Ambipolar Diffusion in a Plasma Consisting of Electrons, Negative Ions and Two Types of Positive Ions
Abstract
In this work we investigated the ambipolar diffusion in electronegative plasma. The case of a plasma containing electrons, one kind of negative ions and two kinds of positive ions is considered. The formulas for the coefficient of ambipolar diffusion are obtained, which in extreme cases (one kind of negative ions, electropositive plasma) give the well-known results. It is shown that in a plasma with a density of negative ions more than 10 times higher the density of electrons, it is necessary to take into account the mobility of positive and negative ions. It was found that in strongly electronegative plasmas diffusion is no longer ambipolar, the ambipolar diffusion coefficients of charged particles are approximately equal to their free diffusion coefficients.
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