UC San Diego

The Direct Fusion Drive (DFD) is an advanced deep-space propulsion technology that utilises a field-reversed configuration (FRC) plasma core based on the PFRC-II laboratory test-bench located at the Princeton Plasma Physics Laboratory. A rigid-body model is derived for the translational kinematics of the FRC plasma and a numerical solver is developed in MATLAB to aid controller design and analysis for the FRC plasma centroid position. Two types of coil actuators are considered: superconducting flux-conservers and constant-current electromagnets. For constant-current coil actuators, the open-loop response of the FRC plasma centroid position to radial perturbations is shown to exhibit standing radial oscillations about the origin at constant frequency (closed trajectories neither decaying nor growing), while for axial perturbations, the FRC plasma position is shown to be axially unstable (driven away from the origin axially). Results for flux-conservers are inconclusive, requiring further work. A well centred FRC plasma is critical for interpretation of diagnostics and analysis of experimental data, the rigid-body model and numerical solver devised are attempted first steps toward this goal.