The Oscillating Two Stream and Parametric Decay Instabilities in a Weakly Magnetized Plasma.
Abstract
We consider the effects of a weak ambient magnetic field on the oscillating two stream and parametric decay instabilities, with particular emphasis on the dependence on the angular variation of the instability thresholds and growth rates on the magnetic field. A dispersion relation is derived in the limit in which omega sub e >> Omega sub e (where omega sub e and Omega sub e are the electron plasma and cyclotron frequencies respectively), and is solved for dipole and monochromatic pump spectra. The analysis shows that the presence of a magnetic field can substantially enhance thresholds and reduce growth rates for waves propagating at an oblique angle with respect to the magnetic field and (k lambda sub e)-squared approximately = (Omega sub e/omega sub e)-squared (where k is the wavevector of the perturbation and lambda sub e the Debye length). Thus, the magnetic field has a stabilizing influence on the off-parallel propagating modes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 23, 1979
- Accession Number
- ADA072396
Entities
People
- H. P. Freund
- Konbtantinopsa Dennis Papadopoulos
Organizations
- United States Naval Research Laboratory