Landau Damping of Low- and High-Power Slow Electrostatic Waves

Waves were excited in a warm plasma, and strong absorption has been observed in agreement with the predictions of linear Landau damping. At a certain critical power level consistent with the power required to flatten the velocity distribution, the absorption disappears. Above this level evidence has been obtained for the appearance of an enhanced electron tail in and above the energy range where Landau damping should occur.