能X射线辐射装置的设计与单色性研究

Design and Monochromaticity of a Monochromatic X-ray Calibration Device

通过晶体布拉格衍射产生单能X射线,具备能量连续可调的优点,是X射线探测器标定的首选方案。为了建立0.5~30keV单能X射线辐射装置,开展了晶体单色器和光栅单色器的衍射研究,调节不同的布拉格角度时要求出射的单能X射线光束的位置保持不变,以准确地进行探测效率标定。建立的单能X射线标定装置由X射线机、衍射晶体、同步旋转装置构成,覆盖能量范围5~30keV。根据放射源对硅漂移探测器标定实验的结果得到其能量分辨与能量关系式,结合对单能X射线源测量结果计算出其单色性,根据实验条件推算了单能X射线源的能量展宽。计算结果显示,单能X射线源本身的单色性非常好,其能量展宽主要是由入射角度造成的。

The monochromatic X-rays produced by crystal Bragg diffraction has the advantage of continuously adjustable energy, and is the preferred solution for X-ray detector calibration. In order to establish a 5~30 keV single-energy X-ray radiation device, the Bragg diffraction study of crystal monochromator and grating monochromator is carried out. The position of the single-energy X-ray beam required to be emitted is adjusted when different Bragg angles are adjusted. To accurately perform detection efficiency calibration. The established single-energy X-ray calibration device is mainly composed of an X-ray machine, a diffractive crystal, and a synchronous rotating device, and covers an energy range 5~30 keV. Combined with the single-energy X-ray source measurement results, the monochromaticity is calculated, and the energy broadening of the single-energy X-ray source is calculated according to the experimental conditions. The calculation results show that the single-energy X-ray source itself has very good monochromaticity, and its energy broadening is mainly caused by the size of the limiting beam, that is, the incident angle.