자료유형  

 학위논문

Control Number  

0017165123

International Standard Book Number  

9798346855798

Dewey Decimal Classification Number  

629.1

Main Entry-Personal Name  

Sabiston, Graeme.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of California, Los Angeles., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

203 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-06, Section: B.

General Note  

Advisor: Wirz, Richard E.

Dissertation Note  

Thesis (Ph.D.)--University of California, Los Angeles, 2024.

Summary, Etc.  

요약Generation and confinement of high-energy plasmas require materials that reduce wall-borne plasma contamination and provide desirable device lifetimes. A new category of materials, referred to as volumetrically complex materials (VCMs), have showcased robustness in extreme plasma environments [1, 2]. However, further investigation is needed to elucidate the physical principles that govern this behavior and to begin the process of designing and optimizing VCMs for varying plasma settings. Advancing the understanding of the plasma-material interactions (PMI) relevant to VCMs necessitates a comprehensive analysis of interconnected, spatially and temporally evolving mechanisms, including plasma-infusion, sputterant transport, and charged species behavior. High energy density applications such as fusion and advanced space propulsion technologies exhibit high plasma densities near the wall that lead to life and performance challenges. For VCM surfaces, these conditions lead to fully infused plasma conditions that can be exploited to improve material life and system performance. This research uses a combined experimental, computational, and theoretical approach to understand the underlying plasma-infusion physics and plasma material interactions for material design and optimization.A reduced-order simulation framework of sputtering based upon binary-collision approximation (BCA) data uniquely predicts sputter yields and analyzes material transport within plasma-facing VCMs [3]. This approach, grounded in the validated BCA code TRI3DYN, addresses key limitations in existing models by accurately capturing ion-solid interaction physics not accounted for in existing analytical methods.This simulation framework is then extended to analyze sputtering mitigation in EP vacuum chambers, demonstrating how volumetrically complex materials reduce sputterant deposition and optimize chamber design for reliable in-space propulsion [4].Advanced methods such as additive manufacturing are an attractive approach to creating optimal VCMs, however, additional considerations must be taken into account in the design phase in order to accommodate this process. Steel cage VCMs were created via laser powder bed fusion additive manufacturing, and underwent sputtering erosion [5]. Artifacts such as track-width overrun, spalling, and voids were noted. While Li and Wirz [1] demonstrated reduced sputter yield in VCMs, the transport of sputtered material within them remains largely unexplored; this is especially true for VCMs in non-plasma-facing infusion regimes. Recent sputtering experiments on stochastic aluminum foam VCMs, analyzed through X-ray tomography and SEM [6], provide insight into sputter deposition in forward and back-scattered directions, as well as the degradation of VCM structures and surface features in transitional, and plasma-infused regimes.Using the results from the abovementioned investigations, a canonical plasma-infusion experiment was developed to directly interrogate the subsurface plasma material interactions. Ultimately, the resulting analysis of the intra-VCM plasma transport led to the discovery that the negative density gradient into the material resulted in the full range of plasma-infusion conditions from fully-infused to transitional to plasma-facing.

Subject Added Entry-Topical Term  

Aerospace engineering.

Subject Added Entry-Topical Term  

Plasma physics.

Subject Added Entry-Topical Term  

Materials science.

Subject Added Entry-Topical Term  

Computational physics.

Index Term-Uncontrolled  

Fusion energy

Index Term-Uncontrolled  

Infusion

Index Term-Uncontrolled  

Space propulsion

Index Term-Uncontrolled  

Sputtering

Index Term-Uncontrolled  

Plasma environments

Added Entry-Corporate Name  

University of California, Los Angeles Aerospace Engineering 0279

Host Item Entry  

Dissertations Abstracts International. 86-06B.

Electronic Location and Access  

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Control Number  

joongbu:657728