Oxygen ion spectra in a two-elemental laser plasma

The mass-charge and energy spectra of oxygen ions are studied in a plasma produced by laser irradiation of targets containing heavy elements with different masses (Sc, Ce, Lu) and close thermal parameters. The dependence of the maximum multiplicity of O²⁺ oxygen ions on the laser radiation intensity is determined. The maximum multiplicity is found to be independent of the elemental composition of a two-element target. The variation of the O⁺ and O²⁺ ion energy spectra and the broadening of the spectra of Sc, Ce, and Lu ions with multiplicities Z = 1 - 3 towards higher energies with increase in the mass of a heavy component (Sc, Ce, Lu) is found to occur owing to the energy exchange between light (O) and heavy (Sc, Ce, Lu) plasma ions.