Relativistic laser plasma from micron-sized argon clusters as a debris-free x-ray source for pulse x-ray diffraction

We have demonstrated diffraction from Si(111) crystal using x rays from highly ionized Ar ions produced by laser irradiation with an intensity of 6×1018W∕cm2 and a pulse duration of 30 fs acting upon micron-sized Ar clusters. The measured total photon flux and linewidth in the Heα1 line (3.14 keV) were 4×107photons∕shot∕4πsr and 3.7 eV (full width at half maximum), respectively, which is sufficient to utilize as a debris-free light source for time-resolved x-ray diffraction studies.