【摘要】 等离子体中子源是托卡马克中子学分析的重要输入，是连接核聚变等离子体物理和工程设计的桥梁。为了更精确地描绘中子壁负载（Neutron Wall Loading,NWL）的空间分布，开发了一组处理中子源和NWL的独立代码。对托卡马克中的氘氚聚变等离子体放电进行研究，构建了核聚变反应类型以及中子源释放模型，同时也建立了高能量中子对第一壁轰击的理论模型。基于托卡马克等离子体位形，采用“复丝”方法开展了中子源和NWL分布的数值模拟研究。研究结果表明，NWL最大值在外侧中平面附近，比在内侧中平面的高100%以上，应特别注意位于外侧中平面附近关键部件的辐射屏蔽和辐射防护。NWL的最小值位于顶部板或底部板，因此非中子诊断设备可优先考虑安装到顶部板和底部板。同时，还研究了密度峰化（Density Peaking,DP）因子对中子学分析的影响。随着密度峰化的增加，NWL在外侧中平面和内侧中平面的峰值均减小。然而，NWL的下降幅度非常小：当中子源峰值增加约1.5倍时，NWL的值仅下降了10%。因此，DP因子对托卡马克装置的NWL分布影响较小。最后，还研究了温度分布对中子学分析的影响。随着温度的增加，聚变功率和中子壁负载都是增加的，表明在托卡马克装置中等离子体温度对NWL分布具有显著影响。更多还原

【Abstract】 [Background] As a crucial input for the neutronics analysis of tokamak devices, the plasma neutron source serves as a bridge connecting the realms of fusion plasma physics and engineering design. [Purpose] This study aims to depict the spatial distribution of the neutron wall loading（NWL） more accurately by developing a set of independent codes dealing with the neutron source and NWL. [Methods] In respect of the deuterium-tritium fusion plasma discharge in tokamak, the types of nuclear fusion reactions and the release model of neutron sources were constructed, and the theoretical model of energetic neutron bombardment to the first wall was also established. The numerical simulation of neutron source and NWL distribution was carried out by employing the "multifilament" method in tokamak configuration. Finally, the effects of plasma density peaking（DP） factor and temperature distribution on neutron source distribution and neutron wall load distribution were investigated. [Results] Simulation results show that the maximum of NWL is located near the outboard midplane and exceeds ～100% of that on the inboard midplane, and hence the necessity of paying special attention to the radiation shielding and the protection of key components situated on the outboard midplane. As DP increases, both outboard and inboard peak NWL values decrease. However, the decrease in NWL is very small, the value of NWL decreases by only 10% when the peak of the neutron source increases by a factor of about 1.5. As the temperature ratio is increased from 0.6 to 1.4, the fusion power is increased from 361.4 MW to 1 580.0 MW and the peak value of NWL in the outer midplane is increased from 0.510 MW·m^-2 to 2.10 MW·m^-2, while the peak value of NWL in the inner midplane is increased from 0.22 MW·m^-2 to 0.99 MW·m^-2. [Conclusions] Results of this study demonstrate that the peak NWL is consistently near the outboard midplane, and the density peaking has slight effect on the NWL distributions in tokamaks, but both fusion power and NWL increase with the increase of temperature, indicating the temperature has a significant impact on the NWL distribution in tokamak devices.更多还原