1. [1] A. Iiyoshi, A. Komori et al., Nucl. Fusion 39, 1245 (1999).
2. [2] T. Hino, Y. Nobuta et al., Fusion Eng. Des. 82, 1621 (2007).
3. [3] M. Matsuyama et al., J. Nucl. Mater. 290-293, 437 (2001).
4. [4] M. Matsuyama et al., J. Nucl. Mater. 417, 900 (2011).
5. [5] M. Matsuyama et al., Fusion Sci. Technol. 41, 505 (2002).