ESTIMATING THE DIAMETER OF THE PLASMA IN A PROPULSION MOTOR PLUME.
Abstract
The diameter of a plasma intersecting the beam of a microwave diagnostic probe must be known to calculate the electron density in the plasma. The ambition to determine the diameter of a small scale model rocket plume by a simple, reliable analysis of the experimental conditions and data obtained by the probe was not completely realized. But some concepts and numbers were developed that have advanced the art of the analysis of the data. The results of an experimental determination of the energy distribution in the microwave beam has been used to calculate the attenuation of this energy by the plasma in an intersecting flame with given attenuation characteristics. The wavelengths of the two microwave beams used were 1.25 cm or 3.0 cm. A method was developed to calculate the attenuation, and a correction factor has been identified to be applied to the apparent attenuation to account for the relative size of the plume when the ratio of the beam diameter to the plume diameter is known. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1969
- Accession Number
- AD0691199
Entities
People
- J. P. Weston
Organizations
- United States Naval Research Laboratory