Nuclear resonance fluorescence measurements of high explosives

Pacific Northwest National Laboratory and Passport Systems have collaborated to perform nuclear resonance fluorescence (NRF) experiments using several high quality high-explosive simulant samples. These measurements were conducted to determine the feasibility of finding and characterizing high explosive material by NRF interrogation. Bremstrahlung photon beams, produced from electron beams of 5.1, 5.3, 8.3, 9 and 10 MeV, irradiated the samples. Gamma-rays emitted from the samples were detected using high-purity germanium detectors. Nitrogen-to-carbon ratios of the high-explosive simulants were extracted from the 5.1 and 5.3 MeV data and compare favorably with accepted values. Analysis of the 8, 9 and 10 MeV data is in progress; preliminary isotopic comparisons within the samples are consistent with the expected results.