Elemental imaging plays an important role in characterizing the chemical and physical properties of large samples. In this work, a position-sensitive technique using prompt gamma ray neutron activation analysis (PGNAA) was applied to image the internal composition of large samples with 10–20 cm thicknesses. An inelastic neutron scattering system consisting of a D-T neutron generator and a high-purity germanium (HPGe) detector was built and used for elemental distribution analysis of a large metal sample containing iron, titanium, and copper. The 2D elemental imaging of the three elements was performed using the designed system. The effect of inhomogeneous neutron field was also corrected using Monte Carlo simulations. The results indicate that ~4 cm spatial resolution can be achieved. The position-sensitive elemental analysis based on inelastic neutron scattering reaction is efficient for bulk metal sample analysis.

元素成像在表征大样品的化学和物理特性中起着重要作用。在这项工作中，采用了瞬态伽玛射线中子活化分析（PGNAA）的位置敏感技术，对厚度为10–20 cm的大型样品的内部成分成像。建立了由DT中子发生器和高纯锗（HPGe）检测器组成的非弹性中子散射系统，并将其用于包含铁，钛和铜的大型金属样品的元素分布分析。使用设计的系统对三个元素进行了2D元素成像。非均匀中子场的影响也使用蒙特卡洛模拟进行了校正。结果表明可以实现〜4 cm的空间分辨率。