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

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 beta and higher system mass. The Z-pinch has no magnetic field coils and unity beta; however, it is unstable to MHD modes. 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 concept with Q>1. An SFS Z-pinch fusion space propulsion system presents unique spacecraft control challenges: control-centric modeling including dynamics, state and control constraints; offline and online minimum fuel/time trajectory design and redesign; and robust and accurate trajectory tracking. 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 (~10⁷ m/s) and high thrust (~10⁶ N) with low system mass, as will be shown through calculations that account for input power, repetition rate, and duty cycle.