Study on Short-Wavelength Soft X-Ray Phase Contrast Microscope

1)相衬X射线显微镜的研制我们研制了第一台带位相板的Zernike相衬X射线显微镜。使用了来自高能物理研究所光子工厂的弯曲磁铁光束线BL3C2的同步辐射。9keV的单色X射线入射到样品上。利用Wolter镜将透射物图像放大10倍，由于使用了镜面环形孔径的一小部分，镜面面形误差对子午线方向的影响较大，只能成像一维方向。在沃尔特镜的后焦平面上设置了一块厚度为5微米的铝箔相位板。直径为5-10微米的聚邻苯二甲酸乙二酯的相衬像在9keV处清晰地聚焦，这在明场下是观察不到的。2)暗场软X射线显微镜的研制我们研制了第一台带Wolter镜的暗场软X射线显微镜。从激光产生的等离子体源产生的软X射线用聚光镜聚焦，聚光镜具有物镜的略小的环形孔径。样品的散射软X射线被聚焦在一台ccd相机上。可以观察到PMMA图案和生物样品的边缘增强的暗场图像。3)沃尔特镜的制造用NC车床和金刚石单点刀具车削无氧铜的芯棒。表面粗糙度约为Rq(RMS)9 nm。然后，制作了PYREX玻璃复制品。反射镜的表面粗糙度约为RQ(RMS)20-30 nm，这种制造Wolter镜的工艺可以缩短Wolter镜的制造周期，但表面粗糙度不足以满足软X射线和X射线的需要，需要抛光心轴和复制的玻璃复制品。

1) Development of a phase contrast x-ray microscopeWe developed the first Zernike phase-contrast x-ray microscope with a phase plate. Synchrotron radiation from the bending magnet beamline BL3C2 at the Photon Factory, Institute for High Energy Physics was used. Monochromatic x-rays at 9keV were incident on a specimen. Using a Wolter mirror, the transmission image was enlarged with the magnification ratio of 10. The microscope could image only one-dimensional direction, because the small part of the annular aperture of the mirror was used, and the figure error of the mirror was severely affected to the meridional direction. A phase plate of an aluminum foil of a 5mum thickness was set at the back focal plane of the Wolter mirror. A phase-contrast image of poly(ethylene telephthalate) wires of a 5-10mum diameter was clearly focused at 9keV, that could not be observed in the case of bright field.2) Development of a dark-field soft x-ray microscopeWe developed the first dark-field soft x-ray microscope with Wolter mirrors. Soft x-rays from a laser-produced plasma source were focused with a condenser mirror with the slightly small annular aperture of an objective mirror. Scattering soft x-rays from a specimen were focused on a CCD camera. Edge-enhanced dark-field images of a PMMA pattern and biological specimens could be observed.3) Fabrication of a Wolter mirrorMirror mandrels of oxygen-free copper were turned with a NC lathe and a diamond single-point tool. The surface roughness was about Rq (rms) 9nm. Then, the Pyrex glass replicas were fabricated. The surface roughness of the mirrors was about Rq (rms) 20-30nm, This process of a Wolter mirror fabrication would shorten a fabrication term of a Wolter mirror however the surface roughness was not small enough for soft x-rays and x-rays, and it was necessary to polish a mandrel and a replicated glass replica.