Study of Relationship between NQR Signal Amplitudes and Nitrogen Contents in Explosive Simulants

Abstract

This paper investigated the relationship of the nuclear quadrupole resonance (NQR) signal amplitudes with nitrogen contents and frequencies of explosive simulants based on the NQR explosive detection principle. The NQR signals of urea, urotropine and sodium nitrite were detected by experiment at room temperature, and the signal spectra of the nitrogenous compounds with different weights were obtained. The results indicate that the NQR signal amplitudes of the same mimic are increasing linearly with the increase of weights under the same experimental conditions, meanwhile, the higher the frequency, the greater the signal amplitude. The NQR signal amplitudes of different mimics do not rely on the nitrogen contents, but depend on the other internal factors such as relaxation times, NQR frequencies and so on. The experimental data are consistent with the theoretical predictions. The results will be of value to the detection of NQR signals in explosives and the research on how to improve the signal-to-noise ratio (SNR).