Jefferson Lab Weekly Briefs
January 25, 2012
12 GeV Upgrade
The warm compressors for the new Central Helium Liquefier, CHL2, have been placed in the new building, and installation of interconnect piping is underway. The eighth cavity string for the new C100 cryomodules is complete. Cryomodule C100-5 is being tested in the Cryomodule Test Facility. The final cathode power supply for the new radiofrequency systems has been delivered. An rf separator cavity was tested successfully at power levels above that needed for 12 GeV. Tests and refinement of the installed new linac zones (cryomodules and rf) continue.
Due to the outstanding efforts of the target group, the replacement polarized target has been installed on the pivot in Hall A. This puts Hall A on track for being ready for beam in mid-February and on target to achieve the primary goals of both the g2p and Gep experiments.
In Hall C, the Q-weak experiment is continuing production data taking at 180 microamps.
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JSA/JLab Graduate Fellowship Program
JSA/JLab Sabbatical Support Program
The week began with Accelerator Operations staff trying to understand the high background rates in the Hall C Compton polarimeter and a 52 Hertz noise signal in the injector rf controls. Optics work in the injector on Tuesday improved the background rates, while the 52 Hz noise was determined to be caused by the flow of nitrogen through the cooling shield of the cryomodule, which induced microphonics (minute vibrations that affect the tune of the superconducting cavity). Dipole magnet power supplies for Arcs 1, 3 and 7 caused multiple headaches and down time. After much work during the week on magnet power supplies, accelerator running over the weekend was quiet. The Arc 1 power supply would still occasionally trip on overload, but it would quickly recover.
Center for Theoretical and Computational Physics
JSA/JLab Distinguished Theory Student Fellowship Program
The first material delivery of the BCOM magnets, a 12 GeV magnet procurement, has been received. These are the first magnets in the spreader areas and the last magnets in the re-combiner areas that must bend up to five separate beams running at different energy levels. In addition, the spreader/re-combiner dipole curved vacuum chamber contract has been awarded. Procurements of the new stand, girders, and beamline components are progressing. The Arc 10 vertical support stand has been received and inspected. The reworked M15 beam position monitors are back on site; so far, no leaks have been found.
A model used in a particle physics simulation package has been successfully translated for use in an engineering simulation package (FLUKA to ANSYS), allowing the steady state thermal analysis of a beam/target interaction. This is a positive step in extending the capabilities of the radiation analysis with the Radiation Control group. FLUKA is a fully integrated particle physics Monte Carlo simulation package. It has many applications in high-energy experimental physics and engineering, shielding, detector and telescope design, cosmic ray studies, dosimetry, medical physics and radio-biology.
Environment, Safety, Health and Quality
Scald Prevention Tip Sheet
Computing and Networking Infrastructure
Linux Patches Planned for Thursday
Annual Computer User Account Audit
Onsite Blood Drive Is Friday
Tracking Thomas at JLab
Congratulations this week go to Doug Higinbotham, Stephen Smith, Gwyn Williams, Ron Bartek and Samika Hawkins, who were the first to correctly identify the Jan. 18 location. Honorable mentions go to Michael Haddox-Schatz, Paul Letta, John Leckey, David Lawrence, Debra Brand, Mark Stevens, Brian L. Agor, Michelle Shinn, Stephanie Vermeire, Jason Willoughby, Dennis Merritt, Ryan Bodenstein, Harry Fanning, Mike Martin, DeAnn Maddox, Casey Heck, Rebecca Yasky, Josh Foyles, Anthony Dela Cruz, David Anderson and Karen Bartek. 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
Jan. 27: American Red Cross Blood Drive