Doubly charged ions resulting from the multiphoton atomic ionization of alkaline-earth metals

Abstract

The study of the creation of doubly charged ions upon the laser-induced multiphoton ionization of alkaline-earth metals is reviewed. The results show that the features of the creation of the doubly charged ions depend on the spectral range of the ionizing laser radiation. In the ionization of the alkaline-earth atoms by the visible laser radiation, the cascade creation of the doubly charged ions is predominantly implemented when the ions result from the multiphoton ionization of singly charged ions created in the presence of the same laser pulse. In the multiphoton ionization of the alkaline-earth atoms by the IR laser radiation, the two-electron process occurs when the doubly charged ions are directly created from neutral atoms owing to the ionization via induced resonances with strongly perturbed states of these atoms.