MODULATIONAL INSTABILITY, MODE CONVERSION, AND RADIO EMISSION IN THE MAGNETIZED PAIR PLASMA OF PULSARS

摘要

A theoretical analysis of coupled mode equations describes the evolution of plasma wave turbulence in the strongly magnetized pair plasma of the pulsar polar cap. The onset of turbulence is a modulational instability of a large-amplitude electrostatic wave. Numerical solution follows the nonlinear evolution toward a strongly turbulent state characterized by the multidimensional collapse of wave packets. The turbulence generates electromagnetic modes that can escape the plasma. The modulational conversion process provides a fairly simple scenario for pulsar emission: an electrostatic plasma wave instability and the subsequent modulational mode coupling to escaping radiation.