Applicability of Child–Langmuir collision laws for describing a dc cathode sheath in N2O

Abstract

It is established which of the Child–Langmuir collision law versions are most appropriate for describing the processes in the cathode sheath in the N2O. At low pressure (up to 0.3 Torr), the Child–Langmuir law version relating to the constant ion mobility holds. At N2O pressure values starting from 0.75 Torr and above, one has to employ the law version for which it is assumed that the ion mean free path within the cathode sheath is constant. In the intermediate pressure range (between 0.3 and 0.75 Torr), neither of the Child–Langmuir law versions gives a correct description of the cathode sheath of the glow discharge in the N2O.