Balmer α emission in collisions of H, H+, H2+and H3+with CH4

The production of Balmer H alpha radiation in the passage of H, H + , H 2 + and H 3 + through CH 4 has been investigated with the energy range of 10-100 keV. The experimental technique, which involved the separate detection of Doppler-shifted and unshifted radiation, allowed the determination of cross sections for the production of fast H(3s) atoms, H alpha emission from the fast projectile and H alpha emission arising from dissociative excitation of CH 4 .