Numerical simulation of multiphoton photodetachment ofH−ions

We present results of a numerical simulation of photodetachment of ${\mathrm{H}}^{\mathrm{-}}$ ions by an intense laser. We perform a direct integration of the one-dimensional Schrödinger equation, where a model potential is selected to provide the electron with a single bound state and short-range attraction. The numerical integration employs the Crank-Nicholson algorithm, and a variable space grid greatly reduces the computation time. In order to obtain the energy spectrum of the detached electrons, the final wave function is projected onto the discrete, but closely spaced, positive eigenstates of the model potential. The photodetachment rate is computed for wide ranges of laser intensity and frequency. Plots of detachment rate versus intensity display sharp variability with minima that correlate with suppression, at threshold, of peaks in the electron energy spectrum.