Jefferson Lab Weekly Briefs July 31, 2013

Jefferson Lab Weekly Briefs
July 31, 2013

12 GeV Upgrade

In-tunnel testing of cryomodule C100-6 has been completed; the total voltage for that cryomodule was 108 Megavolts. Final alignment is complete for the east recombiner, the 0L0R area, and the west arcs. All components are in place in the east spreader and west recombiner. The new coils for the Lambertson magnet have arrived. Assembly of the new radiofrequency separator cavities is complete. Fabrication of the Personnel Safety System beam stoppers/diffusers continues. Procurement of all electronics for the Hall D tagger beam dump is complete. A total of 120 of the new 20 Amp trim supplies are now on site; 60 of the units have been installed. The new box supply for arc 1 has been delivered; vendor testing of the new box supply for arc 2 has been completed, and the unit has been prepped for shipment to Jefferson Lab.

Free-Electron Laser

Steve Benson, Bob McKeown and Gwyn Williams attended a meeting of the Basic Energy Sciences Advisory Committee of the DOE Office of Science in Bethesda, Md. The meeting’s focus was future light sources. The committee recommended an R&D path aimed toward a fully coherent X-ray FEL based on the continuous wave superconducting linear accelerator technology implemented successfully at the Jefferson Lab FEL, but scaled up in energy. Work continues on the shielded ceramic purchase for the new DC photocathode gun. The titanium rings that were being tested last week did not meet specifications, so the vendor is working to re-polish them to meet the specification before brazing.

Center for Theoretical and Computational Physics

For several years, it was thought the spectrum of charm quarks was well understood experimentally, but recent experimental results continue to find new states. As the mechanism giving rise to these states is not understood, recent work, both theoretical and experimental, has been directed at unravelling the enigma. A recent theory group paper has made a determination of the highly excited charmed baryon spectrum consisting of three charmed quarks using lattice QCD. Future work will be aimed at determining the spectrum in other charmed baryon channels.


The Survey and Alignment group has been busy in all parts of the accelerator, including:

  • Alignment for hookup in the transport channel and second extractor;
  • Final alignment in the first extractor; and
  • Final alignment in the east recombiner.

In addition, the group has been involved in alignment for the forward carriage in Hall B and the Forward Drift Chambers for Hall D.

JLab Calendar of Events

July 29-31: Q-weak Collaboration meeting
Aug. 2: Summer Interns Poster Session
Aug. 5: Safety Shoe vendor onsite
Aug. 15-16: Hall C Summer Workshop
Aug. 19: Safety Shoe vendor onsite
Aug. 19-22: Accelerator Readiness Review
Aug. 20: American Red Cross Blood Drive
Sept. 2: Labor Day holiday, Lab closed

Environment, Safety, Health and Quality

The issue of unlabeled and orphaned gas cylinders continues to pop up at Jefferson Lab. This issue is becoming more pronounced, because as Jefferson Lab moves from the Long Shutdown back toward operations, cylinders/drums/pails previously moved out of work areas will soon be re-introduced.

This issue recently became apparent when several cylinders of unmarked gases were discovered during a Safety Warden walkthrough by an area Safety Warden and two ESH&Q professionals. The Safety Warden noted that the area generally does not have any gas cylinders and, therefore, was at a loss as to who may have owned the ones found or the identity of the gas contained in them, if any at all. This incident not only presents a danger to those who must move the cylinders, but it also represents a very high cost to determine the type of gas present, as well as a cost to properly dispose of the gases and cylinders.

All containers of chemicals must be properly marked with the contents, associated hazards, and with the "owner" of the container. Make sure that all of the gas cylinders for which you have responsibility have proper and durable identification labels or tags. If identification labels are becoming difficult to read, request help in getting new ones from the manufacturer or Industrial Hygiene, x6381.


Monthly Tornado Siren Test Set for Friday
Jefferson Lab's tornado warning siren will undergo its monthly operational test at 10:30 a.m on Friday, Aug. 2. Depending on weather conditions at the time of the test, the siren may be heard by anyone within a 1.5-mile radius of the lab. Don't respond to the siren; this is a test of the siren system and not a personnel response exercise.

Summer Interns Poster Session Set for Friday
Mark your calendar for the 2013 Summer Interns Poster Session. More than 30 high school and undergraduate interns who spent the summer doing research and working on projects at Jefferson Lab will show off the results of their work. The students are eager to explain and discuss their work, and questions by members of the lab community are encouraged. The session is set for Friday, Aug. 2, in the CEBAF Center lobby, 11:30 a.m.-1:15 p.m.

Construction Zone Restrictions During Demolition of Bldg. 59
The demolition of Building 59, located on the east side of the Test Lab (Bldg. 58), is planned to begin the week of Aug. 12 and continue through mid-September. The area within the barricades will be a construction zone. Only trained personnel associated with the project are authorized to enter this area. Jefferson Lab personnel needing to enter the area or who have questions about the project may contact Suresh Chandra at x7248. More information and a link to a map of the construction can be seen here.

Red Cross Blood Drive Set for Aug. 20
The next American Red Cross Blood Drive is scheduled for Tuesday, Aug. 20, 10 a.m.-4 p.m. in CEBAF Center, Room F113. New and repeat donors are encouraged to attend. Appointments and walk-ins are welcome. To schedule an appointment, contact Johnie Banks, x7539. The linked page lists all eligibility requirements.

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.

Narciso Gomez correctly guessed the location for July 24. 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.