Observation of Structure in Laser-Induced Penning and Associative Ionization in Crossed-Beam Na + Na Collisions

Abstract

The results of double-laser experiments in which ${\mathrm{Na}}_2^{+}$ and ${\mathrm{Na}}^{+}$ are produced in crossed alkali beams under single-collision conditions in the presence of strong optical fields are reported. Structure in the mass-selected product ion intensity as a function laser frequency is observed when the optical field is strongly focused and tuned far off atomic or dimer transitions. These measurements are the first to show that the nuclear motion of the quasimolecular collision intermediate plays an important role in laser-induced collisional ionization.