A 3D measuring method of magnetic properties of impact-generated plasmas

At present, there are several ways to measure the magnetic properties of plasmas during hypervelocity impact. In this paper, we compare and analyze the merits and demerits of these methods. Then a novel technique, christened a spherical three-dimensional coil group (STDCG), is proposed, whose design principles and specific parameters are introduced. In the hypervelocity experiments, spherical aluminum projectiles (AA 2024) have been accelerated by a two-stage light gas gun to impact aluminum plates (AA 2024) at velocities from 4.2 to 6.2 km s ^-1 , where the disk coil, the Rogowski coil and the STDCG are applied separately to detect the induced magnetic field. The results demonstrate that the magnetic properties of hypervelocity-impact-generated plasmas show temporal and spatial regularity, depending on the angle and distance of the coils.