Detection of Explosives Using Nuclear Quadrupole Resonance Technique

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 the14N nuclei in the explosives.However,the amplitude of explosive NQR signal is usually too low(about 10-8V) 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.