Fusion space propulsion system based on the sheared flow stabilized Z pinch

Author: Uri Shumlak, Professor, Aerospace and Energetics Research Program, University of Washington

Abstract Background: Thermonuclear fusion provides a large energy release per reactant mass and offers a solution for rapid deep space propulsion if a configuration can be developed with a small system mass. Many magnetic confinement configurations require large magnetic field coils to stabilize the plasma at the expense of lower plasma beta and higher system mass. The Z pinch has no magnetic field coils and unity beta; however, it generally suffers from MHD instabilities. The sheared flow stabilized (SFS) Z pinch uses axial flows to provide stability, has demonstrated an ability to confine plasmas to fusion conditions without magnetic field coils, and promises a compact fusion device with Q>1. Recent experimental results will be presented that demonstrate high performance plasmas and sustained fusion reactions from the FuZE (Fusion Z-pinch Experiment) SFS Z-pinch device at the University of Washington. High-fidelity numerical simulations indicate that sheared flow stabilization of the Z pinch continues to be effective at reactor-grade plasma conditions. Building on the ZaP, ZaP-HD, and FuZE projects, scaling studies will be presented of an SFS Z pinch as a fusion space thruster, which generates high exhaust velocities and high thrust with low system mass, as will be shown through calculations that account for input power, repetition rate, and duty cycle.