Spectroscopy of the uranium ion using collinear fast-beam—cw-dye-laser modulation spectroscopy. Transition energies and excited-state lifetimes

Using collinear fast-beam---cw-dye-laser modulation spectroscopy, precise transition energies have been measured and excited-state lifetimes determined in the ²³⁸U⁺ ion. Wave numbers are measured using a real-time fringe-counting interferometer calibrated against the I₂ absorption spectrum. The lifetimes are obtained by modulating the cw-dye-laser output by an opto-acoustic wave. A total of 25 excited-state lifetimes have been measured in ²³⁸U II, providing the first direct lifetime determinations in this ion.