First observation of 'supefluorescence' at extreme ultra-violet wavelengthsJames Harries, Hiroshi Iwayama, Susumu KumaPublished Sep 1, 2020• 0 citationsOpenAlexAbstractHere we discuss the first observation of superfluorescence at EUV wavelengths, which was made using free-electron laser pulses to ionise and excite helium atoms.