Jefferson Lab Weekly Briefs
June 26, 2013

12 GeV Upgrade

The tenth and final C100 cryomodule has been installed in the tunnel. In-tunnel testing of C100-7 has been completed; the total voltage for that cryomodule was 108 Megavolts. In-tunnel testing of C100-6 is underway. All of the dipoles and 90 percent of the girders have been installed in the beamline to the Hall D tagger enclosure. The extraction chicane dipoles have been installed. Final alignment of the east arcs is complete and is nearly complete for the west arcs. Installation of the west recombiner and transport channel recombiner are nearly complete; the east spreader is complete except for two septa. The east recombiner is under vacuum. Assembly of the new radiofrequency separator cavities is underway. Fabrication of the Personnel Safety System beam stoppers/diffusers has begun; the associated electronics are on order. Seventy-five of the new 20A trim supplies are now on site; thirty of the units have been installed. Vendor testing of the new box supply for arc 1 is nearly complete; testing of the new supply for the beamline to Hall A has begun. Procurement of the electronics for the new stripline beam position monitors continues.

Center for Theoretical and Computational Physics

A new relativistic formulation of pion loop corrections to the coupling of photons with nucleons is presented on the light-front, explicitly satisfying gauge invariance and Ward-Takahashi identity constraints to all orders in the pion mass expansion. The results are used to compute corrections to moments of parton distributions measured in deep-inelastic scattering experiments or in lattice QCD. Comparisons of results for pseudovector and pseudoscalar coupling of pions to nucleons allows the resolution of a long-standing puzzle in the computation of pion cloud corrections to structure function moments.

Engineering

The Machine Shop is presently manufacturing or continuing to manufacture:

  • Three each ZA vacuum chambers;
  • An assortment of upstream and downstream support mounting brackets;
  • Two each insertion devices, Hall D beam stopper; and
  • One beam switchyard beam diffuser.

The shop has processed 105 job requests since April 13.

JLab Calendar of Events

July 4: Independence Day holiday, Jefferson Lab closed
July 8: Safety Shoe vendor onsite
July 10: PEPPo Collaboration meeting
July 10-11: GlueX Collaboration meeting
July 22: Safety Shoe vendor onsite
July 29-31: Q-weak Collaboration meeting
Aug. 2: Summer Interns Poster Session

Environment, Safety, Health and Quality

Roadway Breakdown Safety
Driving on summer vacation is often worry-free, but occasional breakdowns do occur. In the event of a breakdown, your first priority is to get your car out of the roadway safely. But do you know what you should do next?

People often choose to exit a broken-down car, whether it's to stay cool, retrieve a spare tire or to get better cell phone reception to call for assistance. However, there are safe and unsafe ways to wait on the roadside. When exiting the vehicle, always do so on the side opposite the lanes of travel. Once out of the vehicle, stand slightly to the rear of the vehicle and off to the side of the road, preferably on the non-road side of a guard rail (if present). This location is the safest in the event the disabled car is sideswiped or struck from behind by oncoming traffic.

To assist drivers in avoiding breakdowns, the National Highway Traffic Safety Administration offers valuable tips for preparing for your next roadtrip. If your car does break down, these tips from The Weather Channel may also be useful.

Computing and Networking Infrastructure

Site-Wide Network Outage Set for Saturday, July 20
On Saturday, July 20, a site-wide network outage is scheduled for 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.

Announcements

Revised General Access Radiological Worker Permit
The Radiation Control group has revised the 2013 General Access RWP to reflect changes to items coming out of the north and south linacs. This new revised GARWP must be signed by July 15 by all Radiation Workers to retain their qualifications and to gain entrance to the accelerator site.

The GARWP is titled SAF801kd, and the change is located in the middle of page 3, item #9. A revision date of June 25, 2013, should be shown in the upper left hand corner of this document. Make sure you refresh your browser once you have opened this document, to make sure you have the newest version. You can locate the document on the web-based training page. If you have questions or concerns, contact Becky Mosbrucker, x7236, or the Radiation Control group cell phone at 876-1743.

Reminder: New Electronic Tour Database
Starting July 1, employees/users wanting to escort visitors through the accelerator site to tour radiological areas must request dosimetry (a self-reading personal dosimeter, or SRPD) through a new online system (no more paper forms). This system can be found on the Radiation Control webpage and Insight.

Second Chance: Pressure Systems Safety Awareness Training Offered
Anyone working on equipment that employs a vacuum or pressurized gases should consider taking the Pressure Systems Safety Awareness (SAF130A) course (a list of pressure systems can be found in ES&H Manual Chapter 6151 Pressure and Vacuum Systems Safety Program). This 1.5-hour course will cover the basic considerations and provide insight into the required process for the design, fabrication, testing, inspection, maintenance, repair and operation of pressure systems. SAF130A will be offered July 17 at 10 a.m. in CEBAF Center room F113. To sign up, log in to the Learning Management System and register.

Radiation Worker Classes Available
The next in-person radiation safety-related courses are scheduled for July. On Monday, July 15, a full-day Radiation Worker I class is scheduled for 9 a.m.-5 p.m. The Radiation Worker II half-day class is offered on Thursday, July 18, 9 a.m.-noon. Both classes will take place in Trailer 52C. To sign up, contact Maya Keller or register directly through the Learning Management System.

Personal Dosimeter Change Out Set for Monday, July 8
Jefferson Lab's semi-annual personal dosimeter change out will take place during the afternoon of Monday, July 8. Be sure to put your dosimeter in its place in the personal dosimeter racks no later than 1 p.m. on July 8. This includes the dosimeters of all staff, students, users and subcontractors. If you need to use your dosimeter during the change out period on July 8, you may exchange it that morning in the Radiation Control Dosimetry Office in Trailer 52B, Room 4, 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 rack before departing. If you have questions, contact Becky Mosbrucker, x7236.

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.

Samika Hawkins correctly guessed the location for June 19. Honorable mentions go to David Sheppard, Brita Hampton, Randy Hartman, Danny Lloyd, Connie Adams, Dick Owen, Ron Bartek, Carl Zorn and Michael Haddox-Schatz. 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.