K-shell photoionization of atomic anions

负原子离子在高层大气或星际介质等低温等离子体中发挥着重要作用，在技术应用中也是如此。在这里，将使用来自世界上最明亮的第三代同步辐射源之一的强离子束和可调同步辐射的独特组合，即汉堡的Petra III，对带负电荷的氧和硫离子的K壳光分离进行实验研究。多重脱离的绝对截面将作为光子能量的函数进行测量，并与领先的理论物理学家合作，通过大规模的原子结构计算来解释。根据已经公布的第一批结果，预计拟议的工作将极大地扩大涉及原子阴离子的内壳层光过程(包括双K空穴产生)的数据主体。这些结果将对弱束缚小量子系统中短暂多重激发态的结构和动力学提供详细的洞察。此外，它们还将与其他研究领域相关，如低温等离子体物理学、行星大气物理学和星际气体云中的化学。

Negative atomic ions play an important role in low-temperature plasmas such as the upper atmosphere or the interstellar medium and also in technical applications. Here, K-shell photodetachment of negatively charged oxygen and sulfur ions will be experimentally investigated using a unique combination of an intense ion beam with tunable synchrotron radiation from one of the world's brightest third generation synchrotron radiation sources, i.e., PETRA III in Hamburg. Absolute cross sections for multiple detachment will be measured as a function of photon energy and, in collaboration with leading theoretical physicists, be interpreted by large-scale atomic-structure calculations. In light of already published first results, it is expected that the proposed work will greatly enlarge the body of data on inner-shell photo-processes (including double K-hole production) involving atomic anions. The results will provide detailed insight into the structure and dynamics of ephemeral multiply excited states in weakly bound small quantum systems. Moreover they will be relevant for other fields of research such as low-temperature plasma physics, physics of planetary atmospheres, and the chemistry in interstellar gas clouds.