Soft x-ray resolution and scientific performance of CCD sensors for future x-ray missions

Future mega-pixel imaging x-ray detectors will require excellent spectral response at soft (E<1keV) x-ray energies while operating at fast frame-rates. We have characterized the sub-keV spectral resolution of two low-noise MIT Lincoln Laboratory CCDs in detail. These devices are identical in format but differ in gate structure and output stage design. We report measurements of the shape of the spectral redistribution function as a function of energy for each of these sensor types and compare our measurements with theoretical expectations. We also assess the implications of the observed response functions for scientific performance in deep x-ray imaging and high-resolution spectroscopy applications.