摘要
It is challenging to measure the electron density of the unsteady plasma formed by charged particles generated from explosions in the air,because it is transient and on a microsecond time scale.In this study,the time-varying electron density of the plasma generated from a small cylindrical cyclotrimethylenetrinitramine(RDX)explosion in air was measured,based on the principle of microwave Rayleigh scattering.It was found that the evolution of the electron density is related to the diffusion of the detonation products.The application of the Rayleigh microwave scattering principle is an attempt to estimate the electron density in explosively generated plasma.Using the equivalent radius and length of the detonation products in the bright areas of images taken by a high-speed framing camera,the electron density was determined to be of the order of 10^(20)m^(−3).The delay time between the initiation time and the start of variation in the electron-density curve was 2.77–6.93μs.In the time-varying Rayleigh microwave scattering signal curve of the explosively generated plasma,the electron density had two fluctuation processes.The durations of the first stage and the second stage were 11.32μs and 19.20μs,respectively.Both fluctuation processes increased rapidly to a peak value and then rapidly attenuated with time.This revealed the movement characteristics of the charged particles during the explosion.
作者
Hong CHEN
Xuchao PAN
Yong HE
Junjie JIAO
Jie SHEN
Chi BEN
陈鸿;潘绪超;何勇;焦俊杰;沈杰;贲驰(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,People’s Republic of China;China North Industries Group Corporation,Beijing 100053,People’s Republic of China)
基金
supported by National Natural Science Foundation of China(Nos.11502118,11504173).
