Electrical and Computer Engineering ETDs

Publication Date

Summer 7-30-2024

Abstract

Density Functional Theory (DFT) based Monte Carlo (MC) simulations of the Sec-
ondary Electron Yield (SEY) of metals, alloys, and metal oxides are performed to
find material properties that could help reduce or influence the multipactor effect.
In order to accurately model the SEY of materials, knowledge of the frequency- and
momentum-dependent Energy Loss Function (qDepELF) is required. The qDepELF
is difficult to determine from experiment; however, it can be calculated from first
principles. The DFT-MC approach for simulating the secondary electron genera-
tion, propagation, and emission processes is described herein. Material properties,
which are calculated using DFT and used for MC simulations, include the density
of states, energy band gap, Fermi energy, work function, ionization potential, and
qDepELF. To accurately account for excitonic effects in the metal oxide systems
where an energy band gap often exists, the Bethe Salpter equation formalism is
applied to calculate qDepELFs. This two-body Green’s function approach signifi-
cantly increases computational requirements, but results in more accurate dielectric
properties of metal oxides.

Keywords

density functional theory, multipactor effect, secondary electron yield, oxide surfaces, momentum-dependent energy loss function, ionization potentials

Sponsors

AFOSR MURI Grant No. FA9550-18-1-0062 and FA9550-21-1-0367

Document Type

Dissertation

Language

English

Degree Name

Electrical Engineering

Level of Degree

Doctoral

Department Name

Electrical and Computer Engineering

First Committee Member (Chair)

Prof. Edl Schamiloglu

Second Committee Member

Prof. Ivana Matanovic

Third Committee Member

Prof. Mark Gilmore

Fourth Committee Member

Prof. Dane Morgan

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