Analysis of the 3d⁹ns (n = 5, 6), 3d⁹5p, 3d⁹4f and 3d⁸4s4p configurations of five times ionized arsenic (As VI)

The spectrum of arsenic was photographed in the 100-1250 angstrom region on grazing and normal incidence spectrographs. The spectrum of As VI was extended. Seven out of eight levels of the 3d(9)5s and 6s configurations, 12 out of 12 levels of the 3d(9)5p configuration, 13 out of 20 levels of the 3d(9)4f configuration and 35 levels belonging to the 3d(8)4s4p configuration have been established. Least-Square-Fitted parametric calculations involving configuration interactions both in even and odd parity systems were carried out to adequately interpret the spectrum. One hundred and thirty-two additional lines were classified in the As VI spectrum. A new value of the ionization limit was obtained. Thus, the 3d9(2)D5/2 ground level in As VII lies 977 500 cm-1 (121.17eV) above the As VI ground state.