Enhanced betatron radiation by steering a low-energy-spread electron beam in a deflected laser-driven plasma wiggler

• Published in: arXiv.org 2017-06
• Main Authors: Yu, Changhai, Liu, Jiansheng, Wang, Wentao, Li, Wentao, Qi, Rong, Zhang, Zhijun, Qin, Zhiyong, Liu, Jiaqi, Fang, Ming, Feng, Ke, Wu, Ying, Wang, Cheng, Xu, Yi, Leng, Yuxin, Xia, Changquan, Li, Ruxin, Xu, Zhizhan
• Format: Article
• Language: English
• Subjects: Acceleration; Amplitudes; Electron beams; Electrons; High energy electrons; Laser beams; Lasers; Particle accelerators; Particle in cell technique; Refraction; Steering; Transverse oscillation; X ray sources; X-rays
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1706.01033

Laser wakefield accelerators (LWFA) hold great potential to produce high-quality high-energy electron beams (e beams) and simultaneously bright x-ray sources via betatron radiation, which are very promising for pump-probe study in ultrafast science. However, in order to obtain a high-quality e beam, electron injection and acceleration should be carefully manipulated, where a large oscillation amplitude has to be avoided and thus the emitted x-ray yield is limited. Here, we report a new scheme to experimentally enhance betatron radiation significantly both in photon yield and photon energy by separating electron injection and acceleration from manipulation of the e-beam transverse oscillation in the wake via introducing a slanted thin plasma refraction slab. Particle-in-cell simulations indicate that the e-beam transverse oscillation amplitude can be increased by more than 10 folds, after being steered into the deflected laser-driven wakefield due to refraction at the slab's boundaries. Spectral broadening of the x-rays can be suppressed owing to the small variation in the peak energy of the low-energy-spread e beam in a plasma wiggler regime. We demonstrate that the high-quality e-beam generation, refracting and wiggling can act as a whole to realize the concurrence of monoenergetic e beam and bright x-rays in a compact LWFA.