The Implicit Monte Carlo (IMC) method is widely used for solving the nonlinear thermal radiative transport problems. This method often exhibits teleportation error in problems with strong coupling between radiation and matter. In this article, we propose a new Legendre functional expansion tally method to reduce the teleportation error for gray radiative transfer equations in the IMC method. The piecewise functional expansion tallies of absorbed energy in the previous time step is employed for the distribution of emission energy at the current time step within a cell. Numerical simulations show that our method significantly reduces the teleportation error relative to the source tilting method, and enables the use of lower spatial resolutions that would be required to mitigate the teleportation error using the source tilting method.

隐式蒙特卡洛（IMC）方法被广泛用于解决非线性热辐射输运问题。在辐射与物质之间存在强耦合的问题中，此方法通常会出现隐形传送错误。在本文中，我们提出了一种新的Legendre函数展开计数方法，以减少IMC方法中灰色辐射传递方程的隐形传态误差。在前一个时间步中吸收能量的分段功能展开计数用于在单元中当前时间步处的发射能量分布。数值模拟表明，相对于源倾斜方法，我们的方法显着降低了隐形传送误差，并允许使用较低的空间分辨率，这将需要使用源倾斜方法来减轻隐形传递误差。