The Effect of Axial Magnetic Field on the Lifetime of Micro Cathode Arc Thruster (μ-CAT)

Abstract

Micro cathode arc thruster (μ-CAT) is applied to micro satellites as a propulsion device due to its simple structure, light weight and low power consumption. At present, lifetime is a key factor restricting the promotion and application of μ-CAT. The objective of this paper is to investigate the effect of an axial magnetic field on the lifetime of a μ-CAT. In this paper, a new μ-CAT is designed. The lifetimes of a μ-CAT were tested under 20, 40 A discharge current within different axial magnetic fields. The experimental results show that the axial magnetic field can effectively influence metal contamination on the μ-CAT insulator thus to influence the lifetime. The stronger the axial magnetic field strength is, the greater the effect of the magnetic field on suppressing metal contamination on the μ-CAT insulator is. When the discharge current keeps the same, the delicate balance, during the process of μ-CAT discharge, can be effectively controlled by macroscopically adjusting the magnetic field strength to enlengthen μ-CAT lifetime. For the μ-CAT in this paper, when the discharge current was 40 A and an axial magnetic field strength was about 50 mT, the μ-CAT lifetime is the longest.