Accession Number:

AD0750943

Title:

Electronic Nonequilibrium in a Supersonic Expansion of Ionized Gas,

Descriptive Note:

Corporate Author:

STANFORD UNIV CALIF INST FOR PLASMA RESEARCH

Personal Author(s):

Report Date:

1972-07-01

Pagination or Media Count:

284.0

Abstract:

An experimental and analytical study of nonequilibrium among the populations of the excited levels of electric arc heated potassium vapor injected in argonhelium gas flows passing through a Mach 2.2 supersonic nozzle is presented. Spectroscopic measurements line intensity and line reversal of the gas were performed upstream of the nozzle and at the nozzle exit. As the plasma proceeded through the nozzle the gas temperature dropped from 2500K to 1000K in 0.00003 seconds. The electron temperature also decreased rapidly, causing the free electrons to recombine with ions of potassium. The recombined electrons passing through the energy level structure of potassium formed the basis of the electronic nonequilibrium. A theory was written describing quantitatively the behavior of the excited atom populations. The electronics populations of expanded potassium vapor were observed to depart from equilibrium in qualitative accordance with the theoretical predictions. Author

Subject Categories:

  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE