Interaction of the electromagnetic precursor from a relativistic shock with the upstream flow – II. Induced scattering of strong electromagnetic waves

This is the second in the series of papers aiming to study interaction of the electromagnetic precursor waves from relativistic shocks with the upstream flow. Here, I consider the induced scattering of strong waves. In such a wave, the electrons oscillate with relativistic velocities therefore, the scattering generally occurs in harmonics of the incident wave. I show that the induced scattering occurs predominantly in the first harmonics. I also show that even though in the weak case regime, the induced scattering rate is proportional to the intensity of the incident wave, in the strong wave case, the rate decreases as the wave amplitude grows.