The hard X-ray response of the XIS-CCD for Astro-E: qualification of the X-ray CCD detector

We report on the hard X-ray response of the CCD detector for the X-ray imag ing spectrometer (XIS), to be launched on the next Japanese X-ray Astronomi cal Satellite, ASTRO-E, in February 2000. XIS is prepared by an internation al team, comprised of MIT (USA), ISAS, Osaka University and Kyoto Universit y (JAPAN). We have evaluated the X-ray response of the XIS in its high-ener gy band (1.5-10 keV). Data from the fluorescent line emission of Al, Cl, Ti , Ni, Fe, Zn, Se were used to construct the response function of the CCD de tectors. Details of the response function - including the energy-scale, lin earity, energy resolution, quantum efficiency -, are given as a function of incident X-ray energy. We find that the tail component of high-energy phot opeaks are produced by events with incomplete charge collection. We also co nclude that the size of the charge clouds can be estimated using the shapes of the tail components. (C) 1999 Elsevier Science B.V. All rights reserved .