Displacements per atom (dpa), estimated based on the standard Norgett–Robinson–Torrens (NRT) model, is used for assessing radiation damage effects in fast reactor materials. A computer code CRaD has been indigenously developed towards establishing the infrastructure to perform improved radiation damage studies in Indian fast reactors. We propose a method for computing multigroup neutron NRT dpa cross sections based on SRIM-2013 simulations. In this method, for each neutron group, the recoil or primary knock-on atom (PKA) spectrum and its average energy are first estimated with CRaD code from ENDF/B-VII.1. This average PKA energy forms the input for SRIM simulation, wherein the recoil atom is taken as the incoming ion on the target. The NRT-dpa cross section of iron computed with “Quick” Kinchin-Pease (K-P) option of SRIM-2013 is found to agree within 10% with the standard NRT-dpa values, if damage energy from SRIM simulation is used. SRIM-2013 NRT-dpa cross sections applied to estimate the integrated dpa for Fe, Cr and Ni are in good agreement with established computer codes and data. A similar study carried out for polyatomic material, SiC, shows encouraging results. In this case, it is observed that the NRT approach with average lattice displacement energy of 25 eV coupled with the damage energies from the K-P option of SRIM-2013 gives reliable displacement cross sections and integrated dpa for various reactor spectra. The source term of neutron damage can be equivalently determined in the units of dpa by simulating self-ion bombardment. This shows that the information of primary recoils obtained from CRaD can be reliably applied to estimate the integrated dpa and damage assessment studies in accelerator–based self-ion irradiation experiments of structural materials. This study would help to advance the investigation of possible correlations between the damages induced by ions and reactor neutrons.

根据标准的诺盖特-罗宾逊-托伦斯（NRT）模型估算的每原子位移（dpa）用于评估快堆材料中的辐射损伤效应。本地开发了计算机代码CRaD，以建立基础设施，以在印度快堆中进行改进的辐射损伤研究。我们提出了一种基于SRIM-2013模拟计算多组中子NRT dpa截面的方法。在这种方法中，对于每个中子组，首先使用来自ENDF / B-VII.1的CRaD代码估算反冲或主连锁原子（PKA）光谱及其平均能量。该平均PKA能量形成SRIM模拟的输入，其中反冲原子被当作目标上的进入离子。如果使用SRIM模拟的破坏能，则发现使用SRIM-2013的“快速” Kinchin-Pease（KP）选项计算的铁的NRT-dpa横截面与标准NRT-dpa值相差10％。用于估算Fe，Cr和Ni的综合dpa的SRIM-2013 NRT-dpa横截面与已建立的计算机代码和数据非常吻合。对多原子材料SiC进行的类似研究显示出令人鼓舞的结果。在这种情况下，可以观察到NRT方法的平均晶格位移能为25 eV，再加上SRIM-2013的KP选项提供的破坏能，可提供可靠的位移截面和各种反应堆光谱的积分dpa。中子破坏的源项可以通过模拟自离子轰击等效地以dpa为单位确定。这表明从CRaD获得的一次后坐力的信息可以可靠地用于估算基于加速剂的结构材料自离子辐照实验中的综合dpa和损伤评估研究。这项研究将有助于推进离子和反应堆中子与离子引起的损伤之间可能的相关性研究。