Phase-contrast radiography with a polychromatic neutron beam

Abstract

The phase-contrast imaging is based not only on the absorption contrast like in the conventional radiography but also on the contributions of the phase shifts induced by the propagation of a coherent radiation through the investigated sample. The strong phase changes on the borders between two media can be observed as sharp intensity variations on the radiography image. So the phase-contrast method is an edge-enhancement method which allows to visualize very fine structures where the conventional radiography provides unsatisfactory results. For the aims of the phase-contrast imaging a radiation with a high spatial but not necessarily chromatic coherence is required. In this way phase-contrast radiography experiments with a polychromatic thermal neutron beam possessing a high spatial transversal coherence can be performed. The reported results show that the developed phase-contrast neutron radiography can be used as a standard non-destructive investigation method.