Front- and Back-illuminated X-ray CCD Performance in Low-and High-Earth Orbit: Performance trends of Suzaku XIS and Chandra ACIS Detectors

摘要

Since the launch of the Suzaku X-ray astronomy satellite into low- earth orbit in July, 2005, the performance of the CCD detectors in the X-ray Imaging Spectrometer (XIS) detectors have slowly degraded, as expected, due to accumulating radiation damage. We compare the evolution of front- and back-illuminated XIS CCDs with one another and with that of very similar detectors installed in the ACIS instrument aboard the Chandra X-ray Observatory, which is in a much higher orbit than Suzaku. We attempt to identify effects of the differing radiation environments as well as those arising from structural differences between the two types of detector.