X-ray collimator, particularly for use in computerized axial tomography apparatus

An x-ray collimator for use in computerized axial tomography apparatus includes a plurality of substantially parallel x-ray absorbing laminae disposed in the plane of a wedge-shaped x-ray beam. The length and position of each lamina with respect to a divergent x-ray source is chosen to maximize the ratio of x-ray flux impinging upon a detector array to flux falling within the collimator's penumbra, outside the detector array. A single set of moveable jaws may be disposed at the collimator exit for adjustment of the beam thickness