Double K-shell excitation of Li by 10.6-MeV/nucleon N7+ projectiles

International audienceSingle and double K-shell excitation of Li by 10.6-MeV/nucleon N7+ projectiles is investigated by measuring Li autoionization spectra in the energy range from 50 to 90 eV. The ratio for double K-shell excitation to single K-shell excitation is determined to be about 0.36%. The measured ratio for double-to-single K-shell excitation of Li is about a factor of 2 larger than calculations based on independent interactions between the projectile nucleus and each of the Li target electrons, indicating that the electron-electron interaction plays a dominant role in the double K-shell excitation of Li in these collisions