Characterization of a helicon ion source for Helium-3 fusion in an inertial electrostatic confinement device

Summary form only given. An external helicon ion source is used on HELIOS, an inertial electrostatic confinement (IEC) fusion device in which ions are accelerated radially to fusion-relevant energies by the electrostatic field between the spherical chamber wall and a concentric cathode grid. The external ion source has allowed for the demonstration of ³He-³He fusion in an IEC device for the first time, as part of the advanced fuels program at the University of Wisconsin. The experimental setup has been upgraded to allow for operation at higher ion current and cathode voltage levels, in order to increase the fusion rates for exploration of ³He-³He reaction cross sections and future diagnostic studies to benchmark the single-atomic-species formalism of a numerical code on spherically convergent ion flow. Measurements of the plasma density and electron temperature in the helicon ion source are presented for different configurations of rf antenna and magnetic field geometries. Test results for a new high-voltage feed-through design are also presented.