Studies On Testing Methods And Properties Of The Laser Plasma Shock Wave

Testing methods and properties of the laser plasma shock wave is studied in this paper by analyzing the experimental, data simulation and theoretical result in the lit threshold , the mechanism of action between Laser-Supported Detonation Wave and component of plasma and gas with the variation of laser power densityBased on the phenomena of laser supported combustion or detonation wave occurs because of the interaction between the high-intensity laser and material, a new method is present for diagnosing the ignition threshold of laser supported detonation wave by measuring the jump of the sound peak pressure of laser-target plasma. The ignition threshold can be obtained by analyzing the jump stage between laser power density and the sound peak pressure of laser-target plasma, which generates on the surface of target due to interaction between Nd: YAG laser whose wavelength is 1064 nanometer and aluminum target. The test results are largely in accord with those form other methods。For solving the impulse coupling between laser and target, a new method of combining pendulum with light electric tachometer was presented, which was adopted in the experiment to measure the impulse of laser supported detonation wave impacting target at a series of laser power density. The target's impulse near the focal spot and the relation between impulse coupling coefficient and the laser power density were obtained. Furthermore, the experimental result was explained base on the relational theory. Considering the two direction influence between rarefaction and shock that include lateral and forward directions in the interaction between laser and target, the time scale of shock and rarefaction is founded. Furthermore, the result from the data simulation, which calculates the impulse on the target, is compared with the experimental result. Finally, the difference of specific heat ratio with variation of laser power density, the component in the shock region can be determined.These research results will provide the theoretical, numerical simulation references metal surface treatment and laser propulsion.