Šmíd M, Gallardo González I, Ekerfelt H, Björklund Svensson J, Hansson M, Wood J C, Persson A, Mangles S P D, Lundh O, Falk K
Institute of Physics of the ASCR, ELI-Beamlines, 18221 Prague, Czech Republic.
Department of Physics, Lund University, P.O. Box 118, S-22100 Lund, Sweden.
Rev Sci Instrum. 2017 Jun;88(6):063102. doi: 10.1063/1.4986464.
Highly collimated betatron radiation from a laser wakefield accelerator is a promising tool for spectroscopic measurements. Therefore, there is a requirement to create spectrometers suited to the unique properties of such a source. We demonstrate a spectrometer which achieves an energy resolution of <5 eV at 9 keV (E∕ΔE>1800) and is angularly resolving the x-ray emission allowing the reference and spectrum to be recorded at the same time. The single photon analysis is used to significantly reduce the background noise. Theoretical performance of various configurations of the spectrometer is calculated by a ray-tracing algorithm. The properties and performance of the spectrometer including the angular and spectral resolution are demonstrated experimentally on absorption above the K-edge of a Cu foil backlit by a laser-produced betatron radiation x-ray beam.
来自激光尾场加速器的高度准直的电子感应加速器辐射是用于光谱测量的一种很有前景的工具。因此，需要制造适合这种光源独特性质的光谱仪。我们展示了一种光谱仪，它在9 keV能量下实现了小于5 eV的能量分辨率（E∕ΔE>1800），并且能够对X射线发射进行角度分辨，从而允许同时记录参考信号和光谱。采用单光子分析来显著降低背景噪声。通过光线追踪算法计算了光谱仪各种配置的理论性能。利用激光产生的电子感应加速器辐射X射线束对铜箔K边以上的吸收进行了实验，展示了该光谱仪的特性和性能，包括角度和光谱分辨率。
