Rayleigh–Taylor instability on the pusher–fuel contact surface of stagnating targets

Nonlinear evolution of the Rayleigh–Taylor instability on the pusher–fuel contact surface in the deceleration phase of implosion is investigated in cylindrical geometry using a two‐dimensional fluid code, impact‐2d [J. Comput. Phys. 49, 357 (1983)]. The linear growth rates obtained by simulations agree quite well with analytical values that include the cylindrical geometry effects. The saturation amplitudes of the exponential growth are found to be of the order of half the wavelength. The free‐falling phase following the saturation is studied in detail. The perturbation amplitudes at the maximum compression are estimated as a function of an initial amplitude and its mode number. The reduction of the growth rate caused by electron thermal conduction is also investigated and a large reduction is observed for wavelengths shorter than ten times the electron mean‐free path.