基于高能X射线散射的高原子序数物质探测方法

Method Research of High Z Materials Detection Based on High Energy X-ray Scattering

针对核材料的探测问题,利用其高原子序数(Z)的特性,提出了基于散射能谱解析识别物质原子序数的方法。该方法通过对X射线与物质相互作用所产生的散射光子的测量和分析来进行物质识别,这些光子包括正电子湮没光子、轫致辐射光子和康普顿散射光子,携带了物质原子序数的信息。蒙特卡罗模拟计算结果表明,该方法能够分析核素的原子序数,尤其对核材料等高Z物质的分析更为有效。采用LaBr3(Ce)探测器测量了基于7MeV电子直线加速器的多个样品的散射能谱,结果表明,该方法能有效区分高原子序数物质。

In order to detect nuclear materials the study of the atomic number（Z） identification method based on scattering spectrum analysis and high Z characteristic of special nuclear materials was presened.The method can identify materials by detecting and analyzing positron annihilation photons,bremsstrahlung photons and Compton scattered photons produced by the interaction between X-ray and matter.The results of Monte Carlo simulation show that the method can discriminate Z effectively,especially for high Z materials.An experimental facility based on 7 MeV linac was set up for feasibility study and scattering spectra were observed with a LaBr3（Ce） detector.Preliminary results verify that high Z materials can be discriminated successfully.