New Material Characterization method by Using a pulsed Neutron Transmission Spectroscopic Radiography

利用脉冲中子的中子能谱射线照相技术可以获得材料的结构信息，因为它在每个像素处都有中子截面数据。特别是在低能区截面上出现了反映材料晶体结构的布拉格边。布拉格位置的移动给出了晶体的应变。我们对因弯曲而产生应变的铁样品进行了实验。我们可以清楚地观察到应变的位置和应变量。发现应变出现在特定的晶面上。模型实验还表明，布拉格边附近的中子总截面与晶粒尺寸有关，并表明截面与晶粒尺寸成正比地减小。此外，不锈钢-铁试样和铁-铁试样焊接位置附近的晶体结构变化。两种样品的晶体结构变化趋势相似。当然，离井很远 ...更多信息 d位置的截面呈现出典型的铁和不锈钢的布拉格棱边特征，随着靠近焊缝位置，棱边逐渐变尖，在焊缝处棱边变尖，表明晶粒呈各向同性分布。另一方面，在高能量下，我们可以利用共振吸收来获得元素或原子核的图像。我们对重物质进行透射测量以获得CT图像，并建议该方法也可用于成像元素分布，并且我们可以使用该方法通过分析共振峰来测量温度。研制了基于Gd复合材料的成像探测器传感器。我们成功地制作了一个测试探测器，并利用中子束获得了图像，如上所述，使用脉冲中子源的中子光谱成像是研究材料微观结构的非常有力的工具，如应变，晶粒尺寸，晶粒分布等。通过使用这种高强度光源，我们将获得更高质量的数据，并获得有关样品材料的详细信息。因此，我们现在正处于进一步开发该方法以促进工业应用的阶段。少

Spectroscopic neutron radiography using a pulsed neutron can give structural information of materials since it has neutron cross section data at each pixel. Especially, at low energy region of the cross section Bragg edges appear which reflect the crystal structure of the materials. The shift of the Bragg position gives strain of the crystal. We performed the experiment on the iron sample which would have strain due to bending. We could clearly observe the strain position and amount of the strain. It was found that the strain appeared on specific crystal planes. It is also indicated that the total neutron cross section around the Bragg edge depended on the grain size of the crystalitte and showed that the cross section decreased proportional to the grain size by a model experiment. Furthermore, the crystal structural change around the welded position of the SS-Iron sample and Iron-Iron sample. The crystal structure change had similar tendency in both sample. Naturally, far from the wel … More d position the cross section showed the typical feature of Bragg edges of iron and SS, as approaching the weld position the edge became sharper, and at weld position the edge had a sharp edge implying the isotropic distribution of the crystallittes. On the other hand, at high energy we can utilize the resonance absorption to get image of elements or nuclei. We performed transmission measurement of the heavy material to get CT image, and it is suggested that the method was also useful for imaging the element distribution and also that we may use this to measure the temperature by analyzing the resonance peak. We developed the sensor of the imaging detector based on Gd composite. We succeeded in making a test detector and also obtained images by using the neutron beam.As mentioned above, the spectroscopic neutron imaging using the pulsed neutron sources are very powerful tool to investigate micro structure of the materials, such as strain, crystallite size, distribution of crystallite and so on. Now, the operation of the big proton accelerator neutron source is just about to take place. We will get much higher quality data by using such high intensity sources and also get much detailed information about the sample materials. Therefore, we are now on the stage to develop the method further to promote the industrial applications. Less