NEW MEASUREMENTS OF H-3(+) AND HCO+ DISSOCIATIVE RECOMBINATION RATE COEFFICIENT

Dissociative recombination rate coefficients of H3+, with low vibrational excitation, and HCO+ have been measured by means of a new flowing afterglow apparatus at 300 K. For H3+, it has been obtained alpha(H3+(v less-than-or-equal-to 2)) = 1.5 x 10(-7) cm3s-1 and alpha(H3+(v = 0)) = 1.1 x 10(-7) cm3s-1. The problem of the vibrational state of H3+ is pointed out. For HCO+, the rate coefficient has been measured to be alpha(HCO+) = 2.4 x 10(-7) cm3s-1. It is stressed that this results are in agreement with the recent experiment of Amano, but are in conflict with the FALP study of Adams and Smith.