Monte Carlo simulation of rotational modulation collimator (RMC) patterns for the gamma-ray/neutron dual-particle imager

摘要

This work is to develop a gamma-ray/neutron dual-particle imager, based on Rotating Modulation Collimators (RMC) and Pulse Shape Discrimination (PSD)-capable scintillators, for the nuclear security and safeguard application. We started with performing fundamental simulations on the RMC, to optimize the collimator design and the computing time for the Monte Carlo simulation. We obtained batches of RMC-modulated patterns to study the simulated behavior of the modulated pattern depending on various source locations. Simulated modulation profiles were used to verify the imaging algorithm developed on the basis of the Maximum-Likelihood Expectation Maximization (MLEM) method. An introduction to the current project and the simulation scheme will be presented, followed by brief comments on preliminary results of the simulated profiles.