Using Monte Carlo (MC) transport codes for fusion device shielding calculation is very challenging due to the complexity and heavy shielding of a fusion reactor. An effective on-the-fly (OTF) global variance reduction method was developed and verified before. The OTF method is designed to speed up the general-purpose MC global total neutron distribution by generating and updating the global weight window mesh (WWM) internally in the MC code. In this work, this method has been further extended for accelerating global coupled neutron photon transportation calculation. The goal of this paper is to evaluate the applicability of OTF to enhance the efficiency of the global total neutron and photon fluxes calculation of challenging problems. For verification purposes, the ITER C-model and IFMIF-DONES have been chosen as test cases. The OTF has achieved a substantial reduction in computational time comparing with analogue method.

由于聚变反应堆的复杂性和重度屏蔽，使用蒙特卡洛（MC）传输代码进行聚变装置屏蔽计算非常具有挑战性。之前开发并验证了一种有效的即时（OTF）全局方差减少方法。OTF方法旨在通过在MC代码内部内部生成和更新全局权重窗口网格（WWM）来加快通用MC全局总中子分布。在这项工作中，该方法被进一步扩展以加速全局耦合中子光子传输计算。本文的目的是评估OTF的适用性，以提高挑战性问题的整体总中子和光子通量计算的效率。为了验证，已选择ITER C模型和IFMIF-DONES作为测试用例。