Helicon wave excitation and propagation in a toroidal heliac: Experiment and theory

In this paper a comparison between theoretical calculations and experimental measurements of helicon wave coupling by a partial‐turn shielded antenna in a toroidal heliac is presented. Despite the complicated heliac geometry, the wave dispersion, field profiles, and antenna radiation resistance are described well by a cylindrical uniform plasma theory. It also presents a simple formula relating the radiation resistance to the measured wave magnetic field per unit antenna current. Finally, the scaling of these results to the Heliac‐1 (H‐1) [Fusion Technol. 17, 123 (1990)]; a larger heliac now operating at the Australian National University (ANU), is discussed.