PLASMADIAGNOSTICS WITHIN THE PLASMA WIND-TUNNEL PWK

The IRS plasma wind tunnels were designed to test thermal protection m aterials for space vehicles as well as to qualify numerical codes. The knowledge of the parameters of the plasma jet is a prerequisite for d eveloping erosion models for heat shield materials, relating erosion m easurements to the real re-entry situation and also for corroboration of plasma code modelling calculations. Therefore, a number of methods has been developed and tested for the diagnostics of the high enthalpy plasma flow. These are different mechanical and electrostatic probes, emission spectrometry, Fabry-Perot interferometry and mass spectromet ry. In this paper the results obtained with the different diagnostic m ethods for plasma flow conditions which are typical for a re-entry sit uation of a space vehicle are presented and discussed and first erosio n measurements by mass spectrometry are shown. Applying all experiment al and numerical methods, an air plasma flow can now be characterized from the plasma source downstream to material test positions.