A Zero-Variance-Based Scheme for Monte Carlo Criticality Calculations

Proof of a zero-variance scheme for Monte Carlo criticality calculations using adjoint function biasing is given and demonstrated computationally. Although the scheme is of theoretical value, it is shown that biasing using adjoint functions can improve the variance of the keff estimate. The method is general and can be applied to any type of system, as long as the adjoint functions can be obtained, usually from a deterministic calculation.