Development of a miniature microwave-multicusp plasma source as an electron neutralizer for space propulsion

Summary form only given. The advent of micro space-probes and nano-satellites has prompted the development of miniature plasma based electric thrusters for space propulsion and orbital manouvering¹. Plasma thrusters are capable of providing high specific impulse and greater exhaust velocities with much less fuel load compared to chemical propulsion². Plasma ion thrusters provide the highest specific impulse among the different types of electric thrusters in use today². An electron neutralizer is required in tandem to neutralize the exhaust ion beam and prevent the charging of the space craft. DC and filament based thruster and neutralizer have lifetime limitation, and wave based systems have high input power requirement. Therefore, the development of a wave based plasma source operating at low power is important for modern space applications and is being pursued by various research groups^3,4. A miniature (diameter - 21 mm, length - 40 mm) cylindrical multicusp based plasma source is under development for application as a neutralizer. Xenon plasma would be generated at low microwave power (- 2 W) and mass flow (- 5 μg/s) by electron cyclotron resonance mechanism and confined by the magnetic well structure along the axis⁵. The production and sustenance of plasma would be investigated by experimental measurement of the plasma parameters and extracted electron current by varying the wave frequency, Xe mass flow rate, and tuning of the multicusp magnetic field. Modeling and simulation of wave - plasma interaction would be carried out to support and explain the experimental observations. The results would be utilized for the optimization of the source for efficient plasma generation and electron beam output.