Bibcode
Soler, R.; Díaz, A. J.; Ballester, J. L.; Goossens, M.
Referencia bibliográfica
The Astrophysical Journal, Volume 749, Issue 2, article id. 163 (2012).
Advertised on:
4
2012
Revista
Número de citas
49
Número de citas referidas
46
Descripción
The Kelvin-Helmholtz instability (KHI) has been observed in the solar
atmosphere. Ion-neutral collisions may play a relevant role for the
growth rate and evolution of the KHI in solar partially ionized plasmas
such as in, e.g., solar prominences. Here, we investigate the linear
phase of the KHI at an interface between two partially ionized
magnetized plasmas in the presence of a shear flow. The effects of
ion-neutral collisions and compressibility are included in the analysis.
We obtain the dispersion relation of the linear modes and perform
parametric studies of the unstable solutions. We find that, in the
incompressible case, the KHI is present for any velocity shear
regardless of the value of the collision frequency. In the compressible
case, the domain of instability depends strongly on the plasma
parameters, especially the collision frequency and the density contrast.
For high collision frequencies and low density contrasts the KHI is
present for super-Alfvénic velocity shear only. For high density
contrasts the threshold velocity shear can be reduced to
sub-Alfvénic values. For the particular case of turbulent plumes
in prominences, we conclude that sub-Alfvénic flow velocities can
trigger the KHI thanks to the ion-neutral coupling.
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