Improved System for Inspecting Minefields and Residual Explosives

A next generation system, as an upgrade of a robotic mobile system for anti-personnel land mine clearance, was considered. In contrast to the first generation system where fast neutron activation method and the associated alpha particle imaging (API) was supposed to be used for finding the residual explosives and/or land mines, in the next generation system fast neutrons (FN) was considered to be used only for the confirmation of the explosive in the suspected object previously found by the ground penetrating radar (GPR), metal detector (MD) and infrared imaging (IR). Such system is expected to have the acceptable price and the optimal de-mining vehicle speed of 10 cm/s. In contrast to the previous system only one neutron generator (NG) is needed. In order to study the possibility of FN to confirm the presence of TNT explosive in the real environment the tests were made with the soil of different moisture content. Comparative study was done by using the 7.62 cm x 7.62 cm BGO and 7.62 cm x 7.62 cm LaBr₃:Ce gamma ray detectors. Although nitrogen was easily detected in larger amount of TNT explosive, its signal was weak in detection of Anti-Personal (AP) mine like DLM2.4. The presences of soil additionally diminish the possibility of nitrogen detection even in the Anti-Tank mines (AT). (authors)