Conventional and Propagation-based Phase Contrast Imaging ofNanostructures Using Femtosecond Laser Driven Cluster PlasmaSource and LiF Crystal Soft X-ray Detectors

摘要

Bright source of soft X-ray emission was developed. Soft X-ray radiation was produced by femtosecond laserpulses irradiation of submicron size CO2 clusters. These clusters were produced in custom designed super-sonic nozzle from the mixture of the 10% CO2 + 90 % He expanding gases. Lithium fluorine based soft X-raydetectors was used for registration of absorption images of ultrathin (nanoscale) foils and biological structuresilluminated by the developed source. It was demonstrated that even if the foil is essentially transparent for thesoft X-ray radiation (like 100 nm thick Zr foil), the image contrast could be significantly increased due to theinfluence of propagation-based phase-contrast effect when detector is placed at the proper distance behind thesample.