Theoretical modelling of Rayleigh Taylor instability driven by an ion beam in a plasma having strongly coupled dust grains

Dusty plasma is a partially or fully ionized gaseous state having ions, electrons and micron sized dust particles. Dust is found to be a detrimental component of various laboratory and space plasmas like fusion devices, comet tails, planetary rings, solar wind, earth's ionosphere etc. Dust particles being massive ~ 10¹² times heavier than mass of protons, respond strongly to gravity of earth. Moreover, the density and charge on the dust particles vary with time hence the inhomogeneous density of dust grains in a plasma gives rise to Rayleigh Taylor Instability (RTI) in which a light fluid motion is supported by the heavy fluid (Dust). A theoretical model has been developed to investigate the excitation of RTI by an ion beam in a plasma having strongly coupled dust using generalized hydrodynamic approach. An ion beam propagating parallel to magnetic field through the strongly coupled dusty plasma drives Rayleigh Taylor Instability (RTI) via Cerenkov interaction. The effect of strong correlations among dust grains and beam parameters on the RT instability has also been elucidated. The relevance of the results to astrophysical systems and fusion devices is also discussed. (author)