Jefferson Lab Weekly Briefs
July 13, 2011
12 GeV Upgrade
The 2011 six-month shutdown planning efforts included safety integration. Required pre-shutdown safety training was established and provided for construction workers and contract labor staff. Planning for required permits is identified in the six-month shutdown installation schedule and communicated at weekly progress meetings for the following week’s activities. The pre-shutdown safety meeting included safety awareness for 12 GeV construction projects, as well as a video highlighting some of the 12 GeV project-related work.
In Hall A, the installation continues on schedule; most parts for the septum stand have arrived, the F2Z beamline stand has arrived, and work is nearing completion on the cryogenics. The PAC submission deadline has passed, and there are four new Hall A proposals and one conditional proposal, plus three already-approved proposals being graded by the upcoming PAC. Hall A staffers are in the process of writing technical reviews for the four new and one conditional proposals.
Work on the injector experiment (PEPPo) continues, with detector tests over the weekend using a check source. In the west arc, magnet and beam pipe re-installation continues; the vacuum pump down and leak checks have all rated okay; arc 10 magnet and girder alignments are progressing, and the west arc Personnel Safety System segmentation gate has been re-installed. In the east arc, magnet removal from arcs 7 and 9 has been completed ahead of schedule, so the decision was then made to begin the removal of magnets from arc 5; meanwhile, completed magnets are now being re-installed. The installation of the high-power radiofrequency power supply in the South Linac Service Building is moving nicely; 2L24 is almost complete, and the klystron hoist was moved over to 2L25; the 2L26 power supply has been delivered and moved into place.
Injector work continued with good progress this week. The new valve upstream of the quarter cryomodule passed the leak-through test, allowing the superconducting radiofrequency and the Central Helium Liquefier crews to cool down the injector quarter cryomodule. The cooldown to 4 Kelvin was successful, with no evidence of helium leaking into the insulating vacuum or into the beamline at the 10-9 Torr level. A beamline viewer was installed in the injector beamline, and the whole injector was pumped down. The gun bake is nearly complete.
Center for Theoretical and Computational Physics
Motivated by the desire to study resonances using lattice QCD, researchers in the JLab Theory Center have developed methods to efficiently study excited mesons with non-zero momentum in lattice QCD. These techniques will enable more precise determinations of a wider range of resonant phenomena, as well as allowing the Q2 dependence of matrix elements, such as those relevant for form factors, to be mapped out more fully. This work is part of a program of calculations that will provide the ab initio predictions for masses demanded by experiment and inform expected production rates at GlueX and CLAS12.
The cryogenics group reports that it has completed the 12 GeV south linac warm gas piping modifications scheduled for the six-month shutdown. All south linac controls for the C100 cryomodule locations have been completed. Additionally, cryo reports that the CHL #2 refrigerator cold box internal piping is completed, with only pressure testing and insulation to be scheduled. Delivery of the refrigerator is scheduled later this fall.
Machine Shop Work Request System Is Live
Environment, Safety, Health and Quality
Extension Cord Safety
Lunchtime Seminar on July 19 for Managing Stress in the Workplace
American Red Cross Blood Drive
Tracking Thomas at JLab
Congratulations to Henry Robertson, who was the first person to correctly identify the July 6 location. Honorable mentions go out to Lorelei Carlson, Mike Davis, Andre Newman, Stephanie Vermeire, Dave Fazenbaker, Jason Willoughby, Dena Polyhronakis, Harry Fanning, Dick Owen, John Heckman, Deborah Dowd, Doug Higinbotham and Jodi Patient. 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
July 14: Student Seminar - Discovery of the Quark