Doctoral Dissertations

Keywords and Phrases

Einzel lens; Electron focusing; Field emission; Particle-in-cell; Stationary CT; X-ray source

Abstract

"Multisource architectures enable sweeping one or more x-ray beams across the imaging field-of-view faster than physically moving a single x-ray source and/or a detector. Hence, these architectures are attractive for the applications in which temporal resolution plays an important role, for example, cardiac computed tomography (CT) or real-time CT. One of the recent developments in multisource architectures for CT imaging is stationary CT architecture, whereby two separate stationary arrays -- one for x-ray sources and one for detectors -- are utilized to sweep one or more x-ray beams along the gantry and acquire 360 degree projections. To have a stationary CT architecture and still acquire enough number of projections for a successful CT reconstruction, an array of closely spaced and individually addressable x-ray sources that are compact in size and are capable of producing x-ray pulses at a high frequency is required.

This work is a part of a research continuum toward developing a compact x-ray tube potentially to be used in the said stationary CT architecture. The central hypothesis of the research conducted is that, a field emission (FE) based cold cathode and transmission type anode allow the size of an x-ray tube to be reduced, and still generate a required x-ray pulse. Specifically, this work entails the design of an electrostatic lens for electron focusing in a compact x-ray tube and the initial experimental studies of a prototype compact x-ray tube. Using particle-in-cell code, OOPIC PRO, electron field emission from CNT cathode and electron focusing by three types of electrostatic lenses--Single lens, Double lens, and Einzel lens--were simulated, compared, and studied for anode voltages of 30 kV p to 140 kV p. The first-generation prototype compact x-ray tube was developed and studied. The initial studies conducted to understand the performance of the prototype and its control parameters. After further optimization of size and testing, this compact x-ray tube design holds a potential to be used in a stationary CT architecture for improved temporal resolution"--Abstract, page iv.

Advisor(s)

Lee, Hyoung-Koo

Committee Member(s)

Alajo, Ayodeji Babatunde
Castano Giraldo, Carlos Henry
Liu, Xin (Mining & Nuclear Engr)
Moss, Randy Hays, 1953-

Department(s)

Nuclear Engineering and Radiation Science

Degree Name

Ph. D. in Nuclear Engineering

Sponsor(s)

Missouri University of Science and Technology Department of Mining and Nuclear Engineering
United States Defense Advanced Research Projects Agency
Missouri University of Science and Technology Center for Biomedical Science and Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2018

Pagination

xiv, 72 pages

Note about bibliography

Includes bibliographic references (pages 67-71).

Rights

© 2018 Ashish Vighnahar Avachat, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11414

Electronic OCLC #

1084472307

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