Multiphoton spectroscopy of doubly excited, bound, and autoionizing states of strontium

摘要: We present a theory attempting an interpretation of existing data on three- and four-photon ionization Sr in the wavelength range 557-575 nm at 532 nm. Two-photon resonances with bound excited states three-photon doubly autoionizing are studied. ac Stark shifts broadening resonances, as well singlet-triplet transitions, shown to yield interesting new information atomic structure. The absorption fourth photon above threshold leads final ionic states, having served intermediate resonances. calculation is based configuration-interaction scheme, mixing taken into account either through jl coupling or phenomenologically by adjustment some aspects data. apparatus resonant multiphoton combined scheme. Depending quantity question, agreement between experiment ranges from good semiquantitative.