Luminescence cross sections in the low-energy collisions of H+, H-2(+), and H-3(+) ions with H-2

摘要

Luminescence cross sections for the optical emission of molecular hydrogen in the 200-600 nm spectral range and for the atomic Balmer- line were measured for low-energy ( 1 keV) H+,H-2(+), and H-3(+) ions colliding with H-2 gas targets. Molecular hydrogen transitions between singlet states were observed for all the systems studied, while the emission continuum H-2(a-b) and discrete spectra associated with other transitions between triplet states appeared only in theH(2)(+) + H-2 collisions, where the spin conservation rule is fulfilled. Isotopic substitutions in the H-2(+)/D-2(+) + H-2, D-2 system show that at E-lab = 1 keV, a dominant molecular luminescence mechanism is the collision-induced excitation (CIE) of the target.