Interpretations of Langmuir Probe Data for Positive Ion Number Density of ${\rm N}_{2}{\rm O}$ DC Plasma Discharge

Electronegativity of N₂O dc plasma discharge was investigated by evaluation of the positive ion number density and electron number density. The positive ion number density was obtained using the positive ion current part from recorded I-V characteristic curves. Results obtained employing the Allen-Boyd-Reynolds, current balance, and orbital motion limited methods were found to be compatible, and the floating potential (FP) method was found to be a magnitude of higher order. Electron temperature and number density were also obtained for N₂O by the exponentially rising electron current of the I-V curves. The FP method was also employed by taking advantage of the positive ion current, and part of the I-V characteristic curves was also used in the evaluation of the electron temperature. Electron energy distribution function was evaluated and used to obtain the electron number density and temperature. Electronegativity of the N₂O was deduced using the measured data of electron and negative ion number densities.