新型正电子湮没反符合测量技术及应用研究

正电子湮没对原子尺度缺陷及缺陷的化学环境特别敏感,是研究材料微观结构的有效和特色手段。本项目拟深入开展新型正电子湮没符合/反符合测量技术的研究，建立一套具备多种测量方法、满足不同测量条件或测量环境需求的正电子湮没谱学测量系统，以此为基础，系统研究不同化学结构的聚合物材料以及模拟人体组织中电子偶素形成、热化过程以及电子动量分布随电子偶素湮没时间的变化过程，探讨电子偶素在这些特殊材料中的形成过程、电子偶素湮没寿命和材料微观结构及内部生物环境的关系，为正电子谱学技术在生物科学及医学应用领域的应用提供基础数据。

Positron annihilation is an effective and powerful tool to characterise atomic scale defects and their chemical environment. Based on the preliminary works and deeply understanding to the new technology of coincidence/anticoincidence in positron annihilation spectroscopy, this project intends to develop a new positron annihilation system with multiple measurement methods to meet the demand of different measurement conditions in various applications. By using established system，the mechanism for positronium formation, thermalization process and electronic momentum distribution with the change of positronium annihilation lifetimes, in some materials as polymer and simulating human tissue with different chemical structure, will be investigated systematically to explore the process of positronium formation in these specific materials and to discuss the relationship between the positronium lifetime to the internal biological environment and material microstructure. Some achievements based on the experimental discussions to the application of positron spectroscopy technology in the field of biological science and medical will be hopefully expected in this project.