Accession Number:

AD0618398

Title:

WAVEGUIDE ADMITTANCE FOR RADIATION INTO PLASMA LAYERS-THEORY AND EXPERIMENT.

Descriptive Note:

Research report.

Corporate Author:

SYLVANIA ELECTRONIC SYSTEMS-EAST WALTHAM MASS APPLIED RESEARCH LAB

Personal Author(s):

Report Date:

1965-04-01

Pagination or Media Count:

26.0

Abstract:

Measured admittance of an X-band waveguide radiating into dielectric and plasma layers is compared with variationally computed admittance figures. The waveguide admittance measurements for polystyrene sheets of varying thicknesses compared closely with calculations. The admittance measurements for plasma layers are made during the diffusion controlled afterglow of a pulsed discharge contained in a bell-shaped vessel. The plasma density was measured over approximately 70 percent of the thickness of the plasma layers and was found to be nearly constant in this range which excluded regions near the boundary. Numerical solutions of the equations for ambipolar diffusion during the afterglow in a rectangular geometry show that the lateral plasma density variations are negligible in the vicinity of the waveguide. The measured admittance and plasma density data are shown to agree with calculations made for homogeneous plasma layers, if a correction is made for elevated ion temperatures for times of approximately 10 to 20 microsec. following the discharge. Several computational models consider plasma stratifications near the boundary of the plasma layer but they do not improve the agreement between measurement and calculations.

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE