Jefferson Lab Weekly Briefs June 15, 2011
Jefferson Lab Weekly Briefs
June 15, 2011
12 GeV Upgrade
Excellent progress is being made on the accelerator installation work planned for this shutdown period. Fifteen of the 16 stacks of dipole magnets in the west arcs have been removed from the tunnel. Refurbishment of those dipoles is running somewhat ahead of schedule and field measurements are on schedule. Stacks 1-3 of the refurbished magnets have been reinstalled, and alignment has begun. The expanded linac computer network is functional in zone 23 of the south linac. In-tunnel measurements of the characteristics of the first C100 cryomodule are underway. Assembly of the second C100 cryomodule continues; assembly of the third cryomodule cavity string is underway. A new klystron has been tested successfully; it delivered its rated 13 kilowatts. Populating the new radiofrequency zones with chassis and other equipment continues.
Last week, the Hall A installation schedule continued apace. Meanwhile, the collaboration held its Hall A collaboration meeting on Thursday and Friday, with reports from recently completed experiments, discussion of the upcoming scheduled experiments and presentation of new proposals.
APS Forum on Outreach and Engaging the Public
Tate Medal for International Leadership in Physics
The scheduled accelerator down has been going well. Installation of the equipment for the injector (PEPPo) project continued. Removal and installation of the west arc dipoles were in progress. Microphonics measurements on the C100 superconducting radiofrequency cryomodule were complete and the data will be analyzed. The liquid level of the C100 cryomodule had been set at 25 percent in preparation for warmup. RF control systems cabinets were mounted for zones 22–26 in the north and south linac service buildings. Many other tasks were continued or started.
Preparations continued for warmup of the injector cryounit, so that several injector diagnostic systems and the gun could be repaired.
Center for Theoretical and Computational Physics
A new review article describes lepton-nucleus deep inelastic scattering at small parton momentum fractions x and summarizes the theory and phenomenology of nuclear shadowing, including predictions for the shadowing modifications of the momentum, diffractive and generalized distributions of sea quarks and gluons in nuclei. The article discusses the limits of applicability of the leading twist approximation at extremely small x and the onset of a new regime of strong interactions (the black disk regime). The predictions of this approach can be tested in ultraperipheral nucleus-nucleus collisions and proton-nucleus collisions at the Large Hadron Collider and the Relativistis Heavy Ion Collider, and at a future Electron-Ion Collider (EIC) and Large Hadron-Electron Collider (LHeC).
Facilities Management & Logistics
JLab Vehicles – Use them safely & appropriately
Environment, Safety, Health and Quality
One easy way to help stay current on safety issues is to use the SUPER Weekly Toolbox Safety Briefing, following the SUPER outline:
Semi-Annual Personal Dosimeter Change Out Set for June 29
Travel Credit Card Renewals
Minority Undergraduate Research Assistantship
Tracking Thomas at JLab
Congratulations to Russell Mammei, who was the first person to correctly identify the June 8 location. Honorable mentions go out to Stephanie Vermeire, Christine Hummel, Elaine Zuchowicz, Andy Kowalski, Kevin Jordan, Jason Willoughby, David Fazenbaker, Kim Kindrew, Debra Brand, Jim Follkie, Dick Owen, John Kelly, Mike Koch, Chuck Baldwin, Susan Brown and Cindy Eller. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.
JLab Calendar of Events
June 20: Safety Shoe vendor onsite
JLab Summer 2011 Education Calendar
May 31- June 17: Hampton University Graduate Studies