Luminescence from low-energy impact of Hn+ and Dn+ ions (n = 1,2,3) on a Tore Supra carbon tile

The hydrogen Balmer series was observed when beams of H+, H2+, H3+ and D+, D2+, D3+ ions impinged at 100–1000 eV on a carbon fiber composite tile (Tore Supra). The excitation functions of the Hβ (Dβ) lines demonstrate the validity of the independent particle model. The logarithmic plot of the Hβ (Dβ) line intensity versus the reciprocal projectile ion velocity can be well reproduced by a model in which the hydrogen ion projectiles are neutralized in the entrance phase and subsequently electronically excited in collisions with carbon atoms. Finally, the excited hydrogen atoms leave the solid and emit the observed photons, unless they are quenched in non-radiative processes.