Filters for soft x-ray solar telescopes

Soft x-ray telescopes require filters that block visible and infrared light and have good soft x-ray transmission. The optical properties of possible materials are discussed and the fabrication and testing methods for the filters used in a 10 inch normal incidence telescope for λ = 63Å are described. The best performances in the λ = 44 114Å wavelengths range is obtained with foils of carbon and rhodium. © 1989 SPIE.