Formation and dynamics of Z-pinch plasma in a coaxial plasma gun

Abstract

In this work, the dynamics and formation mechanisms of Z-pinch plasma in a coaxial plasma gun were investigated. By using arrays of magnetic probes, calorimeters, and ballistic pendulums, the profiles of current and Lorentz force density, plasma momentum, and kinetic energy were detected. It was revealed that the flow Z-pinch was governed by a radial compression process consisting of two distinct stages. After being ejected from the inter-electrode gap, the plasma was first concentrated in the near-axis region downstream of the inner electrode and subsequently compressed by the pinching force generated by the axial current, resulting in the formation of a flow Z-pinch. A more pronounced concentration of momentum and energy, favorable for pulsed plasma spraying, was achieved by increasing the capacitor charging voltage and decreasing the gas injection time. A lower but spatially uniform absorbed energy density, suitable for film deposition and plasma etching, was obtained under a prolonged gas injection time. These results elucidated the Z-pinch plasma formation mechanisms in coaxial plasma guns and provided a reference for modulating plasma parameters in material processing applications.