Built in importance estimation in forward Monte Carlo calculations. (November 2022)

• Record Type: Journal Article
• Authors: Jafarikia, S.; Feghhi, S.A.H.
• Is Part Of: Annals of nuclear energy. Volume 177(2022)
• Publication Date: 2022-11
• Subjects: Monte Carlo method -- Importance function -- Built in importance estimation -- Variance reduction; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2022.109298
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: A Monte Carlo (MC) based importance calculation approach has been developed. The technique uses the particle's history in the forward MC calculation for calculating the particle's importance function. GMCNIC as the forward-adjoint method makes possible dynamic variance reduction technique in the MC calculation. Abstract: Recently, Monte Carlo code development has shown the benefits of using deterministic importance functions in radiation transport calculation; however, using Monte Carlo based importance function is less considered regarding the computational costs in this calculation. This paper offers a Monte Carlo based importance calculation method with the capability of application in forward Monte Carlo simulations. The technique uses the tracked particle's history in the forward Monte Carlo calculation for the estimation of importance function. Moreover, the particle population, weight, and pathways can be considered for dynamic Monte Carlo calculation. The ability of the purposed method is shown by some examples in simple and complex geometries. The results show that the method can be used in the Monte Carlo code development that can benefit from a dynamic variance reduction technique in radiation transport calculations.