Stark Ionization of High-Lying States of Sodium

Abstract

By using stepwise excitation in an atomic beam, we have excited slow-moving atoms to pure high-lying quantum states at densities low enough to avoid loss by collision. The atoms were detected with high efficiency by Stark ionization. Results are presented of a study of the threshold field for ionization for $s$ states of sodium with principal quantum number $n$ from 26 to 37.