Grazing-incidence hyperboloid-hyperboloid designs for wide-field x-ray imaging applications
Abbreviated Journal Title
INCIDENCE TELESCOPES; I TELESCOPE; ABERRATIONS; PERFORMANCE; ASTRONOMY; Optics
The classical Welter type I grazing-incidence x-ray telescope consists of a paraboloidal primary mirror and a confocal hyperboloidal secondary mirror. This design exhibits stigmatic imaging on-axis hut suffers from coma, astigmatism, field curvature, and higher-order aberrations such as oblique spherical aberration. Wolter-Schwarzschild designs have been developed that strictly satisfy the Abbe sine condition and thus exhibit no spherical aberration or coma. However, for wide-field applications such as the solar x-ray imager (SXI), there is little merit in a design with stigmatic imaging on-axis. Instead, one needs to optimize some area-weighted-average measure of resolution over the desired operational field of view. This has traditionally been accomplished by mere despacing of the focal plane of the classical Welter type I telescope. Here we present and evaluate in detail a family of hyperboloid-hyperboloid grazing-incidence x-ray telescope designs whose wide-field performance is much improved over that of an optimally despaced Welter type I and even somewhat improved over that of an optimally despaced Wolter-Schwarzschild design. (C) 2001 Optical Society of America OCIS codes: 340.7440, 340.7470, 220.1000, 220.2740.
"Grazing-incidence hyperboloid-hyperboloid designs for wide-field x-ray imaging applications" (2001). Faculty Bibliography 2000s. 8022.