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内容記述 |
In a blanket system of DEMO (Demonstration) fusion reactors, beryllides (beryllium intermetallic compounds) are planned to be used as neutron multipliers. The proposed blanket system will adopt beryllide blocks instead of beryllide pebbles from viewpoints of higher thermal conductivity, lower tritium retention, and simplification for structure. To effectively generate tritium (T) as fuel, the neutron reaction between lithium and neutron (n), and 9Be(n,2n)4He of nuclear reaction is used in beryllide. Since other nuclear reactions between Be and neutrons result in tritium production. The tritium-retaining beryllides can affect the safety and operation of a fusion reactor. Therefore, it is essential to investigate the tritium retention properties due to the reduction in tritium retention and the expectation of tritium desorption behavior. In this study, the deuterium retention properties of the beryllide (Be12Ti) were evaluated using an deuterium ion gun and thermal desorption spectroscopy by comparison to the results in beryllium. Mechanically polished and electropolished Be12Ti samples were used. Under irradiation conditions, deuterium(D) ions were implanted with 3 keV, fluence was 1x1021 D/m2, and irradiation temperatures were from R.T. to 873 K. The bubble behaviors in Be12Ti and Be were observed using a transmission electron microscope with an ion gun under irradiation and annealing. In addition, thermal desorption spectroscopy evaluated apparent desorption activation energies from the electropolished and mechanically polished Be12Ti samples after the irradiation at high temperatures. |
