3 d(2) configuration in six-times-ionized argon, ArVII

The transition array 2p(6)3p3d-2p(6)3d(2) has been identified in the spectr um of magnesium-like Ar vii produced by electrical discharges in the vacuum -ultraviolet region. Twenty-five new transitions have been identified as co mbinations of levels of this transition array. From these transitions we ha ve determined the levels of the 3d(2) configuration. It was also possible t o determine the 2p(6)3p3d(1)D(2)(o) level that was missed in the early rese arch with the Ar vii spectrum. Hartree-Fock calculations with relativistic corrections were used to predict energy levels and transitions. Isoelectron ic comparisons along the Mg I sequence are used to support the experimental results. (C) 2001 Optical Society of America.