R-MATRIX FLOQUET THEORY OF MULTIPHOTON PROCESSES .5. MULTIPHOTON DETACHMENT OF THE NEGATIVE HYDROGEN-ION

Using the recently proposed R-matrix Floquet theory we have performed ab initio calculations for single- and multiphoton detachment of the n egative hydrogen ion, H-. Our method is non-perturbative in the field strength and is a multielectron theory allowing for full correlation b etween the two electrons. We present results depending on frequency up to nonperturbative field intensities for H- in a single-frequency lin early polarized laser. We investigate a wide range of frequencies and intensities from the multiphoton detachment regime to the high-frequen cy regime. Our results include total detachment rates, shifts of the a ttachment energy in the field and partial rates into the various exces s photon absorption and core excitation partial channels. We compare o ur results with other theoretical calculations and with experimental r esults.