Multiphoton detachment ofH−

Multiphoton detachment of ${\mathrm{H}}^{\mathrm{-}}$ is considered. An accurate one-electron model, which reproduces precisely the known ${\mathrm{H}}^{\mathrm{-}}$ detachment energy and the low-energy e-H(1s) elastic-scattering phase shifts, is developed. Generalized cross sections, based on lowest-nonvanishing-order perturbation theory, are evaluated by an accurate and efficient numerical algorithm for the solution of the associated set of inhomogeneous differential equations. Two- to eight-photon detachment cross sections are determined and compared with a recent one-electron model and two-electron ab initio calculations. It appears that the present study provides consistent results with an accuracy for higher-order (n>3) photon-detachment cross sections comparable to that of lower orders (n=2,3). Average detachment rates for linearly polarized light are calculated and compared with recent experimental measurements. It is found that, for higher-order photon detachment, the rates for circular polarization are small in comparison with the rates for linear polarization.