RT in a magnetized plasma
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Consider a magnetized plasma with B = Bz0z^ + By0y^, where z^ and y^ are 
Cartesian unit vectors and Bz0 and By0 are constants.  There is also a 
gravitational field g = -gx^, and a density profile in the equilibrium n = 
n1 + (n2-n1)H(x), where H(x) is the step function and n2 > n1.  Assume 
that the energy in Bz is very large compared with that in By or in the 
gravitational potential energy.

Using reduced equations, show that the above is a good equilibrium. 
Study small oscillations about this equilibrium with d/dz = 0.  Show that 
in the limit By0 = 0 the usual Rayleigh-Taylor instability is recovered 
(see posted notes).  For a given By0, find the critical ky above which the 
RT is stabilized.  Make a sketch of growth rate vs ky.