Jefferson Lab Weekly Briefs
February 9, 2011

12 GeV Upgrade

The construction contractor for the North and South Access low-conductivity water upgrades, D.E. Kirby of Portsmouth, Va., mobilized last week. Silt fencing is in place and excavation for the cooling tower foundations will begin this week, weather permitting. The 5 MVA unit substations for the Central Helium Liquefier #2 compressors were delivered and were set on the concrete pads last week. The pump startup and commissioning of the cooling towers, which provide the condenser water to the compressors, is expected to commence within the next two weeks.

Physics

After improvements in beam quality and reliability, Q-weak has been taking production data on the liquid hydrogen target with very high efficiency. Sufficient data has been acquired to determine that the measured asymmetry is non-zero and of the expected sign. While a much larger amount of data is required to obtain the proposed precision, this gives confidence in the experimental equipment, data acquisition electronics and analysis software. In addition, a significant amount of data with an aluminum target was obtained. This data will be used to subtract backgrounds from the aluminum windows of the LH2 target.

Accelerator

The accelerator has been running well since Friday. On Friday, it was found that the root cause of the injector instability was a misbehaving radiofrequency cavity (0L03-2) in the injector. After lowering the gradient of the cavity, Operations staffers were able to send 150 microamp beam to Hall C with very good halo counts. Also during the investigation of the beam instability, the injector optics were changed, and beam appears to be better.

Free-Electron Laser

The FEL group spent last week performing optical transport upgrades to get ultraviolet FEL light to user labs and prepared for upgrades of the Laser Personnel Safety System for UV use in the labs. The staffers also plan to upgrade several communication links to vacuum hardware

Theoretical and Computational Physics

One fascinating aspect of strong interactions is that the internal structure of hadrons measured in scattering experiments is in a subtle way related to the excitation spectrum seen in hadron-antihadron creation/annihilation processes. Using such "dispersion relations," theorists have calculated the transverse charge density in the pion from the precise data on the e+e- → π +π- process collected at e+e- annihilation facilities. The resulting spatial image of the pion reveals a pointlike quark-antiquark configuration at the center, which represents its fundamental particle content in QCD and can be probed in high-momentum-transfer pion production experiments at Jefferson Lab.

JLab Calendar of Events

Feb. 9: Nanotubes Colloquium and Public Lecture
Feb. 21: Presidents Day holiday: JLab closed
Feb. 23-25: Excited Hadronic States and the Deconfinement Transition Workshop
Feb. 28: Safety Shoe vendor onsite
March 5: Va. Regional Middle School Science Bowl
March 7: Safety Shoe vendor onsite

 

 

 

Environment, Safety, Health and Quality

Workplace Noise May Double Risk of Heart Disease
A new study found that workers exposed to a noisy work environment are two to three times more likely to develop heart disease than those who work in quieter environments. The researchers found that loud noises elicit stress and the release of chemicals that constrict coronary arteries.
 
At JLab, noise is well controlled and loud noise areas are posted. Employees are informed to wear hearing protection in these areas. The Industrial Hygiene group periodically monitors the workplace, participates in work planning to help eliminate noise and conducts ongoing noise dosimeter studies of individual exposures.
 
You can also reduce your exposure to noise off the job. You can choose to turn down the volume on televisions, video game consoles and radios. Alternatively, you can wear hearing protection when using equipment or gadgets that produce loud noise, such as power tools and lawn mowers.
 
If you have questions about the noise in your area or off the job, contact Jennifer Williams, Mary Boggs or Dick Owen. If you have questions regarding your hearing, contact JLab’s Occupational Medicine group.

Computing and Networking Infrastructure

New Mathematica and Maple Versions Available in CUE
Mathematica 8 and Maple 14 are now available in the CUE Linux /apps areas. To use the new versions, type 'use mathematica/8' or 'use maple/14' from the command line. Then start either mathematica or maple as normal to get the new version. If you have questions or run into difficulties using this process, contact the IT Division Helpdesk, x7155.

Redhat Enterprise Linux 6 Now Available in CUE
The latest version of Redhat Enterprise Linux is now available for use at JLab. Since this is the initial release, the scientific computing software, such as ROOT and Geant4, have not yet been installed. The CNI group is working to get this software installed and available. If you would like to install this newest version of Linux, contact the IT Division Helpdesk, x7155, for installation media.

Announcements

Colloquium: Nanotubes - 20 Years and Into the Future
Since the 1991 publication of the seminal paper describing the carbon nanotube, thousands of researchers have explored nanotubes' properties and potential applications. Few realize, however, that carbon’s immediate neighbors on the periodic chart, boron and nitrogen, can also form perfect nanotubes. Mike Smith of NASA Langley Research Center will describe the discovery of a new method for making BNNTs that was developed at JLab’s FEL. For applications from space elevators to nuclear physics, Smith will explore the possibility that better nanotubes have finally arrived in a Feb. 9 colloquium in the CEBAF Center auditorium at 4 p.m.

Celebrate V-Day with the Amoré (Quark) Cafe
On Monday, Feb. 14, The cafe will offer a variety of special selections, including London broil with roasted shiitake mushrooms and crumbled blue cheese, apple caramelized flatbread with Brie, steamed lemon asparagus, lobster mashed potatoes and mini French pastries.

Tech Notes Now Reside in Docushare
Continue to request tech note numbers from, and e-mail completed tech notes to Kim Kindrew. Tech notes will be uploaded to Docushare. Note: Tech notes in Docushare are not available offsite.

Plan Your JLab Tour Now
As spring nears and temperatures rise, interest in tours of JLab also increases. If you or an organization that you represent is considering a tour for a few or many individuals, remember to contact Public Affairs first. All tours of JLab are approved and coordinated by Public Affairs, and at least a two-week advance notice is requested. Tours are scheduled Monday through Friday, 8:30 a.m.-5 p.m. If you are interested in discussing a tour, contact Michelle Lechman. For more information about tours, you can also visit the website tours page.

Onsite TIAA-CREF Counseling Offered
TIAA-CREF will offer individual counseling sessions onsite on Feb. 17, April 1, May 19-20. In these sessions, employees can discuss their personal financial situation with a TIAA-CREF consultant on a confidential basis. To discuss your plan and options for managing your retirement savings or to schedule an appointment with a TIAA-CREF individual consultant, call TIAA-CREF at (800) 732-8353, Monday-Friday, 9 a.m.-8 p.m.