Generation of large scale field-aligned density irregularities in ionospheric heating experimentsThreshold and growth rate for stimulated Brillouin scattering are calculated for a uniform magnetoplasma. These are then compared with the threshold and growth rate of a new thermal instability in which the nonlinear Lorentz force felt by the electrons at the beat frequency of the two electromagnetic waves is replaced by a pressure force due to differential heating in the interference pattern of the pump wave and the generated electromagnetic wave. This thermal instability, which is still essentially stimulated Brillouin scattering, has a threshold which is especially low when the propagation vector of the beat wave is almost normal to the magnetic field. The threshold is then considerably lower than the threshold for normal stimulated Brillouin scattering and therefore this new instability is probably responsible for the generation of large scale field aligned irregularities and ionospheric spread F.
Document ID
19740023711
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Fejer, J. A. (Max-Planck-Inst. fuer Physik und Astrophysik Munich, Germany)
Date Acquired
August 7, 2013
Publication Date
May 1, 1974
Publication Information
Publication: AGARD Nonlinear Effects in Electromagnetic Wave Propagation