Life of a Photon in X-ray Spectroscopy

Abstract: This thesis summarizes the experimental work in which an ultrafastX-ray laser plasma source was combined with variousscalable direct detection schemes to test a novel approach forlab-based time-resolved X-ray absorption spectroscopy. A laserplasma source based on a water jet target was built and commissioned.X-ray and electron emissions of this source were characterizedwith various direct detection schemes. The proceduresfor spectral retrieval with direct detection CCD’s were optimizedwith regard to the laser plasma source. The novel approach of usinga single photon measuring cryogenic microcalorimeter arrayas a high-resolution (DE/E 2000 @ 6 keV) energy-dispersivedetector was investigated. The potentially very high quantumefficiency, large detection angle and straightforward scalabilitymake this device an interesting photon analyzer for low photonyield experiments. In this thesis a prototype version of this detectorwas built (in cooperation), implemented and commissionedinto the laser plasma setup. With this combination of a lab-basedbroad-band source and the free standing microcalorimeter spectrometerhigh resolution X-ray absorption spectra in transmissionmode were achieved. The thesis presents the first hard X-rayabsorption fine structure (XAFS) spectrum taken with this novelapproach and discusses further improvements and applications.