微通道板(MCP)在X 射线的会聚成像方面有视场大、重量轻、对装调精度要求低等优点。基于全反射理论，研究了平面圆孔MCP对X 射线的聚光特性，计算了MCP的像面光照度增益和点扩散函数与微通道板结构参数之间的关系。使用TracePro 软件对直径为25 μm 的圆孔MCP 的聚光效果进行了仿真，仿真结果与计算结果基本吻合。结果表明，MCP 的相对光照度增益与光源距离ls近似成正比，而与MCP 的最大孔径无关，当光源距离为110 mm 时，相对光照度增益大约可达到18 倍。进一步研究了MCP 离轴、俯仰、倾斜等装调误差对像面光斑的影响，结果表明，MCP的离轴对像面光斑影响很小；而角度偏差将影响光斑的位置和形状。

Micro channel plate (MCP) used in X-ray focusing and imaging has such advantages as larger field of view, lower weight, and lower sensitivity to device alignment. Based on the X- ray total reflection theory, the focusing properties of flat circular-channel capillary arrays are discussed, and the theoretical calculation of the relative gain and point spread function (PSF) on focal plane against the parameters of MCP is presented. The calculated results are verified via TracePro software, through which the focusing performance of MCP with 25 μm circular-channel diameter is simulated. Both of the model calculation and the simulation suggest that the relative gain of the MCP is nearly proportional to the source distance ls, while independent on the maximum aperture of the MCP. When the source distance is 110 mm, the relative gain can reach about 18. Furthermore, the performance of MCP with misalignment of off-axis and tilt is discussed, which suggests that the off-axis of MCP barely influence the focal spot while the tilts influence the location and shape of the spot.