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.
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:
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
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
Summer Interns Poster Session Set for Friday
Construction Zone Restrictions During Demolition of Bldg. 59
Red Cross Blood Drive Set for Aug. 20
Tracking Thomas at Jefferson Lab
|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.|