MULTIELECTRON DISSOCIATIVE IONIZATION OF DIATOMIC-MOLECULES IN AN INTENSE FEMTOSECOND LASER FIELD

The multielectron dissociative ionization of diatomic molecules is investigated using an intense laser field at a wavelength of 615 nm, in the 10(15) W/cm2 intensity range, with a 100-fs pulse duration. Comparison with previous experiments performed with 2-ps and 600-fs pulse durations shows that the atomic-ion kinetic-energy releases depend neither on the laser-pulse duration nor on the peak laser intensity. The simple model of Coulomb repulsion between atomic ions is therefore insufficient to account for the dynamics of the multiple-ionization mechanism. Comparison between N2, CO, and O2 experiments indicates that the channel AB2+ --> A+ + B+ remains molecule specific. Conversely, the channels involving molecular ions carring higher charges (AB(p + q)+ --> A(p+) + B(q+) exhibit similar dissociation energies for N2, CO, and O2.