Numerical analysis on the ionization mechanism of pulsed plasma thrusters

In order to gain great insight into the working process in pulsed plasma thrusters (PPT), an ionization model was developed in this paper. The ionization processes of LES-6 PPT and XPPT-1 PPT was simulated by use of the ionization model, and some parameters such as propellant utilization and electron density were obtained. The propellant utilization ratios were 16.32% (LES-6) and 81.04% (XPPT-1), and the electron densities were 6.56×10²¹ m^-3 (LES-6) and 5.83×10²¹ m^-3 (XPPT-1). The results show that the model can correctly reveal the ionization process of PPT, and the simulated values of the propellant utilization and electron density fit well with the experimental values. It is also shown that the electrode voltage can not always meet the ionization threshold value of neutral gas during the discharge process of PPT.