Spectra of 14 Fe-like ions from Ru<sup>18+</sup> to Gd<sup>38+</sup> were observed with laser-produced plasmas and grazing-incidence spectrographs. The wavelengths range from 26 to 78 Å. Line identifications were made for transitions of the 3p<sup>6</sup>3d<sup>8</sup>−3p<sup>5</sup>3d<sup>9</sup> array. The number of identifications varied from 42 in Ru<sup>18+</sup> to 10 in Gd<sup>38+</sup>. Experimental values for many of the energy levels of the 3p<sup>6</sup>3d<sup>8</sup> and 3p<sup>5</sup>3d<sup>9</sup> configurations were derived from the measured wavelengths. Predicted values for missing levels and for ions not observed in the isoelectronic sequence were obtained from parametric fits of the differences between the observed level values and relativistically calculated level values. Results are given for all ions of the sequence from Ru<sup>18+</sup> to Yb<sup>44+</sup>. Wavelengths for magnetic dipole transitions within the 3p<sup>6</sup>3d<sup>8</sup> configuration calculated from the energy levels are given for several ions.
© 1988 Optical Society of America
J. O. Ekberg, U. Feldman, E. O. Hulburt, and J. Reader, "3p63d8−3p53d9 transitions in ironlike ions from Ru18+ to Gd38+," J. Opt. Soc. Am. B 5, 1275-1284 (1988)