Energies of Excited States of Doubly Ionized Molecules by Means of Auger Electron Spectroscopy Part I. Electronic States of N2 2+

Abstract

A new method, Auger electron spectroscopy, is applied to the study of excited states of doubly ionized molecules. The energies of Auger electrons determine directly the vertical energies of doubly ionized states, because the single Auger process leaves the molecule in a state of double ionization. We have investigated the states of N₂ ²⁺ via the K Auger spectrum of N₂. The ionization in the K shell was caused by electron impact. The K Auger electrons, analyzed by means of an electrostatic cylindrical mirror analyzer, gave direct evidence for the following states: x¹Σ_g ⁺, A″ ³Σ_u ⁺ ,A³ Π_g, c¹Πg, d¹Σ_u ⁺ and e¹Σ_g ⁺ .Their energies have been measured and are listed below. Also the energy required to ionize N₂ twofold in the (σ_g 2s) orbital has been determined to be (96.5 ± 1.0) eV.