Effects of helium and ambient water vapor on tritium release from Li2TiO3
Effects of helium and ambient water vapor on tritium release from Li2TiO3
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DOI：
10.1016/j.jnucmat.2014.08.058
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发表时间：
2014-12
影响因子：
3.1
通讯作者：
Makoto Kobayashi;Hiromichi Uchimura;Kensuke Toda;Y. Oya
中科院分区：
文献类型：
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作者：
Makoto Kobayashi;Hiromichi Uchimura;Kensuke Toda;Y. Oya
为了建立氚迁移模型，研究了氚回收气中氢同位素和氦的存在对偏钛酸锂(Li2TiO3)氚释放行为的影响。高能氚离子注入形成了氧空位和悬挂键氧原子的氚捕获位。与吹扫气中水蒸气的同位素交换过程促进了吸附在Li2TiO3表面并捕获在氧空位中的氚的回收。由于氚作为羟基的捕集能较高，因此很难用吹扫气中的氢同位素代替氚作为羟基。氦注入会导致氦气泡的形成，这些气泡会占据辐照损伤，导致氚的俘获中心密度降低。因此，在氚回收气体中添加氢同位素和在氚增殖材料中加入氦有助于氚增殖材料的高效氚回收。
The effects of hydrogen isotopes in tritium recovery gas and the presence of helium on the tritium release behaviors were investigated for lithium meta-titanate (Li2TiO3) to develop a tritium migration model. The tritium trapping sites as oxygen vacancies and oxygen atoms with dangling bonds were formed by energetic tritium ion implantation. Isotope exchange processes with water vapor in purge gas enhanced the recovery of tritium adsorbed on the surface of Li2TiO3and trapped in oxygen vacancies. Replacement of tritium as hydroxyl groups with hydrogen isotopes from purge gas was hardly occurred due to the higher trapping energy of tritium as hydroxyl groups. Helium implantation would induce the formation of helium bubbles, which would occupy irradiation damages, contributing to the decrease in the densities of trapping site for tritium. Consequently, the addition of hydrogen isotopes in the tritium recovery gas and the presence of helium in tritium breeding materials can contribute to the efficient tritium recovery for tritium breeding materials.