Die zeitliche Entwicklung einer Townsend-Entladung

Oscillographic studies of the current of a Townsend-discharge—started by 10³ to 10⁵ electrons within some mμsec—demonstrate the temporal development of the discharge in separated generations of electrons. Experiments were made in N₂, CH₄, CO₂ and mixtures of N₂/CH₄, and A/Air (gap-length 1·8 to 3 cm, pressure 50 to 400 mm Hg). A careful curve-fitting with calculated currents proves the agreement between measured and calculated curves. This correspondence shows that the discharge is governed by a) ionisation by collisions and b) secondary-photoeffect at the cathode.