Analysis of metrological potentialities of a high-current arc in plasma generators with a diverging channel

The paper is concerned with substantiating a high metrological "quality" of the cathode section of a stationary electric arc in plasma generators which have a current density of over $2$ kA/cm$^2$, a diverging anode channel, and vortex stabilization. An automated spectroscopic system and a system for fast visualization of plasma filament are used to demonstrate the high reproducibility and stability of the electrical parameters of the arc and of the space and time radiating characteristics of highly ionized plasma of the cathode region of the discharge. The results of analysis of the thermodynamic state of plasma in the cathode region of the discharge point to the validity of the conditions of partial local thermodynamic equilibrium in this region. The use of the developed system of automatic acquisition and processing of spectroscopic information enables one to obtain unique (as regards the scope and accuracy) data on the radiating characteristics of lines of atoms and ions of different multiplicity.