Lower hybrid waves in finite‐β plasmas, destabilized by electron beams

The linear and quasilinear theories of lower hybrid waves in a finite‐β inhomogeneous plasma with electrons streaming parallel to the magnetic field are examined. These waves are found to be unstable for very low‐β and to be stabilized in finite‐β plasmas. The quasilinear feedback of unstable waves is shown to result in heating of ions perpendicular to the equilibrium magnetic field. Thus, unstable lower hybrid waves may play a role in producing ion conies in the auroral zone, and in heating ions in the solar plasma.