Exotic negative ions

VERA’s high abundance sensitivity is exploited to investigate exotics among negative ions. Rare dianions (doubly-charged negative ions) of small molecules like C₁₀²⁻ provide insight into the fundamental properties of negative ions and their behavior in excited state following production in a sputter ion source. The smallest dianion-molecule found to date is LiF₃²⁻.
The existence of the lightest molecular anion imaginable, H₂⁻, was also proven at VERA by AMS – despite that it lives only for several microseconds. Apart from the obvious interest from a fundamental research point of view, this molecular anion may have played an important role in the formation of H₂ in the early universe – and without H₂ none of the larger structures like stars and galaxies would have emerged.

Contact:		Robin Golser
References:		Golser, R., Gnaser, H., Kutschera, W., Priller, A., Steier, P., Wallner, A., Cizek, M., Horacek, J., & Domcke, W. (2005). Experimental and theoretical evidence for long-lived molecular hydrogen anions H2- and D2. Physical Review Letters, 94(22), [223003]. Golser, R., Gnaser, H., Kutschera, W., Priller, A., Steier, P., & Wallner, A. (2007). Exotic negative molecules in AMS. Nuclear Instruments & Methods in Physics Research. Section B. Beam Interactions with Materials and Atoms, 259(1), 71-75. Golser, R., Gnaser, H., Kutschera, W., Priller, A., Steier, P., & Vockenhuber, C. (2004). Analysis of doubly-charged negative molecules by accelerator mass spectrometry. in T. Nakamura (Hrsg.), Accelerator mass spectrometry : proceedings of the Ninth International Conference on Accelerator Mass Spectrometry, Nagoya University, Nagoya, Japan, 9 - 13 September 2002 (S. 221-226). Elsevier BV, North-Holland. Nuclear Instruments & Methods in Physics Research. Section B. Beam Interactions with Materials and Atoms, Band. 223-224.
Research partners:		Hubert Gnaser, Department of Physics, University of Kaiserslautern, Germany