Abstract:

An explosive detection system based on nuclear quadrupole resonance (NQR) is introduced. A special excitation pulse sequence was used to excite and generate NQR signal from the ¹⁴N nuclei in the explosives. However, the amplitude of explosive NQR signal is usually too low (about 10^-8 V) to be observed reliably in natural environment. To overcome this problem, an effective multi-pulse sequence combined with small signal detecting and processing techniques was employed when building the NQR measurement system. Using the system developed, we successfully obtained the NQR signal from a 100 g RDX explosive sample at room temperature with a probetosample distance of 5 cm and an acquisition time of 5 s.

Key words: nuclear quadrupole resonance, explosive detection, RDX,  ¹⁴N nuclei