DEVICE FOR SLIT RADIOGRAPHY

摘要

An apparatus for slit radiography is provided with a slit diaphragm (2) to form a fan-shaped X-ray beam with which a body can be scanned. Controllable attenuating elements (20) interact with the slit diaphragm (2) to influence sectors of the fan-shaped X-ray beam. They are controlled by signals (12) representing the instantaneous transmission of the body in the corresponding sectors. The hardness of the fan-shaped X-ray beam is varied periodically in a predetermined manner. Synchronously with the periodic variation of the hardness of the X-ray beam the attenuating elements are oscillated. The oscillation of the attenuating elements is superimposed at each instant on the instantaneous position (20', 20'') determined by the signals representing the instantaneous body transmission. The amplitude of the oscillation is less than the height (h1) of the slit of the slit diaphragm. The influence on the X-ray beam is most at the instants at which the hardness is greatest.