@Article{2019g,
  author =    {M D Cunha and H T C Kaufmann and D F N Santos and M S Benilov},
  title =     {Simulating changes in shape of thermionic cathodes during operation of high-pressure arc discharges},
  journal =   {J. Phys. D: Appl. Phys.},
  year =      {2019},
  volume =    {52},
  number =    {50},
  pages =     {504004},
  abstract =  {A numerical model of current transfer to thermionic cathodes of high-pressure arc discharges is developed with account of deviations from local thermodynamic equilibrium occurring near the cathode surface, in particular, of the near-cathode space-charge sheath, melting of the cathode, and motion of the molten metal under the effect of the plasma pressure, the Lorentz force, gravity, and surface tension. Modelling results are reported for a tungsten cathode of an atmospheric-pressure argon arc and the computed changes in the shape of the cathode closely resemble those observed in the experiment. The modelling has shown that the time scale of change of the cathode shape during arc operation is very sensitive to the temperature attained by the cathode. The fact that the computed time scales conform to those observed in the experiment indicate that the model of non-equilibrium near-cathode layers in high-pressure arc discharges, employed in this work, predicts the cathode temperature for a given arc current with adequate accuracy. In contrast, modelling based on the assumption of local thermodynamic equilibrium in the whole arc plasma computation domain up to the cathode surface could hardly produce a similar agreement.},
  doi =       {10.1088/1361-6463/ab4510},
  url =       {https://doi.org/10.1088%2F1361-6463%2Fab4510}
}