Jefferson Lab Weekly Briefs June 24, 2015

Jefferson Lab Weekly Briefs
June 24, 2015

12 GeV Upgrade

The 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.


Jefferson Lab Published Journal Articles June 8-12

  • Tech Note: Keith Welch. "The Impact of Modifications to Hall A and C Beam Dump Atmospheric Controls on Radioactive Emissions" JLAB-TN-15-021
  • Tech Note: David Douglas. "Twiss Parameterization of Flat Beam Transforms Including Beam Divergence" JLAB-TN-15-022

Remember to submit your papers for approval to the Jefferson Lab Publications database.

Center for Theoretical and Computational Physics

In 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.


During 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:

  • Remove survey and alignment control point shielding;
  • Repair of low-conductivity water (LCW) leaks;
  • Open, close and re-fill North Linac and South Linac penetrations;
  • Install a water dam to protect the XP magnet in 5C line (this magnet sits just off the floor);
  • Relocate IDL0R08 & IDA5C00 isolation valves in air lines to service buildings; and
  • Continue progress on the Hall C Dump demolition and the Hall C 12 GeV beamline upgrade.

The vacuum SAD work includes:

  • Linac viewer bellows replacements;
  • VIP troubleshooting/repair/replacements; and
  • Replacing valve position switches to a more robust all-metal switch.

Facilities Management and Logistics

The 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 Events

June 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
Across the Jefferson Lab campus, there are many types of drains. These drains are not necessarily connected together, and some are deliberately separated (stormwater vs. sanitary sewer). For instance, roadside and parking lot drains convey stormwaters into local reservoirs and rivers, while sanitary sewer drains located in restrooms funnel wastewater to a Hampton Roads Sanitation District wastewater treatment plant. If you have a process or operation that requires the draining of liquids, there are certain drains to use and permit processes required. Using the wrong type of drain for your operation may: 

  • Cause reactions;
  • Damage the piping system;
  • Cause pollution in area reservoirs or waterways;
  • End up negatively impacting the sewage treatment efficiency; or
  • Cause legal/liability issues for Jefferson Lab as related to existing environmental regulations and permits.

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
The Radiation Control Department plans to re-number most of the dosimetry racks in the next few weeks, so the location of your dosimeter on its assigned rack is likely to change. Be sure to check that the dosimeter you are wearing is really yours and not someone else's! If you are not sure of your dosimeter number or rack location, or if you would like to check your dose records or address on file, you can find that information and more in the Dosimetry Online System. If you need to change/update any of this information, email Becky Mosbrucker. Lastly, If you find a dosimeter that looks lost (found in the grass, etc.), inform Becky at x7236.

Tech Center Apartment Construction Has Begun
Construction of the new apartment buildings on the Tech Center site has just begun. Over the next few weeks, the contractor will be removing trees, bringing in select sand fill and preparing for building pads. There will be two construction entrances to the site on Hogan Drive between Jefferson Ave. and Hofstadter Road. Four buildings are planned for the site: a single-story clubhouse with a pool; a four-story structure on a slab; and two, four-story apartment buildings with parking decks on the ground floors.

Personal Dosimeter Change Out Set for Wednesday, July 1
Jefferson Lab's semi-annual personal dosimeter change out will take place during the afternoon of Wednesday, July 1. This includes the dosimeters of all staff, students, users and subcontractors. Be sure to put your dosimeter in its assigned place in the dosimeter racks no later than 2 p.m. on July 1. If you need to use your dosimeter during the change out period on July 1, you may exchange it that morning in the Radiation Control Dosimetry Office located in the ARC Library between 8 a.m.-1 p.m. If you are leaving for an extended Independence Day holiday break, be sure to put your dosimeter in its assigned rack before departing. If you have any questions about he change out, contact Becky Mosbrucker, 269-7236.

Graduate Students Sought for Tour Program
The Public Affairs office is seeking graduate students who are interested in working as tour escorts during lab tours. In addition to learning about other areas of the lab, meeting new people and practicing your public speaking skills, students can receive payment for assisting as tour escorts and/or tour subject matter speakers. For more information about this program, see the All-Staff Memo or contact Mike Robbins, x7617.

Annual Fraud Awareness Briefing Offered July 1
Mike Adams, DOE Office of Inspector General, will visit Jefferson Lab on July 1 to give the annual Fraud Awareness briefing. The briefing is set for 10 a.m. in the CEBAF Center auditorium. The meeting is open to all members of the lab community.

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.