Parametric Decay Instability of Ion Acoustic Waves Caused by a Finiteness of Pump Wave Amplitude

抄録

The possibility of the parametric decay instability is examined in the system of ion acoustic waves which have a non-decay type of dispersion relation in a linear sense. The finiteness of the pump wave amplitude yields the frequency shift due to the nonlinear self-interaction, making the resonant decay condition satisfied. The threshold of this instability is discussed.