X-ray Microscopy
at Stony Brook (2)

1. Why Soft X-ray Microscopy
2. The Scanning Transmission X-ray Microscope
3. X-ray Lenses: Fresnel Zone Plates
4. Example: Biological Applications
5. Example: Environmental Sciences and Cluster Analysis
6. Soft X-ray Diffration and Holography
7. Acknowledgements

The Scanning Transmission X-ray Microscope (STXM)

Our group operates two identical Scanning Transmission X-ray Microscopes (STXMs) at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory.

Coherent radiation from the X1 undulator is monochromatized and focused to a spot using a Fresnel zone plate. The specimen is scanned through the focus pixel by pixel. For each pixel, the transmitted intensity is recorded by a large area detector, resulting in an absorption contrast image of the specimen. Currently, we can achieve a spatial resolution of about 30 nm.

Enju working at the beamline

By recording the spatial distribution of the intensity in the detector plane using a segmented detector, we are able to acquire phase contrast images as well.

A cryo-STXM, keeping the specimen at cryogenic temperatures to avoid radiation damage, has been developed by our group and is currently undergoing a major upgrade.

A segmented detector chip (inset) and images obtained from Silica spheres. Separate images from all the segments are recorded simultaneously. From specific combinations of these signals, one can extract phase information about the specimen.

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