Jefferson Lab Weekly Briefs March 7, 2012
Jefferson Lab Weekly Briefs
March 7, 2012
12 GeV Upgrade
The 12 GeV team is working to re-plan FY12 and FY13 installation activities in response to the reduced FY12 funding and subsequent extension of the machine shutdown to a 16-month duration starting in mid-May 2012. Revised schedules and resources are being coordinated with the "Long Shutdown" planning team.
Hall A was active last week, getting ready for the g2p experiment. The beamline was finished and a first alignment was done for straight-through beam. Beam was delivered to Hall A on Friday, and scientists spent the weekend commissioning various pieces of apparatus, such as beamline instrumentation, spectrometer optics, detectors and polarimeters. It was a very productive weekend, although some problems remain, which staffers are working on this week. The group hopes to move to production data-taking on g2p rather soon.
In Hall C, Q-weak took production data with the liquid hydrogen target and some data with an aluminum target to measure target wall backgrounds. Some extra Moller (polarization) measurements were made to attempt to null out transverse components of the beam polarization.
Users Group Town Hall
Last Chance to Apply for the JSA/JLab Graduate Fellowship Program
Last Chance to Apply for the JSA/JLab Sabbatical Support Program
Accelerator operations staffers began the week with Hall B receiving 70 picoamps of beam current and Hall C receiving 180 microamps. Hall A continued setting up for the next experiment. On Tuesday, the accelerator was turned off to allow a full day of maintenance to be performed. Maintenance items addressed include cooling water leaks, the repair of multiple beam position monitors, oxygen sensor head change outs, vacuum ion pump troubleshooting and lots of radiofrequency (RF) systems work. Returning to operation proved a challenge. Initially, a faulty limit switch prevented a vacuum valve from opening to allow beam through, then the Arc 5 dipole power supply would not turn on. This was determined to be from shorted wiring on a thermal protection switch. With that fixed, beam delivery was stalled beyond the South Linac, because the timing of the RF cavities had changed from the work performed during the maintenance day. Beam was back to Hall C just before noon Wednesday. Friday finally saw beam into Hall A; however, that night was plagued with RF separator faults turning off the beam. Electrical Engineering Support worked well into the night to fix it. Sunday night saw the failure of the South Linac local oscillator drive line coupler, which took out the RF for most of Owl shift. Overall, it was a rough week, with multiple down times lasting several hours.
The FEL team continued efforts to set up high-power electron beam last week and successfully energy-recovered 1.5 milliamps of continuous-wave beam. Staffers also continued installation work on the ultraviolet wiggler chamber, which is required for future optics tests. Re-certification of the optical system is in progress. On Friday night, the team re-established CW lasing in the FEL. This week, the team is hosting the International ICFA Workshop on Future Light Sources for 150 attendees.
The g2p/GEp beamline is now installed and prepared for the start of physics. The challenges in developing this beamline were in satisfying the breadth of the four beam energies and the low beam current (50-130 nanoamps). Several new diagnostics and their associated applications software were created to support measuring beam position and beam current at the low current levels. A movable chicane that must be adjusted for the different beam energies added to the complexity of the beamline.
JLab Calendar of Events
March 5-9: International ICFA Workshop on Future Light Sources
Environment, Safety, Health and Quality
What do pizza makers and JLab staffers have in common? Both have the potential for working in potential oxygen deficient environments. On Dec. 15, the Occupational Safety and Health Administration issued a willful health violation to a pizza manufacturer for exposing workers to an oxygen deficient environment when processing pizzas in the liquid nitrogen cryogenic freezer. The freezer creates the potential for an oxygen deficient atmosphere due to the buildup of nitrogen gas in the production area.
If you see these signs and don’t know the hazards or how they can impact you, it is extremely important to speak with your supervisor and determine if you need the ODH training (SAF 103).
Education Seeks Projects for Summer Honors Interns
United and Continental Merger and Frequent Flyer Accounts
JLab Publications Seminar
Shred-It Truck Stops at JLab on March 16
Annual T-Shirt Contest is Underway!
Tracking Thomas at JLab
Congratulations this week go to Michelle Shinn and Subashini De Silva, who were the first to correctly identify the Feb. 22 location. Honorable mentions go to Ryan Bodenstein, Joshua Magee and Harry Fanning. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.