Speaker
Holger Kreckel
(MPIK, Heidelberg)
Description
As an ever increasing number of molecules are observed in interstellar space, accurate laboratory data on their formation and destruction processes will be required to understand interstellar reaction networks. Astrochemical models have identified ion-molecule reactions as one of the drivers for the buildup of molecules in space. On the other hand, dissociative recombination with free electrons often terminates an ionic reaction chain and determines which neutral products are being formed. In order to model the abundance of individual species reliably, energy-resolved rate coefficients for all competing processes will be required.
At the Max-Planck-Institute for Nuclear Physics we intend to combine various experimental techniques to yield a comprehensive description of the relevant reactions for chosen important species. The new Cryogenic Storage Ring (CSR) will be equipped with a low-energy electron cooler and a neutral atom beamline. These facilities will allow for absolute rate coefficient measurements of dissociative recombination (DR) and ion-atom collision processes, involving cold molecular ions. Furthermore, a cryogenic 22-pole ion trap can be used for pre-cooling molecular ions, performing reaction studies with cold neutral molecules, and state-specific spectroscopy at variable temperatures.
With these techniques we aim to shed light on the puzzling nuclear spin distribution observed for interstellar H3+, where exchange reactions with molecular hydrogen play a role, as well as the nuclear-spin dependence of the DR reaction with cold H3+. Furthermore, we will investigate the gas-phase route to water formation, which begins with H3+ + O collisions and ends in the DR of cold H3O+, resulting in the formation of water in space.
Additional fields of research will be the formation and destruction of organic molecules under interstellar conditions and early universe chemistry.
Author
Holger Kreckel
(MPIK, Heidelberg)