J. Phys.: Conf. Ser. 1412 062006 (2020)

Negative ion relaxation and reactions in a cryogenic storage ring

H T Schmidt¹, S Rosén¹, R D Thomas¹, M H Stockett¹, W D Geppert¹, Å Larson¹, P Löfgren¹, A Simonsson¹, A Källberg¹, P Reinhed¹, M Björkhage¹, M Blom¹, J D Alexander¹, P K Najeeb¹, M Ji¹, N Kono¹, E K Anderson¹, G Eklund¹, M K Kristiansson¹, O M Hole¹, D Hanstorp², H Hartman³, P S Barklem⁴, J Grumer⁴, K Hansen^5,2, M Gatchell^6,1, H Cederquist¹ and H Zettergren¹

1 Stockholm University, Department of Physics, 10691 Stockholm, Sweden

2 University of Gothenburg, Department of Physics, 41296 Gothenburg, Sweden

3 Malm¨o University, Department of Physics, 20506 Malm¨o, Sweden

4 Uppsala University, Department of Physics and Astronomy, 75236 Uppsala, Sweden

5 Tianjin University, Department of Physics, 300072 Tianjin, P R China

6 Universit¨at Innsbruck, Institut f¨ur Ionenphysik und Angewandte Physik, 6020 Innsbruck,Austria

Abstract

An overview of recent experimental results of studies of negative atomic and molecular ions in the Double ElectroStatic Ion-Ring ExpEriment, DESIREE is given. Metastable level lifetimes in atomic negative ions have been measured by time-dependent laser photodetachment. Rotational relaxation of diatomic anions is studied by near-threshold photodetachment. Spontaneous decays of small metal cluster anions by electron emission and fragmentation is studied with decay-channel specificity. Finally, mutual neutralisation of pairs of negative and positive ions has been investigated with initial and final state selectivity.