变宽度压弯椭圆柱面聚焦镜的光学参数可调性

Tunability of optical parameters of width-variable bent elliptical microfocus mirror

由变宽度压弯椭圆柱面微聚焦镜理论,推导了聚焦镜光学参数(源距、像距和掠入射角)偏离设计值时所需的压弯力矩和镜面剩余斜率误差的计算公式。对上海光源硬X射线微聚焦光束线微聚焦镜进行了计算,结果表明,改变压弯力矩,微聚焦镜的源距和掠入射角可以在较大范围内调节,而较小范围的像距调节会产生较大的剩余斜率误差。

Bent elliptical mirrors are often used as X-ray microfocus device in synchrotron radiation beamlines. In this paper, the theory of width-variable bent elliptical microfocus mirror was reviewed. The formula for calculating the required bending moments and residual slope error when the working condition （source distance, grazing incident angle and image distance） of the mirror differed from the designed values was deduced. The microfocus mirror of the SSRF X-ray microfocus beamline was calculated as an example. The results show that, by adjusting the bending moments, a large range of the grazing incident angles and source-to-mirror distances can be of choice, and the resulted additional slope error can be negligible. However, a relatively small change of image distance will result in large slope error.