Simbol-X: x-ray baffle for stray-light reduction

Abstract

Simbol-X, an hard X-ray mission proposed by a consortium of European laboratories, will operate on a broad energy range (0.570 keV) providing a large collecting area ( ~ 1500 cm² at 1.5 keV and ~ 450 cm² at 30 keV) and a good imaging capability over the entire energy range. Relying on two spacecrafts in a formation flight configuration, Simbol-X will use, for the first time, a 20 meters focal length X-ray concentrator with multilayers coated mirrors that efficiently focalize photons above 10 keV and enhance the sensitivity up to 70 keV. Thanks to a ray-tracing code, we simulated the Simbol-X optics performance and investigated the contamination at the focal plane caused by stray−light from diffuse cosmic X-ray background. A dedicated X-ray baffle is mandatory to minimize this contamination that otherwise, would strongly affect the telescope sensitivity. In this paper we investigate different X-ray baffle designs and show their efficiency in reducing the stray−light.