Population densities in a titanium hollow cathode

Measurements are reported of population densities in the energy level systems of neutral and singly ionised titanium. The discharge under investigation was a high-current hollow cathode operated in argon or neon as a buffer gas. The measured kinetic and population temperatures of the neutral species differ by more than a factor of two. For the metal ions there is direct evidence of the effects of charge transfer and Penning collisions producing departures from a Boltzmann distribution. For the Ar-Ti hollow-cathode system inversion between the populations of the 5s and 5p configurations has been found