L. Dimou et Fhm. Fraisal, MULTIPHOTON DETACHMENT OF H- IN INTENSE ELECTROMAGNETIC-FIELDS, Journal of physics. B, Atomic molecular and optical physics, 27(14), 1994, pp. 120000333-120000339
Multiphoton detachment of hydrogen negative ions (H-) is investigated
using the non-perturbative Floquet close-coupling theory. Quantitative
agreement between the theory and the experiment is obtained within th
e single-active-electron ansatz and including the effect of core polar
ization on the process. The well known threshold law of Wigner is conf
irmed for the multiphoton detachment process in H- and the experimenta
lly observed range of its applicability is shown to be governed by the
polarization potential, The effect of channel-opening and its depende
nce on the intensity of the field are determined. The total rates of d
etachment of H-, for the fundamental frequency (omega = 1.17 eV) of th
e Nd laser are presented in the strong coupling domain of intensities;
the results show that die 'rate' parameter tends to be comparable to
the field frequency for quiver radius alpha0 > 4.5 au, indicating a po
ssible upper limit for the validity of the widely used adiabatic Floqu
et ansatz, in this system.