Simulating Magnetized Particle Dynamics in Z-Pinch Plasmas

Mikhail Dorf | 18-ERD-007

Project Overview

In this project, we adapted and applied the gyrokinetic Eulerian code COGENT to an emerging area of highly magnetized Z-pinch plasma systems. Simulation efforts for these plasmas currently use either (1) magneto-hydrodynamic (MHD) fluid codes, which suffer from fidelity being restricted to narrow plasma conditions; or (2) fully kinetic particle-in-cell methods, which suffer from the run-time needed to resolve the very small spatial and temporal scales required for the plasma conditions. Progress toward achieving detailed theoretical understanding of Z-pinch plasma systems can be greatly expedited using some combination of gyrokinetic and drift-ordered MHD models, developed in the tokamak community and implemented in the COGENT code. These formulations are applicable to a much larger parameter space than standard MHD models, while providing a substantial speed-up in run-time over fully kinetic codes.

In this project, we successfully adapted and applied the gyrokinetic formalism implemented in the COGENT code to study a flow-stabilized Z-pinch (FSZP) system—a promising fusion concept in which a sheared axial flow is used to provide stability against large-scale ideal-MHD modes. Results of gyrokinetic simulations with COGENT agree well with those from fully kinetic simulations while requiring approximately 500 times less run-time. We successfully explored novel capabilities in understanding Z-pinch kinetics, which can support transformational discovery in the physics of Z-pinch plasmas.

Mission Impact

Highly-magnetized Z-pinch plasmas—such as the dense plasma focus, FSZP, and high-current inertial Z-pinches—represent an emerging mission space important to the Department of Energy and play a central role in national inertial confinement fusion and high-energy-density (HED) science programs. In addition, this work supports Lawrence Livermore National Laboratory's HED science core competency.

Publications, Presentations, and Patents

Angus, J., et al. 2018a. "Drift-Ideal MHD Simulations of Z-pinch Plasmas," The 45th IEEE International Conference on Plasma Science, Denver, CO, June 2018. LLNL-POST-760482

——— 2018b. "Drift-Ideal MHD Simulations of Flow-Stabilized Z-Pinch Plasmas." 60th Annual Meeting of the APS Division of Plasma Physics, Portland, OR, November 2018. LLNL-ABS-753640

——— 2019a. "Drift-Ideal Magnetohydrodynamic Simulations of m = 0 Modes in Z-pinch Plasmas." Phys. Plasmas 26, 072505. LLNL-JRNL-958625

——— 2019b. "Numerical Simulations of Z-pinch Plasmas," Physics Research Orientation Day, Marshall University, October 2019. LLNL-PRES-793660

——— 2020a. "Eigenmode Analysis of the Sheared-Flow Z-pinch," Phys. Plasmas, 27, 22108. doi:10.1063/5.0029716. LLNL-JRNL-814236

——— 2020b. "One-Dimensional Theory and Simulations of the Dynamic Z-pinch," Phys. Plasmas 27, 012108. LLNL-JRNL-772662

——— 2020c. "Applying The Gyrokinetic Formulation of Magnetized Particle Dynamics to Z-Pinch Plasmas," First Z-NetUS Workshop, La Jolla, CA, January 2020. LLNL-POST-800385

Dorf, M., et al. 2018. "Gyrokinetic Simulations of Drift-Wave Instabilities in Flow-Stabilized Z-pinch plasmas," The 45th IEEE International Conference on Plasma Science, Denver, CO, June 2018. LLNL-POST-752551

Geyko, V. I., et al. 2019a. "Gyrokinetic Simulations of m = 0 Mode in Sheared Flow Z-pinch Plasmas." Phys. Plasmas 26, 062114. LLNL-JRNL-769250

——— 2019b. "Electrostatic gyrokinetic simulations of sheared Z-pinch," IEEE Pulsed Power and Plasma Science Conference, Orlando, FL, June 2019. LLNL-PROC-768153

——— 2019c. "Electrostatic gyrokinetic simulations of m=0 mode in sheared flow Z-pinch plasmas," 61st Annual Meeting of the APS Division of Plasma Physics, Fort Lauderdale, FL, October 2019. LLNL-PROC-780478

——— 2020. "Simulation of FuZE pinch axisymmetric stability using gyrokinetic and extended-MHD models," 62nd Annual Meeting of the APS Division of Plasma Physics (online), November 2020. LLNL-ABS-812052