Nonsequential multiple ionization in intense laser pulses: interpretation of ion momentum distributions within the classical `rescattering' model

The classical `rescattering' model is used to give an interpretation of ion momentum distributions for multiple ionization of atoms in intense fs laser pulses. Kinematical constraints for the ion momenta derived from simple classical considerations reproduce the positions of the maxima observed in experimental momentum distributions of Ne 2+ and Ne 3+ ions. Based on these constraints we present a first prediction on the principle structure of differential ion momentum distributions for multiple ionization. We show that different ionization channels can be characterized by their kinematics, leading to specific ion momentum distributions. A qualitative analysis of the intensity dependence is also given.