Development Of An Optically Recording Velocity Interferometer System For Free-surface Measurement In Laser Induced Shockwave Experiments

With the development of laser technolgy, laser has become a primary means to the research of the equation fo state(EOS) in laboratory. But the Shockwave produced by laser is a high-velocity process, the time that the shockware exists is very short, and is about several nanosecond or shorter. So the diagnosis method become a very important part in the research of EOS.Laser velocity interferometer technique has been rapidly developped during the past several decades. It has become an important means to measure free-surface velocity or particle velocity. Recently, a more advanced equipment was developped to measure free-surface velocity or particle velocity. It is called "Optically Recording Velocity Interferometer System(ORVIS)" , and its best time resolution reachs tens of picoseconds. Laser velocity interferometer technique is an untouched means of measure, and can record the velocity change of the free surface velocity continuously. In this paper, an ORVIS are established, and it will be used in laser induced Shockwave experiments. Its time resolusion can vary from tens of picoseconds to hundreds of picoseconds.In chapter 1, a brief background introduction is given firstly. Then, the main function of ORVIS in EOS experiments is explained. The development history of ORVIS and the using of ORVIS at home and abroad are introduced. At last,the necessities of ORVIS are analyzed.In chapter 2, the basic principle of the laser velocity interferometer is introduced.In chapter 3, the basic structure of ORVIS and the formula of ORVIS are analyzed in detail.In chapter 4, an 1-D hydrodynamic code-Hyades is utilized to simulate shocks in a certain condition. This can provide some reference to the succedent experiments.In chapter 5, It is the main part of this paper. The design of ORVIS is explained in detail,some embedded analyse is done in this part. We redesign the new input system and the interferometer system with good performance.We bring forward several methods tosolve the problem of fringe-lost.In chapter 6, a new ORVIS with the spatial resolution is analyzed.After the establishment of the ORVIS, it will be using in EOS experiments gradually.