My research project
Experimental demonstration and characterisation of novel molecular propellants for electric propulsion applications
This research project investigates the potential of a selection of novel molecular propellants as alternatives to xenon, for use in electric propulsion. The performance characteristics of the propellants is directly measured for operation with a low-power Cylindrical Hall Thruster. Due to the molecular nature of the propellants, the dissociation and fragmentation processes that occur within plasmas produced with the propellants, and the thruster exhaust plumes are investigated. Mass spectra are measured and compared with optical emission spectra taken directly from the thruster exhaust plumes. Findings from the spectral analysis are supported by analysis of deposits found within the thruster chamber. The performance results so far indicate that the propellants provide a viable alternative to xenon.
We present the AQUAJET propulsion system, a cathodeless, ambipolar thruster test bed operating on multiple propellants including water. It is based on Electron Cyclotron Resonance (ECR) at 2.45 GHz using a simple permanent magnet configuration of the plasma source. We discuss the theoretical background of the technology, our flexible modular design that allows testing of many thruster geometry configurations, and modelling work done in preparation for testing.
The Halo thruster is a low-power plasma propulsion concept, currently under investigation and development within the Surrey Space Centre at the University of Surrey in collaboration with Surrey Satellite Technology Ltd, Airbus DS and Imperial College London. The device is based on the electrostatic acceleration of propellant ions produced in a DC-powered magnetized plasma discharge characterized by a closed-loop electron drift sustained by the combination of electric and magnetic fields. Current research and development activities include: (i) experimental testing of different laboratory models to optimize the thruster performance in the 100 – 200 W power range; (ii) detailed plasma measurements to determine the underlying plasma physics; (iii) implementation of a plasma model for hollow cathode design; (iv) design and manufacturing of an optimized Halo thruster Engineering Model, including a tailored hollow cathode. This paper presents an overview of the aforementioned activities.