Nonlinear Dynamics of Induced Compton and Undulator Processes

Abstract

In this chapter, we will consider the interaction of charged particles with superstrong radiation fields of relativistic intensities in induced coherent processes in vacuum where there is no restriction on the field intensity taking place at the induced Cherenkov interaction in dielectric-like media. Those are the induced Compton and undulator processes. In the presence of a second wave of different frequency, the Compton scattering, as well as spontaneous undulator radiation in the external EM wave field acquire induced character. Because of its coherent nature (as the Cherenkov one) these induced processes have the same peculiarity and, consequently, the nonlinear interaction of charged particles with the mentioned fields leads to analogous threshold phenomena of particle “reflection” and capture by the plane EM waves in vacuum. On the other hand, it is clear that the second wave in the induced Compton process or the undulator field perform the role of the third body for the real radiation/absorption of photons by the free electrons in vacuum. Hence, irrespective of revelation of new phenomena the consideration of nonlinear dynamics of induced Compton and undulator processes in current superstrong laser fields is of great interest, especially from the point of view of FEL and laser accelerators. Further, the significance of the undulator (wiggler) is great enough as the unique version of the current FEL and expected X-ray laser due to its large coherent length and effective power of the static magnetic field for relativistic particles. To achieve relatively large coherent lengths in the induced Compton process we will consider the case of counterpropagating waves. Then, taking into account the significance of heavy particles/ions acceleration problem, specifically toward the interaction with the matter at extreme conditions in ultrashort space–time scales (that have attracted broad interest over the last years conditioned by a number of important applications, such as generation and probing of high energy density matter, inertial confinement fusion, isotope production, hadron therapy, etc.), we will study laser acceleration of ions/nuclei from nanoscale-solid-plasma targets with counterpropagating ultrashort laser pulses on the base of the particle “reflection” phenomenon.