样品颗粒度对X射线荧光强度影响模拟方法研究

摘要

Construct face-centered cubic structure of uniform particles with MCNP method,copper sulfate and zinc reference layer as example,to study the relationship between fluorescence intensity and ratio of fluorescence intensity of copper and zinc excited by X-ray. Use standard sieves to filtrate the grinded copper sulfate particles and prepare infinitely thick samples for fluorescence measurement to examine the validity of the method; study the influence of particle size effect on finitely thick samples with the method. The results indicate that fluorescence intensity of infinitely thick unconsolidated samples decreases when particle size increases,corresponding to the simulation results,while the difference is less than statistical fluctuation. As particle size increases,the ratio of fluorescence intensity of copper and zinc decreases with areal density constant.%通过MCNP软件建立均匀颗粒的面心立方最密堆积模型,以硫酸铜-锌组合样品为例,研究样品在X射线激发下的荧光强度随颗粒大小的变化情况.采用研磨方法制备不同颗粒度的无限厚样品并进行实验,以验证建模方法的正确性;在此基础上研究颗粒度效应对有限质量厚度样品荧光强度的影响.结果表明,自然状态的无限厚硫酸铜颗粒样品的荧光强度随颗粒尺寸增加而下降,变化程度小于统计涨落,与相同条件下的模拟结果基本一致;在质量厚度相同的情况下,样品颗粒尺寸增大,铜-锌荧光强度之比减小.