Electron-ion radiative recombination assisted by a bichromatic elliptically polarized laser field
Electron-ion radiative recombination assisted by a bichromatic (two-component) elliptically polarized laser field is analyzed in the frame of the $S\text{-matrix}$ theory. The second Born approximation is applied in the expansion of the $S\text{-matrix}$ element where the first term in the expansion corresponds to the direct recombination of electrons with ionic targets, while the second term corresponds to the recombination preceded by an electron-ion scattering. The latter process is possible in the presence of a laser field. If the electron scatters on an ionic target, it may be subsequently driven back by the laser field and recombine with the same ion. The photon emitted in this process may have a high energy. We have studied the dependence of the energy spectrum on various laser-field and incident electron parameters. The energy spectra obtained show plateaulike structures with abrupt cutoffs. These cutoffs are explained by a classical analysis.