A flag-based algorithm and associated neutron interrogation system for the detection of explosives in sea–land cargo containers

Recent efforts in the simulation of sea–land cargo containers in active neutron interrogation scenarios resulted in the identification of several flags indicating the presence of conventional explosives. These flags, defined by specific mathematical manipulations of the neutron and photon spectra, have been combined into a detection algorithm for screening cargo containers at international borders and seaports. The detection algorithm's steps include classifying the cargo type, identifying containers filled with explosives, triggering in the presence of concealed explosives, and minimizing the number of false positives due to cargo heterogeneity. The algorithm has been implemented in a system that includes both neutron and photon detectors. This system will take about 10min to scan a container and cost approximately $1M to construct. Dose calculations resulted in estimates of less than 0.5mSv for a person hidden in the container, and an operator annual dose of less than 0.9mSv. •Monte Carlo model of explosives screening in cargo containers using fast neutrons.•Monte Carlo model also explores neutron detector response.•Development of an explosives detection algorithm using active neutron interrogation.•Implementation of the algorithm, including equipment, infrastructure, cost and dose.•System will cost ~1M USD and an entire container may be scanned in ~10min.