Creating Super-Bright X-rays
This Research in Action article was provided to LiveScience in partnership with the National Science Foundation.
Synchrotron light sources are huge machines that produce extremely intense, focused x-ray beams that are used to study all sorts of materials and produce high-resolution pictures. They are essential tools in the sciences, medicine and engineering.
In biomedical applications, X-rays reveal how the parts of cells are put together, with details all the way down to the structures in DNA and proteins that comprise our bodies. In engineering applications, X-rays can penetrate deep inside dense materials, like titanium metals used for airplane engines or wings, to see the grain structure of the minerals and early formation of cracks or crevices that can lead to fatigue and failure.
To advance the scientific fields that use such tools, researchers need X-ray sources that can image a wider variety of materials with much higher resolution — atomic resolution. Existing synchrotrons fall short because they produce mostly incoherent light, meaning the light source is too large or too divergent to create the weak interference effects that scientists need to see the smallest features in materials.
In order to generate X-ray beams via synchrotron radiation, it is first necessary to accelerate electrons to nearly the speed of light. The photo above shows the first prototype seven-cell superconducting accelerator cavity built for the proposed Cornell University Energy Recovery Linac, a novel type of machine to make superior X-ray beams.
The cavity shown in this image is mounted to a vertical test apparatus. The unique geometry of the cavity supports radio-frequency electromagnetic waves. Those waves are necessary to accelerate electrons that can then be fed into an Energy Recovery Linac to produce super-intense and super-bright X-ray beams.
With support from the National Science Foundation, a team of researchers at Cornell University has been inventing, designing and prototyping superconducting Energy Recovery Linac technology as a basis for a next generation source of X-ray beams far brighter than any synchrotron in existence.
The program goals are to prove that electron beams of unmatched quality can be created and accelerated to produce continuous X-ray beams with the laser-like property of coherence. No such X-ray source presently exists.
Editor's Note: Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the Research in Action archive.
