Improving the moderator geometry of an anti-personnel landmine detection system

The optimum moderating geometry using an 241Am–Be neutron source for detecting landmines has been investigated. The experimental setup composed of a Pb cylindrical shell enclosing the neutron source, embedded in a fixed-size high-density polyethylene cylinder with a variable thickness of the upper and lower moderator/reflector. According to the fact that the increased flux of thermal neutrons in the mine position yields increased prompt gamma rays, some groups of experiment have been done to measure several moderator configurations’ responses, replacing a thermal neutron detector with the landmine and counting the neutron capture events.