Jefferson Lab Weekly Briefs
July 22, 2009
The Scheduled Accelerator Down continued with maintenance on RF (radio frequency), magnets, the control system, the personnel safety system and more. The inverted gun was installed and is ready for high-voltage testing. The annual tunnel cleanup was conducted and the tunnel is much cleaner.
The FEL team spent the week setting up for high-average current and optimizing performance in preparation for some short Rayleigh-range tests and other optics tests this week.
The nucleon's "pion cloud" influences not only its low-energy hadronic properties but also the partonic structure probed in high-momentum transfer electron-scattering processes. Using a novel formulation based on generalized parton distributions and 3-D spatial structure, theorists have computed this universal large-distance component of the nucleon's quark and gluon densities and studied its properties <arXiv:0906.3267>. In particular, it was found that the pion cloud accounts for only a small fraction of the experimentally observed sea quarks in the nucleon, proving that they mostly sit in the nucleon's "core" at small transverse distances.
JLab's Safety Numbers
7 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
July 24: FEL Photon Science Workshop
Environment, Safety, Health & Quality
Lightning can occur at any time of the year, but it's much more frequent during the summer months. Here are some tips from the National Lightning Safety Institute for lightning safety:
More lightning and other severe weather safety information is available in Chapter 3510-T4, Severe Weather Procedures in the JLab EH&S Manual.
ESH&Q Lesson Learned: Reporting Events
It's very important to report all work-related physical occurrences and symptoms as soon as they occur. This is true even if the event appears related to the workplace but not to the work. For instance, you should promptly report such seeminlgy minor events, such as a foreign object blowing into your eye, an insect sting, wrist discomfort when working on a computer, or a trip and fall.
These types of events must be reported, regardless of severity, so that proper medical attention is given; the underlying reasons or trends can be properly identified; and lessons learned can be incorporated as solutions into JLab work planning.
If an event is trivial, such as a paper cut or a minor bump or scrape, you can simply report it by calling Occupational Medicine. During phone reports, staff will trust your judgment if you think you don't need to be seen by medical staff.
American Red Cross Blood Drive
Public Affairs Offers CEBAF Tours
25th Anniversary DVD