Rh i isoelectronic sequence observed from Er23+ to Pt33+

The TEXT tokamak was used to obtain spectra of highly ionized Er, Yb, Hf, W, and Pt. Injection of these elements into the plasma was achieved by laser ablation of thin films of metal deposited on glass slides and mounted at the inner wall of the vessel. The spectra were photographed with a 2.2-m grazing-incidence spectrograph set at a grazing angle of 4 degree. These spectra occur in a very small wavelength interval, for example, ∼2 A at 50 A in W. In this spectral range we previously classified lines of the Ag and Pd isoelectronic sequences. We have now classified lines of the Rh isoelectronic sequence 4d9--4d84f, which accounts for the remaining strong lines in this dense but well-resolved group. No lines of this array have previously been identified. They were classified by comparison of observed and calculated transition energies along the isoelectronic sequence