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

研究了电离能谱和主击原子能谱对陶瓷绝缘体物理性能的影响。本研究所研究的陶瓷为化学计量比和非化学计量比的铝酸镁尖晶石、氧化铝和氧化镁。在透射电子显微镜加速器上进行了离子和电子同时辐照下的显微结构演变的原位观察。我们发现，强电离和/或亚阈值核能，即不产生原子位移的核能，抑制了陶瓷中间隙位错环的形成或促进了气泡的形成。从电离与核阻止功率之比、级联位移能量密度和聚焦电子束的注量分布等方面对计算结果进行了讨论。研究发现，低能电子辐照驱动的阳离子扩散对同步辐照效应具有重要意义。本研究研制了一种用于高压电子显微镜中电子辐照下电导率原位测量的专用电子显微镜夹持器。在辐照初期，电离辐射使陶瓷绝缘子的电导率(RIC：辐射感生电导率)增大。在高剂量辐射下，弥散损伤可能是重要的。我们还讨论了热刺激导电性的机理，这可能是熔融绝缘子的一个关键问题。

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.