Evolution of the FoM gain for every time step simulated in the kinetic scenario presented in Figure 5. The displayed FoM gain values for every time step are computed choosing combing (top) or Russian roulette on precursors (bottom) as the population control strategy. In both cases we investigate a broad range of importance ratio values, spanning from 10³ to 10¹². The circle represents the FoM gain obtained using the value of R determined from the solution of the adjoint point-kinetics equations.