Patent ID: 6169287
Filing Date: 2001-01-02
Classification: G01T

Abstract:
A method of detecting the position of x-ray or gamma-ray photons, the method comprising: providing a volume of detector material capable of absorbing the photons and generating, for each such absorbed photon, a plurality of mobile charge carriers whose average number depends on the energy of the absorbed photon; applying an electric field across the volume of detector material so that mobile charge carriers, so generated, will drift across the volume of detector material; providing a plurality of electrodes disposed over an area on a surface of the volume of detector material, toward which surface at least some of the mobile charge carriers drift, the electrodes being spaced along a line of direction X; for each electrode j, measuring a primary signal q.sub.j (t) representing the time varying charge induced in that electrode by the motion of the drifting mobile charge carriers; for one or more electrodes i, generating a secondary signal which depends on the primary signal q.sub.k (t) for at least one other electrode k; and analyzing the secondary signal to determine the photon's point of interaction along the line of direction X within the detector.