Steady-State Kinetic Treatment of the Emission from Reduced Pressure Microwave Induced Discharges in Helium

A steady-state kinetic treatment of the number density of excited atoms In a helium discharge has shown these populations to be consistent with electron impact excitation. This study was initiated since it has been well established that the electrons are the activating species in discharges. The calculated number densities of excited atoms were obtained by consideration of the processes which cause excitation and deactivation. The processes which produce the population of a particular state are the following: electron Impact and radiative cascading from higher levels. The processes which reduce the population of a particular state are radiative and nonradiative deactivation. The results of this kinetic treatment compare remarkably well with experimental number densities obtained from emission studies.