Adsorption and diffusion of strontium in simulated rock fractures quantified via ion beam analysis
Adsorption and diffusion of strontium in simulated rock fractures quantified via ion beam analysis
复制标题
通过离子束分析量化模拟岩石裂缝中锶的吸附和扩散
作者：
Toshiaki Ohe;B. Zou;K. Noshita;I. Gomez;C. Jeynes;Peter M. Morris;R. Wogelius
本文提出了一种测定锶在低渗透地质材料中有效扩散系数和分配系数的实验方法。这种技术，微反应器模拟通道法（MRSC），允许快速确定污染物传输参数与所得值相比，由更传统的方法确定的，也创建产品表面，适合直接化学分析。一种尝试，以进一步限制质量通量完成了详细的离子束分析抛光凝灰岩表面（凝灰岩是一个多晶polyminerallic聚集为主的硅酸盐相），已与Sr溶液在10-5，10-3和10-1摩尔1-1的浓度反应。使用质子束（使用粒子诱导X射线发射和弹性背散射光谱法或EBS）和α粒子束（使用卢瑟福背散射光谱法）进行离子束分析。离子束分析表明，随着溶液浓度的增加，表面浓度增加，在最高浓度实验中，Sr渗透到主界面以下至少4 μm处。在实验中，起始溶液浓度分别为10 ~（-5）、10 ~（-3）和10 ~（-1）mol ~（-1）时，由EBS测定的Sr表面浓度分别为0.06（±0.05）、0.87（±0.30）和2.40（±1.0）原子重量%。
Abstract An experimental technique has been developed and applied to the problem of determining effective diffusion coefficients and partition coefficients of Sr in low permeability geological materials. This technique, the micro-reactor simulated channel method (MRSC), allows rapid determination of contaminant transport parameters with resulting values comparable to those determined by more traditional methods and also creates product surfaces that are amenable for direct chemical analysis. An attempt to further constrain mass flux was completed by detailed ion beam analysis of polished tuff surfaces (tuff is a polycrystalline polyminerallic aggregate dominated by silicate phases) that had been reacted with Sr solutions at concentrations of 10-5, 10-3 and 10-1 mol 1-1. Ion beam analysis was carried out using beams of both protons (using particle induced X-ray emission and elastic backscattering spectrometry or EBS) and alpha-particles (using Rutherford backscattering spectrometry). The ion beam analyses showed that increased solution concentrations resulted in increased surface concentrations and that in the highest concentration experiment, Sr penetrated to at least 4 μm below the primary interface. The Sr surface concentrations determined by EBS were 0.06 (±0.05), 0.87 (±0.30) and 2.40 (±1.0) atomic weight % in the experiments with starting solution concentrations of 10-5, 10-3, and 10-1 mol 1-1, respectively.