Semiclassical theory of laser-assisted dissociative recombination

We study the process of laser-assisted dissociative recombination of an electron with a molecular cation

using a semiclassical approach. In the region outside a reaction sphere the electron motion in

the combined laser and Coulomb fields is treated classically. Within the sphere the laser-field

effects are neglected, and the recombination probability is derived from quantum-mechanical

cross sections calculated for the laser-free process. Specific calculations are performed for

dissociative recombination of H₂⁺ in the field of the intensity 2.09 GW/cm² and the wavelength

22.8 μm. In the energy region above 1 meV the cross section is significantly

enhanced, as compared to the field-free case, due to the Coulomb focusing effect [1,2]. The influence of

the indirect process due to electron capture into Rydberg states is also investigated. Although the Rydberg

resonances are washed out due to the field effects, they influence significantly the

magnitude of the dissociative recombination cross section.

[1] H. B Ambalampitiya and I. I. Fabrikant, Phys. Rev. A 99, 063404 (2019).

[2] I. I. Fabrikant and H. B Ambalampitiya, Phys. Rev. A 101, 053401 (2020).