DEVELOPMENT OF ACCELERATING-VOLTAGE MODULATOR FOR REAL-TIME DEFOCUS IMAGE MODULATION PROCESSING ELECTRON-MICROSCOPE

A modulating system of an accelerating-voltage has been developed for a real-time Defocus Image Modulation Processing Electron Microscopy (D IMP-EM) which enables spherical-aberration-free TEM observation to be performed in real-time. The system provides arbitral modulating-signal s with both the lime-resolution of 65.1 mu sec., and voltage resolutio n of 180 mV. The driving circuit of this system was mounted in a high- voltage generating tank unit of an electron microscope, JEM-100C-FEG, to modulate directly an accelerating-voltage of 80 kV over the range o f +/- 100 V. The generated digital data for the modulation were transf erred through optical coupling from the signal generator to the drive circuit in the tank so as to ensure the accelerating-voltage modulatio n without any degradation. The results has confirmed successful perfor mance of the system by operating the electron microscope as an oscillo scope, leading to realization of a real-time DIMP-EM.