Patent ID: 7525098

Claim:
Apparatus for detecting radiation, comprising; a multiplicity of planar detectors arranged in a stack so as to interact with photons of the radiation, each detector comprising: a semiconductor plate having first and second sides; a cathode coupled to the first side of the semiconductor plate; a plurality of anodes, which are coupled to the second side of the semiconductor plate in different respective locations and are configured to sense respective charge distributions in response to interactions of the photons with a region of the semiconductor plate in proximity to the respective locations; a cathode detector circuit, which is coupled to the cathode and is configured to output a timing pulse in response to each of the interactions; respective anode detector circuits, which are coupled to the anodes and are configured to output respective charge signals in response to the sensed charge distributions; and readout circuitry, which is coupled to receive the timing pulse from each cathode detector circuit, and which is configured, in response to receiving the timing pulse from the cathode detector circuit of any of the detectors, to receive the respective charge signals that are output by the anode detector circuits of all the detectors within a preset time period following receiving the timing pulse, and to output a signal indicative of an energy distribution of the interactions in response to the received output charge signals.