Rayleigh-Taylor instability of magnetized density transition layer

In presence of a uniform magnetic field for a smoothly varying density prof ile in a limit of small Atwood numbers, an analytic solution is obtained. T he spectrum of unstable modes is defined. It is shown that this spectrum is two-side-bounded. The external magnetic field stabilizes some or all modes of the spectrum. It was shown that a finite width transition layer undergo es stratification. The magnetic field makes the stratification smoother. A velocity shear between the newly formed sublayers takes place. (C) 2000 Ame rican Institute of Physics. [S1070-664X(00)02601-X].