Three-dimensional modeling of a direct current glow discharge in argon: is it better than one-dimensional modeling?

To obtain a better insight in the glow discharge, one-dimensional and three-dimensional models were developed for describing the behavior of the different species present in the discharge. In general, three-dimensional models are more complex and consume more computer time than one-dimensional models. To test whether it is really necessary to develop three-dimensional models or whether the one-dimensional approximation yields already a satisfactory description of the glow discharge, the results of both approaches have been compared. For the investigated cell geometry, the results are more or less comparable. Hence, one-dimensional models are in a first approximation sufficient to obtain a better insight in the glow discharge. However, three-dimensional models can give additional information (e.g., crater profiles at the cathode) and are therefore a progress when a more complete description of the discharge is intended.