Fast neutron resonance radiography for elemental imaging: theory and applications
Fast neutron resonance radiography for elemental imaging: theory and applications
复制标题
DOI：
10.1109/nssmic.2001.1009729
复制
发表时间：
2001-11
期刊：
影响因子：
--
通讯作者：
Gongyin Chen;R. Lanza
中科院分区：
文献类型：
--
作者：
Gongyin Chen;R. Lanza
快中子共振射线照相术（NRR）已被设计为一种元素成像方法，其应用例如违禁品检测和矿物分析。在NRR中，氢、碳、氮、氧和其他元素的总和的2-D元素映射是从在不同中子能量下拍摄的快中子射线照相图像获得的，所述中子能量被选择为覆盖一个或多个元素的共振截面特征。图像形成使用透镜耦合塑料曝光器-CCD组合。在初步实验中，我们已经产生了各种模拟物的NRR图像，使用可变能量束的基础上的Li（p，n）Be反应和可变能量质子束。作为这种方法的替代方案，我们研究了NRR成像使用D-D反应在固定的入射D能量和扫描通过各种中子能量通过使用中子能量的角度变化。物体和探测器一起围绕中子源旋转;可以从目标的不同角度获得不同能量（2至6 MeV）的中子。射线透射图像提供元素含量总和的2-D映射（通过衰减系数加权）。在不同的中子能量（角度）下进行的透射测量然后形成一组线性方程，然后可以求解该线性方程以绘制单个元素含量。
Fast Neutron Resonance Radiography (NRR) has been devised as an elemental imaging method with applications such as contraband detection and mineral analysis. In NRR, a 2-D elemental mapping of hydrogen, carbon, nitrogen oxygen and the sum of other elements is obtained from fast neutron radiographic images taken at different neutron energies chosen to cover the resonance cross-section features of one or more elements. Images are formed using a lens-coupled plastic scintillator-CCD combination. In preliminary experiments we have produced NRR images of various simulants using a variable energy beam based on the Li(p,n)Be reaction and a variable energy proton beam. As an alternative to this method, we have studied NRR imaging using the D-D reaction at fixed at fixed incident D energy and scanning through various neutron energies by using the angular variation in neutron energy. The object and detector rotate together around the neutron source; different energy (2 to 6 MeV) neutrons can be obtained at different angles from the target. The radiographic transmission image provides a 2-D mapping of the sum of elemental contents (weighted by the attenuation coefficients). Transmission measurements taken at different neutron energies (angles) then form a set of linear equations, which can then be solved to map individual elemental contents.