Jefferson Lab Weekly Briefs
June 25, 2008
12 GeV Upgrade
The design effort on the conventional facilities to support the 12 GeV CEBAF Upgrade is near completion. JLab Facilities & Logistics personnel are incorporating design review comments for the FY10 and FY11 procurements and completing the design of an FY12 procurement. The focus has turned to preparations for the Department of Energy, Director of Project Assessment Independent Project Review (IPR) of the 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) Upgrade Project scheduled for July 22-24 and the acquisition of the FY09 procurements. The Hall D Complex Selection Committee convened this week and started the evaluation of construction contractors’ qualification proposals. The commissioning plans consisting of the functional performance checklists for the Hall D Complex and CHL Addition are complete.
A site-wide power event that occurred on Sunday was caused by a temporary failure of Dominion Power gear. This resulted in a loss of power to many pieces of equipment onsite, causing the equipment to trip breakers (including the 40MVA substation and the 4160V transformer that supplies the cryogenics equipment). Numerous staff members worked diligently on Monday (June 23) to bring all of the equipment back online. In the injector, Gun 3 was reconditioned. Substation planned maintenance continued around the site, as each substation was shut down, maintenance work performed, and the unit brought back into service. The Central Helium Liquefier is now completely off the Main Cold Box, with the Standby Refrigerator taking its place online.
Progress is being made on reassembling the FEL gun, and a mild bake on the gun test stand is proceeding to reduce background water so as to improve quantum efficiency (QE) lifetime. Several user labs have been certified for laser ops and training, and certification for the new Laser Personnel Protection System is proceeding. FEL staff began mounting magnet girders for the amplifier/ultraviolet leg.
Properties of bound nucleons (deep inelastic structure functions, elastic form factors, etc.) are modified by the nuclear medium. Using the results of the Quark-Meson Coupling model, which predicts these modifications, and assuming that the bound nucleon generalized parton distributions are modified in proportion to the corresponding bound nucleon elastic form factors, a new approach was developed by Theory Center staff (arXiv:0806.3288 [hep-ph]) to calculate the effect of medium modifications on observables measured in deeply virtual Compton scattering (DVCS). As an example, incoherent DVCS on 4He is studied in the 4He(e,e'γp)X reaction, which will be measured in the near future at JLab, and predictions are made for the pattern of the xB- and t-dependence of the ratio of the bound to free proton beam-spin asymmetries, ALUp*(φ)/ALUp(φ).
JLab's Safety Numbers
254 Days since Last Recordable Accident (JLab record: 319)
JLab Calendar of Events
June 30-July 2: Science & Technology Review
Environment, Safety, Health & Quality
There are about 140,000 disabling eye injuries every year from work-related causes. Most of these injuries, as many as 90 percent, were easily preventable. Proper eye protection, worn correctly, is all that's needed to protect eyes from many hazards. Here are a few good tips regarding eye protection:
An article about how eye protection saved one JLab employee's eyesight can be found in the JLab OnTarget newsletter.
Computing and Networking Infrastructure
Networking Changes in CEBAF Center
Here is the schedule for upcoming changes:
Individual machines may be registered here at any time by using a web browser on that machine. If you are unsure about your machine registration, it is fine to register again. Please contact the HelpDesk, x7155, about other registration-related queries.
Another Phishing Scam
Summer TLD Change Out is Friday
JSA Initiatives Fund Website Update
Red Cross Accepting Donations for Flood Relief