Jefferson Lab Weekly Briefs
September 12, 2012
12 GeV Upgrade
The third sector of the PreShower Calorimeter for CLAS12 is complete and has been tested successfully with cosmic rays. The sixth wire chamber sector for Region 2 has been started at Old Dominion University, the third and fourth Region 1 chambers are being strung at Idaho State University, and the first two Region 3 chambers have been strung at JLab. High-voltage and readout boards are being added to the strung sectors and cosmic ray testing is underway.
The first items of tooling for assembling the Silicon Vertex Tracker were built and sent to Fermilab, where the sensor modules will be put together. The last of five types of mirror substrates are being built for the high threshold Cerenkov counter. Assembly of the forward time-of-flight 1-b slats has reached the half-way point at the University of South Carolina. The existing time-of-flight slat arrays are being removed from CLAS and checked prior to refurbishment, as are the sectors of the existing Cerenkov counter.
Analyses of the cold masses, which includes the coils and their cases, continued for the torus magnet. Bids for the solenoid magnet have been received from commercial vendors and are being evaluated.
Work continued on the removal of the DarkLight setup. Ancillary signal and power cables have been removed from the 3F05-06 region. The 6F and 8F viewer and video cables have been restored back to their original configuration. All diagnostic hardware has been removed and is ready to be moved into the Drive Laser Clean Room once the 16 channel device server gets installed. Effort has begun on rotating quadrupole magnets MQX3F04S and MQX3F05S back to their original skew orientation. In ongoing beam dynamics studies, the team continued the merger analysis work to explore linac acceptance and match dependencies of output beam quality in an effort to cross-check and further illuminate simulations of the installed Penner bend. The FEL team participated in the "Frontiers of THz" workshop at SLAC, with a presentation reviewing several state-of-the-art terahertz studies at JLab and other facilities.
Center for Theoretical and Computational Physics
In a new lattice QCD analysis, the scattering lengths of the isospin-3/2 Dπ, Dsπ, DsK, isospin-0 D‾K, and isospin-1 D‾K channels are calculated. Using a chiral unitary effective theory to next-to-leading order accuracy, and input from the lattice calculation, predictions for other channels can be made. The results are consistent with the interpretation of the D*s0(2317) state as a DK "molecule," and predict that the isospin-breaking hadronic decay width ΓD*s0(2317) → Dsπ is (89 ± 27) keV.
Facilities Management and Logistics
Central Material Storage Area Access Information
Computing and Networking Infrastructure
CNI Maintenance Period Set for Sept. 18, 5-7 p.m.
No TED Building Access Overnight Thursday
Major JLab Cryogenics Advancements Being Used by NASA
DOE Hosts Science Lecture Series
Engineering Seeks its Portable Thermometer/Data Logger
Tracking Thomas at JLab
Congratulations this week go to Annie Tran, Lori Zukerman and Stephanie Vermeire, who were the first to correctly identify the location for Aug. 22. Honorable mentions go to Chris Stanislav, Connie Adams, Brian Agor, Jodi Patient, Doug Higinbotham, Ron Bartek, Dipangkar Dutta, Samika Hawkins, Robert Martin, Sasa Radovic, Jim Follkie, Michelle Shinn, Brita Hampton, Tonya Evans, Ryan Bodenstein, Casey Heck, Narciso Gomez, Dena Polyhronakis, Michael Haddox-Schatz, Marcy Stutzman, Sue Witherspoon, Pashupati Dhakal, Harry Fanning, David Jenkins and Debra Brand. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.
JLab Calendar of Events
Sept. 14: United Way Day of Caring