On beam instability of plasma in the magnetosphere of pulsars.

The beam instabilities that can arise in a near-pulsar, ultrarelativistic plasma are determined. It is shown that with known plasma parameters for a pulsar magnetosphere, the development of a beam instability must include a hydrodynamic stage. The beam can thus be spread. The generation of radiation is qualitatively analogous to the case treated by Benford and Buschauer (1977), except that here the plasma is relativistic and the beam is spread. In an electron-positron plasma in which the ratio of the relativistic factor of the beam to that of the plasma is approximately 1000 and thef ratio of the beam density to the plasma density is approximately 0.001, a kinetic beam instability of the longitudinal waves does not develop.