RUI: Valence and Inner-shell Negative Ion Spectroscopy

Denison University, Granville OH

Investigators

Abstract

This RUI project studies the interactions of photons with negative ions in two series of experiments. The extra electron in a negative ion is bound predominantly by electron correlation effects and therefore negative ions provide a fertile testing ground for state-of-the-art atomic physics calculations regarding these multi-body interactions. In the first series of experiments, lanthanide negative ions will be investigated on-campus at Denison University using tunable infrared laser light to detach outer-shell electrons. Accurate measurements will be made of the electron affinities and resonance structure of the lanthanides, which are among the least well-understood atomic negative ions. The second series of experiments will investigate inner-shell photodetachment from negative ions, such as selenium and carbon-60, using ultraviolet and X-ray photons at the Advanced Light Source (ALS) synchrotron at Lawrence Berkeley National Laboratory. These experiments continue a series of studies by the PIs investigating short-lived excited states of negative ions and multi-electron decay processes. The broader impacts of the program include the education of undergraduate students and connections to other scientific fields. The project will enhance the research and teaching infrastructure of Denison University, an undergraduate college. Students will participate in the experiments both on-campus and at the ALS, providing important research experiences for young scientists including technical training in electronics, computers, lasers and optics. The detailed studies of negative ions will yield insights into dynamical many-body interaction, which is a general phenomenon of interest for a broad range of fields in physics, chemistry, and materials science.