Patent ID: 7528377

Claim:
Apparatus for detecting radiation, comprising: a detector which is configured to generate electrical charges responsive to incidence of a photon thereon; a plurality of detector circuits coupled to the detector at different respective locations, each circuit comprising: an amplifier which is configured to generate a pulse in response to the charges; a first pulse shaper, having a first time constant, which is configured to produce a metric representative of an energy of the pulse; a second pulse shaper, having a second time constant greater than the first time constant, which is configured to produce an indication that the metric is representative of an energy of the photon; and a summing device which is coupled to sum the metric of each of the detector circuits in response to the respective indication, wherein each detector circuit comprises comparator circuitry which is configured to generate a ratio relating the metric to the indication, and to generate a summing trigger in response to the ratio, and wherein the apparatus further comprises a coincidence verifier circuit which receives each summing trigger and in response provides a coincidence signal, representative of coincidence between each pulse, to the summing device, so as to cause the device to sum.