The Glow in a Three-Body Recombination Dominated Afterglow

At low pressures and sufficiently high initial plasma densities (>10¹⁷ m^-3), the afterglow is governed by three-body recombination. A characteristic for this process is the formation of highly excited states followed by emission of photons and the appearance of spectral lines not present in the power-on phase. Here, this process has been illustrated using a fast streak camera to record the afterglow spectrum.