Impact of Optimized Electrodes on Generation Characteristics of Vacuum-Discharge Plasmas

Electrode structures have an important effect on the electric-field strength at the cathode tip in vacuum. Effectively increasing the electric-field strength at the cathode tip can contribute to increasing the density and energy of vacuum-arc discharge plasmas. In this paper, a tubular electrode is designed and employed as the anode. The electric-field distribution of the electrode was simulated using the software package Maxwell 3-D. Through a series of simulated experiments, the factors that affect the electric-field distribution were explored, including the length of the tubular anode and the relative positions of the electrodes. In addition, the effect of an insulator situated between the cathode and the anode and optimal designs for the electrode structures are discussed. The plasma parameters and thrust were measured using a Langmuir probe and a piezoelectric thin-film sensor, respectively. The experimental and simulated results indicate that optimizing the electrode structure can effectively reduce the weight of the electrodes, increase the field strength at the cathode tip, and generate higher plasma density and greater thrust.