Determination of electron density in a wall stabilized Ar-CO ${\mathsf{_2}}$ thermal plasma

The electron density is measured in an argon-CO₂ thermal plasma by optical emission spectroscopy. Electron density is deduced from the Stark broadening of the argon line and hydrogen (H ) line. Different theories are used and compared. The effect of CO₂ molecule upon this plasma is studied as a function of the Ar-CO₂ mixture composition and discharge current. The electron density is ranging from 3 x 10²¹ m^-3 to 5.6 x 10²² m^-3. The influence of the arc confinement is studied and the electron density gradients are evaluated. Departure from local thermal equilibrium is also discussed.Received: 5 September 2003, Published online: 21 October 2003PACS: 52.70.Kz Optical (ultraviolet, visible, infrared) measurements - 52.80.Mg Arcs; sparks; lightning; atmospheric electricity