Low-frequency solitary wave propagations in complex plasmas: the effect of trapped non-thermal polarization force

Abstract

ABSTRACT The effect of trapped non-thermal polarization force on low-frequency solitary waves (dust acoustic solitons) is addressed in a collisionless complex plasma. For this purpose, we have firstly redefined the three-dimensional Cairns–Gurevich distribution that describes, simultaneously, the evolution of the energetic ions and those trapped in the plasma potential well, and derived the associated both density and polarization force expressions. The polarization force effects are remarkably modified due to the presence of the trapped non-thermal ions. In particular, we have found that the polarization force magnitude decreases with the increase of ion non-thermality character. Next, the modifications arising in dust-acoustic (DA) solitons and its energy due to the presence of these trapped non-thermal density and polarization force are analyzed. In particular, we have found that the presence of the polarization force leads to an increase in the amplitude and width of DA solitary wave can be propagated in different complex plasma media. Finally, a complementary study on the polarization force effects on the DA energy, associated with both space and experimental dusty plasmas, is also carried out. Our numerical results have shown that more is strong the polarization force more is higher the energy transported by DA solitons.