Pulsar geometries. I. Basic model

A ''geometrical'' model for pulsar emissions is presented according to which they occur perpendicular to organized magnetic field structures, but in finite sets of narrow beams that rotate with constant speed in the plane perpendicular to the field; such a ''wagon wheel'' pattern might arise out of interference among wedgeshaped patterns of coherent synchrotron radiation near the surface of the neutron star, or it may be related to standing plasma waves in a circumstellar magnetic field. No further requirements are necessary with regard to this emission mechanism to interpret the existence and preferred location of interpulses, fast and slow pulse-amplitude modulations, and drifting subpulses in terms of the inclination of magnetic field and rotational axes of the neutron star, and the accidental latitude position of the observer