Experimental validation of a coupled neutron-photon inverse radiation transport solver

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• 作者：John Mattingly ; ^{jkmatti@sandia.gov} ; Dean J. Mitchell ; Lee T. Harding
• 关键词：Gamma spectrometry ; Neutron multiplicity counting ; Radiation transport ; Inverse problems
• 刊名：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• 出版年：2011
• 出版时间：1 October, 2011
• 年：2011
• 卷：652
• 期：1
• 页码：537-539
• 全文大小：1K

文摘

Sandia National Laboratories has developed an inverse radiation transport solver that applies nonlinear regression to coupled neutron-photon deterministic transport models. The inverse solver uses nonlinear regression to fit a radiation transport model to gamma spectrometry and neutron multiplicity counting measurements. The subject of this paper is the experimental validation of that solver. This paper describes a series of experiments conducted with a 4.5 kg sphere of ¦Á-phase, weapons-grade plutonium. The source was measured bare and reflected by high-density polyethylene (HDPE) spherical shells with total thicknesses between 1.27 and 15.24 cm. Neutron and photon emissions from the source were measured using three instruments: a gross neutron counter, a portable neutron multiplicity counter, and a high-resolution gamma spectrometer. These measurements were used as input to the inverse radiation transport solver to evaluate the solver's ability to correctly infer the configuration of the source from its measured radiation signatures.