An associated particle-based inspection apparatus is described. The apparatus includes a grounded target region and a neutron generator that produces a neutron and one or more corresponding charged particles. The apparatus further includes an associated particle imaging (API) detector comprising a particle detector that detects the one or more corresponding charged particles, wherein the particle detector comprises at least one particle detector element that facilitates determining a trajectory, origination time, and a velocity of the neutron based upon a detection, by a particular one of the at least one particle detector element, of the corresponding charged particles.