Stimulated scattering instability of lower hybrid waves

The excitation of a low‐frequency quasimode together with two lower hybrid sidebands by a lower hybrid pump is analyzed for laboratory plasmas. This instability is excited in a narrow spectral range around the scale length of the quasimode which is about half the pump wavelength. The growth rates are of order of the ion cyclotron frequency. This instability can modify the intensity distribution of the pump wave and as a consequence affect the energy deposition of the pump wave in plasmas. The smaller parallel phase velocites of the forwardscattered lower hybrid sidebands are conducive to the acceleration of bulk electrons along the magnetic field.