Jefferson Lab Weekly Briefs
October 24, 2012
12 GeV Upgrade
The eighth C100 cryomodule has been completed; assembly of the coldmass for the tenth and final C100 has begun. The fourth and fifth C100s have been put in place in the tunnel. Re-installation of all the arc dipole magnets has been completed and hook-up of the vacuum lines is underway. Re-installation of the east recombiner is nearly complete. Installation of the east spreader and the reworked injector beamline is underway. Installation of the new radiofrequency systems for the new cryomodules has re-started after a period of inactivity due to the reduced FY12 funding. Installation of the moveable shielding wall at the downstream end of the tunnel to the Hall D tagger enclosure is nearing completion. Oxygen Deficiency Hazard system installation for Hall D continues. Installation of the refrigerator and transfer line for the Hall D solenoid is on schedule.
Long Shutdown activities are progressing well. The Cryogenics group is performing required maintenance and continuing installation work for the Hall D solenoid magnet in preparation for cooldown of the linacs and the solenoid. South Linac and east arc initial alignment continues as support for the magnet installation work as well as support for the halls. The Central Helium Liquefier cooling tower project is progressing well, with the goal to flow water by mid-November. Stands, base and ceiling plates have been removed from the transport region. B-Comm dipole magnets in the 1R region have been removed. FEL Personnel Safety System certification has been completed, as the FEL staff make preparations for running in the New Year.
The FEL team continues to make progress on the new injector beamline design and construction of a loadlock for the new gun. Staffers assembled a mockup of the ring resonator to test length measurement system resolution and sensitivity to alignment.
Center for Theoretical and Computational Physics
A new model to calculate spin-dependent nucleon-nucleon amplitudes at GeV energies has just been completed. JLab kinematics, where experiments have been performed for the electrodisintegration of the deuteron, allow for high-energy nucleons interacting in the final state, and accounting for these final state interactions is crucial in order to describe the data. The new amplitudes will provide a completely spin-dependent, relativistic description of the final state nucleons, allowing a greater understanding of the deuteron electrodisintegration process.
The Mechanical Systems Installation and Vacuum group has made excellent progress on the 12 GeV Upgrade, working in all areas of the accelerator. The Installation group has installed most of the east recombiner and injection chicane dipoles and girders, the east spreader floor to ceiling stands, the west recombiner floor and ceiling plates, the east arc pass 1 and 3 dipoles, and 70 percent of the Hall D tagger shield wall. The Vacuum group has completed girder rebuilds for the east recombiner, west spreader and injection chicane, 75 percent of the west recombiner, 70 percent of Line D, and 60 percent of the east spreader. The crews installed the beamlines on the south side of the east arc for pass 1 and 3. In addition, both groups have supported others with transfer line alignment, cryogenics maintenance, penetrations, power supply moves, magnet refurbishment, and 6 GeV accelerator maintenance.
JLab Calendar of Events
Oct. 24: JAG Oktoberfest
Environment, Safety, Health and Quality
This time of year, we are treated to nature's color pallet, with the leaves adopting new hues. But as pretty as the autumn colors can be, they can also cause trouble. Leaves that have accumulated on sidewalks and roadways can make these surfaces slick, reducing traction for pedestrians and vehicles and potentially causing slips or falls. According to Injury Facts 2011, falls account for more than eight million trips to the emergency room in the U.S. each year and are one of the leading causes of unintentional injuries. Here are some quick tips for preventing falls due to autumn leaves:
Come Out and Enjoy JAG Oktoberfest!
Drivers Speak Out – Commuter Survey Results
JLab Library Offers Access to the Info You Need Most
Mobile Mammography Unit Onsite in December
JLab Map Updated
Name That Cryomodule Contest Underway!
Congratulations this week go to Samika Hawkins and Harry Fanning, who were the first to correctly identify the location for Oct. 17. Honorable mentions go to Darrell Spraggins, Doug Higinbotham, Debra Brand and Dick Owen. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.