Masters Theses

Keywords and Phrases

Deterministic simulation; Scatter Correction; Thermal neutron radiography; Tomography

Abstract

"In recent years, thermal neutron radiography and tomography have gained much attention as one of the nondestructive testing methods. However, the application of thermal neutron radiography and tomography hindered by their technical complexity, radiation shielding, and time-consuming data collection processes. Monte Carlo simulations have been developed in the past to improve the neutron imaging facility's ability. In this present work, a new deterministic simulation approach has been proposed and demonstrated to simulate neutron radiographs numerically using a ray tracing algorithm. This approach has made the simulation of neutron radiographs much faster than by previously used stochastic methods (i.e Monte Carlo methods). The major problem with neutron radiography and tomography simulation is finding a suitable scatter model. In this paper, an analytic scatter model has been proposed that is validated by a Monte Carlo simulation. Two simulation geometries have been analyzed in this work. One is a highly scattering medium, another is medium scattering media. It has been shown that this algorithm works well in the medium scattering media. The scatter model has been verified using Monte Carlo method (MCNP5).There are some empirical parameters that have been determined using curve fitting methods using MATLAB. There are some disadvantages of using the scatter correction algorithm proposed in this work, but the advantages are far more rewarding. This method of simulation reduces the time of simulation in 5-10 seconds compared to several hours using Monte Carlo methods and can be used for rapid prototyping for neutron imaging facilities. Filtered back-projection with a ramp filter has been used for reconstruction"--Abstract, page iii.

Advisor(s)

Liu, Xin (Mining & Nuclear Engr)

Committee Member(s)

Lee, Hyoung-Koo
Alajo, Ayodeji Babatunde

Department(s)

Nuclear Engineering and Radiation Science

Degree Name

M.S. in Nuclear Engineering

Sponsor(s)

U.S. Nuclear Regulatory Commission

Comments

Supported by the U.S. Nuclear Regulatory Commission grant NRC-HQ-12-G-38-0039

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2016

Pagination

ix, 56 pages

Note about bibliography

Includes bibliographical references (pages 53-55).

Rights

© 2016 Rajarshi Pal Chowdhury, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Neutron radiography -- Simulation methods
Thermal neutrons
Tomography -- Simulation methods
Thermal neutrons -- Scattering

Thesis Number

T 10974

Electronic OCLC #

958293839

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