Related Experiment Video
Updated: Feb 8, 2026

Routine Collection of High-Resolution cryo-EM Datasets Using 200 KV Transmission Electron Microscope
Published on: March 16, 2022
Illumination semiangle of 10-9 rad achieved in a 1.2-MV atomic resolution holography transmission electron microscope
Tetsuya Akashi1,2, Yoshio Takahashi2, Ken Harada3
1Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka, Fukuoka, Japan.
Abstract:
The coherency of a 1.2-MV transmission electron microscope was evaluated through illumination semiangles calculated from lengths over which Fresnel fringes can be observed. These lengths were determined from the diameters of circular holes fully filled with Fresnel fringes, i.e. this method allows lengths to be accurately measured even if micrographs are subjected to distortions. The smallest illumination semiangle of 4.0 × 10-9 rad was obtained for a circular hole with a diameter of 191 μm. In addition, electron beam brightness was estimated to be approximately 3 × 1014 A/m2·sr from the obtained illumination semiangle values and current densities. The results provide us with essential information that can be referred to in future electron holography studies aimed at detecting weak electromagnetic fields in materials.
More Related Videos
Related Concept Videos
Electron Configuration of Multielectron Atoms
Transmission Electron Microscopy
Electronic Structure of Atoms
An atom comprises protons and neutrons, which are contained inside the dense, central core called the nucleus, with electrons present around the nucleus. Taking into account the wave–particle duality of electrons and the uncertainty in position around the nucleus, quantum mechanics provides a more accurate model for the atomic structure. It describes atomic orbitals as the regions around the nucleus where electrons of discrete energy exist, characterized by four quantum...
Atomic Structure
Atomic Orbitals
Electron Affinity

