Jefferson Lab Weekly Briefs December 12, 2012
Jefferson Lab Weekly Briefs
December 12, 2012
12 GeV Upgrade
Progress continues on the detector construction for the Hall B CLAS12 spectrometer. The fourth sector of the preshower calorimeter is complete, and the stacking of lead sheets and scintillator bars threaded with wavelength-shifting fibers is half-completed for the fifth sector. The sixth and last wire chamber sector for Region 2 has been completed at Old Dominion University, the third and fourth Region 1 chambers have been strung at Idaho State University, and the second pair of Region 3 chambers is being strung at JLab. Most of the approximately one dozen items of tooling for assembling the modules of the silicon vertex tracker barrel have been built and sent to Fermilab, where the sensor modules will be put together and wire-bonded. All the mirror substrates are built for the high threshold Cerenkov counter. Assembly of the forward time-of-flight 1-b slats has passed the half-way point at the University of South Carolina. Construction of tooling for winding the prototype coil for the torus magnet has started at Fermilab. The contract for the solenoid magnet has been awarded, with a vendor meeting set for late December.
2013 Postdoctoral Research Prize Deadline Nears
2013 Outstanding Nuclear Physicist Award Deadline Nears
Work is proceeding on the new gun, as well as upgrades to the existing beamlines. The FEL team successfully produced the first ball structure of the new gun. The existing gun was processed to high voltage in preparation for operation in January.
Center for Theoretical and Computational Physics
A new global QCD analysis of parton distribution functions has been performed by the CTEQ-JLab (CJ) collaboration, including target mass and higher twist corrections needed for the description of deep inelastic scattering data at large x and low Q2 and nuclear corrections for deuterium targets. The new "CJ12" distributions correspond to three different models for the nuclear effects and provide a more realistic uncertainty range for the down quark distribution, in particular, compared with previous fits. A user interface for utilizing the distributions is provided at the CJ website.
The Installation group has accomplished the following during the past few weeks:
The Vacuum group has completed all the girder rebuilds for the east and west recombiners and spreaders, as well as the injection chicane and has installed the injection line beam pipes.
Both the installation and vacuum groups worked to fabricate, clean and leak check the new east recombiner beam pipes. Other activities for installation and vacuum have been supporting others with transfer line alignment, cryogenics maintenance, penetration repairs, PEPPo experiment material moves, magnet refurbishment, and 6 GeV accelerator maintenance.
JLab Calendar of Events
Dec. 17: Safety Shoe vendor onsite
Environment, Safety, Health and Quality
GFCI Pigtails and Their Use
Computing and Networking Infrastructure Group
CNI Maintenance Day Set for Tuesday, Dec. 18, 5-7 p.m.
Limited Cafeteria Service on Friday, Dec. 21
A Cookie for Your Thoughts, Dec. 12-13
Personal Dosimeter Change Out Set for Dec. 17
General Access RWP Available for Signature
Annual Open Enrollment for TIAA-CREF 401(k) GSRA Ends Friday, Dec. 14
Tracking Thomas at JLab
Congratulations this week go to Narciso Gomez and Harry Fanning, who were the first to correctly identify the location for Dec. 5. Honorable mentions go to Doug Higinbotham, Anna Shabalina, Steve Suhring and Ron Bartek. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.