A 252Cf neutron transmission technique for bulk detection of explosives

A 252Cf fast-neutron transmission method for bulk detection of nitrogen-rich explosives, concealed in passenger luggage, is presented. The technique utilizes the cross-section resonances of two elements dominant in explosives (nitrogen and oxygen). These resonances are portrayed in the pulse-height distribution of transmitted neutrons measured with a helium-3 detector. Monte Carlo simulations are used to support the theoretical concept of the method. The feasibility of the technique is demonstrated in the laboratory employing an explosive-like material (nitrogen-rich fertilizer).