Materials Radiation Effects

Professor

  • KINOMURA, Atsushi, e-mail: akinomura<atmark>

Associate Professor

  • XU, Qiu e-mail: xu<atmark>

Assistant Professor

  • YABUUCHI, Atsushi e-mail: yabuuchi<atmark>

* replace <atmark> with @rri.kyoto-u.ac.jp

Irradiation of high-energy particles induces the interaction with atoms in solids and the loss of their energies. In order to understand the irradiation effects for various materials such as metals and semiconductors, we perform (1) developments and preparations of neutron, ion and electron irradiation facilities, (2) research on characterization techniques for irradiated materials using positron annihilation spectroscopy and electron microscopy, and (3) numerical simulation for interactions of irradiation-induced defects.

As irradiation techniques of high-energy particles, we have developed facilities for neutron irradiation at high temperatures by Material Controlled Irradiation Facility (SSS) of Kyoto University Reactor (KUR), and electron irradiation at low, ambient and high temperatures by electron linear accelerator of Research Reactor Institute (KURRI-LINAC). Further developments of irradiation facilities using ion accelerators are in progress.

As surface characterization techniques for irradiated materials, a slow positron beam system using KUR is under development (Fig. 1). This system is one of the most advanced facilities in the world and has been developed for positron annihilation lifetime spectroscopy, Doppler broadening, and coincidence measurements with these analytical techniques. Other analytical techniques such as radioisotope-based positron annihilation lifetime spectrometry have been used for applied research on various materials.

It is expected that research in this field promotes materials developments for new-type nuclear systems and fusion reactors. In addition, it is possible to get information on damage mechanism and lifetimes of neutron-irradiated materials in nuclear power plants as well as damage reduction in fabrication processes of semiconductor devices.

Fig. 1.  Slow positron beam system at the KUR B1 hole.