The magneto-Rayleigh–Taylor (MRT) instability limits
the performance of dynamic z pinches. This instability
develops at the plasma-vacuum/field interface, growing in amplitude
throughout the implosion, thereby reducing the peak plasma velocity
and spatial uniformity at stagnation. MRT instabilities are
believed to play a dominant role in the case of high wire number
arrays, gas puffs and foils. In this article, the MRT instability
is discussed in terms of initial seeding, linear and nonlinear
growth, experimental evidence, radiation magnetohydrodynamic
simulations, and mitigating schemes. A number of experimental
results are presented, where the mitigating schemes have been
realized. In general, the problem is inherently three dimensional,
but two-dimensional simulations together with theory and experiment
enhance our physical understanding and provide insight into
future load design.