Progress of Laser-Driven Betatron Radiation in IOP

Abstract

Betatron x-ray source generated in the process of laser wakefield acceleration has been studied in IOP using different species of gas. For helium plasmas, the generation of bright betatron radiation in electron acceleration via self-injection was studied in experiment and simulation. Two electron bunches with different qualities were injected sequentially into the wakefield driven by a super-intense laser pulse. Hosing instability causes the enhancement of transverse oscillation of the second electron bunch with GeV energy which results in the high yield of betatron radiation. For nitrogen plasmas, we observed the generation of stable quasi-monoenergetic electron beams having energy of 130 MeV and energy spread of ~ 20 %. And the betatron x-ray emission had a small divergence of 7.5 mrad and a critical energy of 4 keV. We believed that the laser wakefield acceleration process was stimulated in ionization injection.