Soft x-ray contact microscopy using laser plasma sources

The feasibility of using high-power pulsed lasers (several tens of joules per pulse) to produce plasmas as soft X-ray sources for contact microscopy is discussed and demonstrated for a wide range of biological and other material. As in other forms of X-ray microscopy, complicated and probably artefact-inducing specimen preparation is not necessary. The short pulse lengths of the lasers mean that, for single shot exposures, images can be obtained before radiation damage has altered the structure of the specimen, and this higher resolutions are possible, in principle, than for other forms of X-ray microscopy.