Electron-exchange parameter measurements for molecular open-shell-targets

Abstract

Low-energy electron exchange collisions with simple open-shell molecules such as O2, NO or NO2 play an important role in both atmospheric physics and plasma chemistry Due to the paramagnetic properties of these molecules, electron exchange collisions are experimentally observable. In our experiment, exchange collisions are investigated directly by measuring the change of spin polarization after scattering of polarized electrons from unpolarized molecules. Since previous experimental results and theoretical calculations with O2 and NO as targets were not in satisfactory agreement, we revived these measurements to gain a deeper insight into spin-exchange effects with open shell-molecules. Additionally, we achieved the first inelastical exchange parameter measurements for O2. For NO2, we present the first experimental results for differential elastic electron exchange scattering at low energies.