Relative excitation functions for singly-excited and core-excited levels of S v–S ix populated by the beam-foil interaction

We have investigated the relative excitation functions for low-lying singly excited and low-lying core-excited levels in S v (S⁴⁺) to S ix (S⁸⁺) after beam-foil excitation using ions in the energy range 2--10 MeV. The spectral line intensities have been normalized to the same number of particles at each ion energy and corrections for the level lifetimes have been made. The overall accuracy of the measured relative excitation function at each energy and charge state is estimated to be better than 2%. A comparison of the relative excitation functions for singly excited and core-excited lines shows a difference in S vii, but not in S vi.