Doctoral Dissertations

Keywords and Phrases

Anode; Cardiac; Computed Tomography; Cylinder; Heat; X-Ray

Abstract

"The reduction of motion blur in computed tomography (CT) drives the current research for multisource CT. Due to their compact nature, the current multisource systems utilize stationary angled anodes. Unfortunately, these configurations neither simplify the imaging geometry, nor satisfy the need for managing the high thermal loads demanded by real-time CT (30 acquisition frames per second). To add to the current field of knowledge, two x-ray tube concepts are presented in this dissertation. First, a simulation of transient thermal analysis was performed on a compact transmission-type x-ray tube anode operating in pulse-mode. A correlation was found between deposited beam power and maximum anode temperature for any anode thickness beyond 0.5 mm.

A second approach was developed for higher current applications: a rotating cylindrical anode. A modified Oosterkamp equation was developed and used to investigate three beam-sweeping sequences. It was found that although increasing beam sweeping speed increased the maximum power, the deposited energy in the focal spot per acquisition time decreased. Ultimately the step-and shoot sequence was found to be optimal for the cylindrical anode. Next, MCNP was used to find the angular dependence of the fraction of energy that the backscattered electrons carry away from the focal spot for a curved anode. That information was then used in COMSOL to find the electron beam efficiency and maximum power for different incident angles using various focal spot lengths and anode diameters. After that a correlation between maximum deposited power, focal spot length, and rotational surface speed was found. Finally, design considerations are reported based upon a sensitivity analysis of a preliminary design for the cylindrical multisource anode"--Abstract, page iii.

Advisor(s)

Lee, Hyoung-Koo

Committee Member(s)

Castano Giraldo, Carlos Henry
Frimpong, Samuel
Mueller, Gary Edward
Zhang, Tiezhi

Department(s)

Nuclear Engineering and Radiation Science

Degree Name

Ph. D. in Nuclear Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2020

Pagination

xiii, 90 pages

Note about bibliography

Includes bibliographic references (pages 81-89).

Rights

© 2020 Wesley William Tucker, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11694

Electronic OCLC #

1164778414

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