Chemical imaging and diffusion of hydrogen and lithium in lithium aluminate

JOURNAL OF NUCLEAR MATERIALS

卷:511

Article

Jiang, Weilin¹  Spurgeon, Steven R.¹  Zhu, Zihua¹  Yu, Xiaofei¹  Kruska, Karen¹  Wang, Tianyao²  Gigax, Jonathan²  Shao, Lin²  Senor, David J.¹ 

[1] Pacific Northwest Natl Lab, Richland, WA 99354 USA

[2] Texas A&M Univ, Dept Nucl Engn, College Stn, TX USA

关键词: Chemical imaging;    Diffusion;    Ion irradiation;    Tritium breeder material;    LiAlO2;   

DOI  :  10.1016/j.jnucmat.2018.08.057

来源: Elsevier

【 摘 要 】

Tritium (H-3) must be replenished for strategic stockpile and fusion reactors. Li-6-enriched gamma-LiAlO2 pellets have been used for H-3 production by thermal neutron irradiation. A fundamental study of H-3 and Li-6 diffusion processes in irradiated gamma-LiAlO2 pellets is needed to assess and predict the long-term material performance. This study focuses on identifying the trapping sites and diffusion pathways of H-1 (a surrogate for H-3) and Li atoms in polycrystalline y-LiAlO2 pellets irradiated with both He-4(+) and H-1(2)+ ions. A combination of STEM-EELS, Nano-SIMS and APT is employed for chemical imaging at nanoscale resolution. There is direct evidence for preferred Li diffusion pathways along grain boundaries. Isolated voids are identified as possible Li trapping sites in the irradiated gamma-LiAlO2 pellets. Possible lithium hydrides and/or hydrates are precipitated on the surface of the irradiated pellets. This study improves our understanding of H and Li diffusion processes and provides data for modelling and simulation to predict material performance during neutron irradiation of gamma-LiAlO2 pellets. (C) 2018 Published by Elsevier B.V.

【 授权许可】

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