Sharp pulses from x-ray lasers | Max-Planck-Gesellschaft https://www.mpg.de/11438024/x-ray-laser-x-ray-sources-sharp-spectrum?c=11969087
A team of researchers around J. Evers at the Max Planck Institute for Nuclear Physics has succeeded in using a mechanical technique to narrow the spectrum of pulses emitted by x-ray sources such as x-ray lasers.
from the Max Planck Institute for Nuclear Physics in Heidelberg