Passive Neutron Assay of Plutonium Materials: Monte Carlo Procedures to Simulate Generation of Neutron Pulse Trains and the Application of the Neutron Coincidence Counting Method

The development and setup of a procedure to simulate passive assays of plutonium dioxide samples by the neutron coincidence counting technique are presented. The main topics are pulse train simulation methodology, application of the neutron coincidence counting technique to the simulated pulse trains and subsequent Reals rate calculation, validation of the simulation procedure by direct comparison with experimental data from 1 × 10¹ g ÷ 2.5 × 10³ g PuO₂ reference standards, application of the simulator for studying ideal well counters, and presentation of further developments concerning possible applications of the simulator as a design tool for well counters and for studying dead-time and induced fission correction formulas.