Drift Tube Study of One-Electron Capture Reactions between Double-Charged Ions and Rare Gas Atoms

Abstract

An injected-ion drift tube mass spectrometer was used to study the one-electron capture reactions in the systems Kr⁺⁺+Ne and Xe⁺⁺+Ar. The drift tube was cooled with liquid nitrogen so as to widen the energy range from 10 meV to several eV. The cross sections for the ground state of primary ions were separated from those for the low-lying metastable states by applying both the attenuation method and the threshold measurement. It was found that a large difference exists in the absolute magnitudes or cross section according to the electronic states of primary ions. The reaction Xe⁺⁺(³P)+Ar has a very large cross section of 10⁻¹⁴ cm² at 0.02 eV, while the reaction Xe⁺⁺(excited)+Ar is immeasurable. This difference is explained with a curve crossing model.