Need Ultrashort X-ray Pulses?
Try Aluminum Foil
Slotted foil: The open "V" (bottom) allows one bunch of electrons
through; the double-slot "V"s (middle and top) create two
narrow bunches. The width of the V determines the bunch
width (single bunch) or timing between bunches
(double-slot). (Image courtesy Paul Emma.)
Last week, users on the Atomic, Molecular and Optical science instrument at the Linac Coherent Light Source experimented with a novel piece of technology that aims to make the world's quickest X-ray pulses even quicker.
Some of nature's most thrilling mysteries—such as the processes behind the forming and breaking of chemical bonds—occur in a matter of femtoseconds, or millionths of one billionth of one second. But capturing images of these events requires a camera with a flash and shutter speed on the same fleeting time scale. The LCLS was built, in part, to provide pulses of X-rays bright enough and quick enough to do just that.
"The reaction time of atoms can be less than 10 femtoseconds, which you can't see with longer pulses," said SLAC accelerator physicist Paul Emma.
Bay Area Particle Accelerators
on the Air Tonight
Tune into TV channel KQED's series Quest tonight at 7:30 p.m. PDT to
explore the history of Stanford/SLAC and U.C. Berkeley atom smashers in "Homegrown
Particle Accelerators." For additional air times, see KQED's
schedule of upcoming Quest broadcasts.
Linear Collider in One Minute Flat
The folks working on the proposed International Linear Collider have created a one-minute animation that flies you through its 30-kilometer-long tunnel. It has no sound, but the visuals speak for themselves: electrons and positrons are generated on opposite arms of the collider, circle in opposite directions in a damping ring, fly out to the ends of the machine and jet back into the middle, where they collide. For more details about the humongous project—which
was scheduled to present a progress report at the International Conference on High Energy Physics last Saturday—go here.
New Conference Attendance Approval System: Live!
With the requirements gathered, the design and testing done, demonstration and training sessions completed, and a few enhancements thrown in, the new
conference attendance approval system
went live yesterday, July 26. Many thanks to the directorate conference coordinators and all those who helped with testing and
The new form is located on the Office
of the Chief Finance Officer site.
The coordinators hope you will enjoy the basic conference information being collected only once per conference, rather than from every candidate-attendee-to-be; online forms and approval to assist with status tracking and off-site entries; and the auto-filled forms to save time while providing accuracy. We will continue to make enhancements to the system, and will keep in mind integration with the travel processes as a longer-term goal.
Questions or comments? Please send email to
email@example.com or check with your directorate conference coordinator.