基于HIRFL-CSR的类氦重离子2E1双光子跃迁实验研究

项目名称： 基于HIRFL-CSR的类氦重离子2E1双光子跃迁实验研究

项目编号： No.U1532130

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 邵曹杰

作者单位： 中国科学院近代物理研究所

项目金额： 56万元

中文摘要： 双光子跃迁能谱的形状能够细致反映原子内部结构和跃迁方式；针对现有的2E1双光子跃迁能谱测量技术的局限，依托兰州重离子加速器冷却储存环和气体内靶装置，高选择性地产生特定激发态类氦重离子，结合内靶实验的低本底和离子-光子符合技术的高效率，大幅度地提高能谱测量的精度和效率，细致测量激发态类氦重离子的双光子跃迁能谱（尤其是两翼能谱），以检验相对论条件下的理论预言，探索相对论效应、电子关联效应、甚至强库仑场QED效应对原子内部结构及其跃迁方式的影响。

中文关键词： 高电荷态离子；X射线；电子关联；相对论效应；双光子跃迁

英文摘要： According to the theoretical prediction, relativistic effects on the two-photon spectral shape are the most pronounced in heavy highly-charged ions. Therefore it would be of particular advantage to perform measurement of the two-photon decay in such systems. A novel experimental approach for studying two-photon decay in He-like high-Z ions will be developed relying on HIRFL-CSR and its internal target facility. In this technique, excited He-like heavy ions will be formed by K-shell ionization of initially Li-like ions in the collisions with a low-Z gas target, and x-ray spectra from the decay of the He-like ions were measured coincident with up-charged ion measurements. The very high level of selectivity of the system makes this process particularly suited for the study of the two-photon energy distribution, and thus for a detailed investigation of the structure of high-Z He-like atoms. The method allowed for a background-free measurement of the two photon decay. The experimental study will be very helpful for investigating reletivistic effects, electron correlation, and QED.

英文关键词： Highly Charged Ions;X-ray;Electron Correlation;Relativistic Effects;Two-photon Transition