  A detailed study of the refraction of an ordinary wave in the magnetosphere
of radio pulsars was carried out. For this, a consistent theory of the
generation of secondary particles was constructed, which essentially takes into
account the dependence of the number density and the energy spectrum of
secondary particles on the distance from the magnetic axis. This made it
possible to determine with high accuracy the refraction of the ordinary O-mode
in the central region of the outflowing plasma, which makes it possible to
explain the central peak of three-humped mean radio profiles. As shown by
detailed numerical calculations, in most cases it is possible to reproduce
quite well the observed mean profiles of radio pulsars.
