Analyze with fast thermal neutrons for explosives detections

Explosives contain various chemical elements such as H,C,N,O. Neutrons, because thay are not charged, have the ability to penetrate through various materials to large depths and to interact with materials nuclei. As a result of the interaction y - rays with characteristic energies are emitted. These y-rays are indicator of the chemical composition of the object being subjected to interrogation. By measuring the y-rays with a specific energy the quantity of a certain chemical element within the object can be determined. By comparison of the ratios C/N and/or C/O with the ratious of these elements with known explosives one can judge if certain object contains explosive or not. In this paper, the techniques of detection of anti-personnel mines by means of pulsed, fast and thermal neutrons, is described