Velocity Analysis of Supersonic Jet Flow in Double-Cone Ignition Scheme

Abstract In the double-cone ignition schemes (DCIS), the deuterium-tritium target shell is ablated and compressed by a high-power nanosecond laser in u-cones to generate plasmas. Under the actions of spherical symmetric compression and acceleration along the Au cone, they will be ejected out of the cone mouth and collide with each other. The plasmas witness conversion from kinetic energy to internal energy at the vertex of the geometric center of two Au cones that are symmetric to each other, because of which, fusion high-density plasmas are preheated. This key physical process has undergone experimental verification on the Shenguang-II upgraded facility of China. Apparently, the improvement and optimization of the velocity of plasmas in hypersonic jet flow at the cone mouth are crucial for the success of DCIS. In the DCI-R7 experiment for the Shenguang-II upgraded facility, a velocity yield of approximately 130-260 km/s was achieved for the plasmas at the cone mouth, with a result of nearly 300 km/s based on numerical simulation. In this paper, theoretical analysis is performed as regards the process, in which target shells are ablated and compressed by laser to generate high-velocity plasmas ejected through jet flow. Based on this analysis, the formula for the velocity of plasmas in supersonic jet flow at the cone mouth is proposed. This study also provides measures that are more effective for improving the kinetic energy of plasmas and optimizing energy conversion efficiency, which can serve as theoretical references for the adjustment and optimization of processes in subsequent experiments.