Swiss Bank On X-Rays

VENICE, ITALY--The Swiss government has given the green light to construction of a machine that is expected to produce the world's brightest and most coherent x-ray beam. The Swiss Light Source (SLS), as it's called, will be built at the Paul-Scherrer Institute in Villingen, Switzerland, and will be used for structural analysis of proteins, analysis of nanostructures, and other materials science experiments.

The SF159 million ($110 million) SLS will accelerate charged particles to energies of 2 giga–electron volts, generating intense synchrotron radiation--the light and x-ray beams emitted by charged particles as they speed around a curved path. The SLS's superconducting bending magnets will make the x-rays highly coherent, keeping the crests and troughs of their waves in step.

The coherent x-rays should allow the researchers to do macromolecular crystallography to determine the structures of large proteins, a technique that only the highest energy synchrotrons can readily tackle. "There is so much demand for this technique," says Giorgio Margaritondo, experimental division coordinator at the Elettra synchrotron in Trieste, Italy, "that even all of the facilities planned or approved will not be enough." The SLS is expected to be up and running by 2001. More information on the project can be found at