Stabilization of circular states of the hydrogen atom in a strong field

A solution of the three-dimensional time-dependent Schrödinger equation, describing the ionization dynamics of the hydrogen atom in a circular state in an electromagnetic field, is obtained by direct numerical integration. It is shown that the observed stabilization effect can be interpreted on the basis of the Kramers-Henneberger approach. A simple analytical model is proposed, which qualitatively describes the basic laws of the ionization process under the conditions of the reported calculations and laboratory experiments on ionization of the circular hydrogenlike 5g, m=4 state of the Ne atom.