Discrimination of the Explosives from Other Materials by Using the Tagged Neutron Beam

Measurements made with the 100kg of the explosive Semtex 1 a and 64.4 kg of the paper show that there is a very poor difference in the gamma ray spectra between the explosive and the paper. The nitrogen peak at 5.1 MeV is overlapped with the second escape peak from the 6.1 MeV oxygen line while the peak at the 2.3 MeV is not recognizable at all. By using the triangular diagram the way was found to separate the signature of the Semtex 1 a from that of the paper. The triangular diagram coordinates are the number of counts in carbon peak, the number of counts in oxygen peak and the number of counts in transmitted neutron peak.