Investigation of autoionization spectra of Sm atoms using an isolated-core excitation method

Abstract

Using the isolated-core-excitation scheme and three-step laser resonance ionization spectroscopy approach, this paper, for the first time, has systematically investigated the autoionization spectra of atomic Sm, belonging to the 4f66pnl and 4f55d6snl (l = 0,2) configurations. In the experiment, the first two tunable dye lasers are employed to excite the Sm atom from its initial state to the different 4f66snl bound Rydberg states, then the third dye laser is scanned to drive the atom to the doubly-excited autoionizing states. With the above excitation scheme, the measured transition profiles of the autoionizing states are nearly symmetric, from which the level energies and widths can be easily obtained.