current monitor girder;
  • for Hall B's Heavy Photon Search experiment, a vacuum chamber and hex cell support;
  • 12 alignment cartridge/caps assemblies;
  • girder plate assemblies for radiofrequency separator; and
  • for Hall C, a Noble gas Cherenkov detector.

 The shop has also worked on various small machining jobs for lab customers.

Jefferson Lab Calendar of Events

Nov. 7-8: SoLID Collaboration meeting
Nov. 12: Colloquium: Neutron Stars
Nov. 12-15: CLAS Collaboration meeting
Nov. 14: g2p Collaboration meeting
Nov. 17: Safety Shoe vendor onsite
Nov. 18-20: Future Directions in Spectroscopy Analysis
Nov. 21-22: Q-weak Collaboration meeting
Nov. 27-28: Thanksgiving, Jefferson Lab closed
Dec. 8-9: Hall A Collaboration meeting
Dec. 10: Colloquium
Dec. 15-16: PREX/CREX Collaboration meeting
Dec. 24-Jan. 2: Holidays and Shutdown Days, Jefferson Lab closed


Environment, Safety, Health and Quality

Adapt Your Driving to Changed Sunlight Conditions
As we all recently participated in the clock-changing ritual, you have probably noticed that lighting conditions during the drive, walk or bike to and from work have likely changed. What used to be dark or dim is now bright, or vice versa, and sunlight now reflects differently off of objects and people at different times of the day. Here are some simple tips for driving safely as you adjust to changed lighting conditions:

  • Use your headlights, beginning a half hour before sunset and up to a half hour after sunrise;
  • Pay extra attention to shadowed areas along roadways and city streets that can make people or slick surfaces difficult to see;
  • Clear your vehicle windows of all moisture (dew, frost and snow) to reduce blind spots and glare; and
  • On colder days, take shadowed curves at lower speeds to avoid the possibility of sliding on ice patches.

If everyone follows these simple tips, our roads may be a little safer for us all.

Computing and Networking Infrastructure

Brief Internet Outage Set for Thursday, Nov. 6
There will be a brief interruption in the lab's internet connection Thursday, Nov. 6, at 5:30 p.m. The total outage time is expected to be no more than 10 minutes. This outage is being scheduled to accommodate equipment upgrades. If you have any questions or concerns about this outage, contact the IT Division Helpdesk at x7155, or


Thanksgiving Buffet in the Quark Café
The annual Quark Café Thanksgiving Feast is set for Thursday, Nov. 6, 11:30 a.m.-1:30 p.m. This year's buffet will feature roast turkey with cornbread sage dressing, gravy, fresh orange-cranberry sauce, wild mushroom ravioli in a Boursin® cream sauce, carved peppercorn-crusted tenderloin of beef, Yukon gold garlic mashed potatoes, sweet potato casserole, green beans almondine, maple-walnut Brussels sprouts, dinner rolls and assorted pies. The buffet is $10.13 (plus tax) and includes a medium fountain drink. Buffet items will be available for a la carte purchase.

Tornado Warning Siren Test Set for Friday, Nov. 7
Jefferson Lab's tornado warning siren will undergo its monthly operational test at 10:30 a.m. on Friday, Nov. 7. Don't respond to the siren; this is a test of the siren system and not a personnel response exercise. Individuals planning to be in the Central Materials Storage Area (where the siren is located) while the test is taking place must have with them and wear two layers of hearing protection.

Colloquium: Neutron Stars in the Multi-Messenger Era: Extreme Matter and Extreme Phenomena
Neutron stars are some of the most extreme astrophysical phenomena. In this talk, Sanjay Reddy, University of Washington, will discuss how the properties of matter at extreme density shape observable aspects of these phenomena. He will highlight the role of nuclear and neutrino physics in core collapse supernovae, neutron star mergers, nucleosynthesis, and transient phenomena observed in accreting neutron stars and magnetars. Quantitative predictions for future multi-messenger signals (photon, neutrino and gravitational wave) are within reach, and these predictions rely on combining advances in theory, simulation and terrestrial experiments. The colloquium is scheduled for 3 p.m. on Nov. 12 in the CEBAF Center auditorium.
Order Thanksgiving Desserts from Quark Café

The café will start accepting holiday dessert orders on Thursday, Nov. 6, during breakfast, lunch and Wednesday snack hours. The café is offering a selection of whole pies, including pumpkin, southern pecan, french silk and fruits of the forest. Pumpkin cheesecake is also available. Orders will be accepted through Friday, Nov. 21. Pre-ordered desserts will be available for pickup on Tuesday, Nov. 25, 11:30 a.m.-2 p.m. and Wednesday, Nov. 26, 8 a.m.-1:30 p.m. Pick up your order form and get more information in the Quark Café.

Food Drive Continues
Donations in support of the local Foodbank of the Virginia Peninsula are being accepted in drop boxes in the ARC, SSC, CEBAF Center and TED Building lobbies through Nov. 21. To participate, bring unopened, canned or boxed, nonperishable food items and place in the nearest donation box.


JLab Weekly Briefs is an ongoing publication providing information on the status of safety, accelerator operations, experiments, free-electron laser, reviews, upcoming activities and special events. Deadline for submission is every Tuesday by 10 a.m. Submit new items to: Public Affairs or contact Kandice Carter at x7263.