Two-dimensional photoelectron spectroscopy of Br atom using [2+1] resonance enhanced multiphoton ionization

Abstract

The [2+1] resonance enhanced multiphoton ionization (REMPI) of bromine atom formed from the photodissociation of $CF_2Br_2$ have been studied in the wavelength region between 250-277nm. The resonance enhanced multiphoton ionization-photoelectron spectroscopy has been utilized to determined the initial, intermediate and final states of reacting system. The REMPI-ion spectra composed of ground state $^2P^o_{3/2}$ and first spin-orbit excited state $^2P^o_{1/2}$ are obtained first to investigate the image of the photoelectrons of bromine atom in these wavelength region. The strong ionization peaks via doublet to quartet transitions are observed in this experimental condition. The state selection of product ions is dependent on the ionization wavelength and intermediate state. The $^3P_2$ state of bromine ion is dominant in the ionizations via doublet - quartet transition, and $^3P_{1,0}$ state is major in the ionizations via doublet - doublet transition. Although the ion core preserving ionization to $^3P_J$ state of bromine ion is a main path of general ionization process, the non ion-core preserving ionization is considerably observed in several transitions.