The unified gas-kinetic wave-particle (UGKWP) method is proposed for the neutron transport equation, addressing the inherent multiscale nature of neutron propagation in both optically thin and thick regimes. UGKWP couples macroscopic diffusion and microscopic transport processes within a unified time-dependent framework, allowing a smooth transition between the free transport and diffusion regimes. This method is readily extended to multi-group neutron transport models and is applicable to both steady-state and eigenvalue problems. Several numerical examples, including the 1D and 3D single-group and 3D multi-group problems, are studied, indicating UGKWP a promising framework for scalable and accurate simulation of multigroup neutron transport in complex geometries.
Liu et al. (Fri,) studied this question.