An Auger-electron–ion coincidence experiment on ${\mathrm{N}}_2$ was performed using a recently developed electron–ion coincidence imaging spectrometer equipped with a photoemission electron gun. Clear electron–ion energy correlations were observed and used to determine the state-selected dissociation channels and their corresponding dissociation limits. Molecular-frame Auger-electron angular distributions were also obtained and used to determine the symmetry of the contributing dicationic states. Triple-coincidence measurements further demonstrate that Auger electrons in the 350–360 eV region arise predominantly from $1s$ shake-off ionization, followed by Auger decay into low-lying ${\mathrm{N}}_2{}^{3+}$ states that dissociate into ${\mathrm{N}}^{2+}+{\mathrm{N}}^{+}$. These results establish electron-impact-induced Auger-electron–ion coincidence spectroscopy as a powerful tool for state-selective studies of molecular dication and trication fragmentation dynamics.

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• Autoionization & Auger processes
• Electronic excitation & ionization
• Molecular dissociation