Jefferson Lab Weekly Briefs February 1, 2012
Jefferson Lab Weekly Briefs
February 1, 2012
12 GeV Upgrade
Beneficial occupancy of the Hall D Counting House, Service Building, and Tagger Area was established Tuesday. JLab Facilities Management & Logistics has completed various tasks related to safety, including verification of proper operation of the emergency lighting systems. The construction contractor is working on the remaining punchlist items.
In Hall A, the g2p experiment is making progress on installation, with the aim of starting data taking on Feb 15. A problem was found with calculations of the magnetic field in the septum magnet; in reality it is a factor of about 1.5 lower than calculated (the error was found in the meantime). This will result in either eliminating some higher Q2 points from the run plan, or adding shim material to the magnet.
School on Radiation Technologies Application Deadline Extended
Problems with Hall B beam last week required that some magnet shunt modules be replaced and optics be optimized in the injector. This also cleared up beam current limitation being experienced by Hall C. C100 zone 2L24 was recovered during beam studies; thanks to advances made by the engineers working on its control system, it is running without introducing beam instabilities to the halls. During an accelerator maintenance period on Thursday, an additional C100 zone was moved from the Test Lab to the accelerator tunnel. PEPPo installation continues in preparation for running in the summer. Beam ran well throughout the weekend.
Center for Theoretical and Computational Physics
A new Theory Center paper reports the first attempt at a global analysis of spin asymmetries in semi-inclusive deep inelastic scattering (SIDIS) and proton-proton collisions, using the transverse momentum dependent (TMD) and twist-3 formalisms for the SIDIS and pp reactions, respectively. Contributions from the so-called Sivers effect (gluon pole matrix element) are considered, and additional missing contributions to the normal asymmetry AN in pp collisions from twist-3 fragmentation are identified. A future, more complete analysis is planned in order to study the contribution from twist-3 fragmentation functions.
JLab Calendar of Events
Feb. 4: Va. Regional High School Science Bowl
Environment, Safety, Health and Quality
Parking Lot Safety
Computing and Networking Infrastructure
PCs and Macs Available for Purchase
Big Game Tailgate Lunch in Quark Cafe on Friday, Feb. 3
Come Out and Play on the JLab Softball Team!
Take Time to Tango - Part Two
Onsite TIAA-CREF Counseling Offered
Tracking Thomas at JLab
Congratulations this week go to Narciso Gomez, who was the first person to correctly identify the Jan. 25 location. Honorable mentions go to Samika Hawkins, Doug Higinbotham, Michael Haddox-Schatz, Stephanie Vermeire, Maurizio Ungaro, Annie Tran and Joe Arango. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.