Effects of laser pulse shape on forward Thomson scattering

Abstract

The effects of super-cycle (or sub-cycle) and super-Gaussian laser pulse shapes on the forward Thomson scattering by an electron moving in a linearly polarized laser field are investigated. The numerical results show that for forward scattering spectra, there are only harmonics of odd orders. With increasing the super-cycle parameter, the intensity of the scattering spectra increases and more harmonics orders appear. In the case of sub-cycle laser pulse shape, decreasing the sub-cycle parameter leads to a gradual decrease in the interval between the adjacent harmonics and scattering spectra exhibiting quasi-continuity. Furthermore, the intensity of the high-order harmonic increases and the harmonic with peak intensity shifts from fundamental to higher order with increasing super-Gaussian parameter. Besides, the effects of the electron's initial direction and speed as well as the carrier envelope phase on the scattering spectra are also explored. Our results indicate the possibility of future application in X-ray source devices based on Thomson scattering.

Enhanced radiation of nonlinear Thomson backscattering by a tightly focused Gaussian laser pulse and an external magnetic field

“…The results show that the radiation intensity of the high frequency part can be enhanced by adjusting the strength of the external magnetic field, especially when the cyclotron frequency of the electron in the external magnetic field is close to the laser frequency, the electron can sufficiently obtain energy from the combined field [11]. For the laser pulse with uniform transverse intensity distribution, the influences of different longitudinal laser envelopes, such as Gaussian envelope, cosine envelope and super Gaussian envelope on the Thomson scattering have been studied [18][19][20][21][22][23]. For instance, Tian et al have investigated the dynamics and harmonics emission spectra of a single electron moving in a laser pulse with longitudinal Gaussian envelope and have demonstrated the shifting and broadening of the radiation spectrum, which depend sensitively on the intensity and the pulse width of the laser pulse [18].…”

Thomson backscattering in combined two laser and a magnetic fields

“…On the other hand, the present research topic has still some open problems. For example, we only discuss backscattering under two laser fields and a magnetic field, while scattering in other directions is interesting and important, as we considered before with respect to forward and full-angle scattering under a single laser field [25,26]. Another very interesting and invaluable point is to consider the more realistic laser with profile and electron bunch with initial distribution.…”

Electron Scattering Processes in Non-Monochromatic and Relativistically Intense Laser Fields

“…Special attention was paid there to the comparison between quantum and classical results and the limit in which both of them coincide. More recently, Huang et al [57] determined the effects of a Gaussian (or the so-called super-Gaussian) pulse envelope on the Thomson process. In 2014, Krajewska and Kamiński [26] centered their attention on spin and polarization effects and how they influence the Compton scattering as compared to its classical (spinless) counterpart.…”