Jefferson Lab Weekly Briefs November 9, 2016
Jefferson Lab Weekly Briefs
November 9, 2016
12 GeV Upgrade
Last week was very productive for the 12 GeV Upgrade project, with major achievements realized in both Halls B and C. In Hall B, the energization of the Torus magnet achieved full current of 3,770 Amps on Friday afternoon, Nov. 4. Mapping of the magnet field then commenced, and, once complete, the Torus will be powered down and installation of the remaining detectors will restart.
In Hall C, while the Q2 magnet was being prepared for service on the Super High Momentum Spectrometer (SHMS), Jefferson Lab staff and university collaborators installed the drift chambers on the detector stand within the SHMS shield house. The Physics Division convened the Experiment Readiness Review committee to examine Q2 and the other two magnets (Q3 and Dipole) coming from the same vendor. The committee assessed the design, fabrication, installation, protection systems and operational procedures for the magnets, and concluded that these support safe and efficient magnet operation.
The Dipole magnet was delivered to Jefferson Lab and installed on the SHMS carriage. Due to the weight of the Dipole, the in-house crane was inadequate and special preparation was required. The subcontractor who transported the Dipole from the Norfolk port to the site had to provide a mobile crane capable of handling the load; this was anticipated and a custom lift plan was approved well in advance. The crane was carefully maneuvered inside Hall C. The crane lift path took it across the SHMS structure, which required several handrail sections to be removed to provide clearance. The Dipole was placed on the lower yoke without incident. Hall C staff completed installation of the upper yoke steel and strong-back around the magnet.
Because of its size, the Dipole could not be fully assembled prior to shipment to the lab. The final connection to its cryogenic control reservoir will now begin in the hall. With two of the three Hall C superconducting magnets built in France now installed, work will continue with the acceptance tests and commissioning. Also, during the first week of November, the Q3 magnet was wrapped, crated and shipped out from the factory in France. This, the last of the five SHMS magnets, is now on its way to Jefferson Lab.
Jefferson Lab Published Journal Articles, Oct. 16-22
Center for Theoretical and Computational Physics
The Landau-Khalatnikov-Fradkin transformations show how a Green's function translates between gauges. These relations have been previously deduced in coordinate space. In a new paper, members of the Theory Center re-derive these in momentum space by using a spectral representation for certain Green's functions, valid in QED. This simplifies the demonstration that the transformations between covariant gauges form a group in any number of dimensions. In a further paper, it is shown that this procedure enables key equations of the theory to be evaluated explicitly as Feynman-like integrals even in a strong coupling limit in both the spacelike and timelike regions of Minkowski space. This is a step towards understanding the strong dynamics that controls the confinement of quarks and gluons in QCD.
Jefferson Lab Calendar of Events
Nov. 11-12: MOLLER Collaboration Meeting
Environment, Safety, Health and Quality
End Of Daylight Saving Time Can Be Deadly
Computing and Networking Infrastructure
IT Division Conducts Survey of Computer Systems
IT Maintenance Planned for Nov. 15, 5-7 p.m.
Military Veterans: Here’s Your Chance to Help Recruiting Reach Out to Fellow Service Members
Subcontracting Officer Technical Representative (SOTR) Training Offered
Place Orders by Nov. 18 at Quark Cafe for Thanksgiving Desserts
Jefferson Lab Offering Financial Planning Workshop
JAG Fall Food Drive Underway
|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.|