Jefferson Lab Weekly Briefs December 1, 2010
Jefferson Lab Weekly Briefs
December 1, 2010
12 GeV Upgrade
12 GeV installation planning for the upcoming six-month accelerator shutdown (May – November 2011) incorporates transfer of 12 GeV equipment ownership, as appropriate, to the Accelerator Division. Related equipment documentation, training and commissioning plans are being developed to ensure smooth integration into the existing accelerator. 12 GeV participation in weekly labwide integrated schedule meetings continues to ensure effective communication and optimized installation work planning.
Hall B has successfully completed the PrimEx-II run, a high-precision measurement of the π0 lifetime. This is a fundamental quantity predicted directly from QCD. The installation of the eg5-TPE experiment has been completed. The goal of this experiment is to directly measure the two-photon contributions to elastic electron-proton scattering. This experiment will help clarify large discrepancies observed in elastic scattering experiments at JLab and worldwide when using different measurement techniques to determine the electromagnetic form factors of the proton. The Hall B experiment will use a beam with an equal mix of electrons and positrons and measure the ratio of elastic electron-proton to positron-proton cross sections. This ratio depends directly on the two-photon exchange contributions.
PAC 37 Proposals Due Today
JSA Postdoctoral Research Prize Nominations Due Today
Last Tuesday was a beam studies day with injector optimization and testing; it ended with a spin dance for the halls to set the Wein angle. On Wednesday, all areas were taken to controlled access for radiation surveys at 2 p.m. The halls remained in controlled access, while the rest of the main machine was brought back to power permit to allow the radiofrequency and magnets to be turned back on and left in hot standby mode. Reduced staffing on Thursday kept everything warm and stable until Friday morning at 8 a.m., when all areas were brought to beam permit, and beam was sent back into Halls A and C within an hour. There were issues with a CAMAC crate controller and instabilities with phase and energy control in the South Linac, along with instability in the first-pass separator over the weekend. Beam was magnetically extracted into Hall A, with Hall C performing no-beam pedestal runs until the separator amplifier was replaced Monday morning.
The FEL team used the short week for machine maintenance.
Center for Theoretical and Computational Physics
Researchers at JLab, DESY in Germany and KEK in Japan have calculated the "bump" in the cross section associated with the ρ-meson resonance. Using the methods recently developed in <arXiv:1011.5288>, it is becoming more feasible to calculate the strong decays of hadrons directly from the fundamental theory of QCD using lattice methods. It is expected that these techniques will also work for baryons, such as the Δ resonance, allowing for theoretically clean calculations of properties of unstable hadrons.
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 are finalized. If you have any immediate questions, contact Rusty Sprouse in FM&L, x7589.
JLab Calendar of Events
Dec. 6: Safety Shoe Vendor onsite
Environment, Health, Safety and Quality
Free Reusable Solvents Available on Webstock
Wi-Fi Access Policy for JLab Business Flyers
Discounts on airplane Wi-Fi is available from GogoInflight.com, when purchased before the flight. Currently, the special lets you buy a pass good for Wi-Fi on multiple flights in a 24-hour period for $11, a $1.95 savings over the regular price. GoGo provides service on AirTran, Delta, American, US Airways and United. For the holidays, you can get free Wi-Fi on all AirTran and Delta flights through Jan. 2. If you know of other in-flight Wi-Fi service providers, contact Carol Kinsey.
Personal Dosimeter Change Out Will Be Dec. 22
JAG Offers JLab Merchandise Through Online Store
Holiday Hideaway at the SURA Residence Facility
JLab Children Invited to Winter Wonderland Party