Radiative characteristics of carbonaceous ablation layers with reflection effects

The equilibrium composition and spectral absorption coefficient of SiC abla tion layer plasmas have been calculated for temperature of 5 000 to 7 000 K , layer thickness of 0 to 7.5 mm, and pressure of 0.1 to 1.0 MPa. The radia tions included were molecular bands, atomic lines, and continuum processes. The absorption coefficient thus calculated was applied to a simplified sho ck layer model for the Jupiter entry probe to investigate the effectiveness of the ablation layer in reducing the radiative heating from a shock layer to a body surface. It was found that the SiC ablation layer is very effect ive to protect the body from radiative heating and that the photoionization processes of atomic carbon and silicon were mainly responsible for radiati ve absorption at high photon energy range. Furthermore the molecular carbon bands were effectively absorptive in relatively low photon energy range, p articularly at low temperatures.