Department of Biology, RHBNC, Egham Hill, Egham, Surrey TW20 OEX, United Kingdom.
J Xray Sci Technol. 1990 Jan 1;2(3):172-9. doi: 10.3233/XST-1990-2303.
The optimum wavelengths for soft x-ray contact microscopy of biological specimens are between 2.2 and 4.4 nm as, relative to water, this gives maximum contrast between carbon- and oxygen-containing constituents. Irradiation outside of this so-called "water window" interferes with either the resolution and/or the contrast that can be obtained. The previous belief that silicon nitride windows act as an effective filter for the longer wavelength, XUV radiation generated from laser-produced plasmas is shown to be suspect. However, in this study the use of aluminum-coated windows, which effectively exclude these longer wavelengths, still permits successful imaging of biological specimens. The added strength imparted to coated windows also ensures their survival during the imaging process, thereby demonstrating that the tissues can remain hydrated at the time that the image is formed in the photosensitive resist material used in this technique.
用于生物标本软 X 射线接触显微镜的最佳波长在 2.2nm 到 4.4nm 之间，因为相对于水，这在碳和含氧成分之间给出了最大的对比度。在此所谓的“水窗”之外的辐照会干扰可获得的分辨率和/或对比度。先前认为氮化硅窗口可有效滤除激光等离子体产生的较长波长的 XUV 辐射的观点，现在看来是值得怀疑的。然而，在这项研究中，使用有效排除这些较长波长的镀铝窗口，仍然可以成功地对生物标本进行成像。涂覆窗口所赋予的额外强度也确保了它们在成像过程中的存活，从而证明在用于该技术的光致抗蚀剂材料中形成图像时，组织可以保持水合状态。
