Imaging spectrometers for future X-ray missions

摘要

Based on the operational experience with the EPIC pn-CCD system on board of XMM-Newton [1], new imaging X-ray spectroscopic detector systems for future X-ray missions will be introduced in terms of energy, position and time resolving detectors. As the readout speed requirement in the case of single photon counting detectors increases drastically with the collecting area and improved angular resolution, but noise figures have to be on the lowest possible level, new detector schemes must be developed: Active pixel sensors (APS) for X-ray detection have the capability to randomly select areas of interest and to operate at noise levels below 1 electron (rms). About 1000 frames per second can be read out with a relatively low level of electric power with the proposed DEPFET arrays. One prominent candidate for the use of an APS is ESA's XEUS - the X-ray Evolving Universe Spectroscopy mission. It represents a potential follow-on mission to the cornerstone XMM-Newton, currently in orbit. The XEUS mission is considered as part of ESA's Horizon 2000~+ program within the context of the International Space Station (ISS).