Figure 1
Experimental (dashed blue) and theoretical (solid red) electron energy spectra of Ar clusters, with average sizes of (a) 
~100, (b) 
~300 and (c) 
~1000, recorded at the XFEL photon energy of 5 keV at a peak fluence of ~50 μJ/μm2. As a reference, panel (d) shows a theoretical spectrum for single Ar atoms irradiated at the same conditions. Characteristic lines between 100–300 eV(em dash) and below 50 eV correspond to LMM and LLM Auger electrons, respectively.
