Equilibrium and nonequilibrium electron density measurements in transient shock-heated hydrogen-helium plasmas

Autor: P. T. Y. Poon, F. R. Livingston
Rok vydání: 1976
Předmět:
Zdroj: 14th Aerospace Sciences Meeting.
DOI: 10.2514/6.1976-121
Popis: In the NASA planetary program, atmospheric entry probe missions to Jupiter, Saturn, and Uranus are potential programs now being planned for the 1980's. The work reported in this paper is concerned with predicting the electron density, and resulting radiative emission from the shock layer which must be accommodated by the entry probe heatshield. Within the hydrogen-helium plasma surrounding the forward heatshield, there are regions of near thermochemical equilibrium whose properties are predictable - however, there are uncertainties in these electron density calculations necessitating further measurements by H-beta line broadening and holographic interferometer fringe shift as reported here. There is good agreement between the results obtained from the holographic measurements and the spectroscopic measurements which lends confidence to each of the two completely independent diagnostic techniques. The equilibrium electron density determined from the experimental measurements is somewhat higher than that predicted.
Databáze: OpenAIRE