同步辐射X射线成像光束线劳厄双晶单色器设计

Double Laue-Crystal Monochromator for an X-Ray Imaging Beamline with Synchrotron Radiation

上海光源X射线成像光束线采用多极扭摆器(wiggler)作为辐射光源,提出一种劳厄双弯晶单色器的设计方案．计算结果显示,可获得固定出口的平行单色光束,能量调谐范围覆盖19—120keV,在33keV时,输出光子通量及通量密度分别为1．9×10^(13)phs/s和3．8×10^(10)phs/s/mm^2．分析了劳厄晶体的聚焦及单色化性能,计算了输出光子通量及单色器的热负载情况．与传统的双平晶方案相比,本设计在获得高通量和解决热负载等方面有明显的优越性,并能有效控制热形变．

A new optical configuration of monochromator for X-ray imaging beamline, which allows one to obtain a parallel monochromatic beam with fixed exit by using two asymmetrically cut bent-crystais in Laue geometry, has been proposed. Based on the W14 multi-pole wiggler at SSRF, a preliminary design for the monochromator has been presented. The tunable photon energy range is 19-120keV, the flux output and flux density is 1.9× 10^13phs/s@33keV and 3.8×10^10phs/s/mm^2@33keV respectively. The flux and energy resolution of the monochromator is estimated, which indicates that the heat-load is tolerable and the design meets the demands of the X-ray imaging experiments. The results show that the new configuration of monochromator, compared with traditional design in double flat-crystal, is more powerful in dealing with the high flux and high heat-load.