Sub-natural linewidth Auger electron spectroscopy of the 2s hole decay in H 2S

Abstract

Threshold photoelectron-Auger electron coincidence spectroscopy has been applied to the sulphur 2s region of H 2S, where the Auger electron spectrum is measured in coincidence with threshold electrons. Formation of H 2S ++[(S2p) −1( V) −1] states via the L 1 L 2,3 V Coster–Kronig transitions is observed above the S2s photoionization threshold. Even below threshold, formation of these H 2S ++ states is seen and is due to direct double ionization. A sub-natural linewidth regime is achieved with this coincidence method and three structures resulting from overlaps of the H 2S ++[(S2p) −1( V) −1] states appear in the spectra. The three structures probably correspond to H 2S ++ states with the 2b 1, 5a 1 and 2b 2 holes.