Interaction of kinetic Alfvén wave solitons in nonthermal plasmas

Abstract

The interaction of Kinetic Alfvén (KA) wave solitons is examined in a finite β (me/mi < β < 1) electron-ion plasma with kappa distributed electrons. Following the extended Poincaré-Lighthill-Kuo method, coupled Korteweg–de Vries (KdV) equations are derived for the interaction of two moving opposite Kinetic Alfvénic solitons and the corresponding phase shifts are estimated. The procedure is then extended to the multiple soliton interaction of Kinetic Alfvén waves. By using the Hirota bilinear method, the solution of two-sided double and two-sided triple KA KdV solitons and their corresponding phase shifts are obtained. The profiles of head-on collision in multiple soliton situations are shown; the present model supports only compressive sub-Alfvénic soliton structures. It is found that plasma β, obliqueness, and the superthermality index significantly alter the phase shifts (due to head-on and overtaking collisions). The magnitude of the phase shift due to overtaking collision is more compared to that with the head-on collision. The present study is relevant to space and laboratory plasma underpinning sub-Alfvénic soliton.