中国先进研究堆瞬发γ元素成像技术研究

无损分析样品内部的元素分布,对于材料、考古、地质科学等领域的研究具有重要意义。本文基于瞬发γ活化分析方法,结合中子照相技术,分析了模拟样品的结构和对称性,首次利用中国先进研究堆(CARR)水平孔道聚焦的微束中子束流,开展了样品瞬发γ扫描分析和材料内部元素分布研究。通过蒙特卡罗软件(MCNP)对样品元素分布实验模型进行分析,模拟结果获得了样品不同区域的元素分布,基本实现了元素空间分辨。MCNP计算结果表明在瞬发γ扫描分析中,优化准直几何参数和提高中子通量能进一步提高元素空间分辨和元素测量准确度。

Elemental Imaging by Prompt Gamma Activation Analysis at China Advanced Research Reactor

Nondestructive analysis of the element distribution within samples is of great significance for the research in materials, archaeology, and geological sciences. Based on prompt γ activation analysis and combined with neutron radiography, the structure and symmetry of the simulated sample were analyzed. For the first time, the micro-beam neutron beam focused by the horizontal aperture of the China Advanced Research Reactor (CARR) was used to carry out the prompt γ scanning analysis of the sample and the study of the element distribution within the material. The experimental model of the element distribution of the sample was analyzed by Monte Carlo software (MCNP). The simulation results obtained the element distribution of different regions of the sample, basically realizing the spatial resolution of the element. The MCNP calculation results show that in the prompt γ scanning analysis, optimizing the collimating geometry parameters and increasing the neutron flux can further improve the spatial resolution and measurement accuracy of the element measurement.