The formation of reverse shocks in magnetized high energy density supersonic plasma flows

Abstract

A new experimental platform was developed, based on the use of supersonic plasma flow from the ablation stage of an inverse wire array z-pinch, for studies of shocks in magnetized high energy density physics plasmas in a well-defined and diagnosable 1-D interaction geometry. The mechanism of flow generation ensures that the plasma flow (ReM ∼ 50, MS ∼ 5, MA ∼ 8, Vflow ≈ 100 km/s) has a frozen-in magnetic field at a level sufficient to affect shocks formed by its interaction with obstacles. It is found that in addition to the expected accumulation of stagnated plasma in a thin layer at the surface of a planar obstacle, the presence of the magnetic field leads to the formation of an additional detached density jump in the upstream plasma, at a distance of ∼c/ωpi from the obstacle. Analysis of the data obtained with Thomson scattering, interferometry, and local magnetic probes suggests that the sub-shock develops due to the pile-up of the magnetic flux advected by the plasma flow.