Excitation Temperatures in the Microwave-Induced Active-Nitrogen Afterglow

Abstract

A systematic study of the excitation temperature obtained from microwave-produced active nitrogen is reported. Iron atoms are used as the thermometric species, and the excitation temperatures are calculated with the use of the two-line ratio method. The excitation temperatures determined cover the range of approximately 3000 K to 4000 K, depending on the region of the plasma viewed. The large difference between the excitation temperature and the thermal temperature, as well as the fact that the excitation temperature is relatively insensitive to operating conditions, gives credence to the excitation mechanism proposed for active nitrogen systems.