A Neutron-Gamma Method and Apparatus for Detection and Identification of Hidden Objects in Brick (Concrete) Walls

Abstract

When considering problems of fighting terrorism, it may be of interest to imagine a situation when explosive materials or mines are hidden inside walls of buildings, pillars, piers and other barrier-type constructions made of materials like bricks and concrete. When the barrier can be accessed only from one side, detection of objects hidden inside it becomes similar to detection of land mines. Various techniques have been proposed to detect and identify explosives buried in soil. Most of them use penetrating radiation having qualitatively different characteristics of interaction with components of explosives and surrounding materials. The source of primary radiation and the detector are placed on the same side of the barrier and scattered primary or secondary radiation is registered. The most frequently used sources of primary radiation are sources of neutron, γ-rays and electromagnetic waves. An apparatus of this type makes it possible to detect foreign objects in soil and some of them (mainly those using neutron sources) are able to identify hidden materials by their elemental composition.