Subatomic, High Energy and Plasma Physics seminar series: Dag Hanstorp

Abstract: Negative ions, which are formed when an electron is attached to a neutral system, are unique quantum systems. The lack of a long-range Coulomb force causes the inter-electronic interaction to become relatively more important. As a consequence, the independent particle model, that adequately describes atomic structure under normal conditions, breaks down. Experimental studies of negative ions can therefore serve to probe the electron correlation and hence be used to test theoretical models that go beyond the independent particle approximation. 

I will in this talk give an overview of experimental methods to study negative ions and present recent experimental highlights. I will focus on the photodetachment process, where one or more electrons are removed from a negative ion due to the absorption of a photon. The experimental results will be compared with state-of-the-art advanced many-body calculations. I will also show how the simplicity of the structure of negative ions can be used to test and demonstrate various fundamental atomic and molecular processes.  Finally, I will discuss the importance of negative ions in various natural environments and in applications.