Satellite spectra of heliumlike nickel

Spectra of heliumlike nickel, Ni xxvii, have been observed from Tokamak Fusion Test Reactor (TFTR) plasmas with a high-resolution crystal spectrometer. The experimental arrangement permits simultaneous observation of the heliumlike resonance line, the intercombination and forbidden lines, and all the associated satellites due to transitions 1s²nl-1s2l'nl'' with n{≥}2. Relative wavelengths and line intensities can thus be determined very accurately. The observed spectral data are in good agreement with results from the present Hartree-Fock-Slater atomic model calculations and predictions from the Z-expansion method.