Evolution of nonlinear waves in compressing plasma

Through particle-in-cell simulations, the evolution of nonlinear plasma waves is examined in one-dimensional collisionless plasma undergoing mechanical compression. Unlike linear waves, whose wavelength decreases proportionally to the system length L(t), nonlinear waves, such as solitary electron holes, conserve their characteristic size during slow compression. This leads to a substantially stronger adiabatic amplification as well as rapid collisionless damping when L approaches . On the other hand, cessation of compression halts the wave evolution, yielding a stable mode.