Evaluating Importance Maps for TRIPOLI-4® Using Deterministic or On-Line Methods

摘要

Variance reduction is a key ingredient for solving radiation-protection problems with Monte-Carlo particle-transport codes. Many variance-reduction methods require the definition of an importance map and exhibit optimal performance if the importance map is given by the adjoint flux, the solution of the adjoint Boltzmann equation. This paper presents the implementation of the Consistent Adjoint-Driven Importance Sampling (CADIS) methodology via a coupling between the TRIPOLI-4® Monte-Carlo particle-transport code and the IDT deterministic solver. Additionally, we describe the implementation of a new TRIPOLI-4® score that makes it possible to estimate the adjoint flux during a direct Monte-Carlo calculation. These new features are expected to simplify the solution of difficult shielding problems.