A prism for x rays.

The article reports on scientific findings related to x-rays. Physicists using the Advanced Photon Source at Argonne National Laboratory have spread out a beam of x-rays into a rainbow of colors with the help of an asymmetrically cut crystal, whose atomic planes are not parallel to the crystal surface. The diffracted x-ray beam is spread out prismatically into its component wavelengths. The technique can lead to very-high-resolution x-ray spectrometers and to a compression of x-ray pulses.