Excitation of Alfven Waves and Pulsar Radio Emission

Abstract

We analyze mechanisms of the excitation of Alfvén wave in pulsar magnetospheres as a possible source of pulsar radio emission generation. We find that Cherenkov excitation of obliquely propagating Alfvén waves is inefficient, while excitation at the anomalous cyclotron resonance by the particles from the primary beam and from the tail of the bulk distribution function may have a considerable growth rate. The cyclotron instability on Alfvén waves occurs in the kinetic regime still not very closed to the star: $r \geq 50 R_{NS}$. We also discuss various mechanisms of conversion of Alfvén waves into escaping radiation. Unfortunately, no decisive conclusion about the effectiveness of such conversion can be made.