Representation of the Electric Field of Longitudinal Waves in a Plasma,
Abstract
The use of electroacoustic probes to determine the electron density in the boundary layer of reentry flow fields constitutes one of the many applications of the phenomenon of longitudinal wave propagation in plasmas. The interaction of intense laser radiation with plasmas can excite longitudinal waves, create instabilities, and thereby lead to an anomalous plasma resistivity. Collisionless (Landau) damping and electron-neutral collisions are two mechanisms responsible for the attenuation of longitudinal waves. The dispersion relation for longitudinal waves is derivable from Maxwell's equations and the linearized Boltzmann equation in which electron-neutral collisions are represented by a Bhatnagar-Gross-Krook (BGK) model that conserves particles. The dispersion relation predicts that for a given signal frequency an infinite number of complex wavenumbers can exist. Using several theorems from complex variable theory, an explicit representation of the electric field can be derived in terms of an infinite sum of confluent hypergeometric functions. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 28, 1973
- Accession Number
- AD0762905
Entities
People
- P. Lindstrom
- R. J. Papa
Organizations
- Air Force Cambridge Research Laboratories