Chemical kinetics of radio-frequency driven atmospheric-pressure helium-oxygen plasmas in humid air

ORAL

Abstract

We describe the chemical kinetics of radio-frequency (rf) driven atmospheric-pressure helium-based plasmas in ambient air as determined through a zero-dimensional time-dependent global model. The effects of humid-air admixtures on the plasma-induced chemical reactions and the evolution of species concentrations in the helium-oxygen mixture (He-O2, helium with 5000 ppm admixture of oxygen) are studied for wide air impurity levels of 1-5000 ppm with the relative humidity of 0-100\%. Comparisons made with experiments using an rf driven micro-scale atmospheric pressure plasma jet and one-dimensional simulations suggest that the plausible air impurity level in the experiments is not more than hundreds ppm. Effects of the air impurity containing water-humidity on electro-negativity and chemical activity are clarified with particular emphasis on reactive oxygen species.

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Authors

  • Tomoyuki Murakami

    Tokyo Institute of Technology

  • Kari niemi

    Centre for Plasma Physics, Queens University Belfast, Belfast, BT7 1NN, Northern Ireland, UK, Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK, Queens University Belfast, Centre for Plasma Physics, Queen's University Belfast, Belfast BT7 1NN, UK

  • Timo Gans

    York Plasma Institute, Department of Physics, University of York, Heslington, York, YO10 5DQ, UK, York Plasma Institute, Department of Physics, University of York, York YO10 5DD, UK, University of York, York Plasma Institute, Department of Physics, University of York, York, YO10 5DD, UK

  • Deborah O'Connell

    York Plasma Institute, Department of Physics, University of York, York YO10 5DD, UK, University of York, York Plasma Institute, Department of Physics, University of York, York, YO10 5DD, UK

  • William Graham

    Queens University of Belfast, Queens University Belfast, Centre for Plasma Physics, Queen's University Belfast, Belfast BT7 1NN, UK