Decay channels of core-excited and ionized HCl studied by time-of-flight mass spectroscopy

The decay channels of HCl after excitation of Cl 2p electrons to different resonance states below the ionization threshold have been studied by measuring the ionic fragments using time-of-flight mass spectrometry. The fragmentation at resonances is found to deviate significantly from that obtained above the ionization threshold. The fragmentation is also observed to depend strongly on whether the 2p Cl electron is excited to the antibonding sigma * orbital or to the Rydberg orbitals. The interpretation is based on theoretical calculations.