Development of the bremsstrahlung counting method for in-situ measurements of tritium absorbed into materials.

研究和发展降低燃料循环中氚存量的技术是建立热核聚变反应堆所必不可少的。为此，有必要发展原位无损测量材料中氚溶解量及其深度分布的技术。从这个角度来看，（i）氚的深度分布和韧致辐射X射线光谱之间的相关性和（ii）分析的韧致辐射X射线光谱与计算机模拟已在本研究中进行了检查。首先，我们发展了一个模拟程式，利用电脑模拟韧致辐射x光光谱分析来评估氚在材料中的深度分布。为了检验所开发的程序的有效性，测量韧致辐射的x射线光谱使用的有机聚合物材料作为模型材料均匀标记的氚，它与计算机模拟得到的光谱进行了比较。作为 关于我们 结果，可以看出，从模拟获得的光谱与通过测量观察到的光谱非常一致，并且对于主要由低Z元素如碳组成的丙烯酸树脂，可以确认可以测量存在于从表面到约1mm的深度中的氚。结果表明，所开发的模拟程序对含氚材料的韧致辐射X射线谱的分析是有价值的。在这些实验之后，检验了本方法对具有不均匀的氚深度分布的金属材料如Pd、Zr和ZrNi的适用性。在这些材料中，观察到特征X射线谱沿着韧致辐射X射线谱，因此改进了上述模拟程序，以分析由两种X射线谱组成的复杂谱。改进后的程序完全适用于复谱的再现。因此，它的结论是，本方法是非常有用的原位和无损测量的氚深度分布的金属材料组成的多组分。少

Research and development of techniques to lower tritium inventory in a fuel cycle is indispensable for the establishment of a thermonuclear fusion reactor. For this purpose, it is necessary to develop the techniques to measure in-situ and nondestructively the amount and the depth profile of tritium dissolved into materials. From this viewpoint, (i) correlation between a depth profile of tritium and a bremsstrahlung x-ray spectrum and (ii) analysis of a bremsstrahlung x-ray spectrum with a computer simulation have been examined in the present study. First of all, a simulation program has been developed to evaluate the tritium depth profiles in materials from analyses of a bremsstrahlung x-ray spectrum by means of a computer simulation. To examine validity of the developed program, a bremsstrahlung x-ray spectrum was measured using an organic polymer material labeled uniformly with tritium as a model material, and it was compared with the spectrum obtained by a computer simulation. As a … More result, it was seen that the spectrum obtained from the simulation agreed quite well with that observed by measurements, and for acrylic resin mainly consisting of low-Z elements such as carbon, it was confirmed that it is possible to measure tritium which exist in the depth from the surface to about 1mm. From those results, it was revealed that the developed simulation program is valuable for the analyses of a bremsstrahlung x-ray spectrum emitted from the materials containing tritium. After these experiments, applicability of the present method to the metallic materials such as Pd, Zr and ZrNi having a non-uniform depth profile of tritium was examined. In these materials a characteristic x-ray spectrum was observed along with a bremsstrahlung x-ray spectrum, and the simulation program mentioned above, therefore, was improved to analyze a complex spectrum consisting of two kinds of x-ray spectrum. It was seen that the improved program is thoroughly applicable to reproduction of the complex spectra. Accordingly, it was concluded that the present method is quite useful for in-situ and nondestructive measurements of a tritium depth profile for metallic materials constituted of multi-components. Less