Jefferson Lab Weekly Briefs February 29, 2012
Jefferson Lab Weekly Briefs
February 29, 2012
12 GeV Upgrade
The first of two new coldboxes for the new Central Helium Liquefier, CHL2, has been shipped. The C100-1 and C100-2 cryomodules continue to be used for beam operations; as of Feb. 27, they were operating at 85 Megavolts and 80 MV. All 10 cavity strings for the new cryomodules have been completed. Adjustments to the FY12 work plan continue in response to the reduction in FY12 funding relative to the baseline funding profile.
In Hall A, staffers are reasonably optimistic that the hall can start taking beam and taking data this week on the g2p experiment, possibly Wednesday night. There are a number of fairly straightforward jobs that need to be completed, including beamline instrumentation, vacuum system and target work.
In Hall C, the Q-weak experiment continued taking production data with the hydrogen target.
JSA/JLab Graduate Fellowship Program
JSA/JLab Sabbatical Support Program
Hall B switched from photon running on the HDIce target to electron running. Hall C continued to receive 180 microamps throughout the week. Beam studies were carried out during which the operations staff and Electrical Engineering Systems group technicians received training on C100 operation. Accelerator operations staffers continue to push C100 gradients to higher levels. C100 radiofrequency zone operation continues to give data in parallel with physics operation. A vacuum valve problem resulted in several hours of lost beamtime, while low-conductivity water repairs on the cooling tower also resulted in a short down. Problems with the machine protective system resulted in the loss of an entire shift of beamtime on Friday. Repairs by the Safety Systems group allowed good beam transmission through the weekend.
FEL staffers continued bringing the beam back up this week on swing shift with success in getting the beam around as far as re-injection to energy recovery. The injector setup appears robust but may need minor adjustments once the team begins lasing. Staffers also had good progress getting the ultraviolet wiggler chamber installed in the beamline during day shift. The team will continue the installation of the chamber diagnostic hardware next week and will also work on re-establishing infrared lasing. Disassembly of the Admiral cryomodule was initiated for cavity reprocessing.
Center for Theoretical and Computational Physics
A new paper investigates the singlet channels of nucleon-nucleon scattering in the framework of chiral effective field theory. It is argued that the rather large regularization dependence at leading order requires a subleading short-range force to appear at one order lower than two-pion exchange - the subleading long-range force. Interestingly, this eventually leads to a power counting scheme for the singlet channels that resembles that of the pionless theory, in which pion exchanges are "integrated out."
JLab Calendar of Events
March 3: Virginia Regional Middle School Science Bowl
Environment, Safety, Health and Quality
Safety By the Numbers
FEL Vault Is Now a Radiologically Controlled Area (RCA)
Also, remember that if you will be bringing visitors onsite to tour the FEL vault, they must have temporary dosimetry. A self-reading pocket dosimeter may be issued to the visitor for this purpose. Visit the Radiation Control department trailer, 52B, to obtain dosimetry and fill out the Visitor Information Sheet. If you have a large tour (more than five visitors), you must contact Michelle Lechman in the Public Affairs Office, x7617. Keep in mind that Public Affairs is not able to support general tour requests until after the Open House on May 19.
Ends Today: JLab's 2012 Benefits Open Enrollment
United Airlines and Continental Airlines Merge Systems
Annual T-Shirt Contest is Underway!
Excess Furniture Wish List
Golf Car Rain Coats Available in Freestock
ORNL Announces Opening of Guest House
Travel Guidance Q&A on the JLab Website
JLab Cafeteria to Be Busy After 12:30 p.m., March 5-9
Tracking Thomas at JLab
Congratulations this week go to Katherine Myers, John Leckey, Wouter Deconinck and Joshua Magee, who were the first to correctly identify the Feb. 22 location. Honorable mentions go to Bryan Moffit, Rob Mahurin, Joshua Hoskins and David Armstrong. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.