Flowing-afterglow study of electron-ion recombination of para-H+3 and ortho-H+3 ions at temperatures from 60 K to 300 K.

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, ^pa_bin and ^oa_bin, especially at very lowtemperatures. The measurements cover temperatures from 60Kto 300 K. At the lowest temperature of 60 K, recombination of para-H⁺₃ is at least three times faster than that of ortho-H⁺₃ (^pa_bin = (1.8 ± 0.4) × 10^-7 cm³ s^-1 vs. ^oa_bin = (0⁺⁵_-0) × 10^-8 cm³ s^-1). [ABSTRACT FROM AUTHOR]