<title>Development of a balloonborne hard x-ray telescope using a Pt/C multilayer supermirror</title>

Abstract

High sensitivity hard X-ray data by means of focusing optics is crucially important to investigate active galaxies and cluster of galaxies. We have developed focusing telescopes with platinum-carbon multilayer coatings. The energy band is broadened by multilayers with graded periodic length, so called `Supermirrors'. We were successful to obtain hard X- ray images in the energy band from 25 to 40 keV with a demonstration model of telescope with 20 mirror shells of supermirrors. The flight model of supermirror telescope is now in production for balloon flight in the summer of 2000. The current status of the balloon mission and future application of supermirror technology is discussed.