Towards the development of an explosives detection system using Neutron Resonance Radiography
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2007.
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| Other Authors: | |
| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2008
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| Online Access: | http://dspace.mit.edu/handle/1721.1/41290 http://hdl.handle.net/1721.1/41290 |
| _version_ | 1811069060215996416 |
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| author | Raas, Whitney |
| author2 | Richard Lanza. |
| author_facet | Richard Lanza. Raas, Whitney |
| author_sort | Raas, Whitney |
| collection | MIT |
| description | Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2007. |
| first_indexed | 2024-09-23T08:05:04Z |
| format | Thesis |
| id | mit-1721.1/41290 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T08:05:04Z |
| publishDate | 2008 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/412902019-04-09T16:33:27Z Towards the development of an explosives detection system using Neutron Resonance Radiography Raas, Whitney Richard Lanza. Massachusetts Institute of Technology. Dept. of Nuclear Science and Engineering. Massachusetts Institute of Technology. Dept. of Nuclear Science and Engineering. Nuclear Science and Engineering. Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2007. Includes bibliographical references (leaves 183-188). Detection of conventional explosives remains a challenge to air security, as indicated by recent reports detailing lapses in security screening and new requirements that mandate screening 100% of checked luggage. Neutron Resonance Radiography (NRR) has been under investigation as a supplement to conventional x-ray systems as a non-invasive, non-destructive means of detecting explosive material in checked luggage. Using fast (1-6 MeV) neutrons produced by an accelerator-based D(d,n)3He reaction and a scintillator-coupled CCD camera, NRR provides both an imaging capability and the ability to determine the chemical composition of materials in baggage or cargo. Theoretical studies and simulations have shown the potential of NRR. This thesis takes the first step towards experimental implementation using a deuterium target for multiple-element discrimination. A new neutron source has been developed to provide the high-flux neutron beam required for NRR while simultaneously minimizing gamma ray production. The gas target incorporates a 4 atm D2 gas chamber, separated from the accelerator beamline with thin, 5 [tm tungsten or 7 [im molybdenum foils supported by a honeycomb lattice structure to increase structural integrity and provide a heat removal pathway. An argon gas cooling system is incorporated to cool the target and thus increase the neutron flux. The gas target has been shown to withstand 3.0 MeV deuteron beam currents in excess of 35 ýLA for extended periods without failure, resulting in a neutron flux of 6.6 x 107 neutrons/sr/LA/s. A neutron imaging system was designed to detect the fast neutrons and produce a digital image of objects for analysis. (cont.) Two neutron detectors, Eljen plastic scintillator EJ-200 and a ZnS(Ag) scintillating screen were tested for their suitability to NRR. Although ZnS(Ag) has a lower detection efficiency, its resolution, minimal light dispersion, and insensitivity to gamma rays made it the more favorable material. An Apogee Instruments, Inc., Alta U9 CCD camera was used to record the light from the scintillator to create radiographs. The gas target and neutron detection system were used to evaluate the results of experimental work to determine the feasibility of NRR. These experiments ultimately indicated that although NRR has promise, significant challenges regarding neutron flux and image processing must be overcome before the technique can be implemented as an explosives detection system. Suggestions are made for improvements. by Whitney Lyke Raas. Ph.D. 2008-11-10T19:56:48Z 2008-11-10T19:56:48Z 2007 2007 Thesis http://dspace.mit.edu/handle/1721.1/41290 http://hdl.handle.net/1721.1/41290 213499129 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/41290 http://dspace.mit.edu/handle/1721.1/7582 188 leaves application/pdf Massachusetts Institute of Technology |
| spellingShingle | Nuclear Science and Engineering. Raas, Whitney Towards the development of an explosives detection system using Neutron Resonance Radiography |
| title | Towards the development of an explosives detection system using Neutron Resonance Radiography |
| title_full | Towards the development of an explosives detection system using Neutron Resonance Radiography |
| title_fullStr | Towards the development of an explosives detection system using Neutron Resonance Radiography |
| title_full_unstemmed | Towards the development of an explosives detection system using Neutron Resonance Radiography |
| title_short | Towards the development of an explosives detection system using Neutron Resonance Radiography |
| title_sort | towards the development of an explosives detection system using neutron resonance radiography |
| topic | Nuclear Science and Engineering. |
| url | http://dspace.mit.edu/handle/1721.1/41290 http://hdl.handle.net/1721.1/41290 |
| work_keys_str_mv | AT raaswhitney towardsthedevelopmentofanexplosivesdetectionsystemusingneutronresonanceradiography |