Division of Quantum Science and Engineering, Graduate School of Engineering, Hokkaido University, Kita-13 Nishi-8, Kita-ku, Sapporo, 060-8628, Japan.
Solid Mechanics Research Group, Department of Mechanical Engineering, University of Bristol, Bristol, BS8 1TR, UK.
Sci Rep. 2023 Jan 13;13(1):688. doi: 10.1038/s41598-023-27857-0.
Thermography using energy-dependent neutron transmission imaging can non-invasively and non-destructively visualize a real-space distribution of interior temperatures of a material in a container. Previously, resonance absorption broadening analysis and Bragg-edge shift analysis using energy-resolved neutron transmission have been developed, however some issues remain, e.g., imaging efficiency, substance limitation and temperature sensitivity. For this reason, we propose a new neutron thermography using the temperature dependence of inelastic scattering of cold neutrons. This method has some advantages, for example, the imaging efficiency is high because cold neutrons are measured with moderate wavelength resolution, and light elements can be analysed in principle. We investigated the feasibility of this new neutron thermography at pulsed neutron time-of-flight imaging instruments at ISIS in the United Kingdom and HUNS in Japan. A Rietveld-type transmission spectrum analysis program (RITS) was employed to refine temperature and atomic displacement parameters from the inelastic scattering cross-section analysis. Finally, we demonstrated interior thermography of an α-Fe sample of 10 mm thickness inside a vacuum chamber by using a neutron time-of-flight imaging detector at the compact accelerator-driven pulsed neutron source HUNS.
使用能量依赖型中子透射成像的热成像，可以非侵入性和非破坏性地可视化容器中材料内部温度的真实空间分布。 以前，已经开发出了使用能量分辨中子透射的共振吸收展宽分析和布拉格边缘移动分析，但是仍然存在一些问题，例如成像效率、物质限制和温度灵敏度。 为此，我们提出了一种使用冷中子非弹性散射温度依赖性的新型中子热成像。 该方法具有一些优点，例如，由于可以用中等波长分辨率测量冷中子，因此成像效率高，并且原则上可以分析轻元素。 我们在英国 ISIS 的脉冲中子飞行时间成像仪器和日本 HUNS 上研究了这种新型中子热成像的可行性。 使用 Rietveld 型透射谱分析程序 (RITS) 从非弹性散射截面分析中细化温度和原子位移参数。 最后，我们使用紧凑型加速器驱动脉冲中子源 HUNS 的中子飞行时间成像探测器对真空室内 10 毫米厚的α-Fe 样品进行了内部热成像。
