DEVELOPMENT OF ONE DIMENSIONAL ANGULAR CORRELATION OF POSITRON ANNIHILATION RADIATION MEASU REING WIDE MOMENTUM REGION FOR NON-DESTRUCTIVE INSPECTION OF NUCLEAR REACTOR PRESSURE VESSEL

核反应堆压力容器无损检测宽动量区正电子湮灭辐射测量一维角关联法的研制

• 批准号: 12358005
• 负责人: HASEGAWA Masayuki
• 金额: $ 23.09万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12358005/
• 关键词: POSITRON ANNIHILATION; LIFE MANAGEMENT OF NUCLEAR POWER REACTOR; WIDE RANGE MOMENTUM DISTRIBUTION MEASUREMENT; POSITION SENSITIVE GAMMA-RAY DETECTOR; 陽電子消滅; 原子炉圧力容器鋼; 非破壊検査; 角相関; 照射脆化

Ensuring safe operation of nuclear power reactors is a recent urgent issue since the reactors of the first generation are going over their initially designed operating lifetimes. One of the most important problem is the embrittlement of the reactor pressure vessel (RPV) steels by neutron irradiation, which is considered to be caused by the ultrafine precipitation of Cu impurities contained in the RPV steels (〜O.3 %) of the first generation induced by neutron irradiation. However, little is known about the irradiation-induced Cu precipitates or aggregations because it is very difficult to observe them even by current high-resolution transmission electron microscopes (HR-TEM). The aim of this work is to develop a new type of one-dimensional angular correlation of positron annihilation radiation (1D-ACAR) apparatus for non-destructive inspection of the RPV steels. Our final goal is to establish the method, using the apparatus, to analyze the formation process and the structure of the ultr … More afine Cu precipitates, difficult to detect by other techniques, utilizing affinity-induced positron confinement in the Cu precipitate which we have recently found.For the above purpose, we have to develop a new 1D-ACAR apparatus which enables us to measure the momentum distribution of not only conduction electrons but also core electrons with high momentum resolution (〜1x10^<-3>mc). Thus, we developed a pair of position sensitive gamma-ray detectors with high position resolution (〜2 mm), high counting rate (wide effective area : 150 mm x 150 mm) and high time resolution. One detector was mounted on a fixed support, and the other detector was mounted on a support movable vertically. In the next step, the sample chamber for low temperature (〜15K) measurements and the support for the chamber were constructed. Finally, the electric system for the coincidence measurement of a pair of positron annihilation gamma-rays was set up.We performed a test measurement of the new 1D-ACAR apparatus for the evaluation of the performance. A long tail in the high momentum region was observed, which results in high background and poor position resolution. We found that this was caused by the reflection of the scintillation photons at the light-guide surfaces. To remove this effect, the detectors are now improving the setting of the light-guide geometry and the amplifiers for the timing outputs. Less

确保核电反应堆的安全操作是最近的紧急问题，因为第一代的反应堆正在跨越最初设计的运营寿命。最重要的问题之一是中子辐照的反应堆压力容器（RPV）钢的覆盖，这被认为是由中子辐射引起的第一代RPV钢（〜O.3％）中的CU杂质的超细精度引起的。然而，对于辐照引起的库培或聚集的知之甚少，因为即使通过当前的高分辨率透射电子显微镜（HR-TEM），也很难观察它们。这项工作的目的是开发一种新型的阳性歼灭辐射（1D-ACAR）设备的一维角相关性，以对RPV钢进行非破坏性检查。我们的最终目标是建立使用该设备的方法，分析超级……更多亲和力CU沉淀的形成过程和结构，难以通过其他技术检测到，利用了亲和力引起的cu限制，我们最近发现了我们最近发现的cu沉淀。对于上述目的，我们仅能通过逐步衡量新的1D型仪表，而不得衡量该量的电源，该分配量是否能够进行启动，使得该量度的分配能力，使得该分量的范围，该量是否能够进行启动，该量是否能够启动，该量是否能够构成计算的范围。动量分辨率（〜1x10^<-3> mc）。这，我们开发了一对具有高位置分辨率（〜2 mm），高计数速率（宽有效面积：150 mm x 150 mm）和高时间分辨率的位置敏感伽马射线检测器和高度分辨率。一个检测器安装在固定支撑上，另一个检测器安装在支撑上，可垂直移动。在下一步中，构建了低温（〜15K）测量的样品室和对腔室的支撑。最后，建立了一对正电子歼灭伽马射线的巧合测量的电系统。我们对新的1D-ACAR设备进行了测试测量，以评估性能。观察到高动量区域的长尾巴，从而导致高背景和较差的位置分辨率。我们发现，这是由于光照表面上闪烁照片的反射引起的。为了消除这种效果，探测器现在正在改善轻固定几何形状的设置和定时输出的放大器。较少的

项目成果

Y.Nagai et al.: "Role of Vacancy-Solute Complex in the Initial Rapid Age Hardening in an Al-Cu-Mg Alloy"Acta Materialia. 59. 913-920 (2001)

Y.Nagai 等人：“空位-溶质复合体在 Al-Cu-Mg 合金初始快速时效硬化中的作用”材料学报。

永井康介, 長谷川雅幸: "陽電子消滅法によるFe-Cuモデル合金中の微小Cu析出物の解析"金属. 71・8. 742-748 (2001)

永井浩介、长谷川正幸：“利用正电子湮没法分析 Fe-Cu 模型合金中的微小 Cu 析出物”金属 71・8（2001 年）。

Y. Nagai et al.: "Study of Ultrafine Cu Precipitates in Neutron-Irradiated Fe Utilizing Positron Quantum-dot-like States"Material Science Forum. 363-365. 91-93 (2001)

Y. Nagai 等人：“利用正电子量子点态研究中子辐照铁中的超细铜沉淀”材料科学论坛。

Z.Tang et al.: "Density Functional Study of Metastable bcc Copper : Electronic structure and momentum density of positron-electron pairs"Physical Review B. (掲載受理). (2002)

Z.Tang 等人：“亚稳态 bcc 铜的密度泛函研究：正电子对的电子结构和动量密度”Physical Review B.（接受出版）。

Y.Nagai et al.: "Study of Ultrafine Cu Precipitates in Neutron-Irradiated Fe Utilizing Positron Quantum-dot-like States"Material Science Forum. 363-365. 91-93 (2001)

Y.Nagai 等人：“利用正电子量子点态研究中子辐照铁中的超细铜沉淀”材料科学论坛。