Autoionizing Distribution of the Triply Excited Double Rydberg States in La Atom

Abstract

The autoionization distribution o f the triply excited double Rydberg states (TEDRS) 5d5/2NLnl (N 5 22; n 5 50; L , 1 < 4) o f La has been investigated by using five-laser resonance excitation in combination with a method of sequential ionization by a pulsed electric field and a constant electric field. The experimental results exhibit that the La atoms in TEDRS predominantly single-autoionize to the ionic Rydberg states located in a few Rydberg manifolds. Furthermore, a difference of autoionization mechanisms between TEDRS above and those below the double ionization threshold is found.