Abstract
We have measured electron impact ionization (EII) of the beryllium-like ion . The use of an isotopically pure beam of ions is established as a method to eliminate all metastable levels, including the extremely long-lived metastable level , which, for this isotope, decays by hyperfine-induced radiative transitions. The energy dependence and absolute size of the EII cross section were measured from the resulting pure ground-state population at energies from below the threshold at 652.2 eV up to 3000 eV. These data provide an experimental benchmark for theory.
- Received 10 February 2012
DOI:https://doi.org/10.1103/PhysRevA.85.042713
©2012 American Physical Society