TECHNIQUE TO GENERATE LASER-LIKE X- RAY BEAM DEVELOPED AT UNIVERSITY OF COLORADO

A TEAM OF RESEARCHERS AT THE UNIVERSITY OF COLORADO, BOULDER has developed a new technique to generate laser-like X-ray beams, removing a major obstacle in the decades-long quest to build a tabletop X-ray laser that could be used for biological and medical imaging.

For nearly half a century, scientists have been trying to figure out how to build a cost-effective and reasonably sized X-ray laser to provide super-high imaging resolution, according to CU-Boulder physics professors Henry Kapteyn and Margaret Murnane, who led the team at JILA, a joint institute of CU-Boulder and the National Institute of Standards and Technology. Most of today's X-ray lasers require so much power that they rely on fusion laser facilities the size of football stadiums, making their use impractical.

A paper on the subject by Murnane and Kapteyn, CU-Boulder graduate students: Xiaoshi Zhang, Amy Lytle, Tenio Popmintchev, Xibin Zhou, and Senior Research Associate Oren Cohen of JILA was published in the online version of the journal Nature Physics.

To generate laser-like X-ray beams, the team used a powerful laser to pluck an electron from an atom of argon, a highly stable chemical element, and then slammed it back into the same atom. The boomerang action generates a weak, but directed beam of X-rays.

According to Kapteyn, the obstacle they needed to hurdle was combining different X-ray waves emitted from a large number of atoms to generate an X-ray beam bright enough to be useful. In other words, they needed to generate big enough waves flowing together to make a strong X-ray.

Henry Kapteyn and Margaret Murnane lead the team at JILA, a joint institute of CU-Boulder and the National Institute of Standards and Technology.