Andrei Benediktovitch, Laurent Mercadier, Olivier Peyrusse, Andreas Przystawik, Tim Laarmann, Bruno Langbehn, Cédric Bomme, Benjamin Erk, Jonathan Correa, Caroline Mossé, Daniel Rolles, Sven Toleikis, Maximilian Bucher, Christoph F. O. Bostedt, Alvaro Sanchez-Gonzalez, Stepan Dobrodey, Michael A. Blessenohl, Alexander Nelde, Maria Müller, Daniela Rupp, Thomas Möller, José R. Crespo López-Urrutia, and Nina Rohringer
Phys. Rev. A 101, 063412 (2020) - Published 22 June, 2020
Extreme-ultraviolet emission at 65-nm wavelength from xenon nanoclusters irradiated by an intense pulse of soft x rays from a free-electron laser is investigated in a joint experimental-theoretical study. Clear indications of a long-lived population inversion, and subsequent amplified spontaneous emission, are identified.