Fourier transform microscope for x-ray and/or gamma-ray imaging

Abstract

A Fourier transform microscope for use in imaging a source of x-ray and/or gamma-ray radiation includes first and second grids arranged in proximity to the source. The first grid includes an arrangement of first subgrids elements with a first predetermined number n of approximately parallel, equally-spaced linear first ribs which are opaque to the radiation of interest, and first radiation-transparent regions which are arranged in alternation with the first ribs. The second grid includes an arrangement of second subgrids elements which are larger than the first subgrids elements, and which have a common field of view with corresponding first subgrid elements. Each second subgrid element has a second predetermined number n+m of approximately parallel, equally-spaced linear second ribs which are opaque to the radiation of interest, and second radiation-transparent regions which alternate with the second ribs. Each first subgrid element and its corresponding second subgrid element is termed a `subgrid system`. Each subgrid system can be used to derive an amplitude and phase of an associated Fourier component. A position-sensitive detector detects a Moire or fringe pattern from wach subgrid system and generates a signal indicative of the radiation intensity distribution image of the source in spatial frequency domain which can be converted into a radiation intensity distribution image of the source in spatial domain using a Fourier transform.