Wavelengths and energy levels of potassium-like Ni x

An analysis of potassium-like Ni x in the 15-170 nm wavelength region is re ported following observations involving collision-based spectroscopy and la ser plasma spectroscopy. Ferry five transitions from different excited stat es in Ni x are identified. Twenty new energy levels of Ni x have been estab lished. The analysis was supported by Hartree-Fock calculations, isoelectro nic comparison and the consistency of energy differences between transition s from common initial stares. Compared to isoelectronic ions of lower Z, th e doubler structure in this spectrum is effectively destroyed by 3p(6)5d, 6 d + 3p(5)3d4p, 3p(4)3d(3) configuration interaction.