Abstract
The results of a numerical simulation of a dc gas discharge in a mixture of neon + 0.1% argon are presented. The simulation is based upon a Townsend avalanche mechanism (direct ionization) and the ion secondary effect. The effect of the delayed electron due to Penning collision (indirect ionization) in the mixture is fully accounted for. Comparisons with the experimental results of Penning and co-workers are also made.