Making Soft X-Rays
Krypton clusters—produced from supersonic expansion in vacuum (center) of krypton gas from a high-pressure nozzle (top)—are irradiated by a high-power, few-cycle laser (right) to produce soft X-rays, emitted in all directions. X-rays going through the vacuum-chamber differential pumping hole (left) are detected by a soft-X-ray spectrometer (Optica, doi: 10.1364/OPTICA.471084). [OPN 2022 Photo Contest Editors’ Choice]
—Pierre-Alexis Chevreuil, Ultrafast Laser Physics Group, ETH Zurich, Zurich, Switzerland