Nonlinear effects in Thomson backscattering

Abstract

We analyze the nonlinear classical effects of the X= radiation produced by Thomson/Compton sources. We confirm the development of spectral fringes of the radiation on axis, which comports broadening, shift, and deformation of the spectrum. For the nominal parameters of the SPARC-LAB Thomson scattering and of the European Proposal for the gamma source ELI-NP, however, the radiation, when collected in the suitable acceptance angle, does not reveal many differences from that predicted by the linear model and the nonlinear redshift is subdominant with respect to the quantum recoil. An experiment aimed to the study of the nonlinearities is proposed on the SPARC-LAB source.

Design and optimization of a highly efficient optical multipass system forγ-ray beam production from electron laser beam Compton scattering

“…Several factors, including the acceptance angle, beam quality, and laser pulse parameters, are indeed limiting the finesse of the γ-ray spectral width [5,6,28,29]. Accordingly, the full width at half maximum of the laser spectral distribution Δν L must be limited and, due to detrimental effects of ponderomotive forces and nonlinearities, the laser pulse intensity at the IP must be well below the critical intensity for multiphoton absorption [29].…”

“…Accordingly, the full width at half maximum of the laser spectral distribution Δν L must be limited and, due to detrimental effects of ponderomotive forces and nonlinearities, the laser pulse intensity at the IP must be well below the critical intensity for multiphoton absorption [29]. This threshold is usually characterized by the laser pulse peak normalized amplitude [6] …”

Spectral characteristics of Compton backscattering sources. Linear and nonlinear modes

“…Authors of numerous papers have considered the process of nonlinear scattering of the high intensity laser radiation by relativistic electrons using classical [7][8][9] and quantum [10][11][12][13] approaches.…”

Femtosecond pulse trains of polychromatic inverse Compton γ-rays from designer electron beams produced by laser-plasma acceleration in plasma channels

“…As the ILP is shorter than 5% of its Rayleigh length, and the electron beam spot size is in the sub-micron range, the interaction occurs in an almost planar-wave geometry. To avoid broadening the ICS spectra [28,29], a linear interaction regime is chosen, with the ILP normalized vector potential a int = 0.1. Once the orbits of individual electrons are obtained, the energy density radiated per unit frequency ω and solid angle Ω per electron by the ensemble is obtained by…”