TEM study of radiation damage and annealing of neutron irradiated zirconolite
TEM study of radiation damage and annealing of neutron irradiated zirconolite
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中子辐照锆英石辐射损伤及退火的TEM研究
DOI：
10.1557/proc-412-329
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
R. G. Blake
中科院分区：
文献类型：
--
作者：
G. Lumpkin;Katherine L. Smith;R. G. Blake
用中子辐照来模拟锆英石的α衰变损伤，在剂量为4--25 × 10{sup 19} n/cm{sup 2}（E {ge} 1 MeV）时，导致从晶态到非晶态的转变。随着剂量的增加，辐照损伤的微观结构类似于：（1）天然锆英石中的{sup 232}Th和{sup 238}U的α衰变，（2）合成样品中的{sup 238}Pu或{sup 244}Cm的α衰变，以及（3）重离子辐照样品中的碰撞级联。严重受损的锆英石在1,000 ℃退火后恢复为缺陷萤石相.结构回复的主要阶段发生在600- 800 ℃。加热后的微观结构取决于损伤的初始水平：具有低至中等损伤水平的锆英石晶粒退火成不完美的单晶，而严重损伤的晶粒再结晶成多晶微观结构。在这项工作中遇到的并发症包括裂变径迹的生产（由于微量的U）和不均匀分布的损害在较高的剂量水平（可能是由于电子束加热）。
Neutron irradiation was used to simulate alpha-decay damage in zirconolite, resulting in a transformation from the crystalline to the amorphous state at doses of 4--25 {times} 10{sup 19} n/cm{sup 2} (E {ge} 1 MeV). With increasing dose, the radiation damage microstructures resemble damage caused by: (1) alpha-decay of {sup 232}Th and {sup 238}U in natural zirconolites, (2) alpha-decay of {sup 238}Pu or {sup 244}Cm in synthetic samples, and (3) collision cascades in samples irradiated with heavy ions. Heavily damaged zirconolite recovers to a defect fluorite phase on annealing at temperatures up to 1,000 C. The main stage of structural recovery was found to occur at temperatures of 600--800 C. The microstructures after heating depend on the initial level of damage: zirconolite grains with low to moderate levels of damage anneal to imperfect single crystals, whereas heavily damaged grains recrystallize to a polycrystalline microstructure. Complications encountered in this work include the production of fission tracks (due to trace amounts of U) and a non-uniform distribution of damage at higher dose levels (possibly due to electron beam heating).