Can small scale mechanical test data be used for structure critical design?' is it in collaboration with Culham Centre for Fusion Energy (CCFE) and my

该博士项目将研究氦对含锂陶瓷材料中氢（用作氚的类似物）扩散的影响，并开发氦气泡形成和热演化的概念模型。锂陶瓷是围绕聚变反应堆堆芯的氚增殖包层材料的候选者，其中氚是通过在捕获聚变中子之后锂的嬗变产生的。氚的产生也导致氦原子的形成。该项目将研究在预测的增殖包层工作温度下，氦原子是否会聚集形成氦气泡;氦气泡是否优先在晶界或内在缺陷处成核;以及气泡的形成和演变是否取决于材料的微观结构和成分。该项目的第二部分将研究氦原子/气泡是否作为氢的捕获点，减少氢的扩散。如果发现由于氦的相互作用，氢保留增加，这可能对氚扩散有影响。氚扩散的减少将降低效率并影响增殖包层的寿命。候选Li陶瓷将通过例如固态合成来生产。离子注入将用于将氦和氢结合到选定的材料和材料微观结构中，并通过XRD、SEM/EDX和TEM表征离子注入引起的缺陷。氦原子/气泡对氢扩散的影响将使用热脱附光谱（TDS）进行研究。这项研究将发展我们对陶瓷中气体离子相互作用的基本理解，这也与核裂变应用有关，例如核燃料中裂变气体的容纳，以及含锕系元素的陶瓷废物中氦的容纳

This PhD project will investigate the effect of helium on the diffusion of hydrogen (used as an analogue for tritium), in Li-containing ceramic materials, and develop a conceptual model of helium bubble formation and thermal evolution. Li-ceramics are candidates for the tritium breeder blanket material surrounding a fusion reactor core, in which tritium is produced by the transmutation of lithium following capture of a fusion neutron. The production of tritium also results in the formation of helium atoms. This project will investigate whether, at predicted breeder blanket operating temperatures, helium atoms will agglomerate to form helium bubbles; helium bubbles preferentially nucleate at grain boundaries or at intrinsic defects; and if bubble formation and evolution is dependant on material microstructure and composition. The second part of the project will investigate if helium atoms/bubbles act as trapping sites for hydrogen, reducing hydrogen diffusion. If hydrogen retention is found to increase due to the interaction of helium, this could have implications for tritium diffusion. Reduction in tritium diffusion would reduce efficiency and affect the life-time of the breeder blanket. Candidate Li-ceramics will be produced by, for example, solid-state synthesis. Ion implantation will be used to incorporate helium and hydrogen into selected materials and material microstructure and ion implantation induced defects characterised by XRD, SEM/EDX and TEM. The effect of helium atoms/bubbles on hydrogen diffusion will be investigated using thermal desorption spectroscopy (TDS). This research will develop our fundamental understanding of gas ion interactions in ceramics, which is also relevant to nuclear fission applications e.g. the accommodation of fission gasses in nuclear fuels, and accommodation of helium in actinide containing ceramic wasteforms