Revised and extended analysis of transitions and energy levels in then= 3 complex of Mg-like Ca IX-Ge XXI

Spectra emitted from laser-produced plasmas of Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga and Ge have been recorded in the region 170-800 Å. In magnesium-like Ca IX-Mn XIV transitions establishing all the levels of 3 s 2 , 3 s 3 p , 3 s 3 d , 3 p 2 and 3 p 3 d have been identified, and new and improved level values have been derived. In Fe XV-Zn XIX additions have been made to recent analyses. In Ga XX and Ge XXI some strong lines in the 3-3 transition array have been identified. Ab initio and parametric calculations support the identifications and provide eigenvector components. Numerous observed transitions connect the singlet and triplet systems, and the wavelength of the resonance intercombination line 3 s 2 1 S 0 –3 s 3 p 3 P 1 has been derived from the energy levels for Ca IX-Zn XIX.