Jefferson Lab Weekly Briefs
August 3, 2011
12 GeV Upgrade
The subcontractor for the beam switchyard addition and the new tunnel penetrations mobilized on Aug. 1. Existing utilities are being relocated this week in preparation for the new work. Next week, the subcontractor will start erection of the steel for the expanded power supply room and start drilling the earth to the tunnel roof. The tunnel penetration construction is an 11-step process to ensure a water-tight sleeve to the tunnel roof prior to core drilling the concrete tunnel roof. The tunnel is below the water table, and the water-tight sleeve is needed to keep groundwater from entering into the tunnel during construction of the new penetrations.
The eleventh scheduled week of the Six Month Shutdown went well. Checkout for the injector experiment (PEPPo) continues. In the magnet refurbishment and re-installation program, stack 8 magnets in the east arc have been completed and DC power checks for the east arc are ongoing; in the west arc, magnet alignment is underway. Four cryomodules saw action this week: 2L21 (nicknamed The Admiral) was removed to the Test Lab; alignment was completed for 2L23; testing continues on 2L24; and installation continues on 2L25. Many other tasks were continued or started.
This week, FEL staffers continued high-voltage commissioning of the gun (first in vacuum and then in krypton), achieving 395 kilovolts.
Center for Theoretical and Computational Physics
Semi-inclusive deep-inelastic scattering experiments, such as those performed at JLab, allow us to probe the motion of quarks inside the proton in terms of transverse momentum dependent parton distribution functions (TMD PDFs); this information, however, is convoluted with fragmentation functions (TMD FFs) and soft factors. It has long been known that weighting the measured event counts with powers of the hadron momentum before forming angular asymmetries de-convolutes TMD PDFs and TMD FFs in an elegant way -- but at the expense of introducing an undesirable sensitivity to high momentum contributions. Using Bessel functions as weights, a new paper finds a natural generalization of weighted asymmetries that preserves the de-convolution property and soft-factor cancellation, yet allows less sensitivity to high transverse momenta.
JLab Calendar of Events
*Note: calendar links may not be available offsite*
Environment, Safety, Health and Quality
The hurricane season is in full swing, with Tropical Storm Emily now churning in the Caribbean and predicted to impact the East Coast. Now's a good time to review your preparations for staying safe pending landfall of a hurricane or tropical storm. The Virginia Department of Transportation has issued the interactive Virginia Hurricane Evacuation Guide, which provides information regarding evacuation routes, shelters and essentials to include in evacuation kits. For additional severe weather preparation and planning guides, visit the Virginia Department of Emergency Management. Finally, stay informed about potential tropical threats and track storms on the National Weather Service's National Hurricane Center website.
JLab Website Is Available from Offsite
Open House Save the Date: May 19, 2012
Onsite TIAA-CREF Counseling Offered
Mont on the Six Month Shutdown
Six Month Shutdown Safety Briefing
DOE Food Drive Ends Friday
Engineering Announces Special Cryo Seminars
Save the Date: JAG Luau Set for Wednesday, August 17
Tracking Thomas at JLab
Congratulations to Dave Fazenbaker, who was the first person to correctly identify the July 27 location. Honorable mentions go to Jason Willoughby, Stephen Smith, Stephanie Vermeire, Linda Ceraul, Bobby Lawrence, Lori Lawson, Marty Hightower, Andy Kowalski, Cynthia Lockwood, Michael Haddox-Schatz, Rob Mahurin, Jodi Patient, Deborah Dowd, Lawrence Ferbee and Doug Higinbotham. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.