Effect of the width and number of rings of concentric split ring resonator on plasma generation for miniature ion thruster

Abstract

The objective of this study is to compare the plasma generated by concentric split ring resonators with different parameters like the width of the inner rings and the number of rings for use in miniature ion engines. The concentric split ring resonators are operated with argon gas at ~350 mTorr chamber pressure and ~7.25 W forward power. Five different designs of the resonator were tested. The plasma density and electron temperature produced by the resonators were first mapped in a 2D plane using double Langmuir probes. Next, all the designs were placed into a miniature ion thruster and the thruster performance was measured. The 2 ringed split ring resonator with thinner inner ring performed better than the other designs in both plasma properties and thrust. The thrust for the best design ranged from 1.58 µN to 2.34 µN and the specific impulse was 2662 seconds. The total power consumption ranged from 34.7 W to 38.9 W.