自支撑透射光栅的周期加强筋结构在降低光栅的通光面积、减少光栅衍射效率的同时,也影响了光栅原有的衍射模式,致使其应用更加复杂.为了应对这一问题,作者提出了利用在高Z材料薄膜上准随机排布矩形孔实现自支撑透射光栅的技术方法.理论分析与实验结果表明,利用新方法制作的透射光栅较好地摆脱了周期性加强筋对透射光栅衍射模式的强加干扰.
Support-mesh structures of a self-supporting transmission grating may decrease the transmission area and diffraction efficiency, thus exert a ill effect on the original diffraction pattern of the grating and make it complicated to apply,especially in soft X-ray region. To solve this problem, we put forward a method to realize a kind of totally selfsupporting transmission grating by arranging the rectangular transmission holes in a high Z foil quasi-randomly. Based on Fraunhofer's diffraction theory, we make a theoretical analysis on the diffraction pattern of this new kind of grating.We also calculate the diffraction pattern of this new kind of grating based on the Kirchhoff's diffraction theory. Further more, we fabricate a sample grating of 1000 lines/mm using a focused ion beam(FIB) technology and then test it with the beam line 4B7 B on the Beijing synchrotron radiation facility. Theoretical analysis and experimental result both show that the diffraction of the transmission grating can remove the ill effect of the support-mesh structures by using this newly designed method. Such a method can profit us in applications of this kind of X-ray dispersive element to a wide extent.