Annealing of ion irradiation damage in nuclear graphite
Annealing of ion irradiation damage in nuclear graphite
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DOI：
10.1016/j.jnucmat.2012.12.001
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发表时间：
2013-03-01
影响因子：
3.1
通讯作者：
Marrow, T. James
中科院分区：
文献类型：
--
作者：
Lasithiotakis, Michael;Marsden, Barry J.;Marrow, T. James
本文研究了抛光和离子辐照石墨和高取向热解石墨(HOPG)在退火热处理过程中拉曼光谱的变化，并与快中子辐照石墨在储能释放过程中的变化进行了比较。推测抛光、离子辐照和中子辐照石墨的拉曼光谱的变化可以归因于晶格缺陷的退火引起的晶体结构的变化。这项工作通过抛光和离子辐照的Gilocarbon和HOPG石墨的热退火过程中动力学参数的变化，即拉曼I-D/I-G比的降低来说明这一点。从活化能和反应级数两个方面研究了几种动力学模型。发现最适合解释拉曼退火动力学的模型是：抛光石墨的二反应模型，离子辐照的石墨和离子辐照的高密度石墨的二反应模型和可能的三反应模型。用这两种反应模型和三种反应模型得到的动力学参数与中子辐照石墨的动力学模型相似。拉曼强度比ID/IG与缺陷量的平方根成正比的假设比直接成比例的假设提供了更好的拟合。(C)2012爱思唯尔B.V.保留所有权利。
Changes in Raman spectra of polished and ion-irradiated Gilsocarbon and Highly Orientated Pyrolytic Graphite (HOPG) during annealing have been investigated and compared with changes reported during stored energy release in fast neutron irradiated graphite. It is postulated that the change in the Raman spectra of polished, ion-irradiated and neutron irradiated graphite can be attributed to crystalline structural changes due to the annealing of lattice defects. This is illustrated in this work by changes in the kinetic parameters, in terms of the decrease of the Raman I-D/I-G ratio, during the thermal annealing of polished and ion-irradiated Gilsocarbon and HOPG graphite. Several kinetic models are investigated in terms of activation energy and order of reaction. The most suitable model to explain Raman annealing kinetics was found to be, a two reaction model for polished Gilsocarbon graphite, and a two and possibly three reaction model for ion-irradiated Gilsocarbon graphite and ion-irradiated HOPG. The kinetics parameters obtained using both the two and three reaction models reveal similarities with kinetic models obtained for neutron irradiated graphite. The assumption that the Raman intensity ratio ID/IG is proportional to the square root of the defect quantity provided a better fit than the assumption of direct proportionality. (C) 2012 Elsevier B.V. All rights reserved.