Jefferson Lab Weekly Briefs May 5, 2010
Jefferson Lab Weekly Briefs
May 5, 2010
12 GeV Upgrade
Coordinated planning is well underway for the upcoming summer 2010 scheduled accelerator shutdown, which includes installing the following: the remaining west arc low-conductivity-water (LCW) supply and return lines, Arc 10 stands, four cryomodule baseplates, RF waveguide hangers and cables. Planning for the 12 GeV assembly and installation efforts includes the identification and coordination of requirements for material handling equipment, transportation and storage/assembly space.
At the request of the Office of Nuclear Physics, Daniel Lehman, Director of the Office of Project Assessment in DOE's Office of Science, convened a team of 13 experts in an Independent Project Review of the 12 GeV Upgrade on April 27-28. The purpose of the review was to assess progress in all aspects of the project since last September. The review committee concluded at the closeout that the project is making satisfactory progress and provided ten recommendations to guide activities in the coming months.
Beam delivery was stopped at 7:30 a.m. on Friday, April 30, to prepare for the May 1 Open House. While the accelerator was down, scheduled maintenance and injector beam studies were performed. After the event, the accelerator was recovered by 8:15 p.m. Then, on Sunday, the Central Helium Liquefier tripped, possibly due to a power glitch, causing more than five hours of downtime. On Monday, the accelerator optics was optimized, and Hall B was changed to pass five.
The FEL team provided beam for optical measurements and to a user group last week to measure the biological effects of terahertz radiation. The group successfully completed a set of measurements.
Focusing on the baryon spectrum, the Hadron Spectrum Collaboration, including members of the Theory Center, computed the excited spectrum of the nucleon and Δ in lattice QCD at three values of the light quark masses <arXiv:1004:5072>. The pattern of states was in reasonable agreement with that observed in experiment. However, the expected multi-particle states in the spectrum were not found, emphasising the need to broaden the operator basis to include multi-hadron operators.
JLab's Safety Numbers
22 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
May 6: TEDF & Construction Town Meeting
Environment, Safety, Health & Quality
Watch for Insects that Bite or Sting
Workers at JLab have experienced insect bites or stings that have been serious enough to require time off from the job. If left untreated or if improperly treated, bites and stings can get infected and result in unnecessary discomfort and lost work time.
When you do your pre-job walk down, look for flying insects and evidence of wasp nests, and be cautious when disturbing grounds, equipment or building locations that have been undisturbed for long periods. If you see evidence of flying, stinging insects, call x7400 and ask Facilities Management and Logistics to respond. FM&L has a pest control subcontractor that routinely applies environmentally friendly insecticide to locations around the site to help manage pests. If you are bitten or stung by a bug of any kind, obtain prompt first aid from Occupational Medicine.
JLab TEDF & General Construction Update Town Meeting
Colloquium and Public Lecture Set for Tuesday, May 11
JAG Run-A-Round Event Registration Closes Tuesday