On high-energy-density field-reversed configurations for sub-microsecond magneto-inertial fusion

Results from theory, simulation, and experiment are presented that support the concept of sub-microsecond formation and compression of centimeter-scale field-reversed configurations (FRCs) for fusion yield. Such FRCs require 10–100+ T of applied field and are intended for compression to high-energy-density conditions in solid liners on the Z-machine and future accelerators. First, MHD simulations including anomalous resistivity are presented. These simulations suggest that empirical scaling laws from the literature might be used to predict the resistive lifetime of high-field FRCs, and these lifetimes are often in excess of 1 μs. The effects of applied field shape/gradients are also explored in simulation, and an analytic prediction for FRC ejection time from the liner is verified. Second, a high-field FRC formation platform on a university-scale pulsed-power facility is detailed. The Z-discharge pre-ionization (ZPI) system is characterized and shown to have critical effects on the plasma. Fast-frame visible image sequences are presented for various gas pressure, bias field, and ZPI settings. The expected plasma dynamics can be seen in the images, with long-lived plasma annuli (possibly FRCs) produced only under the proper conditions. Optimistic conclusions are drawn, and future research directions are recommended.