Drifting subpulses in pulsars.

The properties of drifting subpulses from pulsars are interpreted in terms of a model of plasma behavior near the surface of a rotating neutron star. The model proposed here involves discharge sparking in discrete flux tubes, charge separation of the discharge plasma to establish corotation, and variation of the electric field generated as the plasma streams away from the surface along diverging field lines. The model is shown to be capable of accounting for the following properties of drifting subpulses: the observed drift rate, the direction of drift, the variation of drift rate across the profile, sudden changes in drift rate of several subpulses at once, drift parameters observed in double profiles, and drift behavior following nulls.