Jefferson Lab Weekly Briefs
July 9, 2008
12 GeV Upgrade
An R&D task to re-measure the Higher-Order Mode (HOM) damping in the 12 GeV-style superconducting radio frequency (SRF) cavities has verified last year’s results, i.e. the HOM damping meets the specification comfortably. The cavities have been removed from the Horizontal Test Bed and follow-on measurements in the Vertical Test Area have begun.
Assembly of the first prototype beam transport quadrupole has been completed. Field measurements have begun.
The final specification needed for the procurement of the 4K coldbox was approved last week.
In the injector, 100 KeV characterization studies were performed. Preparations are underway for a bake out of gun 2, while gun 3 is being readied for running. Disassembly of the injector sync light monitor revealed some unpainted lead bricks. Proper procedures were followed after the discovery, including notifications to ESH&Q as well as Radiation Control prior to removal to a lead storage building. The standby refrigerator (SBR) tripped during the holiday weekend. Causes for this event are being investigated Construction continued on the structural steel building at the South Access Building.
Free-Electron Laser (FEL)
A number of magnet girders are being installed in the FEL Ultraviolet/amplifier beamline. The FEL gun is being prepared for reassembly and its support systems for recommissioning. There is also good news from SRF, where the string assembly of the 750 MHz Advanced Energy Systems booster was completed.
A quark-diquark model of the proton's structure was recently used in arXiv:0807.0323 [hep-ph] to calculate transverse momentum distributions (TMDs). When integrated over the parton's transverse momentum, TMDs reduce to the well-known parton distribution functions. The model calculation was used in particular to highlight what kind of information is contained in TMDs (e.g., related to partonic orbital angular momentum).
The Alignment group fiducialized the FEL collimator and turning mirror cassette (TMC) cans for the Optics group. The TMC is part of the optical transport system (OTS), which delivers beam to the user labs in the FEL complex. The Alignment group also completed positioning of all installed QX quadrapole magnets for the FEL UV line.
JLab's Safety Numbers
268 Days since Last Recordable Accident (JLab record: 319)
JLab Calendar of Events
July 8-10: DOE ES&H Inspection - Report Validation and Closeout
Environment, Safety, Health & Quality
On average, 62 people are killed every year by lightning in the U.S. Those who survive a lightning strike suffer from a variety of long-term, debilitating symptoms, including memory loss, attention deficits, sleep disorders, numbness, dizziness, stiffness in joints, irritability, fatigue, weakness, muscle spasms, depression and an inability to sit for long.
The National Weather Service offers these tips for lightning safety:
For more information on severe weather prcoedures at JLab, see the EH&S Manual.
Computing and Networking Infrastructure
CNI Systems Maintenance Planned
Networking Changes in CEBAF Center Begin July 10
Here is the schedule for upcoming changes:
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