Dynamics and Instabilities of Low-Density Gas Plasma on Thin Metal Foil Implosions*

Magnetized liner inertial fusion (MagLIF) targets [Yager-Elorriaga et al. Nuclear Fusion 2021] are subject to detrimental instabilities such as the magneto-Rayleigh-Taylor instability (MRTI) and current driven magnetohydrodynamics (MHD) instabilities, which can lead to degradation of the assembly and confinement of fusion fuel. Simulation show low-density plasma (LDP) originating from the surrounding electrodes [Bennett et al. PRAB 2023] compressing onto the liner’s outer surface prior to the liner imploding. To investigate the effects of LDP on instability development, an experimental platform is developed on the University of Michigan’s MAIZE facility (~0.5 MA, 150 ns rise time). The platform involves magnetically imploding a low-density (10¹⁷ cm^-3 ), annular gas-puff plasma onto a thin (400-nm thickness) metallic cylindrical foil has been axially pre-magnetized. The dynamics of the implosion and instability growth are captured using a 12-frame optical camera. A suite of laser-based diagnostics (shadowgraphy, schlieren, interferometry) enables the measurement of electron density of the LDP layer. Discussion and results from this study will be presented.