Determination of plasma density from spectra of heliumlike ions

A numerical calculation is reported of the ratio of the intensities of resonance and intercombination lines of multiply charged heliumlike ions. The influence of cascade transitions on this ratio is investigated for various values of the plasma density. Detailed calculated results are given for the plasma density range N_e~10¹⁹–10²³ cm^–3 because this range is of interest in laser heating experiments.