Photo-Detachment of Nitrous Oxide in DC Plasma Discharge

This paper is concerned with the determination of total negative ion number density (
n
_–
) in a dc plasma discharge of N
₂
O employing laser induced photo-detachment coupled with an electrostatic Langmuir probe. Electrons resulting from the photo-detachment are investigated and used to evaluate the negative ion number density employing the electron energy distribution function (EEDF) using the recorded
$I - V$
characteristic curves. The electron temperature was found to be dependent on pressure at the lowest discharge power, while it seems to be almost independent of discharge pressure at discharge powers higher than 10 000 mW. The negative ion number density was found to increase linearly as a function of discharge power within the
$10^{13}\text{m}^{\mathrm {-3}}$
scale and also increase as a function of pressure. The electro-negativity of N
₂
O was found to be about 0.03 at the lowest pressure and the lowest discharge power.