Application of SEM-modified X-ray microscope to entomology and histology, and effects of X-ray coherence in imaging

A projection X-ray microscope has been constructed by modifying a scanning electron microscope (HITACHI S-2500CX). Characteristic internal structures and their changes in an aphid, a fly an ant, a water bear and a beetle are observed first, non-destructively, by X-ray microscope. Stereo-pair X-ray m icrographs of Golgi-stained sections of porcine Liver show a network of bil e canaliculi and stellate cells. The very clear micrographs presented indic ate the usefulness of the microscope in studies of entomology and histology . In some micrographs, very thin whiskers or hairs are visible, which sugge sts that a phase-contrast effect is present in the imaging. X-ray micrograp hs of an ant hair taken at various distances between the X-ray source and t he specimen, D-S, indicate that the image enhancement due to the phase cont rast increases with increasing D-S. Degree of the lateral coherence of X-ra ys of wave length 0.1 nm is theoretically estimated near the hair, with the result that the coherence increases from about zero (almost complete incoh erence) at D-S = 0.1 mm to about unity (almost complete coherence) at D-S = 6 mm, in agreement with the observation.