Propagation characteristics of low frequency electromagnetic modes in collisional beam plasma system

A significant change in the dispersion relation of low frequency electromagnetic Alfven modes occurs when ion beam interacts with a magnetized plasma, depending on plasma and the beam parameters. The growth rates and dispersion relation of pure and shear Alfven modes have been estimated. Pure Alfven wave suffers a cyclotron damping when it interacts with the charged particles of beam via linear cyclotron interaction. Only when the beam ions travel in the opposite direction from the shear Alfven wave via fast cyclotron interaction can destabilize the left-hand polarized shear Alfven mode. The Alfven wave dispersion characteristics change due to collisions between plasma components and result in damping of the waves by acting as a stabilizing influence. The growth rate and the frequency of generated Alfven waves get affected differently for right-hand and left-hand polarized Alfven modes due to the collisions between beam ions and plasma components. The growth rate has smaller values in the presence of collisions which show a collisional damping of pure and shear modes in the beam plasma system.