MAGnetic Nozzle ECR Thruster with Augmented performance

Objective

In the context of reduction of the spacecraft size, low power electric propulsion devices have replaced the chemical propulsion traditionally used. Among the different technologies, one particular type produces and ejects a plasma in a diverging magnetic field, called magnetic nozzle. Such devices are said electrodeless because they do not need a cathode to neutralise the plasma beam. The absence of this element simplifies considerably their architecture and reduces significantly their risk of failure. In this project, we propose to investigate new levers to increase the efficiency of an Electron Cyclotron Resonance (ECR) thruster to build MAGNETA: A Magnetic Nozzle ECR Thruster with Augmented performance. Aided by an in-depth study of the fundamental mechanisms at stake in the production and the acceleration of a plasma in a magnetic nozzle, we will propose a simple design and build a prototype able to operate in a wide range of conditions and span different regimes with a precise control of the performance. First, an investigation of innovative microwave patterns and ECR heating zone shapes and their impact on the performance of an ECR source will be led. Aided by experts in microwave engineering, this study will result in a new design of ECR source with an optimised microwave and magnetic scheme. Second, a Thomson scattering experiment will be set up to measure the two components of the electron temperature in the plasma in expansion in the magnetic nozzle of the device. These experimental data, never measured, will guide the development of a two-temperature fluid model of plasma expansion in a diverging magnetic field. This step is essential to propose custom and optimised magnetic nozzle topologies for electrodeless thrusters. Finally, the last step corresponds to the prototyping of MAGNETA, which will feature an innovative microwave pattern and an improved magnetic topology to outperform the state-of-the-art technologies.