Effect of parallel electric field on Alfven wave in thermal magnetoplasma

Dispersion relation, dissipation and growth of Alfven wave in the presence of parallel electric field and electron thermal velocity have been obtained by investigating the trajectories of the charged particles. The effect of parallel electric field is included with the zeroth-order distribution function through modification of the electron thermal velocity parallel to ambient magnetic field. It is found that the parallel electric field and thermal velocity of the electrons enhance the damping/growth rate of the wave according to the direction of electric field. The applicability of theory to explain auroral acceleration in the space plasma has been discussed.