Jefferson Lab Weekly Briefs
March 3, 2010
12 GeV Upgrade
The winter 2010 tunnel work for 12 GeV installation has been completed. Planning efforts for the summer 2010 scheduled accelerator down are in progress. Activities include installation of the remaining west arc low-conductivity water (LCW) supply and return lines, Arc 10 stand installation, the remaining four cryomodule base plates, radiofrequency (RF) waveguide hangers and cable installations. Planning efforts for 12 GeV installation activities during the scheduled six-month accelerator shutdown (May-November 2011) are also in progress.
In Hall C, water and power connections to the Q-weak torus magnet were completed and the magnet has so far been tested to 5000 Amps, which is more than 50 percent of the operating current. The magnet mapping has been completed. The mapping data will be used to check the coil positions and verify the symmetry of the magnet. Installation and alignment of the beamline continues.
The accelerator has been locked up and is in beam permit. Eighty percent of the RF and all of the box supplies have been turned on. Some of the scheduled maintenance work is complete, and the rest is in the final stage.
The FEL team completed a lot of work in preparing the FEL beamline for re-establishment of lasing. However, the team is still awaiting the U-tube connections and cooldown of the new cryomodule and the commissioning of that system. The FEL remains inoperable until it receives support for this work.
Although the Δ(1232) resonance plays a fundamental role in nuclear reactions, its electromagnetic properties are largely unknown, with the exception of scarce indirect information extracted from data on the electromagnetic N to Δ transition, together with very recent lattice QCD calculations. Recently, a relativistic quark model, adjusted to fit both experimental data and lattice QCD simulations, was used to predict the electromagnetic structure of the Δ <arXiv:1002.4170 [hep-ph]>. In addition to the charge and magnetic dipole distributions, the model makes predictions for the higher order electric quadrupole and magnetic octupole form factors, which may be tested by lattice QCD calculations in the near future.
Facilities Management & Logistics
Construction of new cooling towers is underway just inside the accelerator site gate to replace the existing cooling towers, which are 20-45 years old and are located south of the Test Lab. The new site has room for additional towers to support future loads. The pedestrian walkway between the accelerator site gate and the North Access Building has been rerouted to accommodate the construction and will remain in place until this summer. The cooling towers and piping to the Test Lab chiller plant will be installed during March and April. Access to the exterior southwest area of the Test Lab may be limited. For more information, contact Celia Whitlatch, x6299.
JLab's Safety Numbers
40 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
March 6: Virginia Regional Middle School Science Bowl
Environment, Safety, Health & Quality
Most JLab employees use hard hats infrequently. It's good to review a few simple tips about hard hats before using them. The shell should be inspected routinely for dents, cracks, nicks, gouges and any damage that might reduce protection. Any hard hat that shows signs of wear or damage should be removed from service immediately. The shell material may be degrading if the shell becomes stiff, brittle or faded or appears dull or chalky. With further degradation, the shell’s surface may flake or delaminate. A hard hat should be replaced at the first sign of any of these conditions.
Here is a two-part, simple hard hat inspection technique:
• Inspect the suspension system closely for cracks, cut or frayed shell straps, torn headband or size adjustment slots, loss of pliability or other signs of wear. Remove and replace any suspension that is damaged.
New equipment may be obtained from the stockroom. If you have specific questions about your hard hat or the need for hard hats in general, contact your division ESH&Q Liaison or your Safety Warden.
Computing and Networking Infrastructure
CNI Maintenance Day Set for March 9, 5-10 p.m.
Recharge Each Wednesday Afternoon in the Quark Cafe
Education Seeks Mentors for Summer Programs Participants
If you have a project or projects that would be appropriate for a high-achieving high school student or for a small group of dedicated science teachers, e-mail a short project description and the proposed work requirements to Christine Wheeler.
Middle School Science Bowl Practice Session
Physics and Forensics Colloquium and Public Lecture
Annual T-Shirt Design Contest Underway