Study On MRT Instability In Electrical Explosion Of Planar Thin Films

As a kind of new energy,fusion has been highly anticipated by people,and Z-pinch has also attracted people's attention as a way to achieve controlled nuclear fusion.With the development of pulse power technology,the driving capacity of Z-pinch and the power of generating X-rays have been significantly improved,and a big step has been taken on the road of achieving controlled nuclear fusion.However,the rapid development of MRT instability(Magneto-Rayleigh-Taylor instability,MRT instability)will cause the sleeve to penetrate and break during the implosion process.The integrity of the sleeve affects the compression effect.Therefore,how to control the development of MRT instability is an urgent problem to be solved.We carried out an electric explosion experimental study of aluminum flat film driven by MA and 100 ns current on the "Qiangguang-I" facility at Northwest Institute of Nuclear Technology.Combined with the numerical simulation of magnetic fluid program,the effect of surface microstructure on surface MRT instability was studied.In the experiment,an out-push load structure was designed to study the experimental phenomena of planar thin film electrical explosion under different stress conditions.It was found that the wavelength of the inner MRT instability was larger than the outer side at an early stage,and the wavelengths of the late inner and outer MRT instability were almost completely coincident,but as a whole,the amplitude of the outer MRT instability was larger than the inner side.In the asymmetric thin film electrical explosion experiment,as the distance of the film from the reflow column decreases,the difference in the development of the inner and outer MRT instability increases.In the experiment,the microstructures of different sizes are also preset by etching technology on the surface of the film,and periodic unstable seeds are artificially introduced at the initial moment to regulate the natural development process of instability,thereby reducing the overall instability growth rate.Through experiments and numerical simulations,it is found that the microstructures of different sizes have different effects on the MRT instability.Through the comprehensive consideration of the instability growth rate,the regulation time of the microstructure to the instability and the control effect,it is considered that the microstructure with the wavelength of 1mm has the best regulation effect on the instability in the electric explosion.