title: Temperature dependences of rate coefficients for electron catalyzed mutual neutralization.
abstract: The flowing afterglow technique of variable electron and neutral density attachment mass spectrometry (VENDAMS) has recently yielded evidence for a novel plasma charge loss process, electron catalyzed mutual neutralization (ECMN), i.e., A(+) + B(-) + e(-) → A + B + e(-). Here, rate constants for ECMN of two polyatomic species (POCl(3)(-) and POCl(2)(-)) and one diatomic species (Br(2)(-)) each with two monatomic cations (Ar(+)and Kr(+)) are measured using VENDAMS over the temperature range 300 K-500 K. All rate constants show a steep negative temperature dependence, consistent with that expected for a three body process involving two ions and an electron. No variation in rate constants as a function of the cation type is observed outside of uncertainty; however, rate constants of the polyatomic anions (~1 × 10(-18) cm(6) s(-1) at 300 K) are measurably higher than that for Br(2)(-) [(5.5 ± 2) × 10(-19) cm(6) s(-1) at 300 K].
authors.affiliation: Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117, USA.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Shuman
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Miller
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Friedman
authors.forename: Albert A
authors.initials: AA
authors.lastname: Viggiano
authors.forename: Satoshi
authors.initials: S
authors.lastname: Maeda
authors.forename: Keiji
authors.initials: K
authors.lastname: Morokuma