Influence Mechanism of Magnetic Field and Wave Modes on Helicon Plasma Thruster

Abstract

The mechanism of energy deposition on a helicon plasma thruster under a focused magnetic field is different with a uniform magnetic field, and energy coupling efficiency has greatly improved. This paper studies the spatial distribution of power deposition under different magnetic field configurations. The results show that the magnetic field configuration can change the spatial distribution of energy deposition. A focused magnetic field configuration can couple more energy on the antenna downstream and reduce energy loss during plasma transport, which leads to improved propellant utilization efficiency and enhanced thruster performance. Then this paper studies the energy coupling efficiency and energy distribution characteristics for ionization and acceleration under different W modes, including W1 and W2. The results show that, in the W1 mode, the energy is mainly focused on ion acceleration, resulting in higher ion beam energy. In contrast, the W2 mode is focused on propellant ionization, resulting in greater efficiency of propellant utilization. The W2 mode demonstrates a higher energy coupling efficiency and has superior thruster performance compared to the W1 mode, with a thrust increase of about 1.6 times. The paper proposes several suggestions to improve the thrust-to-weight ratio and specific impulse of a helicon plasma thruster, which provides theoretical support for engineering applications.