Dust acoustic soliton energy in a mixed nonthermal high energy-tail electron distribution

Weak dust acoustic (DA) solitary waves are investigated in a mixed nonthermal high energy-tail electron distribution, focusing on the influence of an interplay between nonthermality and superthermality on the DA soliton energy. It is shown that in a pure superthermal plasma (α=0), electron thermalization (κ→∞) leads to an increase of the energy carried by the soliton. Addition of minute quantities of nonthermal electrons drastically modifies the κ-dependence of the soliton energy E _κ,α . The latter first decreases, then exhibits a local minimum before leveling at a constant value. The energy exchange between the non-Maxwellian electrons and the localized solitary structure depends drastically on the interplay between superthermality and nonthermality.