Masters Theses

Keywords and Phrases

Alpha-quartz; Ion tracks; Phonon; Phonon confinement; Raman spectroscopy

Abstract

"The passage of a swift heavy ion through a material can cause columnar, amorphous nano-structures known as ion tracks. Swift heavy ions are present in a number of applications ranging from nuclear reactors to nuclear waste storage and onboard spacecraft. The study of ion tracks has been ongoing since the late 1950s and has led to several technological advancements. In fact, ion beams have been used to enhance material properties and aid in the production of electrical components. Ion beams, and their resultant ion tracks, can therefore be seen as a method to purposefully alter material properties such as thermal diffusivity. One method through which ion tracks can alter material properties is through the alteration of phonon transport. It is expected that phonons are spatially confined between ion tracks.

In this study, Z- and Y-cut α-quartz single crystalline samples were irradiated with 20 MeV nickel 6+ ions. These crystals were irradiated to nominal fluence values of 1.0x109, 1.0x1010, and 1.0x1012 ions cm-2. The crystals were irradiated with varying fluence values in order to understand how the spacing of ion tracks affects phonon transport. An Inelastic Thermal Spike model was also developed to model the track radii. The Thermal Spike model allows for the effects of track size to also be taken in to account. In addition, Raman spectroscopy was performed for each fluence value. The effects of ion tracks on phonon confinement were understood by examining how the peak parameters changed with increasing fluence and comparing the parameters to the phonon dispersion relations for α-quartz"--Abstract, page iii.

Advisor(s)

Graham, Joseph T.

Committee Member(s)

Alajo, Ayodeji Babatunde
Mueller, Gary Edward, 1954-

Department(s)

Nuclear Engineering and Radiation Science

Degree Name

M.S. in Nuclear Engineering

Sponsor(s)

U.S. National Research Council

Comments

This work was made possible by NRC grant NRC-HQ-13-G-38-0026.

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2018

Pagination

ix, 85 pages

Note about bibliography

Includes bibliographical references (pages 79-84).

Rights

© 2018 Bryant Alan Kanies, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 11426

Electronic OCLC #

1084478382

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