Ionization of hydrogen by ion impact in the presence of a laser field resonant to bound–bound atomic transitions

Abstract

We study the impact ionization of atomic hydrogen in collisions with fast ions assisted by the pulse of a weak laser field with a sub-nanosecond duration (T ∼ 10−10 s). The field is linearly polarized and its frequency is resonant to the 1s–2p hydrogen transitions. We consider the field-assisted impact ionization by using a simple model in which the interaction between the atom and the resonant field is described in the rotating-wave approximation and the interaction of the field-dressed atom with the ion is treated using the continuum-distorted-wave-eikonal-initial-state approach. Our consideration for 1 MeV u−1 C6+–hydrogen collisions shows that the presence of the laser field can have a profound effect on all aspects of the impact ionization, including the angular and energy distributions of the emitted electrons, the total ionization cross section and the projectile scattering.