Implementing displacement damage calculations for electrons and gamma rays in the Particle and Heavy-Ion Transport code System
Implementing displacement damage calculations for electrons and gamma rays in the Particle and Heavy-Ion Transport code System
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DOI：
10.1016/j.nimb.2018.01.028
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发表时间：
2018-03-15
影响因子：
1.3
通讯作者：
Iwamoto, Yosuke
中科院分区：
文献类型：
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作者：
Iwamoto, Yosuke
本研究改进了粒子和重离子输运编码系统（PHITS）中的蒙特卡罗位移损伤计算方法，以计算电子（或正电子）和伽马射线照射下的每原子位移（DPA）值。对于电子和伽马射线造成的损伤，PHITS使用电子伽马阵雨版本5 （EGS5）算法模拟电磁级联，并使用反冲能量和mckinley - feshach横截面计算DPA值。PHITS计算的DPA值与蒙特卡罗辅助经典方法（MCCM）计算的DPA值的比较表明，它们在能量小于10兆电子伏特的硅和铁的伽马射线照射下非常一致。在10 MeV以上，PHITS不仅可以计算电子的DPA值，还可以计算由光核反应产生的带电粒子的DPA值。在电子和伽马射线照射下的DPA深度分布中，可以在目标表面附近观察到累积效应。当能量大于30 GeV的质子辐照90 cm厚的碳时，二次电子DPA值占总DPA值的比例大于10%，且随入射能量的增加而增加。总之，PHITS可以计算所有粒子和材料的DPA值，能量范围在1 keV和1 TeV之间，电子，伽马射线和带电粒子，中子在10(-5)eV和1 TeV之间。
In this study, the Monte Carlo displacement damage calculation method in the Particle and Heavy-Ion Transport code System (PHITS) was improved to calculate displacements per atom (DPA) values due to irradiation by electrons (or positrons) and gamma rays. For the damage due to electrons and gamma rays, PHITS simulates electromagnetic cascades using the Electron Gamma Shower version 5 (EGS5) algorithm and calculates DPA values using the recoil energies and the McKinley-Feshbach cross section. A comparison of DPA values calculated by PHITS and the Monte Carlo assisted Classical Method (MCCM) reveals that they were in good agreement for gamma-ray irradiations of silicon and iron at energies that were less than 10 MeV. Above 10 MeV, PHITS can calculate DPA values not only for electrons but also for charged particles produced by photonuclear reactions. In DPA depth distributions under electron and gamma-ray irradiations, build-up effects can be observed near the target's surface. For irradiation of 90-cm-thick carbon by protons with energies of more than 30 GeV, the ratio of the secondary electron DPA values to the total DPA values is more than 10% and increases with an increase in incident energy. In summary, PHITS can calculate DPA values for all particles and materials over a wide energy range between 1 keV and 1 TeV for electrons, gamma rays, and charged particles and between 10(-5) eV and 1 TeV for neutrons.