Ultrafast NEXAFS spectroscopy in the lab using laser-based sources and advanced X-ray optics

Abstract

Laboratory based laser driven short pulse X-ray sources like laser produced plasmas (LPP) and high harmonic generation (HHG) exhibit a great potential for spectroscopy in the soft X-ray range. These sources are complementary to large scale facilities like synchrotrons or free electron lasers. For applications of LPP or HHG sources for time-resolved X-ray absorption spectroscopy in the water window or beyond a high photon flux is crucial. The available photon flux strongly depends on energy, pulse duration and repetition rate of the pump laser. Depending on the experimental needs in timeresolved experiments pulse durations of the X-ray pulse ranging from nanoseconds to sub-femtoseconds are required. In our contribution we will present a highly brilliant LPP source emitting soft X-rays in the photon energy range between 50 and 1500 eV based on CPA and thin disk laser technology as well as the high average power thin disk laser based OPCPA system for high photon flux HHG. In addition we present a new generation of reflection zone plates on spherical substrates, that promises a remarkable high resolution over a wide spectral range making it an ideal and highly efficient diffractive optic for time-resolved NEXAFS experiments in the lab.