Ionization and stabilization of a two-electron atom in a strong electromagnetic field

Direct numerical simulations are performed to analyze stabilization of a two-electron model atom in a strong electromagnetic field. The system is found to be stabilized with respect to both single and double ionization. By comparing the present results with those concerning stability of one-electron atoms, it is shown that stabilization is due to the formation of a Kramers-Henneberger two-electron atom. Ionization and stabilization characteristics of excited singlet and triplet states of an atomic system are examined.