A plasma-wall interaction model for the erosion of materials under ion bombardment

Logarzo, Hernan Javier

Title:

A plasma-wall interaction model for the erosion of materials under ion bombardment

dc.contributor.advisor	Rimoli, Julian J.
dc.contributor.author	Logarzo, Hernan Javier
dc.contributor.committeeMember	Kardomateas, George A
dc.contributor.committeeMember	Walker, Mitchell L. R.
dc.contributor.committeeMember	Di Leo, Claudio V.
dc.contributor.committeeMember	Tupek, Michael R
dc.contributor.department	Aerospace Engineering
dc.date.accessioned	2022-05-18T19:33:08Z
dc.date.available	2022-05-18T19:33:08Z
dc.date.created	2022-05
dc.date.issued	2022-04-20
dc.date.submitted	May 2022
dc.date.updated	2022-05-18T19:33:08Z
dc.description.abstract	Understanding the evolution and behavior of materials exposed to plasma is critical for the design of future electric propulsion devices. As ions are ejected from the device generating thrust, they also impact the ceramic walls. This induces wall erosion, ultimately exposing the magnetic circuit leading to malfunction and failure of the device. This problem is only going to be amplified as the field moves towards high power density devices. There are several models that try to predict this effect by accounting for material sputtering. However, they cannot predict the millimeter-scale surface features that develop after prolonged exposure. In this work, we address this issue by introducing a plasma-material interaction model able to capture the evolution of surface features at the macroscopic scale on materials exposed to plasma over a long period of time. The model is based on (i) data from plasma dynamics simulations, (ii) a probability model of erosion, (iii) geometric effects to account for shadowing effects and feature size and (iv) a continuum finite element model for the thermo-mechanical response of the dielectric walls that uses machine learning to account for the complex response of the material. Results show that the model is able to reproduce not only the mean erosion rate but also the macroscopic anomalous ridges that appear after prolonged exposure. Furthermore, it highlights the need to account for complex thermo-mechanical material behavior to be able to explain such features.
dc.description.degree	Ph.D.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/66573
dc.language.iso	en_US
dc.publisher	Georgia Institute of Technology
dc.subject	electric propulsion
dc.subject	erosion
dc.subject	ceramic erosion
dc.subject	material homogenization
dc.subject	ion bombardment
dc.subject	plasma
dc.subject	Hall effect thrusters
dc.subject	machine learning
dc.subject	finite element method
dc.subject	finite element analysis
dc.subject	FEM
dc.subject	FEA
dc.title	A plasma-wall interaction model for the erosion of materials under ion bombardment
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Rimoli, Julian J.
local.contributor.corporatename	College of Engineering
local.contributor.corporatename	Daniel Guggenheim School of Aerospace Engineering
local.relation.ispartofseries	Doctor of Philosophy with a Major in Aerospace Engineering
relation.isAdvisorOfPublication	27a85786-1cd4-4655-97d0-ba2c66eccfbc
relation.isOrgUnitOfPublication	7c022d60-21d5-497c-b552-95e489a06569
relation.isOrgUnitOfPublication	a348b767-ea7e-4789-af1f-1f1d5925fb65
relation.isSeriesOfPublication	f6a932db-1cde-43b5-bcab-bf573da55ed6
thesis.degree.level	Doctoral