Nonlinear Theory of the E x B Instability with an Inhomogeneous Electric Field.
NAVAL RESEARCH LAB WASHINGTON DC
Pagination or Media Count:
Using analytical and numerical techniques, the nonlinear evolution of the E x B instability with an inhomogeneous electric field has been studied. For the case where the electric field component parallel to the density gradient is inhomogeneous, the author finds that the inhomogenous E x B instability in the nonlinear regime 1 destabilizes short wavelength linear stable modes, 2 evolves into large scale anisotropic finger-like structures, 3 can be described by power laws, Pk sub x varies as k sub x -nx, n sub x asymptotically equal 2, Pk sub y varies as k sub y -n sub y, n sub y asymptotically equal 2-3 where Pk sub x and Pk sub y are the one-dimensional power spectra parallel and perpendicular to the initial density gradient and 4 can be stabilized by quasilinear mechanisms in which the initial density is modified by a finite amplitude wave spectrum. Applications are made both to naturally occurring small scale structures in the auroral ionosphere and striation formation in artificially produced ionospheric plasma clouds. Author
- Numerical Mathematics
- Electricity and Magnetism