Jefferson Lab Weekly Briefs
December 17, 2008
12 GeV Upgrade
Evaluations of the proposals for the FY2009 civil contracts are complete, and DOE Thomas Jefferson Site Office personnel were briefed on Dec 11. Contract awards will be made following the requisite evaluations by DOE.
Interviews for a construction safety representative position in the Facilities Management Group are in progress. In support of the 12 GeV Upgrade project, the construction safety representative will provide safety oversight of the construction contractors’ operations for the Central Helium Liquefier (CHL) building addition and Hall D Complex.
In Hall B, the Deeply Virtual Compton Scattering (DVCS) experiment continues. Hall B staff members are continuing with production data taking. Approximately 70 percent of required statistics have been collected, and the experiment is on track to have full statistics by the end of the run. CLAS12 project engineering design (PED) continues; procurement for the CLAS12 drift chamber systems has begun. Staff members are also preparing for a CLAS dismounting and CLAS12 installation review in spring.
After repairing additional wiring issues with the superconducting magnet for the polarized target, the magnet has been reinstalled in Hall C, where it is currently being cooled down. If the magnet operates properly, then the transverse polarization setup, which includes the use of the pre-target chicane, will be commissioned with beam. This will allow prompt resumption of the Spin Asymmetries of the Nucleon Experiment (SANE) in January.
JSA Accepting Applications for Graduate Fellowships at JLab
The accelerator has been performing well, with low trip rates (about 15 trips per hour). The beam polarization was low for about three shifts due to the Pockel Cell voltage change, which was caused by a failed device in the injector called the zoom box. The problem was identified and addressed. Box supply RSEP8R tripped off a few times. Maintenance is scheduled for this power supply.
Free-Electron Laser (FEL)
With the gun up and running at high voltage, FEL staff was able to proceed in the effort of setting up beam properly around the machine. Although the gun lifetime is more limited than previously, the new cesiator permits rejuvenation in 30 minutes, so the productivity is good. As of today, lasing has been re-established, accomplishing an important milestone before the holiday break.
The photoproduction of the 12ΛB hypernucleus, which is investigated at JLab using virtual photons, has been studied (arXiv:0812.1547 [nucl-th]) within a fully covariant effective Lagrangian-based model, employing the Λ bound state spinors derived from the latest quark-meson coupling model. The kaon production vertex is described via the creation, propagation and decay of N*(1650), N*(1710), and N*(1720) intermediate resonant states in the initial collision of the photon with a target proton. The hypernuclear production cross sections calculated with the quark model-based hyperon bound state spinors are found to differ significantly from those obtained with phenomenological single-particle wave functions.
Environment, Safety, Health & Quality
There has been a great deal of discussion lately on when to report injuries. For the safety and welfare of all employees, all injuries must be reported to supervisors and Occupational Medicine. This will:
- Ensure you get appropriate medical treatment as quickly as possible. Even if the injury is minor, either you or your supervisor needs to contact Occupational Medicine (x7539). Medical staff will assess whether you need to come in for further evaluation. If the injury is truly minor, they will record it in their first aid log and disseminate that information to your supervisor, the Division Safety Officers and ESH&Q.
- Prevent similar or even more serious injuries. Safety staff looks at each incident to figure out how to prevent recurrence. Also, monitoring trends in "minor" events can warn of the potential for more serious events.
We are all responsible for maintaining a safe working environment at JLab for ourselves and our co-workers. The lab goal is that everyone comes to work on a given day in good shape, does the work, and goes home in that same good shape or better.
Computing and Networking Infrastructure (CNI)
Ten Best Tips to Keep Your Computer Running Smoothly
End-of-Year Radiation Badge Change Out
Holiday Bake Sale on Dec. 18
Holiday Pie Orders Taken Through Dec. 19
Holiday Shutdown – Cafeteria Meal Notice
JLab's Safety Numbers
98 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events