Wall Ion Loss Reduction by Acceleration Zone Shifting in Anode-Layer Hall Thruster

TL;DR

This paper investigates how shifting the acceleration zone in an anode-layer Hall thruster reduces wall ion loss and erosion, using guard-ring current measurements to evaluate ion flux and sheath conditions.

Contribution

It introduces a detailed analysis of guard-ring current as a fast method to evaluate wall ion loss and demonstrates that shifting the acceleration zone effectively reduces ion erosion.

Findings

Wall ion loss can be significantly reduced by shifting the acceleration zone.

Guard-ring current serves as an effective indicator of wall ion flux.

Sheath on guard rings is in ion saturation regime, validating current as an ion flux proxy.

Abstract

In this study, wall ion loss and erosion rate are evaluated in the RAIJIN thruster. The novelty of this work is the detailed analysis of measured guard-ring (metallic channel wall) current, which enables a fast evaluation of the wall ion loss and erosion rate. The current-voltage characteristics of the guard-ring current indicate that the sheath on the guard rings is in the ion saturation regime and that the guard-ring current can be used as a wall ion flux indicator. The experimental results demonstrate that the wall ion loss can be significantly reduced in the magnetic configuration of RAIJIN thrusters with the acceleration zone shifting.