Studies3

Research

Studies3

Atomistic Investigation of Radiation Effects and Radiation-Induced Structural Changes in Metals and Ceramics

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Figure 1 Newly developed
High Voltage Electron Microscope
(JEM-1300NEF)
at the Ito Campus of Kyushu University

ABSTRACT:
When alloys and ceramic compounds are irradiated with energetic particles, they transfer the kinetic energy to a local region of the material. This causes the formation of radiation-induced defects and radiation damage. Our research group has investigated radiation-induced microstructure evolution, such as the nucleation-and-growth process of radiation-induced defects, and phase transformation (order-disorder transition), through transmission electron microscopy experiments as well as theoretical investigations. We believe this research provides fundamental knowledge needed for the development of fission and fusion reactors.

DETAILED:
Materials used for fission reactors and future fusion devices are exposed to a variety of radiation. In general, we know that material properties are degraded in such an environment, and this phenomenon is called 'radiation damage.' A fundamental understanding of radiation damage is essential to the safe use and development of fission reactors and fusion devices. Our research group has investigated radiation damage and radiation effects by utilizing transmission and scanning electron microscopy equipment, such as the high voltage electron microscope (JEM-1300 NEF) at the Research Laboratory for the High Voltage Electron Microscope, Kyushu University, for the atomistic understanding of radiation-induced microstructure evolution. Some of our research topics are: (1) Radiation damage in nuclear fuels, inert matrixes for fuel and/or transmutation targets, (2) The microstructure evolution of oxide and nitride ceramics irradiated with swift heavy ions, (3) The synergistic effects of electronic excitation and displacement damage in ceramics, (4) Ion beam modification of nano-structure materials. Our final goal is to gain insights into the physical mechanisms of radiation damage in metals and ceramic compounds, and to find and/or develop radiation tolerant materials that remain durable even under heavy exposure to radiation.

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Figure 2 High resolution electron
micrographs of ion tracks induced by
swift heavy ions (350 MeV Au ions) in
magnesium aluminate spinel (MgAl2O4)


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Figure 4 Electron tomography image of FePt nano particles elongated by swift heavy ion irradiation

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Figure 3 Sequential change in radiation induced defects in stabilized zirconia formed under electron irradiation, showing the characteristic growth process that generates dislocations.


Department of Applied Quantum Physics and Nuclear Engineering,
Faculty of Engineering, Kyushu University
Professor Syo Matsumura
Associate Professor Kazuhiro Yasuda
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