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.

–

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