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Tracking of tritium trapped on/in high-Z materials by BIXS

通过 BIXS 追踪高 Z 材料上/中捕获的氚

基本信息

批准号：
13480133
负责人：
MATSUYAMA Masao
金额：
$ 9.15万
依托单位：
TOYAMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13480133/
关键词：
tritium nondestructive measurement bremsstrahlung x-ray spectrum characteristic x-ray spectrum depth profile tritium inventory accountability safe handling technique 拡散係数

项目摘要

Trap and/or diffusion behavior of tritium in high-Z materials such as W and Mo, which are promising candidate as plasma-facing materials of fusion devices, have been studied by means of β-ray-induced X-ray spectrometry (BIXS). Main results obtained in the present study were as follows :(1) Diffusion behavior of tritium in W at room temperatureA given amount of tritium ions was implanted in a tungsten sample, and then change in β-ray-induced X-ray spectra at room temperature was tracked. The X-ray spectra observed were analyzed by means of computer simulation to estimate tritium depth profiles in tungsten. From change in the depth profiles, the diffusion coefficient of tritium at room temperature was estimated to be 2.4x10^<19> m^2/s.(2) Thermal behavior of tritium ions implanted into WThe tungsten sample irradiated with tritium was stepwise heated from room temperature to 700℃, and an X-ray spectrum was measured after each heating As a result, both X-ray intensities of Ar and W decreased with the increase of temperature, and they decreased to about 10% of the initial intensity at 500℃, indicating hat most of the implanted tritium desorbed from surface layers and bulk of the sample.(3) Effect of He pre-irradiation on the trap and diffusion behavior of tritiumWhen tritium was implanted into the He pre-irradiation sample, the X-ray intensity of Ar was about 5 times great in comparison with the He non-irradiation sample, and no change in the intensity at room temperature was observed for five months. Namely, it was seen that the retention of tritium strongly increased with the He pre-irradiation. The amount of tritium in surface layers decreased with heating, but that in bulk did not change up to 350℃. This indicates that the implanted tritium was strongly trapped at lattice imperfections formed by the He pre-irradiation, and the trapping energy of tritium was estimated to be about 1.2eV.

用β-Ray-Induced X射线能谱研究了氚在高Z材料W和Mo中的俘获和/或扩散行为，这些材料是聚变装置中面向等离子体的候选材料。本研究取得的主要结果如下：(1)室温下氚在钨中的扩散行为研究了一定剂量的氚离子注入钨样品后，室温下β-射线诱导的X射线能谱的变化。用计算机模拟方法对观测到的X射线能谱进行了分析，以估算钨中的氚深度分布。根据深度分布的变化，估算出室温下氚的扩散系数为2.4×10~(-1)~(-19)~(-gT)。M^2/S。(2)将氚离子注入钨样品中的热行为从室温逐步加热到700℃，每次加热后测量X射线能谱。结果表明，Ar和W的X射线强度都随着温度的升高而降低，在500℃时，它们的X射线强度都下降到初始强度的10%左右，表明注入的氚大部分从样品的表层和主体中解吸出来。(3)氦预辐照对氚的陷阱和扩散行为的影响。Ar的X射线强度约为He未辐照样品的5倍，并且在室温下观察到5个月的强度没有变化。也就是说，可以看到，氚的保留率随着氦气预照射的增加而显著增加。表层的氚含量随着加热的增加而减少，但在350℃以下，体相中的氚含量没有变化。这表明注入的氚被强俘获在He预辐照形成的晶格缺陷处，其俘获能量约为1.2 eV。