12 GeV Upgrade
Excellent progress continues to be made on the work planned for the Six Month Shutdown. Magnet rework and re-installation of the south half of the east arcs has been completed and they are back under vacuum. Work is proceeding well on getting the magnets in the north half of all arcs re-installed. All arc magnets have now been refurbished, with only a few left to measure and re-install. The first 12 GeV cryomodule has been installed in the tunnel and connected to one of the new radiofrequency zones. The expansion and upgrade of the Personnel Safety System was completed on schedule last week, which permitted in-tunnel testing of the new cryomodule-RF zone to start this past Monday. The second zone of RF has been completed and good progress has been made on the third. Three more cryomodules are at various stages of assembly.
In the injector, injector experiment (PEPPo) checks continued. Lockup of the south linac and a PSS function test went well, with no problems found. Tunnel cleanup was completed in preparation for daily lockup of the south linac for RF commissioning. Cryomodule 2L24 is in place and hookups are completed. Some RF commissioning and beam switchyard penetration grouting has begun. Lastly, the Central Helium Liquefier mag lev bearing control cabinet has been rebuilt.
The FEL team continued to prepare the gun and drive laser for 350 kilovolt operations. The quarter cryo booster was brought back into operational status. The rest of the cryomodules have been brought into RF operation. The team has a few remaining tasks to complete next week on the machine front end and then beam operations will be ready to recommence.
Center for Theoretical and Computational Physics
The role and implications of spin-flavor symmetries that emerge in Quantum Chromodynamics (QCD) for a large number of color degrees of freedom have been investigated in the real world, where the number of colors is equal to three. This was carried out in a new article by investigating the different decays of negative-parity baryon resonances where π, η or Κ mesons are emitted. This study provides insights into those symmetries and also predictions, which being based on a study that to a large extent is rigorously connected to QCD, should serve as important tests of the strong dynamics of QCD. A main motivation for this kind of study is the N* experimental program at JLab and the quest for understanding strong QCD from the results of that program.
The Machine Shop is presently manufacturing:
The shop has received a mostly positive response from its customers on the use of the electronic Machine Shop Work Request system. The shop has processed 201 job requests since July 5.
Environment, Safety, Health and Quality
Warning Tapes Provide Information for Your Safety
JAG Luau Set for Today
United Way School Tools Drive
Last Chance to Sign Up for 2011 Day of Caring
Fed Travelers and Smartphone Apps
Tracking Thomas at JLab
Congratulations to Jason Willoughby, Stephen Smith, Doug Higinbotham, Michael Haddox-Schatz, David Fazenbaker, Percy Harrell, Marcy Stutzman and Stephanie Vermeire, who were the first to correctly identify the Aug. 10 location. Honorable mentions go out to Harry Fanning, Dick Owen, Mike Martin, Aidan Kelleher, Casey Heck, Cynthia Eller, Michelle Shinn and Mike Davis. 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