Dependence of the transition from Townsend to glow discharge on secondary emission.

, (1991)]]. Sijacić and Ebert stated that this transition strongly depends on secondary emission gamma from the cathode. We show here that the earlier results of von Engel and Raizer on the small current expansion about the Townsend limit actually are the limit of small gamma of the Sijacić and Ebert expression, and that for larger gamma the old and the Sijacić and Ebert new results vary by no more than a factor of 2.