In-situ and real-time studies of the influence of ion irradiation on glass corrosion kinetics and surface alteration layer formation by fluid-cell Raman spectroscopy

硼硅酸盐玻璃用于各种医疗和技术应用，例如，用于从乏燃料中固定化高放射性核废料。一个关键的挑战，特别是对于在玻璃中永久处置核废料的挑战，是开发预测自辐射损伤对水溶液腐蚀过程影响的模型。由于涉及电离以及电子和核碰撞的自辐射过程，硼硅酸盐玻璃经历了重大的结构修改。目前，关于自辐照损伤对硅酸盐玻璃水相稳定性影响的研究非常有限，也只有一些有争议的数据。然而，在80至85°C的温度下，对快速重离子辐照的玻璃进行了新颖的流体池拉曼光谱腐蚀实验，结果表明，玻璃结构的损坏对溶解动力学有不可忽视的影响。建议的研究项目旨在利用流体室拉曼光谱系统地研究辐射损伤的类型和程度与玻璃腐蚀机理(S)和动力学之间的缺失环节。流体池拉曼光谱可以在不中断反应的情况下，以独特的方式原位和实时地研究玻璃的腐蚀。三元硼硅酸盐玻璃和“国际简易玻璃”将受到不同的重离子辐照情景，以模拟玻璃中不同的衰变过程。应通过拉曼光谱对辐射损伤进行表征和量化。然后在不同温度和不同持续时间(长达几个月)下对辐照的玻璃和不同pH值的不同二氧化硅不饱和溶液进行原位流体室拉曼腐蚀实验。为了研究和量化运输和再平衡过程，将使用2H和18O标记的溶液作为同位素示踪剂。这些实验将提供有价值的动力学数据以及关于腐蚀过程中仍有争议的机制方面的信息，这些方面对于模拟受到高能辐射和水溶液的硼硅酸盐玻璃的长期稳定性是必要的。

Borosilicate glasses are used for various medical and technical applications, e.g., for the immobilization of high-level nuclear waste from spent fuel. A key challenge, especially for the permanent disposal of nuclear waste in glasses, is the development of predictive models of the effects of self-irradiation damage on the aqueous corrosion process. Borosilicate glasses undergo significant structural modifications due to self-irradiation processes involving ionization as well as electronical and nuclear collisions. Currently, there is only very limited knowledge and controversial data about the effect of self-irradiation damage on the aqueous stability of silicate glasses. Novel fluid-cell Raman spectroscopic corrosion experiments with a swift heavy ion irradiated glass at temperatures between 80 and 85°C, however, demonstrated a non-negligible impact of the damaged glass structure on the dissolution kinetics. The proposed research project aims to systematically study the missing link between the type and degree of radiation damage and the glass corrosion mechanism(s) and kinetics by fluid-cell Raman spectroscopy. Fluid-cell Raman spectroscopy enables the corrosion of glasses to be investigated in situ and in real time in a unique way without interrupting the reaction. A ternary borosilicate glass and the “International Simple Glass” shall be subjected to different heavy ion irradiation scenarios to simulate the different decay processes in glasses. The radiation damage shall be characterized and quantified by Raman spectroscopy. In-situ fluid-cell Raman corrosion experiments will then be performed at different temperatures and for different duration (up to several months) with the irradiated glasses and different silica-undersaturated solutions with different pH values. To study and quantify transport and re-equilibration processes, 2H- and 18O-labelled solutions will be used as isotope tracers. These experiments will deliver valuable kinetic data as well as information about still controversially discussed mechanistic aspects of the corrosion process, which are necessary to model the long-term stability of borosilicate glasses that are subjected to high-energy radiation and aqueous solutions.