Reactor Irradiation Experiments by Advanced Optical Technology

我们研制了一套高分辨率共振电离光谱系统，可用于亚ppd水平的稳定或放射性同位素的检测。用Xe气体和几种固体元素对该系统进行了测试。固体样品用脉冲烧蚀激光雾化。我们还测试了一个可用于烧蚀和电离的单一激光系统。与传统的活化箔方法相比，电流体系具有更高的灵敏度。对系统的灵敏度进行了定量评估，并对实际系统中存在的问题进行了讨论。激光诱导发射的分辨率为2 mm，可以在中子场中进行在线测量。为了研究辐射诱发现象的快速检测，研制了一套动态CT自动测量系统，并用脉冲电子束对其进行了测试。切伦科夫光和闪烁均以亚纳秒时间尺度显示。还进行了光学辐照实验，用位置湮没测量技术研究了hcp结构中缺陷的形成机理。对观察到的叶栅损伤团簇大小及其稳定性进行了评估。与辐照实验结果相比较，在评价中分离了扩散效应，阐明了缺陷团簇的形成机理。

We have developed a high resolution Resonance Ionization Spectroscopy system that can be used for the detection of stable or radioactive isotopes of sub ppd level concentration. The system was tested using Xe gas and several solid elements. Solid samples were atomized by the pulsed ablation laser. We have also tested a single laser system, which can be used for ablation and ionization. Current system showed a better sensitivity than conventional activation foil method. Quantitative evaluation of the system sensitivity and further issues for the practical system were performed.The resolution of laser induced emission was evaluated to be 2mm and online measurement in a neutron field is possible. On the study of very fast detection of radiation induced phenomena, a dynamic CT automatic measurement system was developed and tested with a pulsed electron beam. Both Cherenkov light and scintillation were visualized with sub ns time scale. Irradiation experiment on optics was also performed.Defect formation mechanism in the HCP structure was investigated by a position annihilation measurement technique. The cluster size observed for the cascade damage and its stability were evaluated. Compared with the results from on irradiation experiments, the diffusion effect was separated in the evaluation and the defect cluster formation mechanism was clarified.