Fast neutron resonance radiography for element imaging : theory and applications

Fast Neutron Resonance Radiography (NRR) has been devised as an elemental imaging method, with immediate applications to detecting explosives and drugs in passenger suitcases. In the NRR method, the 2-D elemental mapping of hydrogen, carbon, nitrogen, oxygen and the sum of other elements are obtained from fast neutron radiographic images taken at different neutron energies chosen to cover the resonance cross section features of one or more elements. A radiographic image provides the 2-D mapping of the sum of elemental contents (weighted by the attenuation coefficients) and transmission measurements taken at different neutron energies form a set of linear equations, which can be solved to map individual elemental contents. Explosives and drugs can be identified by their characteristic elemental composition. The object-detector assembly rotates around the neutron source and different energy (2-6 MeV) neutrons can be obtained at different angles from a DD neutron source. A fixed-energy RFQ (2.3 MeV deuteron energy) with a thick target (0.4-0.8 MeV) can be used to generate fast neutrons. The physics of image formation in fast neutron radiography has been studied and a thick (4 cm) plastic scintillator has been recommended as the neutron detector.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Nuclear Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Chen, Gongyin, 1968-

Advisor dc:contributor.advisor

• Richard C. Lanza.

• Nuclear Engineering.

Statement dc:rights

• 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.

Licence dc:rights.uri

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

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8681

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8681