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

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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.