Jefferson Lab Weekly Briefs July 22, 2009

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.

Free-Electron Laser

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.

Theory Center

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)
315 Days since Last Lost Workday Accident (JLab record: 676)

JLab Calendar of Events

July 24: FEL Photon Science Workshop
July 29: American Red Cross Blood Drive
July 31: Science Education Summer Poster Session
Aug. 5: Safety Glasses Vendor onsite
Aug. 19: Jefferson Activities Group Luau
Aug. 19-21: GPUs for Lattice QCD Workshop
Sept. 7: Labor Day holiday
Sept. 17: JSA's Electronic Commerce Vendor Show




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:

  • Plan your safety measures and escape route in advance. When you first see or hear lightning, get into a fully enclosed building or a vehicle with the windows rolled up. Lightning often precedes rain, so don't wait for the rain to begin before stopping your outdoor activities.
  • If outdoors, make sure that you avoid water, high ground and open spaces. Avoid all metal objects, including electric wires, fences, machinery, power tools and motors.
  • If indoors, avoid water. Make sure that you stay away from doors and windows. Do not use the telephone; a cell phone may be used. Turn off, unplug and stay away from appliances,
    computers, power tools and televisions.
  • Do not resume outdoor activities until at least 30 minutes after the last observed lightning or thunder.

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
Recently, a JLab employee received multiple stings from a yellow jacket. Over the course of a day, the affected areas became swollen and caused severe discomfort. The next day, the employee went to her personal physician and received a prescription, making the case recordable. Occupational Medicine was consulted after the employee had been seen offsite.

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.


The latest Montage is now available online.

American Red Cross Blood Drive
The next American Red Cross Blood Drive is scheduled for Wednesday, July 29, from 10 a.m. - 4 p.m. in CEBAF Center Room F113. New and repeat donors are encouraged to attend. Walk-ins are welcome; however, making an appointment allows the Red Cross to schedule adequate staff for the visit. Volunteers are also needed to help with the blood drive. To schedule an appointment or to volunteer, e-mail Johnie Banks or call x7539.

Public Affairs Offers CEBAF Tours
The Scheduled Accelerator Down period is coming to a close. Before CEBAF is back up and running, take advantage of the opportunity to view the accelerator and one of the experimental halls. Public Affairs personnel will conduct a tour for Jefferson Lab staff, students, users and contractors at least 18 years of age on Monday, July 27, from 3 – 4 p.m. Space is limited and available on a first-come, first-served basis. To reserve your space, e-mail Michelle Lechman or call x7617 no later than Friday.

25th Anniversary DVD
A new DVD for the general public that provides a brief introduction to Jefferson Lab will be unveiled next Wednesday, July 29, in the CEBAF Center auditorium. The showing will be at 11 a.m., and copies of the DVD will be available for free for those wanting a copy.