Using a superconducting cyclotron to detect special nuclear material through multiple monoenergetic gamma radiography and o-axis photon scattering/

This thesis reports on using a superconducting compact proton cyclotron to conduct multiple monoenergetic gamma radiography (MMGR) and measure o-axis photon scattering to nd special nuclear material (SNM). The cyclotron is a small enough accelerator to be a viable option for scanning commercial cargo containers at maritime ports, airports, rail crossings, and other places of interest. This research presents a technique for reconstructing the eective atomic number (Z) and areal density ([rho][subscript A]) of cargo mock-ups using MMGR with the cyclotron, analyzes the sensitivity of the reconstruction technique, and applies the technique to experimental data. However, single-axis radiography is prone to hoaxing by smugglers. It is relatively trivial to make high-Z material such as SNM look like an innocuous, lower-Z material, such as iron, by surrounding the high-Z material with low-Z material like polyethylene or aluminum. To secure MMGR from this risk of hoaxing, this research presents the use of large angle photon scatter ([theta] = 125°) in cargo to gain additional information on its atomic number. The MMGR technique is found to be able to resolve materials of Z < 70 and uranium (Z = 92); however, the technique has difficulty resolving lead from uranium. Off-axis photon scattering is found to contain Z-specfic information in Monte Carlo simulations, but experimental results are inconclusive.

Name thesis:degree_name

Master

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Nuclear Science and Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2018

Author dc:creator

• Nelson, Roberts Grafton.

Advisor dc:contributor.advisor

• Areg Danagoulian.

• Nuclear Science and Engineering.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/121648

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/121648