Abstract
The preliminary results of experimental state selective study of H3 + recombination with electrons are presented. By using different ratios of para and ortho H2 in normal and para enriched hydrogen we produced different populations of para-H3 + in H3 + dominated decaying plasma at 140 K.
Absorption spectroscopy (NIR-CRDS) was used to measure the time evolution of densities of two lowest rotational H3 + states in afterglow plasma. By measuring plasma decays at different populations of ortho- and para-H3 + we were able to evaluate binary and helium assisted ternary recombination rate coefficient of ortho-H3 + and para-H3 +: o bin(140 K) = (0.3 +- 0.9) x 10-7 cm3s-1, p bin(140 K) = (1.3 +- 0.9) x 10-7 cm3s-1, oKHe(140 K) = (0.1 +- 3.3) x 10-25 cm6s-1 and pKHe(140 K) = (4.3 +- 3.3) x 10-25 cm6s-1.