CCD readout for the IXO off-plane grating spectrometer

The International X-ray Observatory (IXO) project is the result of a merger between the NASA Con-X and ESA/Jaxa XEUS mission concepts. The IXO mission outline has an X-ray grating spectrometer operating in the 0.3-1 keV band. CCDs are the ideal detector for the readout of the grating spectrometer instrument and have been flown in similar functions on XMM and Chandra. Here we review the Off-Plane X-ray Grating Spectrometer concept for IXO and discuss the optimization of CCD technology for detection in the 0.2-2 keV X-ray band. We will discuss improvements to the existing technology previously flown, and the use of new technology such as electron multiplying CCDs which can provide enhanced signal to noise at these soft X-ray energies, together with radiation hardening measures and methods of reducing sensitivity to optical stray light. We will also end by discussing alternative CMOS-based technology which may be developed in future years to replace the CCD technology, offering benefits of higher system integration and radiation hardness.