  We study the Rayleigh-Taylor instability (RTI) at a prominence-corona
transition region in a non-linear regime. Our aim is to understand how the
presence of neutral atoms in the prominence plasma influences the instability
growth rate, and the evolution of velocity, magnetic field vector and
thermodynamic parameters of turbulent drops. We perform 2.5D numerical
simulations of the instability initiated by a multi-mode perturbation at the
corona-prominence interface using a single-fluid MHD approach including a
generalized Ohm's law. The initial equilibrium configuration is purely
hydrostatic and contains a homogeneous horizontal magnetic field forming an
angle with the direction in which the plasma is perturbed. We analyze
simulations with two different orientations of the magnetic field. For each
field orientation we compare two simulations, one for the pure MHD case, and
one including the ambipolar diffusion in the Ohm's law (AD case). Other than
that, both simulations for each field orientation are identical. The numerical
results in the initial stage of the instability are compared with the
analytical linear calculations. We find that the configuration is always
unstable in the AD case. The growth rate of the small-scale modes in the
non-linear regime is up to 50% larger in the AD case than in the purely MHD
case and the average velocities of flows are a few percent larger. Significant
drift momenta are found at the interface between the coronal and the prominence
material at all stages of the instability, produced by the faster downward
motion of the neutral component with respect to the ionized component. The
differences in temperature of the bubbles between the ideal and non-ideal case
are also significant, reaching 30%. There is an asymmetry between large rising
bubbles and small-scale down flowing fingers, favoring the detection of upward
velocities in observations.
