Enhancement of betatron X-rays through asymmetric laser wakefield generated in transverse density gradients

Abstract

Laser wakefield acceleration of electrons usually offers an axisymmetry around the laser propagation axis. Thus, the accelerating electrons that are focused on axis often execute small transverse oscillations. In this Article, we propose a simple scheme to break this symmetry, which enhances the transverse wiggling of electrons and boosts the betatron radiation emission. Through 3D particle-in-cell simulations, we show that sending the laser with a small angle of incidence on a transverse plasma density gradient generates an asymmetric wakefield. It first provokes injection and then increases the wiggling of the electrons through the transverse shifting of the wakefield axis which occurs when the laser pulse leaves the gradient. Consequently, we show that the radiated energy per unit of charge can increase by a factor $>20$ when using this scheme, and that the critical energy of the radiation quintuples compared with a reference case without the transverse density gradient.

arXiv comment6 pages, 4 figures

References in corpus (7)

• Enhancement of electron energy to multi-GeV regime by a dual-stage laser-wakefield accelerator pumped by petawatt laser pulses
• Single shot phase contrast imaging using laser-produced Betatron x-ray beams
• Observation of longitudinal and transverse self-injections in laser-plasma accelerators
• Demonstration of the synchrotron-type spectrum of laser-produced Betatron radiation
• Controlling the spectrum of x-rays generated in a laser-plasma accelerator by tailoring the laser wavefront
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Cited by in corpus (2)

• Effect of Nozzle Curvature on Supersonic Gas Jets Used in Laser-Plasma Acceleration
• Attosecond betatron radiation pulse train