标题： 硬X射线光谱仪分辨率超过100微电子伏特 显示英文标题

标题： Hard X-ray Spectrographs with Resolution Beyond 100 micro-eV

摘要： 光谱仪通过将不同能量的光子分散到不同的方向和空间位置，利用阵列探测器对光子光谱进行快照拍摄。 光谱仪需要具有大角度色散率的光学元件作为关键部件。 在可见光光学中，使用衍射光栅来实现这一目的。 在硬X射线范围内，实现大的色散率是一个挑战。 在这里，我们展示了多晶体、多布拉格反射结构的累积角度色散率比单个布拉格反射可达到的值高近两个数量级。 因此，多晶体结构成为硬X射线光谱仪的潜在色散元件。 通过使用多晶体光学元件作为色散元件，在硬X射线范围内以记录的高分辨率$\Delta E \simeq 90 \mu$eV 成像光子谱，证明了硬X射线光谱仪的原理。 这些光谱仪可以提升利用同步辐射和种子XFEL的非弹性超高分辨率X射线光谱学的研究。 显示英文摘要

摘要： Spectrographs take snapshots of photon spectra with array detectors by dispersing photons of different energies into distinct directions and spacial locations. Spectrographs require optics with a large angular dispersion rate as the key component. In visible light optics diffraction gratings are used for this purpose. In the hard x-ray regime, achieving large dispersion rates is a challenge. Here we show that multi-crystal, multi-Bragg-reflection arrangements feature cumulative angular dispersion rates almost two orders of magnitude larger than those attainable with a single Bragg reflection. As a result, the multi-crystal arrangements become potential dispersing elements of hard x-ray spectrographs. The hard x-ray spectrograph principles are demonstrated by imaging a spectrum of photons with a record high resolution of $\Delta E \simeq 90 \mu$eV in hard x-ray regime, using multi-crystal optics as dispersing element. The spectrographs can boost research using inelastic ultra-high-resolution x-ray spectroscopies with synchrotrons and seeded XFELs.