X-ray or gamma ray systems or devices – Specific application – Telescope or microscope
Patent
1998-07-10
2000-10-03
Bruce, David V.
X-ray or gamma ray systems or devices
Specific application
Telescope or microscope
378 84, 378 85, G21K 106, G21K 700
Patent
active
061283649
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a condenser-monochromator arrangement for X-ray radiation in accordance with the features in the preamble of claim 1.
In X-ray microscopy, substantial progress has been made over recent years in the wavelength region of approximately 0.2-5 nm. X-ray microscopes have been developed which are being operated using brilliant X-ray sources. Said X-ray sources include electron storage rings whose deflecting magnets and undulators are sources of intensive X-ray radiation; there have not so far been other X-ray sources of comparable brilliance. To date only the X-ray radiation generated by deflecting magnets has been used for transmitting X-ray microscopes.
At present, only microscope zone plates are used as highly resolving objectives in X-ray microscopes. Microscope zone plates are rotational symmetrical circular transmission gratings with grating constants which decrease outward, and typically have diameters of up to 0.1 mm and a few hundred zones. The numerical aperture of a zone plate is determined very generally by the diffraction angle at which the outer, and thus finest zones diffract vertically incident X-ray beams. The achievable spatial resolution of a zone plate is determined by its numerical aperture. Over recent years, it has been possible for the numerical aperture of the X-ray objectives used to be substantially increased, with the result that their resolution has improved. This trend to higher resolution will continue.
Object illumination of hollow conical shape is generally required for X-ray microscopes which use zone plates as X-ray objectives. Otherwise, the radiation from the zero and the first diffraction orders of the condenser zone plate would also overlap the image at its center. The reason for this is that the overwhelming proportion of the radiation which falls onto the object in a fashion parallel or virtually parallel to the optical axis penetrates said object and the following microscope zone plate (the diffracting X-ray objective) without being diffracted and is seen as a general diffuse background in the direction straight ahead, that is to say in the center of the image field. For this reason, all transmitting X-ray microscopes use annular condensers, and the useful region, not diffusely overexposed region, of the image field becomes larger the larger the inner, radiation-free solid angle region of the condenser.
It is known from the theory of microscopy that the numerical aperture of the illuminating condenser of a transmitted-light microscope should always be approximately matched to the numerical aperture of the microscope objective, in order also to obtain an incoherent object illumination from incoherently radiating light sources, and thus to obtain a virtually linear relationship between object intensity and image intensity. If the aperture of the condenser, by contrast, is less than that of the microscope objective, a partially coherent image is present, and the linear transformation between object intensity and image intensity is lost for the important high spatial frequencies, which determine the resolution of the microscope.
To date, "large-area" annular zone plates have been used as condensers for X-ray radiation. (A. Schlachetzki, K. Dorenwendt: Quantitative Mikroskopie und Mikrostrukturierung [Quantitative microscopy and microstructuring], block seminar from Sep. 13 to 14, 1995, Physikalisch Technische Bundesanstalt, Technische Universitat Braunschweig [Federal Engineering Institute, Braunschweig Technical University], published: PTB-Opt-50, Braunschweig, March 1996, pages 98-116, B. Niemann et al., "X-Ray Microscopy" (see FIG. 3); P. C. Cheng, G. J. Jan: X-ray Microscopy, Springerverlag Berlin Heidelberg 1987, pages 32-38, W. Meyer-Ilse et al., "Status of X-ray Microscopy Experiments at the BESSY Laboratory" (see FIG. 3.1)). They focus the X-ray radiation onto the object to be investigated using the X-ray microscope. The size of such a "condenser zone plate" is matched to the beam diameter, which is typically up t
REFERENCES:
patent: 5177774 (1993-01-01), Suckewer et al.
patent: 5199057 (1993-03-01), Tamura et al.
patent: 5204887 (1993-04-01), Hayashida et al.
patent: 5222113 (1993-06-01), Thieme et al.
patent: 5311565 (1994-05-01), Horikawa
patent: 5361292 (1994-11-01), Sweatt
patent: 5848119 (1998-12-01), Miyake et al.
patent: 6023496 (2000-02-01), Kuwabara
patent: 6028911 (2000-02-01), Kawahara
"X-ray microscopy studies", G. Schmahl et al., May 1993, pp. 95-102.
"Soft X-Ray Imaging Zone Plates with (illegible) Zone Numbers for Microscopic and Spectroscopic Applications," B. Niemann et al., Optics Communications, vol. 12, No. 2, Oct. 1974, pp. 160-163.
"Quantitative Mikroskopie and Mikrstrukturierung," Andreas Schlachetzki und Klaus Dorenwendt, ISBN 3-89429-686-0, pp. 97-116, Sep. 1995.
"X-ray Microscopy," Professor Dr. Ping-Chn Cheng and Professor Dr. Gwo-Jen Jan, ISBN 3-540-18148-2 Springer-Verlag Berlin Heidelberg New York, pp. 32-39, 1987.
Bruce David V.
Dunn Drew A.
Leica Microsystems Lithography GmbH
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