Study of electron beam induced ion-pair dissociation dynamics of O2 using velocity slice imaging spectrometer

Abstract

The ion-pair dissociation (IPD) of molecular oxygen due to 21–35 eV energy electron collision has been studied using the time sliced velocity map imaging technique. The threshold of the process and the kinetic energy and angular distribution of the fragment negative ions are measured. The IPD is found to be occurring due to pre-dissociation of a Rydberg state via ion-pair state for lower incident electron energies as well as from direct excitation to the ion-pair states for higher primary beam energy. The location and symmetry of the excited states are determined from the kinetic energy and angular distribution data respectively.