Development of neutron interrogation techniques for concealed substances detection in port containers

Abstract

This work is aimed at contributing to the effort of nations seeking to control international borders movement of dangerous chemical substances and nuclear material, in accordance with a multitude of agreements signed to that purpose. At this stage, the signature of pure substances: nitrogen (N), uranium (U), chlorine (Cl), chromium (Cr), mercury (Hg), cadmium (Cd), arsenic (As) are trying to be identified and later, to detect their presence in simulated large cargo containers. The technique employed consists in the detection of prompt and early decay gammas induced by incident thermal, epithermal or fast neutrons in the cargo array. Uranium has also been detected through the counting of fast neutrons originated in induced fissions.