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U.S. Department of Energy
Office of Scientific and Technical Information

Phase contrast in high resolution electron microscopy

Patent ·
OSTI ID:7368407

This patent relates to a device for developing a phase contrast signal for a scanning transmission electron microscope. The lens system of the microscope is operated in a condition of defocus so that predictable alternate concentric regions of high and low electron density exist in the cone of illumination. Two phase detectors are placed beneath the object inside the cone of illumination, with the first detector having the form of a zone plate, each of its rings covering alternate regions of either higher or lower electron density. The second detector is so configured that it covers the regions of electron density not covered by the first detector. Each detector measures the number of electrons incident thereon and the signal developed by the first detector is subtracted from the signal developed by the record detector to provide a phase contrast signal. (auth)

Assignee:
U.S. Energy Research and Development Administration
Patent Number(s):
US 3908124
OSTI ID:
7368407
Country of Publication:
United States
Language:
English