Spectra of Ag i isoelectronic sequence observed from Er^21+ to Au^32+

Spectra of highly ionized Er, Yb, Hf, W, Pt, and Au were observed with the TEXT tokamak at the University of Texas at Austin. These metals were injected into the tokamak plasma by laser ablation of thin-film targets. Spectra were photographed with a 2.2-m grazing-incidence spectrograph in the range 40–300 Å. Three strong doublets of the Ag i isoelectronic sequence were identified: 4d104f–4d94f(1P)4f2D, 2F and 2G. Interpolated and extrapolated wavelengths in this sequence were derived from plots of the difference between observed and calculated values for the transition energies. The correspondence of the W wavelengths with previously reported tokamak spectra is shown.