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 10²⁰ m⁻³. The delay time between the initiation time and the start of variation in the electron-density curve was 2.77–6.93 μs. 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 11.32 μs and 19.20 μs, 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.

测量由空气中爆炸产生的带电粒子形成的不稳定等离子体的电子密度具有挑战性，因为它是瞬态的，时间尺度为微秒。在这项研究中，基于微波瑞利散射原理，测量了空气中小型圆柱形环三亚甲基三硝胺 (RDX) 爆炸产生的等离子体的时变电子密度。发现电子密度的演变与爆轰产物的扩散有关。瑞利微波散射原理的应用是尝试估计爆炸产生的等离子体中的电子密度。利用高速分幅相机拍摄的图像亮区中爆轰产物的等效半径和长度，²⁰ m ^-3。启动时间和在电子密度曲线变化的开始之间的延迟时间为2.77-6.93 μ秒。在爆炸产生的等离子体的时变瑞利微波散射信号曲线中，电子密度有两个波动过程。第一阶段和第二阶段的持续时间分别为11.32 μ秒和19.20 μ S，分别。两种波动过程都迅速增加到峰值，然后随时间迅速衰减。这揭示了带电粒子在爆炸过程中的运动特性。