Dissipative dust acoustic solitary waves in an electron depleted dusty plasma with superthermal ions

Dust acoustic (DA) solitary waves are investigated in an unmagnetized dusty plasma comprising of fluid warm dust particles and kappa distributed ions. We assume the electron number density to be sufficiently depleted in this fluid model, i.e., d e n n  . We consider the usual ad hoc damping term, involving the damping rate  due to the dust–neutral collisions; and derived the modified dispersion relation of DA waves. It is found that there is a critical wave number, which should have crit k k  , otherwise overdamping occurs. The critical value of the wave number increases with , while it decreases with . Also, a modified Korteweg-de-Vries (mKdV) equation was derived for description of DA solitary wave. We found that the amplitude, width and velocity of DA solitary waves are modified in the presence of damping term. As the amplitude and velocity of solitary DA wave decreases with , the width of soliton spreads. Also, it is found that the polarity of soliton changes from positive to negative at special value of .