高能X射线基材料分解法基材料选择方法

选择基材料是高能双能X射线基材料分解法的重要环节。为了解基材料对材料识别精度的影响,确定选择基材料的方法和原则,利用美国国家标准与技术研究院(NIST)给出的材料的线性衰减系数,选择不同基材料,分析计算了各种待检测材料的原子序数和电子密度及相对误差。归纳总结出选取基材料的"临近原则",即基材料与待检测材料的原子序数接近,能提高待检测材料原子序数和电子密度的分解计算精度。在此基础上,提出了四能基材料分解法。理论计算表明四能基材料分解法比双能基材料分解法对多种材料的整体识别精度更高,更适合用于多种材料同时存在情况下的识别与检测。运用蒙特卡罗方法模拟验证了四能基材料分解法用于实际的可行性。

Basis material selection principle for high energy X-ray basis material decomposition method

Selection of basis material is a key process for dual high energy X-ray computer tomography basis material decomposition method (BMDM). In order to make clear the influence of different basis materials on material discrimination accuracy and put forward a reasonable principle for the selection of basis material, this article compared the atomic number and electron density of materials being discriminated which were calculated with BMDM based on different basis materials. It further summed up a basis material selection principle named "neighboring principle", i.e., choosing a basis material with the atomic number close to that of the material under discrimination could improve the discrimination accuracy, and four energy basis material decomposition methods are put forward based on the principle. Finally, with the Monte-Carlo technique, the validity of the four energy basis material decomposition methods was verified.