MOSAIC STRUCTURE OF THE RADIATING REGION OF THE PULSAR PSR-0329+54

We present precise-timing observations of the mean profile of the puls ar PSR 0329+54 at seven frequencies between 100 MHz and 10 GHz. The pr ofile structure is determined as a superposition of Gaussian component s. A deviation of the profile structure from the five-component one fo und earlier is revealed. Good agreement is achieved only with six comp onents. This discrepancy puts in question the commonly accepted model of the emitting region consisting of an outer and an inner hollow cone and a central core. We believe that the emitting region is a mosaic s tructure, not conical-axial, shaped as a bundle of discrete jets of em itting relativistic particles. The jets are stretched along the magnet ic lines of force; they are formed by injection from discrete regions of breakdown-emission spots on the polar cap. The proposed structure i s based on the theory of pulsar radio emission of Ruderman and Sutherl and. According to this theory, a number of breakdowns forms in the pol ar-cap gap. The breakdowns are spaced at a distance approximately equa l to the gap height. Mode switching may be due to changes in the activ ity of individual breakdown regions without restructuring of the emitt ing region.