环氧丙烷爆燃转爆轰过程的瞬态发射光谱

Instantaneous Emission Spectra of Epoxypropane in the Process of Deflagration to Detonation Transition

采用爆光时间最短可达 5ns ,且具有像增强功能的光谱探测仪器ICCD ,用自行研制的光电转换器将光触发信号转变为电脉冲去外触发DG5 35数字延迟发生器 ,由DG5 35在设定的延迟时间后开启探测器快门并控制其曝光时间 ,从而使被测光信号与快门的打开达到同步 ,用芯径 1mm的塑料光纤从爆炸激波管端窗引出被测光信号至光谱仪色散后到达ICCD ,直接对环氧丙烷爆燃转爆轰 (DDT)的动态变化过程进行了实时光谱测量 ,拍摄到了环氧丙烷DDT过程不同时刻的、曝光时间为微秒量级的瞬态发射光谱。结果显示 ,在DDT初始阶段光辐射很弱 ,主要是原子线状光谱 ;在DDT中间阶段辐射已比较强 ,既有原子线状光谱 ,也有分子带状光谱以及热辐射背景 ;达到爆轰时光辐射强度呈数量级增加 ,原子线状谱、分子带状谱叠加在热辐射背景之上。

Using an intensified CCD spectroscopic detector (Princeton Instruments, ICCD PI-Max 1024 RB) which can be gated in as little as 5 ns, the synchronization of the measuring system was controlled by a digital delay generator (Stanford Research Systems, DG535), the DG535 was triggered externally by a lab-made electrical pulse generator which transformed the optical trigger signal to an electrical signal, and the light signal from the end window of an explosion shock tube was delivered by an I mm in diameter plastic optical fiber to the entrance slit of the spectrometer (grating of 150 g(.) mm(-1), central wavelength of 550 run). The spectrum measurement of the epoxypropane in the process of deflagration to detonation transition (DDT) was then made. The instantaneous emission spectra of epoxypropane at different time of the DDT process with an exposure time of several microseconds were acquired. Results show that at the beginning of the DDT process, the emitted light was very weak and the line spectra of atoms were observed mainly; in the middle process of the DDT, the emitted light became strong and the spectra observed consisted of line spectra of atoms, band spectra of molecules plus continuous spectrum of the thermal radiation; when the detonation was formed, the emitted light got very strong, and the spectra acquired consisted of both line spectra of atoms and band spectra of molecules superimposed on the strong continuum of the thermal radiation.