Charge fluctuation induced solitary wave anomalous damping in collisionless dusty plasmas: effect of trapped-nonthermal ions

Abstract

The charge fluctuation induced solitary wave anomalous damping in a charge varying dusty plasma with ions following a Cairns–Gurevich distribution is investigated. To examine a such phenomenon, the exact Cairns–Gurevich ion charging current and the associated dust charge frequency are derived here for the first time. In addition, the appropriate modified damped Korteweg–de Vries (mdK–dV) equation, in which the anomalous (collisionless) damping term due solely to the dust charge variation, is established. Our results show that the damping term is sensibly affected by the presence of trapped-nonthermal ions. In particular, we have shown that this anomalous damping becomes stronger as the ions evolve far away from their Maxwellian trapping. Finally, our numerical investigation is extended to highlight the effect of the anomalous damping on dust-acoustic waves profile. We have found that the strength of dissipation becomes significant and may predominate over that of dispersion as the nonthermal character of trapped ions increases. Our theoretical investigation should be useful in further experimental and theoretical studies in space and laboratory dusty plasma systems.