Abstract: An apparatus for determining the intensity of radiation passing through an object as a set of planar beams from a radiation source is disclosed. The radiographic apparatus includes a detector array of adjoining scintillators having wall linings suitable for absorbing radiation, thereby functioning as self-colliminating detectors. The apparatus is also capable of counting the number of individual photons of primary radiation passing through an object along each path from a radiation source operating at the very high count rates used in computer-assisted tomography applications.

Abstract: Apparatus and method for the tomographic examination of planar sections of an object is disclosed which includes a plurality of sources spaced about an object at fixed intervals which emit a set of planar beams of penetrating radiation, such as X-rays or gamma rays, through a planar section of the object and a plurality of self-collimating detector arrays positioned to receive only photons of radiation which pass through the planar section of the object from the source directly opposite the array. The sources and detector arrays are mounted on a mounting apparatus to prevent movement relative to each other. Each of the detector arrays includes a plurality of self-collimating detectors which count the number of individual primary radiation photons passing through the object along the path from the source to the detector without absorption or deflection.