Autoionization spectra of Sm atom

Spectra of autoionizing states of the Sm atom in an energy region between 45948.9 cm^-1 and 46943.6 cm^-1 are systematically investigated by a three-color multi-step resonant excitation scheme with three different excitation paths. The three intermediate states, 4f ⁶6s7s ⁷F₃, 4f ⁶6s7s ⁷F₄, and 4f ⁶6s7s ⁹F₅ are employed for the three paths, respectively. Based on precise calibration of wavelength, the level energies of 112 autoionizing states are determined with the line widths and the relative line intensities of the related transitions. The possible influence of configuration interaction on the line shape of autoionizing state is also discussed. In addition, a unique value of J, the total angular momentum, is assigned to all detected states by comparing the three spectra obtained with the different excitation paths.