Detailed measurements employing a combination of a cryogenic flowing afterglow with Langmuir probe (Cryo-FALP II) and a stationary afterglow with near-infrared absorption spectroscopy (SACRDS) show that binary electron recombination of para H-3(+) and ortho H-3(+) ions occurs with significantly different rate coefficients, Pabin and abln, especially at very low temperatures. The measurements cover temperatures from 60K to 300 K.
At the lowest temperature of 60K, recombination of para H3+ is at least three times faster than that of ortho-H-3(+) Cabin = (1.8 0.4) x 10(-7) cm(3) s(-1) vs. abin = (0+05) X 10(-8) cm(3) S-1 (C) 2015 AIP Publishing LLC.