Balmer line emission from low-energy impact of H+, H2+ and H3+ ions in a beam on a tungsten surface

Emission of atomic hydrogen in the Balmer series was observed when H+, H2+ and H3+ ions with energies in the 30–1000 eV range were scattered on a polycrystalline tungsten surface. The spectra show that even at these low energies, the constituent particles of the polyatomic hydrogen ions act independently to reemerge as excited hydrogen atoms.