Ghost image behavior in Wolter type I x-ray telescopes

Abstract

In Wolter type I grazing incidence telescopes, ghost images result whenever unreflected xrays or singly reflected x rays pass through the telescope and impinge on the focal plane. These ghost images degrade imagequality and can bo eliminated by appropriately positioned stops and baffles. However, conflicting demandsbe placed on an aperture design by requirements for field of view, vignetting, and ghost image control. These problems are particularly severe for high energy x-ray telescopes which require very small grazing angles of incidence. We have developed and used analytical and numerical tools to perform parametric analyses of ghost image behavior and to obtain an aperture plate design capability that can, be utilized to satisfy specific ghost image requirements.