Synchrotron x-ray radiation from laser wakefield accelerated electron beams in a plasma channel

Matsuoka, Takeshi and Kneip, Stefan and McGuffey, Christopher and Palmer, Charlotte Alexandra Jocelyn and Schreiber, Joerg and Huntington, C. and Horovitz, Y. and Dollar, Franklin and Chvykov, Vladimir and Kalintchenko, Galina and Thomas, Alexander George Roy and Yanovsky, Victor and Phuoc, K. Ta and Mangles, Stuart P. D. and Najmudin, Zulfikar and Maksimchuk, Anatoly and Krushelnick, Karl (2010) Synchrotron x-ray radiation from laser wakefield accelerated electron beams in a plasma channel. Journal of Physics: Conference Series, 244 (4): 042026. ISSN 1742-6588

Abstract

Synchrotron x-ray radiation from laser wakefield accelerated electron beams was characterized at the HERCULES facility of the University of Michigan. A mono-energetic electron beam with energy up to 400 MeV was observed in the interaction of an ultra-short laser pulse with a super-sonic gas jet target. The experiments were performed at a peak intensity of 5×1019 W/cm2 by using an adaptive optic. The accelerated electron beam undergoes a so called "betatron" oscillation in an ion channel, where plasma electrons have been expelled by the laser ponderomotive force, and, therefore, emits synchrotron radiation. We observe broad synchrotron x-ray radiation extending up to 30 keV. We find that this radiation is emitted in a beam with a divergence angle as small as 12×4 mrad2 and can have a source size smaller than 3 microns and a peak brightness of 1022 photons/mm2/mrad2/second/0.1% bandwidth, which is comparable to currently existing 3rd generation conventional light sources. This opens up the possibility of using laser-produced "betatron" sources for many applications that currently require conventional synchrotron sources.