2-DIMENSIONAL PHOTOELECTRON IMAGING OF STATE-SELECTED IODINE ATOM BY (2+1) RESONANCE-ENHANCED MULTIPHOTON IONIZATION

The state-selective photoelectron imaging technique is applied to investigate the angular distribution of ejected electrons and the electronic state of the atomic ion produced by (2 + 1) resonance-enhanced multiphoton ionization of iodine atom in the photolysis of CH3I. Strong anisotropic distribution behaviors have been depicted on two electron images observed, one via the two-photon resonance D-2(5/2)o state from ground state iodine and, another via D-4(1/2)o from spin-orbit excited iodine. The configuration of core electrons is preserved in the ionization from the D-2(5/2)o intermediate state, while the ionization from the D-4(1/2)o state shows two distinct ionization paths, a preserved and a non-preserved path of core electrons.