Sarri G, Corvan D J, Schumaker W, Cole J M, Di Piazza A, Ahmed H, Harvey C, Keitel C H, Krushelnick K, Mangles S P D, Najmudin Z, Symes D, Thomas A G R, Yeung M, Zhao Z, Zepf M
School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, United Kingdom.
Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2099, USA.
Phys Rev Lett. 2014 Nov 28;113(22):224801. doi: 10.1103/PhysRevLett.113.224801. Epub 2014 Nov 25.
We report on the generation of a narrow divergence (θ_{γ}<2.5 mrad), multi-MeV (E_{max}≈18 MeV) and ultrahigh peak brilliance (>1.8×10^{20} photons s^{-1} mm^{-2} mrad^{-2} 0.1% BW) γ-ray beam from the scattering of an ultrarelativistic laser-wakefield accelerated electron beam in the field of a relativistically intense laser (dimensionless amplitude a_{0}≈2). The spectrum of the generated γ-ray beam is measured, with MeV resolution, seamlessly from 6 to 18 MeV, giving clear evidence of the onset of nonlinear relativistic Thomson scattering. To the best of our knowledge, this photon source has the highest peak brilliance in the multi-MeV regime ever reported in the literature.
我们报告了通过超相对论激光尾场加速电子束在相对论强度激光（无量纲振幅(a_{0}≈2)）场中的散射产生窄发散度（(\theta_{\gamma}<2.5)毫弧度）、多兆电子伏（(E_{max}≈18)兆电子伏）且超高峰值亮度（(>1.8×10^{20})光子·秒(^{-1})·毫米(^{-2})·毫弧度(^{-2}) 0.1%带宽）的γ射线束。所产生的γ射线束的光谱以兆电子伏分辨率在6至18兆电子伏范围内无缝测量，清楚地证明了非线性相对论汤姆逊散射的开始。据我们所知，该光子源在文献报道的多兆电子伏范围内具有有史以来最高的峰值亮度。
