Measurement of plasma parameters within the discharge channel of a Halo thruster

The Halo thruster is a cusped field thruster currently under investigation at the Surrey Space Centre, University of Surrey. The concept concerns the addition of a novel toroidal cusp layer, the “halo”, to a magnetic field topology closely resembling that of the Cylindrical Hall Thruster. Preliminary low resolution maps are presented of plasma potential, electron temperature and plasma density within an electromagnet Halo thruster discharge channel, produced using a 2-axis translating Langmuir probe arrangement. Potential drops are observed in both the annular and cylindrical parts of the discharge channel, and a region of high plasma density is revealed on the central axis in the cylindrical part, suggesting performance may be improved by adopting a purely cylindrical geometry.