MASS-SPECTROMETRIC AND ELECTROSTATIC-PROBE MEASUREMENTS OF N-2 O-2 PLASMA-FLOW/

Plasma wind tunnels are used at the Laboratoire d'Aerothermique at Meu don to simulate the different parameters of the gas surrounding the su rface of space vehicles during hypersonic flight in the upper atmosphe re, In the present work, mass spectrometric and double electrostatic p robe measurements in a stagnation point are performed in N-2/O-2 plasm as. Axial distributions of electron density and temperature are obtain ed from the fit between experimental data and Laframboise expression f or the double cylindrical probe current. Neutral and ion distributions are measured by mass analysis for different axial positions, and are then compared with a chemical model for air, in order to evaluate the dominant reactions in the plasma flow.