State selective study of H3+ recombination in Cryo-FALP and SA-CRDS experiments at 77K.

Rate coefficients for nuclear spin state-specific recombination of H₃⁺ ions with thermal electrons were measured using FALP and SA techniques at temperatures 77-300 K. For this purpose H2 gas with both thermal and enriched population of the para nuclear spin configuration was used. Measurements have shown that at 77 K para-H₃⁺ exhibits five times higher binary recombination rate coefficient than ortho-H₃⁺: (1.5 ± 0.4) x 10^-7 vs. (3 ± 2) x 10^-8 cm³s^-1. [ABSTRACT FROM AUTHOR]