An air breakdown kinetic model

A kinetic model is developed for the glow phase of a spark gap in air. The model includes heavy-particle collisions leading to thermal ionization and electron-collision processes. Rates for the latter are calculated by a computer program that solves the electron Boltzmann equation, verified using empirical measurements. These rates include attachment and ionization, excitation followed by ionization of the excited species, and dissociation followed by ionization of the atomic species; molecular-impact detachment was found to be necessary to match experimental closing times. With those processes, the model predicts closing times well, over a wide range of voltages above and below the dc breakdown voltage.