基于可移动紧凑加速器D-T中子源的热中子层析实验研究

Experimental Study of Thermal Neutron Tomography Based on D-T Neutron Source with Mobile Compact Accelerator

中子照相是十分重要的无损检测方法之一,尤其是针对含氢材料、同位素等的无损检测,中子照相技术具有其他射线成像不可比拟的优势。中国工程物理研究院核物理与化学研究所基于紧凑型D-T中子源,研发了可移动中子成像检测仪,成功实现了热中子照相和快中子照相实验检测。为确定基于该装置开展热中子层析检测的可行性,本文进行了数值模拟计算,利用该仪器开展了针对轻重材料模拟件的热中子层析成像实验,利用采集的181幅投影图像,在图像信噪较低和采集幅数较少条件下,成功重建了铝和聚乙烯材料包裹下的0.2 mm直径的钆丝。

Neutron radiography(NR)is one of the most important nondestructive testing methods,which could be applied in nondestructive testing of hydrogen containing materials,isotopes and so on.Institute of Nuclear Physics and Chemistry of China Academy of Engineering Physics has constructed a multi-use neutron imaging facility based on D-T neutron source with mobile compact accelerator,which could realize thermal neutron radiography and fast neutron radiography.Thermal neutron tomography parameters based on this facility were confirmed with numerical simulation method.With 181 collected radiography images and test object made of aluminum,polyethylene and gadolinium,and overcoming the conditions of less collected radiography images and low signal to noise ratio in the raw pictures,gadolinium line with diameter of 0.2 mm in the aluminum and polyethylene structure was successfully reconstructed.