BSRF高灵敏度衍射增强成像系统搭建

Development of high sensitivity diffraction enhanced imaging at BSRF

作为一种重要的相位衬度成像方法,衍射增强成像(Diffraction Enhanced Imaging,DEI)是利用晶体的角度选择特性探测样品引起的X射线角度变化来获得样品衬度图像。晶体摇摆曲线是衍射增强成像装置的重要特征,理论上晶体的摇摆曲线越窄,则衍射增强成像灵敏度越高,所获得的图像衬度也会越好。在北京同步辐射装置(Beijing Synchrotron Radiation Facility,BSRF)4W1A成像实验站现有Si(111)晶体DEI装置的基础上,通过选用高精度转台并对晶体采取减少加工应力残余和降低安装夹持应力的措施,设计研制了基于Si(400)和Si(333)晶体的高灵敏度DEI实验装置,并利用标准样品和实际生物样品进行了实验验证。系统摇摆曲线测试及成像结果表明,所研制的成像装置可以开展二维和三维成像实验且具有更高的成像灵敏度。

Background： As an important phase contrast imaging method, diffraction enhanced imaging （DEI） utilizes crystal＇s angular selectivity to detect the X-ray＇s angular change caused by the sample, resulting in sample＇s phase image. Crystal rocking curve is the main feature of DEI setup, and its width decreases when the crystal index of diffraction plane used in the setup increases, resulting in the increased imaging sensitivity. Purpose： At the 4W1A X-ray imaging beam line of Beijing synchrotron radiation facility （BSRF）, DEI experiments are generally carried out with Si（11 l） crystal. This study aims to construct a high-index crystal DEI setup to improve imaging sensitivity. Methods： Based on theoretical analysis, special mechanical design and crystal processing, a new high sensitive DEI setup was developed using Si（400） and Si（333） crystals. The performance of the setup was tested and experiments using standard sample and real biological sample were carried out to verify the usability of the setup. Results： Performance testing results and experimental results show that higher imaging sensitivity can be obtained using the new DEI setup. Conclusion： The high sensitivity DEI setup at BSRF using Si（400） and Si（333） crystals was successfully developed, and this setup can give higher imaging sensitivity to 2D and 3D imaging experiment.