On the particle acceleration near the light surface of radio pulsars

The two-fluid effects on the radial outflow of relativistic electron-positron plasma are considered. It is shown that for large enough Michel magnetization parameter (1969) and multiplication parameter, the one-fluid MHD approximation remains correct in the whole region where |E| < |B|. In the case in which the longitudinal electric current is smaller than the Goldreich-Julian one, the acceleration of particles is determined near the light surface where |E| = |B|. It is shown that, as in the previously considered cylindrical geometry (Beskin, Gurevich & Istomin 1983), almost all electromagnetic energy is transformed into the energy of particles in the narrow boundary layer. The relative thickness of this layer is shown to be of the order of the inverse of multiplication parameter.