【摘要】 地面超高速模拟实验是研究微小空间碎片撞击效应经济有效的手段,其中等离子体加速器为微米量级碎片的主要地面模拟设备。本文研制了在等离子体驱动微小碎片加速器系统并应用于高速飞行微粒速度测量的激光测速系统。该激光测速系统工作原理是,利用主动激光照明,在颗粒飞行路径上形成光墙,通过检测颗粒通过光墙形成的散射激光,得到微粒到达光墙的时间,利用飞行时间法进行高速微粒速度测量。在激光测速系统原理测试实验中,采用信号响应上升时间小于10ns,电子渡越时间小于20ns的高灵敏、快响应的光电倍增管,原理试验测得该探测系统的响应时间仅为约70ns。该响应时间小于速度为15km/s的颗粒通过3～5mm厚度的片状激光束的理论时间,并验证了该系统灵敏度高、响应时间快的特点,可以满足超高速微粒(8～20km/s)通过3～5mm激光墙的时间阈值(约0.1μs)的需求。目前,激光测速系统已经应用于等离子体加速器发射超高速微粒的试验中,能有效测量等离子体加速器所发射的高速微粒的群速度,对15km/s及以上速度的超高速颗粒亦能捕捉到有效信号,实现对微粒速度的测量,达到了良好的预期效果。在等离子体微小碎片加速器上开展的超高速撞击试验中,激光测速系统能够实现无损在线速度测量,对等离子体加速器上开展的超高速撞击试验提供了重要帮助。更多还原

【Abstract】 Simulation of hypervelocity impact experiment on ground is an economical and effective method to investigate small space debris impact effect,with plasma accelerator as the main simulation equipment for testing small space debris on ground.The development and applications of plasma drag small particle acceleration laser velocity measurement system for hypervelocity small particle are presented in this paper.Laser is used to form a light sheet on the flight path of particles and photoelectric cell is used to detect scattering light of the laser sheet when particles passthrough the laser sheet,in this way the time that the particles arriving at the laser sheet is detected and the flight of time method can be used to measure the particle velocity.In the laser velocity measurement system a high sensitivity fast response photomultiplier tube with single up -response time less than 10 ns and electron spread time less than 20 ns is used,and it is shown that the response time of the laser velocity measurement system is about 70 ns,which is less than the time taking by the particle with velocity of 15 km/s passing through the 3～5 mm thick laser sheet,showing that this system has a very high sensitivity and a fast response to meet with the requirement of the threshold time(about 0.1 μs) for hypervelocity particle(8～20 km/s) passing through 3～5 mm laser sheet.The laser velocity measurement system has been used in the plasma accelerator for small particles experiment and the system can effectively measure the group velocity of high speed particles with velocity greater than 15 km/s.In the hypervelocity impact experiment carried out on the plasma accelerator,the laser velocity measurement system can measure online velocity without damage.更多还原