聚变中子辐照下氚增殖剂Li2TiO3的释氚行为与机制研究

氚自持是氘氚聚变能工程应用和稳定运行须解决的关键技术之一。氚被增殖剂中的辐照缺陷俘获，会干扰其释放从而影响氚自持功能。作为氚增殖剂的重要候选材料，陶瓷Li2TiO3的氚释放行为及辐照影响机制是氚自持研究的重点课题。现有实验主要利用裂变中子、高能离子、高能电子和γ射线辐照增殖剂，进行模拟研究；但多个对比实验表明，不同射线由于影响机制等不同，形成的缺陷及对释氚行为的效应可能不同。目前还未见到聚变中子辐照对Li2TiO3释氚性能影响机制的公开报道。本项目拟采用氘氚聚变中子源提供14MeV中子辐照环境，结合释氚系统研究中子辐照参数对氚释放形态的影响，并采用X射线光电子能谱分析等技术探索氚在Li2TiO3材料中的可能占位，阐释中子辐照参数-化学态-释氚性能间的关联关系。该工作可提供Li2TiO3聚变中子辐照下的宝贵实验数据，为预测聚变堆真实服役环境下Li2TiO3的释氚性能、提氚系统的设计提供依据。

Tritium self-sufficiency is one of the key technologies for engineering application and steady operation of deuterium tritium fusion energy. Tritium is easy to be captured by irradiation defects in the breeder, which interferes with its release and affects its self-sufficiency function. As an important candidate material of the tritium breeders, Li2TiO3’s tritium release behavior and irradiation effect mechanism are the key topics of tritium self-sufficiency research. The existing experiments mainly use fission neutrons, high-energy ions, high-energy electrons and gamma rays to irradiate breeders for simulation research; however, many comparative experiments show that the defects formed by different rays and their effects on tritium release behavior may be different due to different influence mechanisms. Up to now, there is no report on the mechanism of the effect of fusion neutron irradiation on the tritium release performance of tritium breeders. In this project, the deuterium tritium fusion neutron source is used to provide 14 MeV neutron irradiation environment. Combined with the tritium release system, the influence of neutron irradiation parameters on tritium release form is studied. The possible occupation of tritium produced by fusion neutron in Li2TiO3 material is explored by X-ray photoelectron spectroscopy, and the correlation between neutron irradiation parameters, chemical state and tritium release performance is explained. This work can provide valuable experimental data of Li2TiO3 under neutron irradiation, and provide basis for predicting tritium release performance of Li2TiO3 under real service environment of fusion reactor and designing tritium extraction system.