Dissociative recombination in argon: Dependence of the total rate coefficient and excited-state production on electron temperature

A three-mode microwave afterglow apparatus and high-speed grating spectrometer are used to study dissociative recombination in argon. The total rate coefficient may be represented by α[Ar₂⁺]=9.1×10^-7×[300Tₑ(K)]0.61 cm³/sec over the electron-temperature range 300≤Tₑ≤8500 K, with T₊=Tgas=300 K. The excited states produced by the dissociative recombination are determined at Tₑ=300 and 7200 K. In both cases, the $4p$ and 4p^' states are found to be the most strongly populated.