Tunneling Rates for Excited States of Sodium in a Static Electric Field

Abstract

We have measured ionization rates for selected Stark states of sodium in the range $n=12-14\mathrm{}$, $\mathrm{}\left|m\right|=2\mathrm{}$. We find that the ionization rates for the lowest Stark components of each term are in excellent agreement with values calculated for hydrogen. The systematics of ionization of the higher sublevels, however, is in serious disagreement with hydrogenic theory because of effects of level mixing.