A spectral nodal method for the adjoint SN neutral particle transport equations in X, Y-geometry: Application to direct and inverse multigroup source-detector problems. (January 2021)

• Record Type: Journal Article
• Authors: Curbelo, Jesús P.; Barros, Ricardo C.
• Is Part Of: Annals of nuclear energy. Volume 150(2021)
• Publication Date: 2021-01
• Subjects: Adjoint transport problem -- Spectral nodal method -- Discrete ordinates -- Multigroup problem -- Source-detector problem -- inverse problem -- Non-multiplying media; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2020.107822
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: The SGF-CN method extended to multigroup adjoint Sn problems in X, Y-geometry. Neutral-particle importance maps for direct and inverse source-detector problems. The Levenberg–Marquardt method for estimating sources in inverse Sn problems. Abstract: In this work, we apply an adjoint technique to solve two-dimensional direct and inverse source-detector transport problems. In order to obtain the neutral-particle importance maps, we have developed the extended adjoint spectral Green's function constant-nodal (SGF † -CN) method to numerically solve multigroup adjoint transport problems in the discrete ordinates formulation. Described here is the methodology to obtain the discretized SGF † -CN equations and the adjoint partial one-node block inversion scheme used to iteratively solve these equations. Then, the Levenberg–Marquardt method is applied to minimize a least-squares difference in order to identify the multigroup sources. To illustrate the accuracy of the present methodology, we present and discuss numerical results to two typical model problems.