Langmuir probe analysis of highly electronegative plasmas

Abstract

A Langmuir probe analysis of highly electronegative plasmas is proposed. Analytical models are used to fit the IV-characteristics and their second derivatives above and below the plasma potential. Ion and electron densities are obtained for α (negative ion to electron density ratio) up to 3000, and the temperature of negative and positive ions is obtained for α ranging from 100 to 3000. The transport across a localized magnetic barrier is studied using this technique. It is shown that an ion-ion (electron free) plasma is formed downstream from the barrier at the highest magnetic field.