基于THz反射光谱的混合炸药中DNMT含量分析

DNMT content detection in mixed explosives based on THz reflectance spectroscopy

为了快速地求解混合炸药中DNMT的含量,设计了一种基于反射型太赫兹(THz)光谱分析的检测系统。系统采用步进电机控制动镜获得大光程扫描范围,将照射在被测粉末上的回波漫反射光和本振光信号做相干处理,从而得到反射吸收光谱数据,由此反演被测粉末中DNMT的含量。推导DNMT含量求解表达式,给出提高反射式DNMT含量检测稳定性的滤波算法及提取要求。实验采用TeraTune型THz激光器配合DSTMS-1型THz探测器完成数据采集,对多组已知DNMT含量的混合样品进行测试,测试结果与TeraSys 4000型THz光谱分析仪作对比。实验结果显示,两种方法均可快速获取样品中DNMT含量,并且测量误低于3.0%。在采用本系统的光谱预处理方法后,在样品混合物种类增多的条件下仍具有较好的测试效果,具有较高的抗干扰能力。

In order to quickly calculate the content of DNMT in mixed explosives,the detection system for content is designed based on the terahertz （THz） reflective spectroscopy.In the system,stepper motor contr ols the movement of lens to obtain the large scanning range of the optical path ,and coherent effects are produced between echo reflected light irradiated on th e measured powder and local oscillator light.The content expression of DNMT is derived,and the filtering algorithm and extract requests are given for increasing the stability of reflective type detection method for DNMT.In the experiment,TeraTune type THz laser and DSTMS-1type THz detectors were used for data acquisition.Multiple sets of mixed samples with known DNMT content were tested by the system.Test results were compared with those of the TeraSys 4000type THz spectrum ana lyzer. Experimental results show that both methods quickly get samples DNMT content and test accuracy is better than 3.0%.When the pretreatment method of spectrum is used with more types in the sample mixture,i t still has good test results,with high anti-jamming capability.