Optimizing the moderator geometry and thickness for a reactor-based slow positron source

Abstract

Abstract Monte Carlo radiation transport simulations were used to calculate the slow positron yields from tungsten foil positron moderators at a reactor-based slow positron source. The slow positron generation rates were coupled to a simple electrostatic extraction model to estimate the yield of extractable slow positrons from the source. These calculations were used to optimize the foil thicknesses, length, pitch, and extraction voltages.