Energy and time response of CCD X-ray detectors

An analysis of X-ray signal charge collection in charge coupled device (CCD) detectors used for X-ray imaging spectroscopy is described. The physics of X-ray signal charge collection are briefly described, and models are compared with experimental data. The implications for event recognition techniques are addressed. It was demonstrated that for the photon counting modes, the serial readout nature of the CCD pixels places a constraint on time resolution and/or count rate capability. However the methods of clocking CCDs are shown to be very flexible, and can offer a range of operating modes that enhance these performance aspects. It is shown that splitting of charge between pixels can be recognized, and a tradeoff between energy resolution and detection efficiency can be performed for some applications. However, this charge splitting places a constraint on the count rate limits attainable. These limits are discussed for a number of readout modes, including integrating count applications