Rovibrational-state-selected pulsed field ionization-photoelectron study of methyl iodide using two-color infrared-vacuum ultraviolet lasers

The methyl iodide in selected rovibrational states was prepared by infrared (IR) excitation prior to vacuum ultraviolet (VUV) photoionization. The IR-VUV-pulsed field ionization-photoelectron (PFI-PE) and IR-VUV-photon measurements provide relative state-to-state cross sections for the photoionization process. Photoions and electrons were produced by crossing the VUV and the CH₃I molecular beams at the photoionization region. The state-to-state cross sections thus obtained are also of importance for the fundamental understanding of photoionization dynamics.