The precipitation of an electron beam injected into the solar atmosphere is
studied for generation of Langmuir wave turbulence in the presence of collisional
and Ohmic losses. The system of quasi-linear time-dependent kinetic equations
describing the evolution of beams and Langmuir waves is solved by using the
summary approximation method. It is found that at upper atmospheric levels
the self-induced electric field suppresses the generation of Langmuir turbulence to
very small regions below injection. With further precipitation into deeper atmo-
sphere the initial single power law distributions of beam electrons are transformed
into energy distributions with maxima at lower energies formed by collisional and
Ohmic energy depletion. The electrons with lower energies (<20 keV) generateon large spatial scales intense low-hybrid and high-hybrid Langmuir waves with
well defined patterns in the corona while higher energy electrons generate moderate low hybrid waves in the chromosphere. The maximum wave density appears
at the maximum of the ambient density. The self-induced electric field reduces
the level and makes narrower the regions with low-hybrid Langmuir turbulence
in the corona and upper chromosphere. The higher the beam energy flux, or its
self-induced electric field, the narrower the regions with Langmuir turbulence.
High hybrid Langmuir turbulence generated in a form of regular patterns in depth and electron energies is also reduced by electric field to smaller
number of patterns shifted to smaller region in the upper corona.
Authors: Zharkova V.V. and Siversky T.V.
Publication Status: Astrophysical Journal, in press
Last Modified: 2011-03-16 15:12