  The Washimi and Karpman ponderomotive interaction due to electromagnetic
waves propagation is investigated for unmagnetized plasmas described by a
isotropic Kappa distribution. We performed a brief analysis of the influence of
the Kappa distribution in the dispersion relations for a low temperature plasma
expansion at the lowest order in which the thermal effects are appreciated. The
spatial and temporal factor of the ponderomotive force is obtained as a
function of the wavenumber, the spectral index $\kappa$ and the ratio between
the plasma thermal velocity and the speed of light. Our results show that for
unmagnetized plasmas non-thermal effects are negligible for the spatial
ponderomotive force when non-relativistic thermal velocities are considered.
However, for unmagnetized plasmas the temporal factor of the ponderomotive
force appears only due to the presence of suprathermal particles, with a clear
dependence on the $\kappa$ index. We have also analysed the role of the
non-thermal effect in the induced Washimi and Karpman ponderomotive
magnetization and the total power radiated associated with it. We have also
shown that the slowly varying induced ponderomotive magnetic field magnitude
increases as the plasma moves away from thermal equilibrium.
