Jefferson Lab Weekly Briefs February 17, 2010
Jefferson Lab Weekly Briefs
February 17, 2010
12 GeV Upgrade
The first lot of beam transport quadrupole magnets was received. The contracts were awarded for the radiofrequency system's cathode power supplies and for the H-iron that will be used to modify the arc and spreader/recombiner dipole magnets. The first batch of warm-to-cold waveguides for the cryomodules was received. In-tunnel installation activities were completed. In addition, data was acquired on the activation of the magnets; this information will be folded into the work plan for the dipole magnet refurbishment.
Overall, maintenance activities and pre-startup checks are going very well. In the injector, Gun2 was conditioned to 100 kV. The capture section startup went well. Injector setup began, with very good early results. A variety of calibrations and signal verifications were checked off the list. Component hot checkout up to the inline dump looked good. Cryomodule installation is going well with NL05, NL06 & NL07 being cooled to 4 Kelvin. In addition, the cryomodule brought from the Test Lab is being installed at 2L21. This cryomodule is the last of the C-50 cryomodules. Calibration of the newly installed cryomodules began on swing shift and a cryo-cycle of NL17 was completed. The annual ODH head maintenance and replacement process was finished.
Progress continues on re-establishing operations early next month, despite battling the inclement weather. Researchers from Vanderbilt University, Old Dominion University, The College of William & Mary and JLab performed resonant infrared pulsed laser deposition (PLD) of organic thin films in December, as had been done previously at the now-decommissioned Vanderbilt FEL. Successful performance was verified and is resulting in a paper as a first for JLab's new PLD facility.
Recent amplitude analyses of pion-nucleon scattering data have established the two-pole structure of the mysterious Roper resonance P11(1440). The most recent paper from EBAC <arXiv:1001.5083 [nucl-th]> shows that, within the coupled-channels framework, such structure appears to be rather model independent and insensitive to the analytic structure of the amplitude below the πN threshold. The number of P11 resonances in the 1.5 <W<2 GeV region could be more than one, depending on how the available pion-nucleon scattering data are fitted within the errors.
JLab's Safety Numbers
26 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
Feb. 25: Safety Shoe Vendor onsite
Environment, Safety, Health & Quality
Free Reusable Solvents Available on Webstock
Computing and Networking Infrastructure
Last Chance for Smartcard Renewal
Linux/Mac Printing Changes
New General Purpose Solaris System Available
JLab’s 2010 Benefits Open Enrollment Underway
Free H1N1 Flu Vaccination Clinics Offered Locally