EAST及CFETR用新型钾泡强韧钨合金的氘滞留行为及机理研究

Retention behavior of deuterium (D) and tritium in plasma facing materials is a fundamental research related to stable operation of fusion reactor. Previous experiments and literature reports indicated that potassium bubbles dispersed tungsten (W-K) is being considered as a promising candidate material for PFM in the future fusion devices because of its excellent performance in terms of toughness at low temperature, microstructure stability at high temperature and thermal load resistance. However, D retention would be increased theoretically due to the introduction of gaseous potassium bubbles in W-K alloy. Furthermore, relevant investigation about D retention behavior in W-K alloy is still blank by now. Therefore, it is necessary and important to evaluate the behavior and mechanism of D retention systematically in W-K alloy. In the present study, we will produce some new W-K alloy bulks with various sizes and number densities of potassium bubbles using a potential large-scale preparation technique. Then D penetration behavior and D plasma irradiation characterization of the self-made W-K alloy will be investigated based on the diffusion and adsorption of D using the gas-driven permeation-thermal desorption spectrometry device (GDP-TDS) and the materials and plasma evaluation system (MAPES) in EAST, respectively to clarify the D retention mechanism in W-K. The ultimate objective of this project is to evaluate the negative effect of gaseous potassium bubbles on D retention quantitatively, and determine whether the new W-K alloy is suit for the application in the EAST and CFETR Tokamak experiments qualitatively.

面向等离子体材料中的氘、氚滞留行为是关乎聚变堆稳定运行成功与否的基础研究。前期实验和文献调研表明钾泡弥散钨（钾钨）因具有较好的低温韧性、高温组织稳定性和优异的高热负荷抗性，而成为未来聚变装置中极具潜力的PFM候选材料。但是，钾钨合金中的气态钾泡可能会增加钨基体中的氘滞留量。目前钾钨合金的氘滞留行为研究尚属空白。因此亟需对钾钨合金进行系统全面的氘滞留行为研究及机理分析。本项目拟采用未来可规模化生产的技术，制备出含不同钾泡尺寸及钾泡密度的新型钾钨合金。从钾泡对钨中氘的扩散行为和吸附行为两方面入手，依托GDP-TDS和EAST-MAPES平台分别对自制新型钾钨合金进行氘渗透行为和氘等离子体辐照行为研究，阐明钾钨合金的氘滞留机理。项目的最终目的是定量评价气态钾泡在氘滞留方面的负面作用程度，为钾钨合金能否在EAST和CFETR托卡马克实验中的应用做出定性评估。

面向等离子体材料中的氘、氚滞留行为是关乎聚变堆稳定运行成功与否的基础研究。前期实验和文献调研表明钾泡弥散钨（钾钨）因具有较好的低温韧性、高温组织稳定性和优异的高热负荷抗性，而成为未来聚变装置中极具潜力的PFM候选材料。但是，钾钨合金中的气态钾泡可能会增加钨基体中的氘滞留量。目前钾钨合金的氘滞留行为研究尚属空白。因此亟需对钾钨合金进行系统全面的氘滞留行为研究及机理分析。本项目采用未来可规模化生产的技术，制备出了含不同钾泡尺寸及钾泡密度的新型钨钾合金。研究了烧结制度包括烧结温度、烧结时间对钨钾烧结坯中普通气孔和充钾气孔的密度、大小、分布及形态的影响规律。同时研究了形变热处理制度包括总变形量、道次变形量、道次退火温度对钨钾中钾管和钾泡特征的影响规律。并揭示了钾掺杂对其微观结构，力学性能，再结晶抗性，高能重离子损伤和氘等离子体渗透、扩散、辐照等性能的影响机制。项目的最终目的是定量评价气态钾泡在氘滞留方面的负面作用程度，为钨钾合金能否在EAST和CFETR托卡马克实验中的应用做出定性评估。