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its own capabilities. The X-ray beam is millions of times brighter than a medical X-ray, like a laser compared to a gently glowing light bulb, Mr. Freeberg said. But to what end? Imagination comes

and 120 million years old. The discovery that could lead to plicated than a couple of extra more accurate depictions of gears. The electron beams, when prehistoric birds in dioramas, they’re deflected properly, genermovies and textbooks, scientists ate X-rays. Parts of the accelerator said in a report. have had strong The Almanac magnets added published a in arrangements related story in “There’s no way to understand the universe that cause the 2009 in which without knowing how the particles behave. We a team of visitenergy beam to wiggle. “The paleontolounderstand only 4 percent of what’s out there.” ing faster the elecgists brought tron is going and with them a —Aaron Roodman, particle astrophysicist the harder you 14 5 -m i l l i o n suddenly turn it, year-old fossil the higher the energy of the light or into play at this point. of archaeopteryx, a proto-bird the shorter the X-ray wavelength,” Some 1,500 scientists reserve preserved in limestone and made SLAC spokesman Andrew Free- time at the SSRL every year. portable as a thin rectangular berg told the Almanac. Among their achievements: slab about two feet on a side. The Stanford Synchrotron designer pharmaceuticals, bet- Thinking there might be softRadiation Lightsource (SSRL), ter fuel cells and better under- tissue residues in the limestone, a circular tunnel that opened standing of the relationship of scientists superimposed a pixel in 1974, generates electrons that genetic mutations to diabetes. map on to the fossil and scanned become X-rays as they’re sent Fossils are not known for the it pixel-by-pixel with a precision around and around. Scientists preservation of soft tissue, but X-ray stylus at the SSRL. at each of 33 stations along the the SSRL in 2011 revealed chemThe scan returned indications circumference can tap into the ical traces of colored feathers in of phosphorous and sulfur in X-rays as needed. Each station has fossilized birds of 100 million the feathers, similar to modern

8NThe AlmanacNTheAlmanacOnline.comNOctober 3, 2012

Scientist John Bozek at the LCLS, a device that generates powerful X-rays. The aluminum foil is necessary to restore a high-quality vacuum in a vacuum chamber.

birds, according to an SSRL report. “Because the SSRL beam is so bright, we were able to see the teeniest chemical traces that nobody thought were there,” physicist Uwe Bergmann said in the report. It’s one thing to observe nature, another to duplicate its ways. One long-term goal at SSRL is to find ways to copy the efficiencies of nature, such as mimicking the way soil bacteria convert nitrogen to plant food. Solving that problem could go a long way toward reducing the huge amounts of energy humans expend to produce nitrogen fertilizer. This and other projects at SSRL are examples of applied research: research that explores the unknown with the intent of developing new and practical applications. Basic research, by contrast, explores the unknown in order to answer fundamental questions. Scientists at the Linac Coherent Light Source (LCLS), founded in 2009, are engaged in basic research, also using X-rays but used with more precision than at the SSRL, Mr. Freeberg said. Another contrast: while the SSRL can run many experiments simultaneously, the LCLS can run only one, though a second track is in the works. The LCLS taps energy from the linac and uses its own magnets — called undulators — to deflect the electrons, creating X-rays that are more than a billion times brighter than SSRL X-rays and shorter in wavelength, meaning that the LCLS can illuminate faster-moving objects than the SSRL. Climate change is an area of LCLS study. What if scientists could find a way to turn atmospheric carbon dioxide into oxygen as is done by daisies, trees and blades of grass every day? The fundamentals of photosynthesis are under investigation at LCLS. “Because (they’re) able to work at a better resolution than anything available before, the (LCLS) researchers

are trying to explain how plants convert sunlight and water into energy,” Mr. Freeberg told the Almanac. Big power

The linear accelerator at SLAC draws about 8 billion volts of electricity to accelerate electrons over that two-mile distance. In measurement terms of 9-volt batteries, that would be 888 million batteries in a line that would stretch from Menlo Park to London, SLAC Instrument Scientist Bill Schlotter said in an email. Monthly electric bills of around $1 million are not uncommon. When all the facilities are operating, not a common occurrence, SLAC uses about 30 megawatts of electricity, Mr. Freeberg said. SLAC has a record of about 70 megawatts from the time when scientists were using the circular accelerators and the entire length of the linear accelerator. “Running all facilities at full power, it’s fair to say SLAC can pull about as much power as a small city or use as much as west Menlo Park,” he said. What does a linear accelerator sound like when it’s running? “It’s really noisy,” Mr. Freeberg said, “like an electrical hum coming from a transformer loud enough (so that) you basically have to shout to hear. We offer ear plugs for people visiting and probably close to half of visitors will take them.” SLAC’s budget from the U.S. Department of Energy for 2012 fiscal year was $324 million, he said. Other minor sources of income include outside researchers who use the facility and patents. DOE budgets have a political element, but SLAC has “fairly uniform bipartisan support, SLAC Director Persis Drell said in an email. But in an era of tight budgets, “we have to keep making the case for the importance of basic research to both the White House and Congress, regardless of who is in charge,” she said. A

The Almanac 10.03.2012 - Section 1  

Section 1 of the October 3, 2012 edition of the Almanac

The Almanac 10.03.2012 - Section 1  

Section 1 of the October 3, 2012 edition of the Almanac