2D RMHD simulation study of nested wire array Z-pinch with foam target

Abstract

Summary form only given. Experiments with nested wire array dynamic hohlraums that include a cylindrical foam target on the axis, and an on-axis radiation exit hole (REH) in the anode, have yielded up to 13 TW of axial X-ray power on the 20 MA Z-machine. We have attempted to model these dynamic hohlraum target experiments with 2D, radiation magnetohydrodynamic simulation. The configuration of interest consists of: (1) a cylindrical target of 1.0 cm long, 0.25 cm radius, 14 mg/cc CH2 foam, (2) an inner array of 120 tungsten (W) wires, 1.0 cm long, located at 1.0 cm radius, with total mass of 1.0 mg, (3) an outer array of 240 (W) wires, 1.0 cm long, located at 2.0 cm radius, with total mass of 2.0 mg, and (4) a 0.12 cm radius REH in the anode. Simulations are 2D, so the wire arrays are modeled using plasma shells whose initial temperature is 1 eV. Magnetic Rayleigh Taylor (RT) instability is initiated through a small amplitude density perturbation on the outer wire array. Results suggest that the character (amplitude, pulse width) of the axial radiation depends on the amplitude and phase (initial seed) of the RT.