TEMPERATURE MEASUREMENTS IN SEEDED AIR AND NITROGEN PLASMAS
Abstract
Temperatures in the range of 2500 to 5000K were measured in the seeded air and nitrogen plasmas produced with a 2 megawatt arc heater. Two specially designed spectra probes were used for these measurements. Mass seed rates of potassium carbonate ranged from 0 to 1.88% by weight of potassium and power levels ranged from 300 kw to 1000 kw. Temperatures determined from measured intensities of the continuous radiation and from atomic spectral lines of potassium were found in the seeded plasmas to agree satisfactorily with the static temperatures determined aerodynamically from an experimentally measured energy balance. Because of the strong dependence of intensity on temperature in the low range encountered, the observed intensity fluctuations in the jet resulted in less than a 10% change in temperature. Corrections of the seed lines for self-absorption brought the measured temperatures within 2% of those obtained from the continuum. The continuous radiation from unseeded air and nitrogen plasmas was measured to be about a factor of 15 higher than any existing theory predicts.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1970
- Accession Number
- AD0699200
Entities
People
- F. L. Kelly
- G. Bedjai
- H. N. Olsen