Radiofrequency plasma thrusters and related studies*

The Space Plasma, Power and Propulsion (SP3) laboratory provides a creative and collaborative environment for industry and academe related projects spanning a wide range of topics such as space plasmas (solar corona and exoplanet research), space missions (QB50, mission to Mercury), space propulsion systems (for low earth orbit, geostationary and deep space) as well as focused ion beams (materials characterisation, forensic studies). Over the past decade the development of a range of electrodeless plasma thrusters based on geometric and magnetic plasma nozzles (i.e. Helicon thruster, Pocket Rocket thruster, Naphthalene thruster) has provided a wonderful platform for a better understanding of basic plasma physics with some prototypes near ready for space use. We use similar radiofrequency plasma technologies for our various thruster concepts and for our focused ion beam studies. Thousands of nano and micro-satellites are expected to be launched over the next decade, many in constellations, and rideshare opportunities are increasing. There is interest in developing miniaturised communications filters which may be achieved using the Coaxial Stepped Impedance Resonator topology. The destructive ‘multipactor’ effect of avalanche electrons in such filters can be further assessed using plasma technology. The development of the Pocket Rocket thruster into a laminar nozzle capable of producing high vibrational temperatures for molecular gases is carried out for implementation onto the SMAUG exoplanet research apparatus which produces non-LTE (Local Thermodynamic Equilibrium) spectra of various molecules characterised using cavity ringdown spectroscopy. Expanding nearly collisionless plasmas can be used to investigate out-of-equilibrium thermodynamics via polytropic index studies both in the laboratory and in space.