DISSOCIATIVE CHARGE-TRANSFER OF ARGON IONS WITH METHANE MOLECULES FROM ULTRALOW TO SUPERTHERMAL COLLISION ENERGIES

Total cross sections, absolute reaction rate coefficients, and product branching ratios are reported for the reaction Ar+ + CH4 at energies from 5 x 10(-4) to 4 eV using two different and complementary techniqu es, Significant deviations from the Langevin theory are observed in th e energy dependence of the total cross section and interpreted in term s of a simple dynamical model. We find the collision energy is ineffec tive in altering the product branching ratios over the whole energy ra nge studied, while the spin-orbit components of Ar+ have a major effec t on the product distribution.