Free Access
Microsc. Microanal. Microstruct.
Volume 4, Number 2-3, April / June 1993
Page(s) 305 - 312
Microsc. Microanal. Microstruct. 4, 305-312 (1993)
DOI: 10.1051/mmm:0199300402-3030500

Development and application of intermittent electron irradiation technique with a high voltage electron microscope

S. Arai1, N. Yokoi1, C. Morita1 et M. Kiritani2

1  1MV Electron Microscopy Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464, Japan
2  Department of Nuclear Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464, Japan

For the purpose to observe and analyze the transient phenomena after the start of irradiation and the relaxation phenomena after the cessation of irradiation, techniques for intermittent electron irradiation are developed with a high voltage electron microscope, utilizing the STEM function installed in H-1250ST. One of the two methods developed is to make move the electron beam along a circle passing the area of interest in each cycle, which has an advantageous feature of invariant accumulated irradiation time regardless of the frequency. In another method, the electron beam goes back and forth between two positions, in which there is a free choice of the combination of the on- and off-time of electron beam. Dynamical control of electron beam position is made with two deflection coils placed at a right angle, which are driven by a computer loaded with two-phase-signal oscillator through D/A converter. Examples of applications are quoted on the relaxation effect of accumulated point defects on the nucleation and growth of interstitial clusters introduced in metals by electron irradiation.

0778 - Electron, positron, and ion microscopes; electron diffractometers.
6180F - Electron and positron radiation effects.
6172 - Defects and impurities in crystals; microstructure.

Key words
High-voltage electron microscopy -- Electron irradiation -- Electron beam effects -- Transients -- Interstitial cluster -- Nucleation -- Point defects -- In situ -- Intermittent irradiation -- Electron beam control

© EDP Sciences 1993