Study On Shock Wave Characteristics Of Laser Plasma Shielding

In the process of explosion,shock wave will be generated,which acts on buildings or human body with overpressure,and has strong destructive effect and even endangers people's lives.Therefore,Shockwave shielding research has obvious value.So far,researchers have carried out extensive research on the expansion dynamics of laser plasma shock wave and the physical process of plasma shielding shock wave,however,since the process of plasma shielding shock waves is very complicated.Therefore,this paper sets up the equipment needed for the experiment to discuss the propagation characteristics of the shock wave.The introduction introduces the relevant knowledge and research status of shock wave,which supports further research.Experimental study on its expansion characteristics was carried out.Firstly,based on the optical shadow imaging method,the expansion shadow image of the air shock wave was obtained.And then adjust energy and delay time to observe its evolution,and its expansion dynamic characteristics were obtained.Secondly,based on optical imaging method,shadow of aluminum plasma shock wave expansion process were studied,by changing the spacing between the cylindrical lens and the target material and parameters such as laser power,analysis of evolution process,its dynamic characteristics,and based on the spectral method according to the time-resolved spectrum of Al plasma shock wave,its spatiotemporal variability characteristics were obtained.Finally,the expansion evolution process of the interaction between the plasma wall and the air shock wave is observed,the influencing factors of the air shock wave being shielded by the plasma are obtained,and the physical mechanism was discussed.By adjusting the energy of the aluminum and the air shock wave and the location of it to the aluminum,it was found that the shielding effect of air shock wave by plasma wall was more obvious when the energy of the two shock wave increases and the closer the center of air shock wave was to the target material.Based on spectral method to analyze the presence of shielding effect other aluminum plasma spectrum changing with time delay distribution,found that delay in 3000 ns spectral intensity of aluminum plasma with shielding was greater than that without shielding,at the same time describes the presence of shielding relation between electron temperature and electron density,found the electron density was the biggest when the front of the shock wave disappeared completely,the aluminum plasma body can top.So as to better block the propagation of the shock wave.In this paper,the evolution process of plasma shielding shock wave was analyzed,which was of great value to reduce the danger of shock wave diffusion caused by explosion.