EFFECT OF DUST CHARGE FLUCTUATIONS ON LOWER HYBRID INSTABILITY IN TOKAMAK IN PRESENCE OF NEUTRAL BEAM AND MAGNETIC SHEAR

Abstract

ABSTRACT A neutral beam propagating through a magnetized dusty plasma drives lower hybrid waves to instability via Cerenkov interaction. A dispersion relation and the growth rate of the instability for this process have been derived taking into account the dust charge fluctuations. The frequency and the growth rate of the unstable wave increases with the relative density of negatively charged dust grains. Also, as the dust grain parameters are varied the growth rate also varies. When the dust grain size is increased the growth rate decreases. Moreover, the growth rate of the instability increases with beam density and scales as the one-third power of the beam density. In addition, when the dust density increases, the growth rate decreases