Active detection of small quantities of shielded highly-enriched uranium using low-dose 60-kev neutron interrogation

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• 作者：Phil Kerr ; Mark Rowl ; Dan Dietrich ; Wolfgang Stoeffl ; Boyd Wheeler ; Les Nakae ; Doug Howard ; Chris Hagmann ; Jason Newby ; Robert Porter
• 关键词：Active neutron interrogation ; Pulse-shape discrimination ; Neutron-induced fission
• 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• 出版年：2007
• 出版时间：August 2007
• 年：2007
• 卷：261
• 期：1-2
• 页码：347-350
• 全文大小：368 K

文摘

Active interrogation with low-energy neutrons provides a search technique for highly-enriched uranium concealed in cargo. We describe the technique and show initial results using a low-dose 60-keV neutron beam. This technique produces a clear induced fission signal in the presence of small quantities of ²³⁵U. The technique has been validated with low-Z and high-Z cargo materials. The technique uses a forward-directed beam of 60-keV neutrons to induce fission in ²³⁵U. Detection of the fast fission neutrons with pulse-shape discriminating scintillators is then the signature for ²³⁵U. The beam of neutrons is generated with a 1.93 MeV proton beam impinging on a natural lithium target. The proton beam is produced by a radio-frequency quadrupole LINAC. The 60 keV neutron beam is forward-directed because the ⁷Li(p, n) reaction is just above threshold for a proton energy of 1.93 MeV.