Jefferson Lab Weekly Briefs June 4, 2014
Jefferson Lab Weekly Briefs
June 4, 2014
12 GeV Upgrade
Hall B Update
Assembly and testing of the CLAS12 Silicon Vertex Tracker (SVT) production modules continues at Fermilab, with over 20 now completed and construction expected to continue until the fall of 2014. A test fit of the SVT modules into their support frame has been performed in the clean room at Jefferson Lab in preparation for assembly of the first three layers of the SVT barrel. The containment vessel for the High Threshold Cerenkov Counter has had the photomultiplier tube supports added and is being readied for mirror installation this fall. All of the coated production mirror segments are on site and tested. For the existing Low Threshold Cerenkov Counter (LTCC), the mirror refurbishment is complete for the first of three types of mirrors and the first batch of the aluminized Lexan strips have arrived from the vendor. The LTCC box modifications and new supports are also underway.
The practice coil for the CLAS12 Torus magnet was sectioned and unfortunately found to have one section that's 70 cm long that was not wetted by the epoxy used to bind the coil turns. Work at Fermilab was re-directed to address this and revise the epoxy impregnation procedure. A second Torus practice coil will be wound, epoxy-impregnated, and then cut apart and examined to verify the new epoxy process before proceeding to further production coil winding. Major parts for the Torus continue to arrive at Jefferson Lab. Pre-assembly of the Torus thermal shields is ongoing, and the first of the vacuum jackets has had all the necessary welding completed. The vendor for the Solenoid magnet has prepared the manufacturing tooling to wind the Solenoid coils and is cleaning the conductor for the Solenoid practice coil, which will be wound starting in mid-June.
Jefferson Lab Published Journal Articles, May 26-30
Remember to submit your papers for approval to the Jefferson Lab Publications database.
Center for Theoretical and Computational Physics
In a recent paper, theorists at Jefferson Lab and the College of William and Mary used lattice QCD to calculate the ratio of leptonic decay constants of the excited states of the pion to that of the ground state. They found that the ratio was only mildly suppressed for the first excited state, but far more strongly suppressed for the second excited state. The strong suppression for the second excited state is consistent with previous lattice calculations by the Jefferson Lab group, suggesting that this state is predominantly "hybrid," in which gluons play a manifest role.
Facilities Management and Logistics
Part of Lawrence Drive to Become One-Way Only
The one-way street will start at the intersection of Lawrence Drive and Hofstadter Road and will continue to Hogan Drive. Those traveling north on Lawrence Drive will be required to turn onto Hofstadter Road to exit the lab. The use of Hofstadter Road will also be required when leaving the Applied Research Center and Support Services Center parking lots if you wish to exit the lab using Hogan Drive.
The one-way conversion of Lawrence Drive will occur on June 15. Awareness signs will be posted around the affected area to provide proper notification of the change.
Training Sessions for Geometric Dimensioning and Tolerancing
Environment, Safety, Health and Quality
If an individual has any questions about whether his or her personal health might be adversely affected by high temperature, he or she should consult a physician and/or Occupational Medicine, x7539.
Computing and Networking Infrastructure
Jefferson Lab Spam and Virus Filter Software Changing
To avoid problems and delays, be sure to have your card renewed between June 2 and July 11. Once the expiration date passes, the card will no longer work, and the user will not be able to log in to Jefferson Lab systems using the card. If you have any questions or concerns, contact the IT Division Helpdesk, x7155.
Pressure Systems Awareness Training Offered
2014 Open House Thank You and Survey
New Travel Options from PHF
Jefferson Lab Calendar of Events
June 2-14: Hampton University Graduate Studies Program
|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.|