Study on Helium Behavior in Metals by Nuclear Reaction Method and Nuclear Magnetic Resonance

本研究通过核反应、核磁共振和电子显微镜等手段对氦在金属中的扩散和析出机理进行了研究。实验条件为：离子能量90keV，5.8×10~(-1)；16~gT；He/cm~2，注入温度为室温。核反应和核磁共振结果表明，这两种方法都是研究氦离子行为的良好工具，注入的氦已经显著地扩散到样品箔中。然后，用JMTR、Joyo和FFTF对样品进行辐照。辐照后的样品用透射电子显微镜观察，测量了辐照后的形貌和氦腔密度。根据合金元素的原子尺寸效应讨论了这些氦的行为。

The present research was undertaken to elucidate the mechanism of diffusion and precipitation of helium in metals by nuclear reaction method, nuclear magnetic resonance and transmission electron microscopy.Helium-3 ions were implanted into tantalum foils by the Extrion Implantor. The condition was follows : ion energy 90keV, 5.8x10^<16>He/cm^2, and implantation at room temperature.The results by nuclear reaction method and nuclear magnetic resonance show that both methods are good tools to research the helium behaviour, and implanted helium already diffuses through the sample foil significantly.For the research by TEM, helium was into vanadium alloys implanted by boron-10 method and tritium trick method. Then, the samples were irradiated by JMTR, JOYO and FFTF. After the irradiation the samples were observed by TEM ; irradiated morphology and helium cavity density were measured. These helium behaviour was discussed in terms of the atomic size effect of alloying elements.