Related Experiment Video
Updated: Aug 16, 2026

Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry
Published on: August 1, 2017
Influence of the excited states on the electron-energy distribution function in low-pressure microwave argon plasmas
A Yanguas-Gil1, J Cotrino, A R González-Elipe
1Instituto de Ciencias de Materiales de Sevilla and Departamento de Física Atómica, Molecular y Nuclear and Química Inorgánica (CSIC, Universidad de Sevilla), Sevilla, Spain. angel.yanguas@icmse.csic.es
Abstract:
In this work the influence of the excited states on the electron-energy distribution function has been determined for an argon microwave discharge at low pressure. A collisional-radiative model of argon has been developed taking into account the most recent experimental and theoretical values of argon-electron-impact excitation cross sections. The model has been solved along with the electron Boltzmann equation in order to study the influence of the inelastic collisions from the argon excited states on the electron-energy distribution function. Results show that under certain conditions the excited states can play an important role in determining the shape of the distribution function and the mean kinetic energy of the electrons, deplecting the high-energy tail due to inelastic processes from the excited states, especially from the 4s excited configuration. It has been found that from the populations of the excited states an excitation temperature can be defined. This excitation temperature, which can be experimentally determined by optical emission spectroscopy, is lower than the electron kinetic temperature obtained from the electron-energy distribution function.
Related Concept Videos
Atomic Emission Spectroscopy: Overview
Inductively Coupled Plasma Atomic Emission Spectroscopy: Principle
The ions and electrons produced interact with the fluctuating magnetic field created by a water-cooled...
Atomic Emission Spectroscopy: Lab
Atomic Emission Spectroscopy: Interference
Atomic Spectroscopy: Effects of Temperature
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
Atomic Emission Spectroscopy: Instrumentation

