Inspecting the minefield and residual explosives by fast neutron activation method

As an upgrade of a robotic mobile system for antipersonnel landmine clearance, a fast neutron probe has been considered for the detection of mines and explosive residues. Laboratory tests were made by using the 14 MeV 6×107 neutrons/sec beam with the associated alpha particle detection and with a LaBr3 gamma ray detector. Simulant of the anti-personal mine was used as a target. Several measurements were made with the target buried into the soil at different depths. For each depth minimal time measurement was estimated for false negative 0.4 % and false positive equal to 10 %. Tests showed that is possible to detect buried landmine as well as residual explosives; however, in order to reach the optimal speed of 10 cm/s for demining vehicle it is necessarily to use several sealed tube neutron generators and few tens of LaBr3 gamma ray detectors.