Space Sciences Laboratory, University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA.
Department of Geology and Environmental Earth Science, Miami University, 250 South Patterson Ave., Oxford, OH 45056, USA.
Sci Rep. 2017 Jan 19;7:40759. doi: 10.1038/srep40759.
Energy-resolved neutron imaging enables non-destructive analyses of bulk structure and elemental composition, which can be resolved with high spatial resolution at bright pulsed spallation neutron sources due to recent developments and improvements of neutron counting detectors. This technique, suitable for many applications, is demonstrated here with a specific study of ~5-10 mm thick natural gold samples. Through the analysis of neutron absorption resonances the spatial distribution of palladium (with average elemental concentration of ~0.4 atom% and ~5 atom%) is mapped within the gold samples. At the same time, the analysis of coherent neutron scattering in the thermal and cold energy regimes reveals which samples have a single-crystalline bulk structure through the entire sample volume. A spatially resolved analysis is possible because neutron transmission spectra are measured simultaneously on each detector pixel in the epithermal, thermal and cold energy ranges. With a pixel size of 55 μm and a detector-area of 512 by 512 pixels, a total of 262,144 neutron transmission spectra are measured concurrently. The results of our experiments indicate that high resolution energy-resolved neutron imaging is a very attractive analytical technique in cases where other conventional non-destructive methods are ineffective due to sample opacity.
能量分辨中子成像是一种非破坏性的分析方法，可以对块状结构和元素组成进行分析，由于近年来中子计数探测器的发展和改进，在明亮的脉冲散裂中子源上可以以高空间分辨率进行解析。这项适用于许多应用的技术，在这里通过对5-10mm 厚的天然金样品的具体研究进行了演示。通过分析中子吸收共振，钯（平均元素浓度约为 0.4 原子%和5 原子%）在金样品中的空间分布被绘制出来。同时，在热和冷能区的相干中子散射分析揭示了哪些样品具有整个样品体积的单晶块状结构。由于可以在热中子、超热中子和冷能范围内同时测量每个探测器像素的中子透射谱，因此可以进行空间分辨分析。热中子、超热中子和冷能范围内的探测器总面积为 512×512 像素，每个像素大小为 55μm，总共同时测量了 262144 个中子透射谱。我们实验的结果表明，在由于样品不透明而导致其他常规无损检测方法无效的情况下，高分辨率能量分辨中子成像技术是一种非常有吸引力的分析技术。
