Effect of polarization force on dust acoustic kinetic Alfven waves in the presence of trapped ions

Most of the space and astrophysical environments have witnessed the presence of dust and have a wide ranging applications in the different fields as well as in the study of astrophysical and space environments. The different observations have revealed the presence of superthermal particles in different kinds of space and astrophysical environments of plasmas. The deformation in the Debye sheath formed by ions around the negatively charged dust grains is termed as polarization force, which is an important frontline area of research in dusty plasma from last few decades. The polarization force is eloquently modified due to the presence of super thermally trapped ions and thus produces the drastic changes in wave dynamics. Kinetic Alfven waves arise when the perpendicular wavelength of ordinary Alfven wave is comparable to the ion Larmor radius. Kinetic Alfven waves play an important role in transporting energy in various space and astrophysical plasma environments, coronal plasma heating, plasma transport in magnetopause as well as in heating Tokamak plasmas, thus heating the plasma to fusion temperatures. Thus, it is imperative to study the dynamics of kinetic Alfven waves in order to understand various energy transport mechanisms in plasmas. The trapping of the particles was shown to be important while investigating the nonlinear characteristics of waves. In the present work, we have discussed the effects of vortex-like distribution of ions on obliquely propagating dust acoustic kinetic Alfven waves in a low β plasma. Using the two potential theory and employing the Sagdeev potential approach, we have investigated the existence of arbitrary amplitude coupled dust acoustic kinetic Alfvenic solitary waves in the frame work of trapped ions distribution. The present investigation may be beneficial in understanding the propagation of nonlinear coherent structures in different space and astrophysical environments where trapped populations of ions have been observed. (author)