CARACTERISTICS OF RADIO FREQUENCY CAPACITIVELY COUPLED DISCHARGE OPERATING ON WATER-VAPOUR AND IN HELIUM-WATER MIXRURES

Ziane Kechidi
Laboratory of Electric engineering and Automatics, University of Medea, Ain D'heb (26000) Algeria

A. H. Belbachir
Laboratory of Analysis and Application of Radiations, Department of Physics, USTO Oran, Algeria

Mohamed Announ
Laboratory of Materials and Environment, University of Medea, Ain D'heb (26000) Algeria

DOI: 10.1615/TFESC1.eep.012555
pages 733-736

Ключевые слова: Atmospheric water-vapour, RF and Nanosecond pulsed source, Electrons cooling by rotational and vibrational reactions, Production of some species potentially used in medical remediation and environmental applications

Аннотация

A one-dimensional fluid model of capacitively coupled discharge driven by radio frequency source at low and atmospheric has been investigated. The simulation has been performed using the Comsol multiphysics platform. The results show that pure water-vapour discharge can be generated by using rf source just at low pressure. However, at atmospheric pressure and room temperature, stable plasma can be created when adding a small fraction 5% of water vapor to 95% of Helium. The process for suppressing plasma ignition in the first case can be attributed to the high rate of electrons cooling. Vibrational and rotational excited states reactions are the main dominant reactions at low energy in electron impact with water molecules. We have tested two ways in order to overcome these obstacles. The first one is by operating on a mixture of small fraction water with another main feed such as helium or Ar. The second one is by using a nanosecond pulsed generator as a driving source. Input parameters for plasma ignition have been identified in both cases. Plasma density profiles have been represented and the production of some important species such as OH, H and UV radiations has been also discussed.