Tagged Neutron Method Analysis: A Technique for Explosives Detection and Identification

Abstract

A laboratory prototype of the device for detection and identification of explosives hidden in luggage has been investigated. The device is based on the Tagged Neutron Method (TNM) by using D-T neutron generator. The unique advantage of the TNM method is to provide the image of the hidden object in three-dimension. At the same time, a large signal-to-background ratio provided by the TNM method significantly facilitates the identification of the hidden substances. The method of spectra analysis in our device is based on sequential analysis. In statistics, sequential analysis is statistical analysis where the sample size is not fixed in advance. Instead data is evaluated as it is collected, and further sampling is stopped in accordance with a predefined stopping rule as soon as significant results are observed. Thus a conclusion may sometimes be reached at a much earlier stage than would be possible with more classical hypothesis testing or estimation. It has been shown that explosive simulants of TNT and ammonium nitrate (300 g, respectively) shielded by 5 cm of dry milk powder or washing powder can be detected within 3 min. The type of explosives (TNT or ammonium nitrate) can be identified within 10 min.