結晶の照射効果に及ぼす電子励起および格子励起の相乗効果

研究了电离和PKA能谱对陶瓷绝缘子物理性能的影响。在这项研究中所研究的陶瓷化学计量和非化学计量的镁铝尖晶石，氧化铝和氧化镁。在TEM加速器设施的离子和电子的同时照射下进行了微观结构演变的原位观察。我们发现，强电离和/或阈下核能，即不引起原子位移的核能，抑制陶瓷中间隙位错环的形成或促进气泡的形成。从电离阻止本领与核阻止本领之比、叶栅位移能量密度和聚焦电子束通量分布等方面对结果进行了讨论。在高压电子显微镜中，低能电子辐照驱动的阳离子扩散是影响电导率的重要因素，本文研制了一种用于电子辐照下电导率原位测量的TEM固定装置。电离辐射在辐射的早期阶段增加陶瓷绝缘体的电导率（RIC：辐射诱导电导率）。在高剂量辐照下，位错损伤可能是重要的。我们还讨论了热刺激电导率的机制，这可能是一个关键问题的融合绝缘体。

We have investigated the role of ionization and PKA (primary knock on atom) energy spectrum on the physical properties in ceramic insulators. The ceramics studied in this study are stoichiometric- and nonstoichiometric- magnesium aluminate spinel, alumina and magnesia.In situ observations of microstructural evolution were carried out under concurrent irradiation with ions and electrons in TEM-accelerator facilities. We have found that the intense ionization and/or subthreshold nuclear energy, that is the nuclear energy which does ont produce displacements of atoms, suppress the formation of interstitial dislocation loops or promote the formation of bubbles in ceramics. Results were discussed in terms of ratio of ionizing to nuclear stopping power, energy density in displacement of cascades and the flux distribution of focused electron beam. An importance of cation diffusion driven by low energy electron irradiation has been found for the concurrent irradiation effects.A special TEM holders has been developed in this study for in situ measurements of electrical conductivity under electron irradiation in a high voltage electron microscope. The ionizing radiation increases electrical conductivity (RIC : radiation induced conductivity) in ceramic insulators at the early stage of irradiation. Displecement damage can be important at high dose irradiation. We have also discussed the mechanism of thermally stimulated conductivity which can be a critical problem for fusion insulators.