Jefferson Lab Weekly Briefs July 17, 2013
Jefferson Lab Weekly Briefs
July 17, 2013
12 GeV Upgrade
Welding of the helium vessel is underway for the Hall C Super High Momentum Spectrometer horizontal bend magnet; the manufacturing of parts for the liquid nitrogen shield and support links has begun; and parts for the vacuum vessel have arrived. The stacking and welding of the steel laminations that form the yoke for the Q1 quadrupole magnet is complete. The Q1 yoke was subsequently separated into four quadrants, and the coils were test fit. Installation of the yoke and coil assembly into the helium vessel is next. The tooling has been readied for coil winding and epoxy impregnation of the dipole magnet. Production consolidation of the conductor for the coil is underway, as well as preparation for the final prototype winding. Parts for the SHMS support carriage have been moved into Hall C. Final machining is complete for the hundred tons of magnet steel yokes for the dipole and for the Q2 and Q3 magnets. Detector construction continues, with drift chamber stringing progressing at Hampton University and the shipment of the vessel for the Heavy Gas Cerenkov Counter.
The FEL team continues to make good progress on the gun and buncher effort funded by the Commonwealth of Virginia. The titanium guard rings for the segmented insulator being manufactured by Friatec (Germany) have been formed, machined and electro-polished, and a sample is being characterized by colleagues at William and Mary. The 7 kilowatt buncher amplifier order has been placed. The team is making progress with the buncher cavity coupler design; and with the electromagnetic design complete, work is proceeding on the thermal design.
The FEL team continues to assist the Jefferson Lab Polarized Source group in testing inverted ceramic insulators in the FEL Gun Test Stand. These tests are using a 5-inch-diameter stainless steel ball electrode, which has been polished with diamond paste and is hanging from the end of the insulator in the middle of the vacuum chamber.
Center for Theoretical and Computational Physics
The distorted spin-dependent spectral function of a nucleon inside an A=3 nucleus was introduced as a novel tool for investigating polarized semi-inclusive deep-inelastic scattering from polarized 3He, beyond the standard plane wave impulse approximation. The effects of final state interactions of the hadronizing quark with the nuclear remnants were analyzed, with the goal of establishing a reliable procedure for extracting the free nucleon parton distributions from polarized 3He experiments. This will be relevant for experiments measuring the helicity-dependent g1 structure function, as well as the transverse Sivers and Collins asymmetries.
The Installation and Vacuum group continues to make good progress during the Long Shutdown. The following magnets and components have been installed:
Additional activities included:
JLab Calendar of Events
Environment, Safety, Health and Quality
Heat Stress Season Is Here
The Jefferson Lab ES&H Manual 6670 Appendix T1 Heat Stress Work Cessation Procedure provides critical information for workers about safely conducting their work in these conditions and provides information for each Heat Index Criteria Stage. Everyone at Jefferson Lab should:
You can check the conditions at Jefferson Lab at any time by viewing the weather station, which continuously displays the Heat Stress Index. Additionally, the weather station triggers pager alerts regarding different heat stress conditions.
Computing and Networking Infrastructure
Site-Wide Network Outage Set for this Saturday, July 20
Windows XP End of Support Coming Soon
Department of Energy Sponsors Food Drive July 15-31
Extra Hands Needed For Tunnel Housekeeping in Early September
Tracking Thomas at Jefferson Lab
|JLab Weekly Briefs is an ongoing publication providing information on the status of safety, accelerator operations, experiments, free-electron laser, reviews, upcoming activities and special events. Deadline for submission is every Tuesday by 10 a.m. Submit new items to: Public Affairs or contact Kandice Carter at x7263.|