Simulation study of the influence of experimental variations on the structure and quality of plasma liners

Abstract

Simulation studies of a section of a spherically imploding plasma liner, formed by the merger of six hypersonic plasma jets, have been performed at conditions relevant to the Plasma Liner Experiment (PLX) [S. C. Hsu et al., IEEE Trans. Plasma Sci. 46, 1951–1961 (2018)]. The main aim of simulations was to study the sensitivity of the detailed structure of plasma liners and their global properties to experimental mass variations and timing jitter across the six plasma jets. Experimentally observable synthetic quantities have been computed using simulation data and compared with the available experimental data. Simulations predicted that the primary oblique shock wave structure is preserved at small experimental variations. At later phases of the liner implosion, primary shocks and, especially, secondary shocks are more sensitive to experimental variations. These conclusions follow from the simulation data and experimental CCD camera images. Small displacements of shock wave structures may also cause significant changes in the synthetic interferometer data at early time. Our studies showed that such global properties of the plasma liners such as the averaged Mach number and averaged ram pressure along the leading edges of plasma liners are less sensitive to experimental variations. Simulation data of the liner structure were largely confirmed by the PLX experimental data.