Analysis of ionization characteristics during single discharge of microcathode arc thruster

Abstract

In this study, to examine the internal discharge process of microcathode arc thruster arc pits, electrical detection was combined with enhanced ICCD spectroscopic detection to diagnose the interpolar ionization characteristics of microcathode arc thrusters with 1-μs time resolution for examining the microsecond-level discharge process. After titanium ion spectroscopic model calculations were used to obtain the ion density distribution in the microcathode arc thruster arc maintenance process, it was found that the microcathode arc thruster cathode emitted plasma density in a single cycle over time, in a bimodal pattern. This phenomenon might be related to the microcathode arc thruster in a single discharge by the combined effect of arc heat transfer and ion current impact. The results showed that changes in the input energy of the power processing unit (PPU) can effectively affect the temporal relationship between electric arc ionization and impact ionization and further affect the ionization concentration of the microcathode arc-thruster cathode.