Aperiodic x-ray multilayer mirrors and their application in plasma spectroscopy

We discuss the potentialities of aperiodic multilayer structures for the reflection of XUV radiation, including attooptical applications. Pilot samples of aperiodic normal-incidence broadband focusing multilayer mirrors are employed in a stigmatic transmission grating spectrograph with an operating range of 12.5–30 nm.This spectrograph was used to study (i) the XUV spectra arising from the charge exchange of laser-produced plasma ions with rare-gas (Xe, Kr, He) jet atoms, (ii) a debris-free Xe-jet plasma XUV source driven by Nd-laser pulses.