Physical bases of testing materials and products by induced radiation method (neutron-gamma type)

A possibility of applying detection of capture γ-radiation under neutron irradiation of an object (laminated and composite articles) for solving problems of nondestructive testing is considered. Realization of the neutron-gamma testing method is based on neutron irradiation of the investigated object and simultaneous detection with spectrometric detectors of γ-radiation of thermal neutrons capture by the corresponding elements. The effect of neutron reflector (moderator) sizes on spatial distribution of the rmal neutron flux density in the object tested are graphically presented. The results of investigation into detection of a defect at different depths of deposition at different position relatively to the measuring unit are described. It is revealed that the quasialbedo nethod based on detection of secondary capture γ-radiation in the 7-9 MeV energy range of detection ensures identification of the defect at depths up to 70 mm