title: Binary and ternary recombination of para-H3(+) and ortho-H3(+) with electrons: state selective study at 77-200 K.
abstract: Measurements in H(3)(+) afterglow plasmas with spectroscopically determined relative abundances of H(3)(+) ions in the para-nuclear and ortho-nuclear spin states provide clear evidence that at low temperatures (77-200 K) para-H(3)(+) ions recombine significantly faster with electrons than ions in the ortho state, in agreement with a recent theoretical prediction. The cavity ring-down absorption spectroscopy used here provides an in situ determination of the para/ortho abundance ratio and yields additional information on the translational and rotational temperatures of the recombining ions. The results show that H(3)(+) recombination with electrons occurs by both binary recombination and third-body (helium) assisted recombination, and that both the two-body and three-body rate coefficients depend on the nuclear spin states. Electron-stabilized (collisional-radiative) recombination appears to make only a small contribution.
authors: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, Prague 18000, Czech Republic.
authors: Petr
authors: P
authors: Dohnal
authors: Michal
authors: M
authors: Hejduk
authors: Jozef
authors: J
authors: Varju
authors: Peter
authors: P
authors: Rubovič
authors: Štěpán
authors: Š
authors: Roučka
authors: Tomáš
authors: T
authors: Kotrík
authors: Radek
authors: R
authors: Plašil
authors: Juraj
authors: J
authors: Glosík
authors: Rainer
authors: R
authors: Johnsen