Date of Award

9-14-2017

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Electrical and Computer Engineering

First Advisor

Robert A. Lake, PhD.

Abstract

A significant problem for satellites, vacuum electron devices, and particle accelerators is multipactor: an avalanche of electrons caused by recurring secondary electron emission (SEE) in a time-varying electric field. The consequences of multipactor range from temporary to permanent device failure. This research studied how surface topography can be engineered to minimize SEE and suppress multipactor. Two new semi-empirical models (one based on a 2D pore, the other based on a 3D pore) were developed to predict the secondary electron yield (SEY) of a porous surface based on pore aspect ratio and porosity. The models were validated with experimental SEY measurements of microporous gold surfaces. The more accurate 3D model predicts that a porous gold surface with pore aspect ratios = 2.0 and porosity = 0.5 will control the maximum SEY to near unity, providing a multipactor-resistant surface. Both the SEY models and experimental results confirm the understanding that the ability of a porous surface to control SEY is not dependent on pore size.

AFIT Designator

AFIT-ENG-DS-17-S-018

DTIC Accession Number

Pending

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