Three-Photon Detachment of Iodine Negative Ions

I- ions formed in an ionic beam from a hot cathode discharge source are submitted to the intense light pulse of a 1.064 μm Nd:YAG laser. The neutral atoms produced by three-photon detachment are detected. Varying the laser pulse energy and recording the corresponding variation of the detachment signal makes obvious the saturation of the three-photon process. This observation gives an approximate value of the generalized cross-section, σ = 1.5 10-37 s-1 W-3 m6.