Evidence for the distribution of iron atoms in argon inductively coupled plasmas according to the Boltzmann population

Abstract

The possibility was demonstrated of using the Boltzmann population to determine the distribution of Fe atoms in an Ar inductively coupled plasma. It is maintained that the contention that Fe atoms in the Ar plasma are not distributed according to the Boltzmann population is based on insufficient data. In the present study 69 wavelength lines of Fe atoms were measured, while the upper level energies of Fe atoms were in the range of 25900–55754 cm^–1. In addition, the values of the oscillator strength or the transition probability, which were taken from previous studies, were obtained by the are method as well as the lifetime method. Results indicate that the function of the number of excited Fe atoms has a linear relation to the upper level energies of Fe atoms. Hence, it is concluded that the Fe atoms are distributed according to the Boltzmann population, and that the temperature of the Fe atoms in the plasma can be obtained by the Boltzmann distribution equation.