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.

Free-Electron Laser

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:

  • Final dipoles now installed in the east spreader completes all magnets in this spreader, and beam pipe installation is nearing completion in this region, also;
  • Four XP 4-meter dipoles were installed in the Hall D beamline;
  • Two ZA (multi-pass) and 3 XX dipoles were installed in the west recombiner/spreader and the transport channel areas;
  • Two final girders in the west recombiner were installed, completing all magnet installation for this recombiner;
  • All 13 dipoles in the southwest extraction chicane were installed, with girder assembly for this region continuing; and
  • The northwest arc tangent dipoles and girders were installed, also completing the installation there.

Additional activities included:

  • Injection line vacuum beamline was completed and pump down is underway;
  • Low-conductivity water (LCW) plumbing installation continues in the east spreader, west spreader & recombiner, transport recombiner and west arc;
  • Installation of the stands and pedestals for the south and west tangents was completed; and
  • Mu-metal hoods were installed on girders 0R01, 0R02 and on all beam line downstream of girder 0L10 through girder 0R09.

JLab Calendar of Events

July 22: Safety Shoe vendor onsite
July 29-31: Q-weak Collaboration meeting
Aug. 2: Summer Interns Poster Session
Aug. 5: Safety Shoe vendor onsite
Aug. 19: Safety Shoe vendor onsite

Environment, Safety, Health and Quality

Heat Stress Season Is Here
This week, meteorologists are forecasting high temperatures and humidity for Hampton Roads. These factors could trigger heat stress conditions at Jefferson Lab. Heat stress presents a significant health hazard, and in 2012 across the U.S., there were more than 13,600 cases of heat stress requiring medical intervention. Heat stress was the number one weather-related killer.

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:

  • Maintain fluid (especially water) intake;
  • Wear appropriate work clothes and Personal Protective Equipment appropriate for work activities assigned;
  • Immediately report heat stress symptoms to supervisor and Occupational Medicine; and
  • Curtail activities, including voluntary athletic programs, at Stage 2 or higher conditions.

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
On Saturday, July 20, a site-wide network outage will occur from 8 a.m.-noon for equipment upgrades. This outage will disrupt Internet access, wifi and landline telephones. Although the outage window is four hours, the most critical services, which include phones, Internet and central servers, will be restored first. This outage does not include the accelerator controls network itself. For questions about this work, contact the IT Division Helpdesk.

Windows XP End of Support Coming Soon
On April 8, 2014, Microsoft will end support for Windows XP. After that date, Microsoft will no longer provide security patches for any XP system, rendering these systems vulnerable to hackers and other security issues. When security patches are no longer available for these systems, they will be removed from the Jefferson Lab network. The CNI group will assist with migrating Windows XP systems to Windows 7. If you have a Windows XP system, visit this webpage and answer a few questions to determine the viability of updating your system and to see what you need to do to prepare for the update. If your XP system can be upgraded, and you would like to do so, contact the IT Division Helpdesk to schedule a time to migrate your system well before next April. Doing this now will ensure that your system is updated in a timely manner.


Department of Energy Sponsors Food Drive July 15-31
The Department of Energy is again participating in the “Feds Feed Families” food drive this year. At Jefferson Lab, the Thomas Jefferson Site Office (TJSO) will be collecting donations from its federal employees to benefit the Foodbank of the Virginia Peninsula. There is no expectation of Jefferson Lab employee participation in this program, although anyone wishing to contribute may do so. If interested, items most needed include canned meats (fish, ham, chicken, beef stew, etc.), canned fruits and vegetables, complete meals (boxed meals, pasta and sauce, mac and cheese, etc.), boxed cereals, rice, granola bars, peanut butter, and hygiene products (shampoo, tooth paste, deodorant, soap, diapers). No glass containers. Marked donation boxes for non-perishable food items will be located in the CEBAF Center lobby July 15-31. For more information on Feds Feed Families, contact Steve Neilson, x7215.

Extra Hands Needed For Tunnel Housekeeping in Early September
Accelerator Operations is starting to prepare for the end of the Long Shutdown and is getting ready for CEBAF accelerator commissioning activities. Before these activities can get underway, general housekeeping will take place in the tunnel, which include dusting components and sweeping the tunnel floor. It's a big job, and volunteers will be needed to help with this work. The housekeeping effort will likely get underway in early September. An announcement with specific dates and details will go out in advance.

Tracking Thomas at Jefferson Lab
Little Thomas is visiting all corners of the Jefferson Lab campus. If you can identify his location this week, email Kandice Carter with your guess. Guesses are accepted through Friday.

Harry Fanning correctly guessed the location for July 10. Check out Tracking Thomas on flickr for a better view of his last location and this week's new mystery photo.

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.