An enlarged image of the transmitted radiation is formed by an objective zone plate lens. Samples, 5-10 micron thick, are imaged at atmospheric pressure and can be in a liquid environment. Wet samples are mounted between two silicon nitride films, each approximately 100 nm thick. The images are recorded directly on an x-ray sensitive CCD camera, using a magnification of typically 2400x, and stored digitally with other parameters of the microscope. The field of view is about 10-15 microns.
Exposure times vary from fractions of a second to several tens of seconds.
The spatial resolution in our x-ray microscope is primarily determined by the width of the outermost zone of the objective lens, which is presently 35 nm. Sample positions and focus in the x-ray microscope sample stage are mutually indexed to the stage of a visible light microscope, which is used to investigate, locate, and align interesting parts of the sample. The positions are recorded in a computer and mutually indexed to same positions in the x-ray microscope stage. Back to the Introduction .