Silicon carbide (SiC) mirrors for lightweight x-ray optics

Abstract

Future x-ray space missions will require high throughput x- ray telescopes with angular resolution of the order of tens arcsec and large effective area. Nowadays the most used technology to obtain thin and light mirror shells is the replica technique by nickel electroforming. This technology has been successfully employed for projects like SAX, JET-X, XMM and ABRIXAS. Nevertheless the high density of the nickel poses some limitations to the possibility of extending the use of this technology for future x-ray space missions. In this respect the use of ceramic materials like silicon carbide and alumina for the manufacturing of x-ray optics appears to be an attractive technology. In the paper we review possible processes for manufacturing x-ray mirror shells using silicon carbide ceramic material and we report the result of an on-going activity aimed to verify the performances of these new technologies in the context of the wide angle x-ray survey project. This is a small satellite mission aimed to survey a large part of the sky in the x-ray band. The project is being developed as a feasibility study in the frame of the Agenzia Spaziale Italiana program for small-medium satellite missions.