LCLS Team Takes Pictures of the Electron Beam
A camera took this image of the LCLS beam's cross section.
How do you take a picture of something as thin as a strand of hair that's moving at the speed of light?
Like professionals who photograph wildlife or fussy babies, the Linac Coherent Light Source
(LCLS) team is not daunted. They've adapted several technologies to take pictures of the LCLS electron beam.
The pictures ensure that the beam still looks and behaves like it's supposed to after being created
by the injector, accelerated, and bent by bunch compressors. For the commissioning work done last
spring and summer, researchers used 14 devices installed along the injection line to help bring the electron beam up to spec for its downstream role in creating ultrafast, ultrashort x-ray pulses.
Near the beam's source, where the beam is still low in energy, researchers are using scintillating crystals to capture the crosswise dimensions of the beam. The beam shoots through the crystals, transferring kinetic energy that makes the crystals emit light, which nearby cameras detect.
At the annual Freebord Rider Awards, Stephen Norum navigated Lombard Street's windy, 16% grade on his 6-wheeled "bord."
San Francisco's picturesque Lombard Street is usually packed with tourists, who battle bumper-to-bumper traffic for a chance to maneuver their vehicles around the road's legendary twists. But on a sunny Saturday afternoon a few weeks ago, the cars were unusually absent—and into the open stretch poured SLAC's Stephen Norum and about
60 other "freeborders," who carved and slid down the serpentine swath like snowboarders slaloming in Tahoe.
The ride was the highlight of the annual "Freebord Rider Awards," which drew freeborders, like Norum, from multiple continents to San Francisco's steep, rolling hills. "Freebords are pretty much like skateboards," said Norum, "but they have two extra wheels in the middle of the board that are lower than the other four." This allows the six-wheeled contraptions—recently invented as part of a Stanford student's master's thesis—to simulate the behavior of snowboards, including 360-degree spins, sliding, switching and carving.
Norum, an electrical engineer with the Linac Coherent Light Source (LCLS), is relatively new to freebording, but his extensive experience with more traditional board sports allowed him to learn quickly. "I got my first skateboard when I was four years old," he recalled. "It was a little yellow skateboard, and I got it at my neighbor's garage sale for about four dollars."
Twenty-one years later, Norum skateboards every day, occasionally riding the one and half-mile commute to SLAC—equipped, of course, with elbow pads, a helmet and formidable sliding gloves. He also meets with a longboarding group at Stanford every Tuesday and insists, "everyone's welcome to come, even if they've never skated before."
Last year, Norum added snowboarding to his boarding repertoire, and was so enchanted that he sought a way to ride in the off-season. "That's when I got into freebording," he said. "It really is like snowboarding on pavement."
Norum now freebords two to three times per week, and is avidly searching for fellow freeborders—or the freebord-curious—to join him on his rides. "I have two freebords, so if people want to come freebording with me, I'd be happy to teach them!"
Travel Paperwork Due by December 3 for
The Travel Reimbursement Office would like travelers to consider turning in travel expenses by December 3 to get a chance to be reimbursed before noon
on December 21, 2007. The Travel Office will try its best to clear as many reimbursements as
they can, working chronologically. Anyone who turns in an expense report after December 3 may have to wait until January to get reimbursed.
Please remember to submit complete documentation with your travel expense reports. Incomplete reports will be placed on the pending or investigation pile and may get delayed.
For more information on travel and travel reimbursement procedures, please visit
the Travel Reimbursement Office
Still Time to Add Your 2¢ to SLAC Vision, Mission
last Wednesday's edition of
SLAC Today, Acting Director Persis Drell asked lab employees and users to
draft Vision, Mission and Core Value statements for the laboratory. If you have not yet
read through and responded to the statements, please consider doing so. These statements help remind us of our ultimate goals, and will serve to keep us on track during this time of transition.
If you have suggestions on how the statements could better reflect the
laboratory, please e-mail them to
firstname.lastname@example.org. Persis and the
Director's Office staff will carefully consider all you have to say.
Thank you for your input in this important process!
of the Week
Even when they are not in use, many appliances like televisions and VCRs continue to use small amounts of electricity to power their clocks and remote controls. If you have a rarely used appliance, such as a TV or clock radio in a guest room, pull its plug. You can also plug stereo, computer and TV equipment into power strips, so you can easily turn off multiple devices at one time when you go to bed.
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