Dust ion-acoustic shock waves due to dust charge fluctuation in a superthermal dusty plasma

The nonlinear propagation of dust ion-acoustic (DIA) shock waves is studied in a charge varying dusty plasma with electrons having kappa velocity distribution. We use hot ions with equilibrium streaming speed and a fast superthermal electron charging current derived from orbit limited motion (OLM) theory. It is found that the presence of superthermal electrons does not only significantly modify the basic properties of shock waves, but also causes the existence of shock profile with only positive potential in such plasma with parameter ranges corresponding to Saturnʼs rings. It is also shown that the strength and steepness of the shock waves decrease with increase of the size of dust grains and ion temperature.

► The presence of superthermal electrons causes the existence of shock waves with only positive potential.
► The strength and steepness of the shock waves decrease with increase of the size of dust grains and ion temperature.
► As the electrons evolve toward their thermodynamic equilibrium, the shock structures are found with smaller amplitude.