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The aim of this project is to develop a "holography electron microscope" capable of observing quantum phenomena in the microscopic world. Utilizing the information on atoms and molecules, not only will it contribute to the progress of cutting-edge advancements in materials science, life science and environmental technologies, it will also contribute to the development of the fundamental science by opening up a new field in the quantum world.
The atomic–resolution holography electron microscope consists of three separate tanks comprised by the microscope column equipped with the electron gun and accelerator tube, the high-voltage generator, and the field-emission (FE) control system to avoid interference between the AC (high-voltage generator) and DC (FE control system and accelerator tube) parts. This assembly system assures stability of high-voltage generation and field-emission electron gun control.
Further advancement of the electron microscope development is in progress based on the technologies of 1-MV holography electron microscope implemented in 2000.
Using the wave characteristic of electrons, this electron microscope can measure electrical and magnetic fields in atomic scales and make three-dimensional observations of quantum mechanical phenomena. The following state-of-the-art devices and technologies are being developed to be incorporated into this machine for the achievement of this performance.
To generate highly coherent and bright electron beams, it is necessary to keep the electron gun environment and the acceleration tube in an ultra-high vacuum state. We employ a non-evaporable getter pump to achieve this ultra-high vacuum.
The electron lens uses a large quantity of special magnetic materials, such as permalloy and permendur. Permalloy is an alloy of iron and nickel with a high magnetic permeability so that it easily responds to small changes in magnetic field. Permendur is an alloy of cobalt and iron with a high permeability at high flux densities with a very high saturation point so that it can create a large magnetic field.
To realize ultrahigh resolution, we implement an aberration corrector. Spherical aberration, which was not removed by rotationally symmetric lenses, can now be removed by the hexapole lens by suppressing higher-order aberrations. In this way, lens performance has been drastically improved.
Suppression of vibration and noises is another important factor to realize high resolution. Not only the vibration of the electron microscope column but also sound vibration created by air conditioners, vacuum pumps, or even scientists using the electron microscope disturb the atomic-level observations As a countermeasure to suppress the sound vibration, we adopt the sound-proof technology by enclosing the electron microscope column and vacuum pumps with sound-proof boxes.
