Radiative Mean Lifetimes of Levels in K II and Rb II

Beam-foil spectra of K II and Rb II were obtained at 600-keV bombarding energy. The lines identified in the spectrum of K II and the measured lifetimes of four $4p$ levels, three $4p^{\prime }$ levels, and one $5s$ level of the ion are presented and compared with other experimental results. The first experimental results on the lifetimes of three $5p$ levels, one $5p^{\prime }$ level, and two $5d$ levels of Rb II and the lines identified in the beam-foil spectrum of the ion are given.