Laser-assisted coplanar symmetric (e, 2e) triple differential cross sections

The modification due to an external linearly polarized monochromatic laser field on the dynamics of the ionization process of an atomic hydrogen by electron-impact is studied theoretically for a coplanar symmetric geometry. The interaction of the laser field with the unbound electrons is treated in a non-perturbative way. The wave functions of the ingoing and outgoing electrons in the laser field are treated as non-relativistic Volkov waves, while the interaction of the bound electron with the laser field is treated by using first-order perturbation theory, assuming that the electric field strength associated with the external laser field is much less than the atomic unit $e/a^2=5\times {10}^{9}V{cm}^{-1}$. The influence of the laser parameters on the angular distribution is analyzed and several illustrative examples are discussed. Significant changes are noted both in the shape and magnitude of the triple differential cross sections (TDCS) by the application of the laser field. Numerical results show that the TDCS are strongly dependent on the dressing of the projectile by the laser field at low frequency in (e, 2e) spectroscopy region. (paper)