DOUBLE EXCITATION IN THE K - SHELL ABSORPTION SPECTRUM OF SULPHUR IN H2S AND D2S

The X- ray absorption spectra of H2S and D2S were studied near the sulphur K - edge at high resolution using synchrotron radiation as a continuous background source. In addition to the well-known single electron excitation lines ws observe two new structures in the continuum. On the basis of single configuration Hartree - Fock calculations we assign these features to two-electron transitions leading to levels of the final state configurations 1s2s2p63s2p34s np,ns, 4p np and 3d np and to excited states of the ion 1s2s2p63s2p3 ns, np, nd εp