Formation of metastable fragments around the Cl 2p ionization thresholds of HCI

Formation of metastable fragments has been investigated in the vicinity of the Cl 2p ionization thresholds of HCl. Efficient productions of H* fragments with their counterpart of Clⁿ⁺ ions are observed around the ionization thresholds. The formations of H*+Clⁿ⁺ pairs result from the dissociation of high-Rydberg HCl⁺ states that are populated either by spectator Auger decay from the inner-shell excited states or by the recapture of slow photoelectrons into the Rydberg orbitals. In addition, H* fragments are shown to be produced through the dissociation of HCl ²⁺ states formed via normal Auger decay of the Cl 2p core-hole states.