X-ray microscopy

Abstract

The subject of X-ray microscopy (high-resolution X-ray imaging of general nonperiodic structures), an area in which much progress has been made in recent years, is reviewed. The main techniques are briefly described. Achievable performance levels, which for many years were highly speculative, can now be understood with fair accuracy in terms of basic X-ray and specimen properties, and techniques have progressed to the point where actual results are nearing those levels. In terms of specimen size and imaging resolution, X-ray microscopies lie between electron and light microscopy, and are thus suited to imaging extremely large and complex structures; in addition, they demand little or no specimen preparation, and can be used to observe local composition and chemical state as well as structure. Thus X-rays, which have played the leading role in imaging crystallizable materials, may also prove to be highly valuable in the imaging of very large non-crystalline structures. Throughout the treatment, attention is paid to the relationships connecting the subject with X-ray crystallography.

Scanning Transmission X-Ray Microscopy: A New Method for the Investigation of Aggregation in Silica

“…microfabrication that now permit zone plates as diffractive Many general aspects of X-ray microscopy and especially focusing elements to be produced and the development of a discussion of physical backgrounds can be found in a high-brilliance synchrotron radiation sources have led to the recent lead article in Acta Crystallographica by Sayre and recent resurgence of interest in X-ray microscopy at soft XChapman (20).…”

High-resolution ab initio three-dimensional x-ray diffraction microscopy

“…This object scattering function may be decomposed into a Fourier representation of 3D spatial frequencies u, with complex amplitudes (1) in which spatial frequency can be thought of as a volume grating. In the case of coherent diffraction imaging a plane wave with wave-vector k in is incident on the object and the intensity of the scattered field in the direction of the wave-vector k out is measured on a 2D pixellated detector (e.g.…”

Dose efficient Compton X-ray microscopy

“…1(a) indicates the dominant interaction for low-Z materials is actually Compton scattering [27], which is usually considered as a noise-producing background in any coherent imaging arrangement. By comparing the cross sections of photoabsorption, coherent scattering, and Compton scattering as a function of photon energy for light elements [28], it is clear that an incoherent microscope based on the latter interaction has the potential for providing much higher imaging signal per dose than is possible with coherent scattering, for samples much thicker than can be imaged by absorption contrast in the water window.…”