Observation of Plasma Resonances by Microwave Emission,
Abstract
Complex plasma admittance and microwave emission, including Tonks-Dattner modes, were observed in Hg-vapor discharge tubes in the 1500-MHz plasma resonance range. Relationships linking transmission, reflection, and emission coefficients were derived using network calculations based on the Nyquist formula. The resulting noise temperatures are about half the electron temperatures obtained from Langmuir-probe measurements, as confirmed by cavity measurements in the axisymmetric plasma mode. Collisionless discharge is explained on the basis of a thick 'semithermionic' emitting zone near the wall, in which the interaction with the external electromagnetic field is concentrated. Parker-Nickel-Gould theory also indicates that a steep electron gradient near the wall would tend to restrict longitudinal waves to this region. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 10, 1968
- Accession Number
- AD0848614
Entities
People
- H. Prinzler
- K. Kliefoth
Organizations
- National Air and Space Intelligence Center