There are a number of detection techniques for the detection of explosives, 14N nuclear quadrupole resonance (NQR) is a very promising technique owing to its unambiguous detection and identification of explosives. with this unique advantage, NQR technique gets more and more attentions around the world. Almost all of the explosives contain nitrogen element, the 14N nucleus is a non-spherically symmetric nucleus and has a quadrupole moment, the same 14N nuclei in different substances have different NQR frequencies, therefore, each substance is characterized by its own NQR frequency. So far, there have been more than 30 NQR probe nuclei, more than 10 thousands of substances have been investigated by the NQR technique and no identical NQR frequencies have been found. China Institute of Atomic Energy (CIAE) has investigated the concealed explosives detection by NQR for many years, this paper introduces the principle of 14N NQR detection, the structure of NQR detection system, and the application of NQR for the detection of explosives, mainly reviews the research activities of NQR at CIAE.
Prototype explosives-detection system based on nuclear-resonance absorption in nitrogen
