THEORETICAL STUDY ON NEW IMAGING METHOD USING PHOTO-EXCITATION IN SOFT-X-RAY MICROSCOPY.

软X射线显微镜主要是因为它可以测量湿态下的生物分子而引起注意。该方法是利用样品中碳、氮原子的电离过程获得物体阴影图像的一种方法。如果我们采用光激发过程，吸收截面将增大几倍到一个数量级。本研究计划的目的是从理论上探讨利用这种光电离过程制作图像的可行性。该项目于1995财政年度开始，1997财政年度结束。(1)从理论上证明了内壳层从Cls到2 p ^<**>轨道的激发可以获得X射线的图像。这为最近的XENES成像随X射线波长变化的实验提供了理论依据。(2)对雷公藤多甙分子的紫外-可见光双共振吸收进行了理论和实验研究。得到了与理论相符合的实验结果。(3)在紫外光用于泵浦辐射和软X射线用于探测辐射的情况下进行了类似的理论分析。并以色氨酸为例进行了实际计算。（4）Iketaki和Yagishita等人进行了紫外-软X射线双共振吸收成像的验证实验，我们在理论上做了初步的研究。对于NO分子，对实验结果进行了分析。X射线吸收光谱分析。(5)利用Kramers-Kronigh关系式和Hartree-Slater程序，得到了光学常数的真实的部分。这对多层光学器件的设计有一定的参考价值。

A soft-X-ray microscope is mainly drawn attention for the reason that it can be measured biological molecules in wet states. This method is a way that shadow image of objects is obtained by making use of ionization processes of carbon and nitrogen atoms in the specimen. If we use the process of photo-excitation, the absorption cross section becoms larger by from several times to one order of the magnitude. The purpose of this research project is to investigated in theoretical way the feasibility of making images by the use of this photo-ionization processes. This project started in 1995 fiscal year and ends in 1997 fiscal year.(1) It was theoretically proved that an image of X-ray can be obtained by an inner-shell excitation from Cls to 2p^<**> orbital. This may give a theoretical foundation on recent experiments on XENES imaging change by X-ray wavelength. (2) Theoretical as well as experimental investigation on UV-visible light double resonance absorption was made for triptophan molecules. We obtained reasonable experimental results to theory. (3) Similar theoretical analysis was made in the case where UV lights were used for pumping radiation and soft X-rays are used for probe radiation. A practical calculation was made in the case of triptophan. It was shown that an image can be obtained using a commercial laser source, (4) Experiments for verification of making image by UV-Soft-X-ray double resonance absorption was made by Iketaki and Yagishita, We have made an theoretical investigation in the preparatory stage. For NO molecules, analysis for the experimental result was made. X-ray absorption spectrum was analyzed. (5) Making use of the Kramers-Kronigh relationship and using Hartree-Slater code, real part of optical constants were obtained. This will become useful for designing of multi-layr optical devises.