Експериментальнi дослiдження i чисельнi моделювання плазми коронного розряду

Abstract

A complete cycle of experimental and theoretical investigations and mathematical modellings of the plasma processes in negative corona under the ambient pressure of nitrogenoxygen and argon-oxygen gas mixtures has been carried out. The oxygen concentration varied within the range of 0,01-21%. The efect of oxygen geometrical and electrical parameters on the current pulsation was investigated. The numerical modelling of the corona current has been realized , using continuity differential equations for fluxes of charges , supplemented by the Poisson s equation for an electrical field in quasi-two-dimensional space. The kinetic model includes the ionization and excitation of Ar atoms and N₂ molecules by electron collisions the ionization by pho tons the attachment of electrons to O2, their detachment from O⁻₂ due to collisions with N₂ in the ground and excited states the charge drift and the surface photo and ion-electron emission The physical mechanisms of complex corona current pulse as the precursor as well as the pulse step and the highfrequency pulsations of current have been determined. It is shown that the peak part shape in N₂+ O₂ mixture is formed due to rise of an electric #eld in the initial phases of a pulse the subsequent increase of high energy excitation of N₂ levels and the photoionization of oxygen molecules. In the case of Ar + O₂ this process is weakened due to the lowered energy of the electrons.