Development of an imaging performance criterion for wide-field grazing incidence x-ray telescopes

摘要

Abstract: For staring, wide-field applications, such as a solar x-ray imager, the severe off-axis aberrations of the classical Wolter Type-I grazing incidence x-ray telescope design drastically limits the 'resolution'. Since surface scattering effects from residual optical fabrication errors are always substantial at these very short wavelengths, the field-weighted-average half-power radius is a far more appropriate measure of aerial resolution. If an ideal mosaic detector array is being used in the focal plane, the finite pixel size provides a practical limit to this system performance. Thus, the total number of aerial resolution elements enclosed by the operational field-of-view, expressed as a percentage of the number of ideal detector pixels, is a further improved image quality criterion. In this paper we describe the development of an image quality criterion for wide-field applications of grazing incidence x-ray telescopes which leads to a new class of grazing incidence designs described in a following companion paper. !16