Comprehensive diagnosis of growth rates of the ablative Rayleigh-Taylor instability

The growth rate of the ablative Rayleigh-Taylor instability is approximated by gamma=root kg/(1+kL)-beta km/rho(a), where k is the perturbation wave number, g the gravity, L the density scale length, m the mass ablation rate, and rho(a) the peak target density. The coefficient beta was evaluated for the first time by measuring all quantities of this formula except for L, which was taken from the simulation. Although the experimental value of beta=1.2 +/- 0.7 at short perturbation wavelengths is in reasonably good agreement with the theoretical prediction of beta=1.7, it is found to be larger than the prediction at long wavelengths.