An arbitrary amplitude fast magnetosonic soliton in quantum electron–positron–ion plasmas

Nonlinear fast magnetosonic waves are studied in a collisionless homogenous, magnetized electron–positron–ion (e–p–i) plasma. The multi-component quantum magneto-hydrodynamic model is used in which ions are assumed to be dynamic whereas electron and positron quantum fluids are taken to be inertialess. The Sagdeev potential approach is used to obtain arbitrary amplitude magnetosonic structures in dense e–p–i plasmas. It is found that the wave amplitude as well as the width of the magnetosonic structure depends on different plasma parameters such as the electron to positron density ratio, plasma beta, quantum parameter and the Alfvénic Mach number. The numerical results have also been obtained for illustration. (paper)