Abstract

The implicit Monte Carlo (IMC) method can exhibit teleportation error in problems with strong coupling between radiation and material. Source tilting method is a technique to reduce the teleportation error by representing the emission source as a linear or higher order function in each zone. In this paper, we propose a new spatial reconstruction scheme for the emission source term in the implicit Monte Carlo method. The new reconstruction scheme takes into account of the propagation direction of each photon. A spatially continuous representation for the emission source can be obtained by the reconstruction. We demonstrate that the new scheme can capture the asymptotic diffusion limit in optically thick regions under certain conditions. Numerical simulations show that the continuous reconstruction scheme can significantly reduce the teleportation error and performs better than the one-sided or central difference reconstruction schemes.

摘要

隐式蒙特卡洛（IMC）方法在辐射与材料之间存在强耦合的问题中会表现出隐形传送误差。源倾斜法是一种通过将发射源表示为每个区域中的线性或高阶函数来减少传送误差的技术。在本文中，我们为隐式蒙特卡洛方法中的排放源项提出了一种新的空间重构方案。新的重建方案考虑了每个光子的传播方向。可以通过重建获得发射源的空间连续表示。我们证明了该新方案可以在某些条件下捕获光学较厚区域中的渐近扩散极限。