Verification of Magnetic Mirror Fusion concepts in ARPA-E BETHE using Gkeyll simulations

In a Mirror Fusion device, magnetic field lines pinched to the ends of the device act like mirrors to reflect charged particles and confine the plasma towards the midplane. The ARPA-E BETHE program presently supports two Mirror Fusion concept projects in search of a low-cost solution for fusion confinement: the UMBC Centrifugal Mirror Fusion Experiment (CMFX), and the Wisconsin High-field Axisymmetric Mirror (WHAM). In CMFX, a supersonic azimuthal flow is set up by a strong radial E field to effectively stabilize, heat, and confine the plasma. WHAM, instead, focuses on using innovative plasma heating and high-field superconducting magnets to increase mirror field strength.

Previously, the CM concept has been studied in single-fluid MHD. Here, we present preliminary two-fluid (electron-ion) studies of stability and heating in CM using two-fluid 5-moment modeling of the CM configuration and focus on non-MHD effects. We also present preliminary gkyrokinetic and gyrofluid simulation results in the context of WHAM, focusing on the E field profile generation, the impact of the expanders, and flows parallel to the mirror B field. All simulations are performed using the open-source Princeton-VT code, Gkeyll (https://gkyl.readthedocs.io).