Abstract

We have studied the excitation and relaxation of Ar⁺ ions populated in resonant Auger decay from the Ar 2p⁻¹ nl core-excited states by using ultraviolet-visible fluorescence spectroscopy and photon-photon delayed coincidence technique. Fluorescence emission yields were measured in the photon energy range of 240–255 eV for the 3s²3p⁴(¹D)5s(²D) → 3s²3p⁴(¹D)4p(²F) (393 nm) and 3s²3p⁴(¹D)4d(²F) → 3s²3p⁴(¹D)4p(²F) (335 nm) transitions as well as for the 380–500 nm wideband emission. Delayed coincidence photon decay curves for the cascade transitions of the 335/459 nm and 393/459 nm lines were measured at the four most intense Ar 2p core excitations and the coincidence yields for both studied cascade channels were obtained at these Ar 2p excitations.