Contact and Phase-Contrast Imaging of Nanostructures by Femtosecond-Laser-Driven-Cluster-Based Debris-Free Soft X-Ray Source.

The high-intensive source of soft X-ray emission was developed by femtosecond laser pulses irradiation of submicron size CO2 clusters, produced in custom designed super-sonic nozzle while mixing the 10% CO2+90% He expanding gases. The LiF crystal soft X-ray detectors have been used for obtaining absorption images of ultrathin (nanoscale) foils and biological structures illuminated by the developed source. It was demonstrated that even if the foil is essentially transparent for the soft X-ray radiation (like 100 nm thick Zr foil), the image contrast could be significantly increased due to the influence of propagation-based phase-contrast effect, by placing the detector at the proper distance from the sample. [ABSTRACT FROM AUTHOR]