Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Mohammed BOUKABBOUT"

DC glow discharge modelling by using electrons transport parameters from the BOLSIG+ code DOI:10.15199/48.2019.01.50

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In a DC glow discharge, the electric field is homogeneous in the inter-electrode space. The ions striking the cathode create secondary electrons. The electron avalanche creates much electron that ions but electrons being 100 times faster than ions, they drift quickly to the anode where they are absorbed. The ions having a lot of inertia accumulate in the inter-electrodes space, then the number of ions accumulates increases and from an accumulation threshold, the electric field is no longer homogeneous while it decreases on the side anode, which has the effect of slowing the electrons that drift towards the anode. The process continues until the electric field at the anode vanishes. The electrons can no longer pass freely to the anode and are considerably slowed down. The electron number density increases until to equal of the density of ions. A plasma is formed near the anode. The number of charged particles increases and the plasma extends from the anode to the cathode. The extension of the plasma compresses the region of strong field towards the cathode. These phenomena continue until the creation of charged particles is equilibrate (creation=losses). Two regions appear, the sheath and the plasma. The majority of electric discharge in gases (plasma) are built upon the Boltzmann equation. In principle, the combination of the Boltzmann equation, together with the Maxwell equations, needed for computation of the electromagnetic field, describes the physics of many discharges completely provided that this set of equations is equipped with suitable boundary conditions. In practice, however, the Boltzmann equation is unwieldy and cannot easily be solved without making significant simplifications. Fluid models describe the various plasma species in terms of average hydrodynamic quantities such as density, momentum and energy density. These quantities are governed by the first three moments of the Boltzmann equation: continuity[...]

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