Multiphoton ionization: a Monte Carlo treatment of a classical hydrogen atom in a classical electromagnetic field

The classical Hamiltonian equation of motion for a hydrogen atom subject to a time-varying intense electromagnetic wave is nonconservative. This allows for absorption of radiation by the atomic electrons and hence for their photoionization. This fact is used to investigate the classical description of the multiphoton ionization process and its dependence on the irradiance and polarization of the electromagnetic radiation. Differences between the classical and quantum-mechanical results are discussed. Differences between the present treatment and previous classical methods are contrasted and emphasized. Above-threshold ionization is seen. Electron angular distributions are given