NONLINEAR SPATIAL DAMPING OF LANGMUIR PULSES IN A PLASMA.

Noncollisional damping of short Langmuir pulses in a plasma is investigated for the case when the transit time of resonance electrons through the pulse is small compared to the damping period of the wave (inverse Landau damping). It is shown that the information regarding the pulse, recorded in the phase memory of accelerated electrons in the reference system of the phase velocity of the wave, permits to reconstruct the form of the pulse in the reference system of the plasma. The damping becomes nonlinear when the increase of the electron velocity in the field of the pulse is comparable to (or exceeds) group velocity of the wave. A pulse with zero area propagates in the plasma without damping.