含表面层的厚靶D-T中子产额计算

Computation of D-T Neutron Yields in Thick-target With Surface Layer

摘要: 本文给出一种含表面层氚钛靶D-T反应中子产额的计算方法，并开发了相应的数值计算程序。以氧化层为TiO₂为例，定量计算了D核在TiO₂中的深度分布统计及透过率、200 keV的D核穿过不同厚度TiO₂的能量分布函数、D核入射含不同厚度氧化层TiT_1.0的D-T中子产额和不同能量D核入射固定厚度氧化层TiT_1.0的D-T中子产额。结果显示，中子产额随氧化层厚度的增加而减小，对于200 keV的D核入射到含TiO₂氧化层的TiT_1.0厚靶，当TiO₂厚度为0.1 μm时，损失约10%的中子产额，厚度为0.2 μm时，损失约20%的中子产额。本方法可推广到其他类型表面层（如污染层、保护层等）的中子产额计算，可用于中子发生器用靶的结构设计和中子产额评估。

Abstract: A calculation program based on Monte Carlo software SRIM was developed to calculate the D-T neutron yield in titanium tritide thick-target with titanium oxide surface layer. The neutron yields of 200 keV deuteron vertical incidence to TiT_1.0 film with various thicknesses of TiO₂top layer were obtained. The neutron yield decreases by 10% and 20% with thickness of TiO₂ layer of 0.1 μm and 0.2 μm respectively. This means can be applied to the calculations of other surface layer, including contamination layer, protective layer, etc.