<title>Characterization Of The Effects Of Scattering On Imaging X-Ray Optics Performance</title>

Abstract

A description of the performance of an X-ray imaging system can be formulated in several ways. The char-acterization can be given in terms of the point spread function (PSF), the line spread function (LSF), the modulation transfer function (MTF), or the edge spread function (ESF). While the different functions are mathematically related, they do not all emphasize the same performance features equally. In this paper we examine the character of each of the descriptions using a simple model of the telescope response which includes the effects of both figure and scattering and illustrate the conclusions using a numerical example. It is shown that the MTF and ESF are strongly affected by scattering and that the LSF and PSF are affected both by scattering and by the figure of the optics. To assess the spatial resolution of an X-ray imaging system, the PSF description is the most useful and the effects of scattering can be approximately isolated from effects due to the optical figure by using the MTF or ESF,