Accession Number:

AD1025707

Title:

Investigation of Hall Effect Thruster Channel Wall Erosion Mechanisms

Descriptive Note:

Technical Report02 Aug 2016

Corporate Author:

Georgia Institute of Technology Atlanta United States

Personal Author(s):

Report Date:

2016-08-02

Pagination or Media Count:

197.0

Abstract:

This work investigates the erosion of insulating materials by an incident plasma. In particular, the work looks to understand the impact of the material microstructure and mechanical stress on the erosion mechanisms. The results of this work provide five distinct contributions to the understanding of plasma-induced erosion. The first contribution of this work is the creation of a 3D raytracing model of plasma erosion of a heterogeneous composite material. The eroded channel wall of the AFRLUM P5 is studied via SEM microscopy and XPS spectrometry. The details of the composition of the M26 borosil composite are explored with detailed SEM images. The second contribution of this work is the creation of a thermo-mechanical model that predicts thermo-mechanical stresses for reasonable estimates of plasma heat-flux to the walls and experimentally measured temperature ranges for multi-kW HETs. The thermo-mechanical modeling provides estimates of the range of thermo-mechanical stresses it is reasonable to expect in kW-class HETs. The third contribution of this work is the development of a hypothesis, called the Strain Relief Hypothesis SRH, is proposed to potentially explain the development of the anomalous erosion ridges in HETs. The theory behind the hypothesis is explained and the governing equations are derived. The fourth contribution of this work is the design and execution of an experiment to test the effect of mechanical stress on the surface features developed during plasma erosion. The experiment is also designed specifically to test the SRH. The fifth contribution of this work is the development of two models that explain the observed development of surfaces for each material in the stressed erosion experiment.

Subject Categories:

  • Electric and Ion Propulsion
  • Physical Chemistry
  • Operations Research
  • Electric and Ion Propulsion
  • Physical Chemistry
  • Operations Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE