利用晶体多重衍射进行同步辐射光子能量标定

Calibration of synchrotron radiation photon energy using crystal multiple diffraction

介绍了多重衍射的基本原理,包括多重衍射的指标化、衍射光强度的计算和入射光方向的确定,并根据晶体多重衍射现象提出了入射X光能量的标定方法。从理论上讲,使用该标定方法在角度扫描精度为1″时,光子能量标定精度可达到1eV。在上海光源14B衍射光束线上对提出的标定方法进行了实验验证,在10keV处用Si(111)为主衍射收集了180°Φ扫描衍射谱,对其中的衍射谷进行了指标化,并根据指标化的结果计算得到标定能量为10.06keV。该实验结果与理论结果相符,验证了在角度扫描精度满足实验要求时,通过该标定方法可进行高精度的光子能量标定。

This paper describes the basic principle of multiple diffraction,including diffraction indexing and its intensity calculation,as well as the direction determination of the incident X-ray that meets the Bragg condition for two specific crystal planes.It proposes a X-ray energy calibration method based on the crystal multiple diffraction.In theory,this calibration method can reach a very high precision of 1 eV when the scanning step is 1″.To verify the feasibility of this method,a test is performed on the 14B diffraction beam line of Shanghai source,and the 180° Φ scanning diffraction pattern for the silicon（111） is collected at 10 keV.All the possible diffraction planes are set up and the glitch is indexed according to the angle difference of them.After indexing of the glitch,the calibrated energy of 10.06 keV is obtained.The experimental results are consistent with the theoretical results well,which proves that the calibration method can achieve a high precise calibration for photon energies when the angle scanning accuracy meets the needs of experiments.