Dissociative recombination study of at CRYRING: absolute cross-section, chemical branching ratios and three-body fragmentation dynamics

Abstract

The paper reports an investigation of the dissociative recombination of at the heavy-ion storage ring CRYRING. The absolute cross-section has been measured as a function of centre-of-mass energy ranging from 1 meV to 0.1 eV. The experiment performed has shown the dissociative recombination of to be dominated by three-body break-up, with a branching ratio of about 78%. Competition between the available three-body channels producing the ground state, P(4 S), and the first two excited states, P(2 D) and P(2 P), is observed. The formation of the first excited state dominates over the other two almost equally probable channels with about 75% of all three-body events. The results indicate that the kinetic energy released in the three-body break-up of is randomly shared between the deuterium atoms. The intra-molecular angle on dissociation has also been investigated. A comparative analysis of the dissociative recombination dynamics for the two isovalent systems, and , is undertaken.