Jefferson Lab Weekly Briefs
June 24, 2015
12 GeV UpgradeThe detector systems in the Hall C Super High Momentum Spectrometer have seen significant progress with the installation of both the S1XY and S2XY scintillator and quartz hodoscopes. These detectors and their frames were built by university staff and students at James Madison University, North Carolina Agricultural and Technical State University, and The College of William and Mary through funding from the National Science Foundation. Installation of the large number of cables that connect to all of the SHMS detectors is now nearly complete, as well. Mirrors for the Noble Gas Cerenkov counter have been coated at CERN and are now safely back at the University of Virginia.
A major milestone for the SHMS dipole magnet construction was passed with the successful collaring of the magnet's coil assembly. Twenty-four precisely-machined aluminum rings, about three feet in diameter and six inches thick, were heated to 300° F to make them expand enough to slip over the twelve-foot long cylindrical coil. Months of planning and rehearsal paid off when all of the 'collars' were fitted on the coil in one eight-hour shift, as required. The same process will be used to collar the final two SHMS magnets in the next several weeks. Checkout of the HB and Q1 magnet systems continues in Hall C.
PhysicsJefferson Lab Published Journal Articles June 8-12
Center for Theoretical and Computational PhysicsIn a new publication, lattice QCD was employed to calculate the neutron-proton to deuteron radiative capture cross section. Using a background magnetic field, the energy levels of the neutron-proton system in a finite box were used to determine the infinite volume transition amplitude, which in turn was converted to the capture cross section using the pionless nuclear effective field theory. The computations were performed at unphysical quark masses, however, the resulting cross section is in agreement, within errors, with experiment.
EngineeringDuring the past few weeks of the Scheduled Accelerator Down, the Installation and Vacuum groups have been busy in the accelerator and end stations with the following work:
Facilities Management and LogisticsThe F Wing of CEBAF Center will be closed on Saturday, June 27, 7 a.m. - 5 p.m. Contractors will be performing work as part of the Utilities Infrastructure Modernization program, which requires de-energizing electrical and mechanical HVAC systems throughout the wing. Facilities Management and Logistics personnel appreciate your patience as this new infrastructure is put in place to facilitate future growth and delivery of Jefferson Lab’s mission. If you have any questions or concerns about this outage, contact Michele Solaroli, x7751.
Jefferson Lab Calendar of EventsJune 29: Safety Shoe Vendor onsite
July 1: Annual Fraud Awareness Briefing
July 3: Independence Day holiday observed; Jefferson Lab closed
July 7-10: Program Advisory Committee Meeting (PAC43)
July 15-16: Super BigBite Spectrometer Collaboration Meeting
July 17-18: Hall A/C Summer Collaboration Meeting
Environment, Safety, Health & Quality
Using Jefferson Lab’s Drains Correctly
Jefferson Lab and DOE take protecting our water resources seriously. Do not endanger our future by misusing the drains. If you are not sure if something can be poured down a drain, contact Jefferson Lab’s Environmental Engineer, Scott Conley, for guidance at x7308.
Computing and Networking Infrastructure*Update* Central File Server Outage Set for Friday, June 26, 6-10 p.m.
There will be an outage of the /home (J: drive) file server on Friday, June 26, 6-10 p.m. During this time, this important file server will be undergoing a major operating system upgrade, and many services may be unavailable. In particular, access to all of the jlabl* systems, all of the login servers, the farm and ifarm systems, and all CUE level 1 Linux desktop systems will have issues while the home directory is offline. Note that CUE level 1 Linux systems may need to be rebooted after the outage to clear up any lingering mount issues, so plan your work accordingly. If you have any comments or concerns, contact the IT Division Helpdesk, x7155.
Notes on Personal Dosimeters
Tech Center Apartment Construction Has Begun
Personal Dosimeter Change Out Set for Wednesday, July 1
Graduate Students Sought for Tour Program
|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.|