Rayleigh-Taylor instability of a composite medium with variable viscosity in hydromagnetics

The frictional effect of collisions of ionized with neutral atoms on the Rayleigh-Taylor instability of a composite medium with variable viscosity is considered in the presence of a horizontal magnetic field. It is found that the simultaneous presence of viscosity, magnetic field and collisions has a stabilizing effect and completely stabilizes the wave-number bandk _* wherek _*=(k _x ² V²L/g). The collisions have no effect as such on the stratification, i.e., stable configuration remains stable and unstable configuration remains unstable. However the growth rate, under either of conditions (25), decreases with the increase of collisions.