Development of a real-time defocus image modulation processing electron microscope. I. Construction

A real-time 'defocus image modulation processing electron microscope' (DIMP-EM) has been developed by the 'Research for the Future Program' which was started in 1996 by the Japan Society for the Promotion of Science (JSPS). This real-time DIMP-EM produces images which are free of spherical aberration when working in either the phase contrast or amplitude contrast modes which are produced in real-time by actively modulating the accelerating voltage. For this microscope it was essential to develop a floating type, high voltage power supply system. The performance of this custom made, floating type 200 kV accelerating voltage system, and the spherical aberration free phase contrast image of a gold particle observed in real-time at 4/30 s are presented. This paper describes the DIMP-EM from two sides, namely, the technical side and application side. We describe the construction of the DIMP-EM in this paper, and the result of observation with DIMP-EM will be described in next paper.