A semi-analytic model of gas-puff liner-on-target magneto-inertial fusion

Abstract

A semi-analytic model is presented for the gas-puff Staged Z-pinch, a magneto-inertial fusion concept in which an annular gas-puff liner implodes onto a deuterium or deuterium-tritium target. The one-dimensional model is a modification of the semi-analytic model for MagLIF (SAMM) [R. D. McBride and S. A. Slutz, Phys. Plasmas 22, 052708 (2015)], that addresses the different set of physics inherent to a Staged Z-pinch implosion: azimuthal magnetic field transport, shock heating of the fuel, separate ion and electron energy equations, and a simplified radiation model that approximates the liner transition from optically thin to optically thick. Following the explanation of the model, three sample problems are presented: first, a Staged Z-pinch implosion on the Zebra driver (1 MA, 100 ns) is modeled and compared with the HYDRA simulation results; second, the MagLIF point design is modeled and compared to the original simulation results [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] and results from SAMM; and third, we conduct a simple parameter scan and scaling study for a Staged Z-pinch implosion on the LTD-III driver (0.8 MA, 160 ns). Some agreement with HYDRA and SAMM is obtained, and deuterium-deuterium (DD) neutron yield scaling with current is consistent with other existing models and HYDRA simulations.