FABRICATION OF Pt/C MULTILAYER-COATED THIN FOIL MIRRORS FOR HARD X-RAY TELESCOPE LOADED IN ASTRO-H SATELLITE

摘要

Next-generation hard X-ray telescopes require highly nested aspherical thin mirrors of 100 nm shape accuracy and less than 0.3 nm rms surface roughness. These telescopes arernconstructed using nested multiple grazing incidence reflecting mirrors consisting of a paraboloid and hyperboloid of revolution. Over two hundred Pt/C multilayer-coated mirrors of different sizes are required. Thin mirror substrates or shells are fabricated by replication from molding dies of high precision. Thus, a machining apparatus that enables the accurate and rapid machining of large aspherical molding dies is necessary. We describe a large ultra-precision single-point diamond turning, polishing and measuring machine for fabricating aspherical molding dies of high precision, which can be applied to next-generation hard X-ray telescope mirrors. We also describe the Pt/C coated thin foil mirrors replicated from the aspherical molding dies.