Charge-Exchange Excitation in the He–Cd Laser

Experiments are described which show a dual involvement of charge exchange and Penning ionization-excitation processes in the helium-cadmium laser similar to that reported earlier by the authors in the helium-zinc ion laser. Charge exchange leads primarily to high-lying states of Cd II in which only the outer electron is excited, whereas Penning ionization mainly leads to the production of excited ionic states involving a ``hole'' in the inner d-shell configuration.