The spatial distributions of characteristic parameters for plasma created by hypervelocity impact

Abstract

In order to better describe the spatial distributions of characteristic parameters for plasma generated by hypervelocity impact, a large number of experiments have been performed by using two-stage light gas gun loading system and measurement system of plasma characteristic parameters. Based on experimental results determining the splash process, the expanding process of the plasma cloud ejected is obtained near the impact point. For physical process of oblique collision, the expansion of plasma cloud is approximately ellipsoidal distribution. Based on expanding characteristics of plasma cloud determine the space layout of triple Langmuir probe, characteristic parameters of plasma generated by hypervelocity impact are acquired at the incidence angles of 45 ${}^{\circ }$ and 60 ${}^{\circ }$ and the impact velocities of about 3 km/s. In the paper, the ellipsoidal equations of the plasma cloud generated by collisions are determined in the three-dimensional space, and the spatial distributions of the plasma characteristic parameters are established. According to the geometric distribution established by hypervelocity impact on 2A12 aluminum plate, the rules and average expanding velocity of the plasma cloud are obtained. Furthermore, the average expanding velocity of plasma cloud increase with the decreasing of the distance from the measured point to impact point at the impact velocities of about 3 km/s and the incidence angles of 45 ${}^{\circ }$ and 60 ${}^{\circ }$ , respectively. Meanwhile, the linear relationships about impact velocities and distances from the measured point to the impact point are more stronger at the incidence angle of 60 ${}^{\circ }$ than that at the incidence angle of 45 ${}^{\circ }$ . It is of great significant to further reveal the physical process of the plasma generated by hypervelocity impact.