Development of a compact electron beam fluorescence instrument for high enthalpy flow characterization

ONERA, BP72, Chatillon Cedex 92322, France

Abstract

A prototype based on the Electron Beam Fluorescence (EBF) Technique is being developed for in-flight measurements in the shock layer of a reentry demonstrator. The measurement objectives are rotational and vibrational temperatures of N₂ as well as the densities of N₂ and NO at different positions in and outside a shock layer. There is a renewal of interest in extending the technique to higher densities and to probe CO/CO₂ flows (Mars atmosphere studies). The present paper gives a brief description of the status of the instrument with details on the optimization work performed to miniaturize the electron gun, the study of induced fluorescence in some gases and mixtures in laboratory vacuum chamber.