Dynamic comparison between the cylindrical and quasi-spherical implosions based on thin-shell models

Abstract

The quasi-spherical electromagnetic implosions are capable of generating hot dense plasmas more efficiently than the cylindrical ones. The dynamic properties of stagnated cylindrical and quasi-spherical shells are compared numerically based on the thin-shell models. The cylindrical implosions are simulated with the zero-dimensional thin-shell model, and the quasi-spherical implosions with the multi-element thin-shell model. The simulated velocity, areal mass density, and areal kinetic energy density of the stagnated quasi-spherical plasma shell increase with the latitude increasing, which is different from the cylindrical case. The kinetic energy densities are optimized for both of stagnated cylindrical and quasi-spherical shells in a quite large span of initial radii and load linear masses. The kinetic energy density in the spherical radiation converter can be over four times as large as that in the cylindrical radiation converter. The numerical results can help optimize quasi-spherical load parameters for Z-pinch driver with peak current of 1.5 MA and rising time of 80 ns, and the method described here is also feasible to optimize load parameters for various-scale Z-pinch drivers.