Status of X-ray Microscopy Experiments at the BESSY Laboratory

Abstract

Soft x-ray microscopy provides higher resolution than visible light microscopy combined with the advantage of an inherent contrast mechanism. Unlike electron microscopy, x-ray microscopy can be used to investigate comparably thick objects of several μm in thickness. The reason of the natural contrast is, that the atomic scattering factors strongly depend on the different atomic species contained in the object under examination. Between 2.4nm and 4.4nm there is about an order of magnitude difference between the absorption coefficients for water and organic components. The natural contrast mechanism and the relative low radiation damage (Niemann et al. 1986) makes the x-ray microscope an useful tool in biology. The absorption is only one effect described by the complex atomic scattering factor, the second effect (the phase shift) is an even more valuable contrast mechanism (Schmahl and Rudolph, 1987).