Baeva, Margarita

In this work we present for the first time a unified model of a low-current short-length arc between copper electrodes. The model employs one-dimensional fluid description of the plasma in argon and copper vapour at atmospheric pressure and the heat transfer in the electrodes made of copper. The solution of the particle and energy conservation of electrons and heavy particles is coupled with the solution of the Poisson equation, from which the self-consistent electric field is obtained. The operation of the non-refractory cathode is based on thermo-field emission.

An appropriate coupling of an arc plasma column in the state of local thermodynamic equilibrium to a refractory
cathode necessarily involves the non-equilibrium boundary layer between them. A model has been developed that

This dataset contains plasma parameters of microarcs generated between a cooled copper anode and a ceriated tungsten cathode by means of a one-dimensional unified non-equilibrium model for gap lengths between 15 and 200 µm and current densities from 2x10^5 up to 10^6 A/m^2. The data show that the decrease of the gap length down to a few tens of micrometers for a given current density results in a progressive shrinking of the quasineutral bulk in the microplasma and its complete disappearance.