Carl-zeiss-stiftung

Gunter Schmahl

Dietbert Rudolph

Augustin Siegel

Bastian Nieman

Jurgen Thieme

The invention is directed to an X-ray microscope having a pulsed X-ray radiation source which supplies an intensive line radiation such as a plasma focus source. The microscope includes a reflecting condenser which focusses the radiation of the radiation source on the specimen to be investigated and an X-ray optic configured as a zone plate. With the zone plate, the specimen is imaged on an X-ray detector with a high resolution. The above combination of elements makes it possible to free an adequately high amount of X-ray energy at the location of the specimen while providing a high resolution free of image errors so that the required short exposure times are provided for the investigation of living cells.

X-ray microscope

For producing phase-contrast images with a microscope which scans the object point-by-point with a beam of illuminating radiation, the illuminating radiation is focused by an objective (31, 32) including a phase-shifting element (33) of preselective geometry. A radiation-sensitive detector (36) is positioned directly behind the object plane (34), seen in the direction of the light; and the shape of the radiation-sensitive area of the detector is adapted to encompass the path of the radiation passing through the geometry of the phase-shifting element (33) of the objective (31, 32), e.g., where the phase-shifting elements (33) comprise an annular aperture, an appropriately conforming annular diaphragm (35) is arranged in front of the detector (36). The advantage of this arrangement is that it does not use any radiation-collecting lens system between the object plane (34) and the detector (36).

Method and device for producing phase-contrast images

An x-ray microscope in which the object is illuminated coherently or partially coherently via a condenser with quasi-monochromatic x-radiation and is imaged enlarged in the image plane by a high resolution x-ray objective. To obtain the highest possible image contrast, there is arranged in the Fourier plane of the x-ray objective an element which imparts a phase shift to a preselected order of diffraction of the radiation. The element extends over the surface region in the Fourier plane which is acted on here by the diffracted radiation to be influenced. The utilization of the phase shift of a preselected order of diffraction of the radiation as compared with the uninfluenced radiation makes it possible to carry out examinations, in particular of biological structures, with a low dose of radiation and nevertheless to produce a high image contrast. Moreover, it is possible to shift the wavelength region of the x-ray radiation to be used toward shorter wavelengths at which, as a result of the lesser absorption, x-ray microscopy was not meaningfully possible heretofore.

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Gottingen, Germany

Gunter Schmahl