LAUSR

This study explores nonlinear frequency shifts and amplitude saturation in dust density waves (DDWs) in the presence of streaming ions. The discrepancy between experimentally measured DDW frequencies and linear theory predictions is attributed to kinetic nonlinear frequency shifts, which depend on the presence of trapped particles. To account for streaming effects and collisions, a non-Maxwellian distribution for streaming ions is considered, while dust particles follow a Maxwellian distribution. The dispersion relation of DDWs helps us to determine the frequency shift for various plasma conditions. Additionally, despite linear theory predicting exponential amplitude growth, the actual finite amplitude of DDW is explained through the saturation of ion-streaming instability, where the energy exchange between streaming ions and DDW stabilizes the instability. The theoretical estimates are compared to experimentally observed frequency and wave amplitudes, which show good agreement.