Heat flux effect in ηi- mode driven solitary and shock waves in electron-positron-ion plasma

Abstract

The distinguishing role of ion heat flux on the characteristics of
the linear and nonlinear ion temperature gradient ($\eta_{i}$)
driven mode in inhomogeneous electron-positron-ion plasma is
presented. Inhomogeneity in density, temperature, and the magnetic
field is considered. A modified linear
dispersion relation is obtained and its different limiting cases: when $\eta_{i}\gg 2/3$, $%
\omega_{D} (\text{gradient in magnetic field})=0$ and $\beta
(\text{density ratio of plasma species})=1$ are discussed. Furthermore, an expression for the anomalous transport coefficient
of the present model is obtained. Nonlinear
structure solutions in the form of solitons and shocks show that
mode dynamics enhance in the presence of ion heat flux in
electron-positron-ion plasma. The present study has its importance
in energy confinement devices such as tokamak because the heat flux
observed experimentally in tokamak plasma is much higher than those
described by collisions. Further, it could be useful to understand
the nonlinear electrostatic excitations in the interstellar medium.