Simulating radiation damage cascades in graphite
Simulating radiation damage cascades in graphite
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DOI：
10.1016/j.carbon.2014.09.031
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发表时间：
2015-01-01
期刊：
影响因子：
10.9
通讯作者：
Marks, N. A.
中科院分区：
文献类型：
--
作者：
Christie, H. J.;Robinson, M.;Marks, N. A.
用分子动力学模拟方法研究了石墨中的辐射损伤级联。通过对大能量范围(100-2500 eV)和大量初始碰撞原子方向的采样，获得了较高的统计精度。化学键使用碳与环境相关的相互作用势来描述。人们发现，石墨表现出与金属和氧化物不同的辐射响应，这主要是因为没有热峰，这会导致点缺陷和断开的损伤区域。其他独特的属性包括极短的级联寿命和分形式的原子轨迹。不同寻常的是，对于固体来说，二元碰撞近似在很大的能量范围内都是有用的，因此剩余损伤与金平-皮斯模型是一致的。这些模拟与已知的实验数据是一致的，并有助于澄清文献中关于级联程度和相关损害的大量不确定性。(C)2014年提交人。爱思唯尔有限公司出版。
Molecular dynamics simulation is used to study radiation damage cascades in graphite. High statistical precision is obtained by sampling a wide energy range (100-2500 eV) and a large number of initial directions of the primary knock-on atom. Chemical bonding is described using the Environment Dependent Interaction Potential for carbon. Graphite is found to exhibit a radiation response distinct from metals and oxides primarily due to the absence of a thermal spike which results in point defects and disconnected regions of damage. Other unique attributes include exceedingly short cascade lifetimes and fractal- like atomic trajectories. Unusually for a solid, the binary collision approximation is useful across a wide energy range, and as a consequence residual damage is consistent with the Kinchin-Pease model. The simulations are in agreement with known experimental data and help to clarify substantial uncertainty in the literature regarding the extent of the cascade and the associated damage. (C) 2014 The Authors. Published by Elsevier Ltd.