Effect of dust size distribution on dust acoustic solitary waves in a six component cometary plasma

The characteristics of dust acoustic (DA) solitary waves in a dusty plasma system composed of positive and negative dust particles whose radii are in a range, together with two components of superthermal electrons with different temperatures and spectral indices and two components of nonthermal ions have been investigated. The Kadomstev-Petviashvili (KP) equation was derived using the reductive perturbation method. The effects of the superthermality of the electrons, nonthermal parameter of the ions and the densities of the dust particles on the amplitude, phase velocity and width of the DA solitary wave have been analyzed. It is observed that for different magnitudes of the power-law index that governs the dust particle distribution and number densities, rarefactive solitary waves are mostly generated in the plasma system. However, for low values of this index, the rarefactive solitary wave transforms into a compressive one. Further, it is found that the DA solitary waves are significantly influenced by the superthermality of the electrons, nonthermal parameter of the ions, the dust particle densities and their sizes.