Multi-parameter optimization of a (3He-252Cf-3He) neutron backscattering sensor for landmine detection

Experimental measurements were carried out to optimize the performance of a (3He-252Cf-3He) assembly for plastic anti-personnel landmine detection in dry soils. This is done by employing a 252Cf source producing 0.7 × 104 n.s−1 and a pair of two identical 3He detectors. The Signal-to-background ratio due to the responses of the two 3He detectors is monitored and analyzed as a function of detector-detector distance, stand-off distance, mine depth and source position while scanning the mine. The laboratory measurements were followed by Monte Carlo simulations to explore the capabilities of the laboratory measurements in the presence of 252Cf sources producing 104n.s−1 and 106n.s−1. The optimal 252Cf source was selected and employed in further Monte Carlo simulations to study the impact of a multi-layer shield on the performance of the (3He-252Cf-3He) assembly.