METHOD FOR THE RADIATION MONITORING OF MOVING OBJECTS AND A RADIATION PORTAL MONITOR FOR CARRYING OUT SAID METHOD

The invention relates to radiation monitoring and can be used for detecting radioactive materials during the unauthorized movement thereof. The method involves registering background gamma quanta and detecting a monitored object in a monitoring zone when the registered gamma radiation exceeds the background radiation. The moment when an object arrives at a distance R from gamma radiation detectors is determined and the moment when the object moves away from the gamma radiation detectors to a distance Rγ is determined. The gamma quanta are registered from the moment when the object arrives at the given distance R from the gamma radiation detectors to the moment when the object moves away from the gamma radiation detectors to the distance Rγ. R =(0.8−1.2)(H+D) and Rγ=(0.8−1.2)(H+D), where H is the height of the horizontal plane that is the plane of symmetry of the position of the gamma radiation detectors; and D is half the distance between two gamma radiation detectors mounted at the same height. The monitor comprises the following components accommodated in a twin-post portal: a controller with a signaling unit, gamma radiation detectors with amplifiers and analog-to-digital converters, an object detection sensor based on an ultrasonic oscillation source and an ultrasonic oscillation receiver, a detection signal amplifier, a detector, a smoothing filter and an object detection and distance recording unit. The invention makes it possible to decrease the smallest detectable mass of radioactive material.