Nonlinear drift-Alfven waves in relativistically hot multicomponent plasmas and their relevance to the fine structure of pulsar radioemissions

A set of equations which governs the nonlinear dynamics of drift-Alfven wav es in an inhomogeneous relativistic electron-positron plasma with a small a dmixture of heavy ions is derived. It is shown that these equations admit a stationary solution in the form of a two-scale dipolar vortex. The conditi ons for the existence of such structures are discussed. It is shown that th e presence of heavy ions in a relativistic electron-positron plasma signifi cantly reinforces the spatial localization of the solitary waves which resu lts in the appearance of exponentially localized vortex structures. It is a lso shown that the small scale micropulse structure of radio pulsar radiati on (e.g., in the case of the pulsar PSR 0905+08) can be interpreted as a si gnature of the vortex structure in the outer region of the pulsar polar mag netosphere.