Field ionization threshold of Stark states of Sr atoms

Abstract The field ionization thresholds of Stark states of Sr atoms for n=17, |m|=0, 1 manifolds are investigated. The thresholds are also calculated by introducing a Stark-effective quantum number n s which is derived from the experimental Stark map of Sr. The agreement between experimental and calculated results is quite good. This study showed, contrary to the hydrogen's, higher-energy states generally have lower ionization thresholds, and that the |m|=0, 1 Sr atoms exhibit partly adiabatic behavior at several avoided crossings in the passage to ionization.