Abstract: A tritium removal device for a lithium loop contains a neutron source (1) for colliding protons on a lithium flow, thereby generating neutrons, a lithium tank (11) for the lithium passing through this neutron source (1) to flow thereto through a flow passage (9), thereby temporarily accumulating it therein, and a lithium pump (17) for circulating and supplying the lithium of this lithium tank (11) to the neutron source (1) through a supply-side flow passage (9?). The lithium tank (11) and the lithium pump (17), into which hydrogen gas containing tritium therein can be easily collected, are enclosed within a hermetically sealed container (7) including an inactive gas therein, so that even if the hydrogen gas including the tritium therein is leaked into the hermetically sealed container (7), it is removed by a hydrogen isotope removal filter.

Abstract: A method of production of a radio frequency accelerator which has a tubular part 1 which forms an acceleration cavity, including a temporary assembly step of making a plurality of component members 11 to 14 which have shapes obtained by splitting the tubular part 1 mate with each other to temporarily assemble them into the shape of the tubular part 10 and a welding step of welding the plurality of component members 11 to 14 together. The temporary assembly step includes a step of placing, inside of the tubular part 1, support members 21 for contacting the inside surface of the tubular part 1 and supporting the tubular part 1 from the inside, and the welding step includes a step of welding the plurality of component members 11 to 14 along the butt lines 51 by friction stir welding.

Abstract: A tritium removal device for a lithium loop comprises a neutron source (1) for colliding proton on a lithium flow, thereby generating neutrons, a lithium tank (11) for letting the lithium passing through this neutron source (1) to flow into through a flow passage (9), thereby for temporality accumulating it therein, and a lithium pump (17) for circulating and supplying the lithium of this lithium tank (11) to the neutron source (1) through a supply-side flow passage (9?). The lithium tank (11) and the lithium pump (17), into which hydrogen gas containing tritium therein can be easily collected, are enclosed within a hermetically sealed container (7) including an inactive gas therein, so that even if the hydrogen gas including the tritium therein is leaked into the hermetically sealed container (7), it is removed by a hydrogen isotope removal filter. It is possible to remove the tritium, with safety, without diffusing the tritium from an inside of the lithium loop for forming a target flow into an atmosphere.

Abstract: A method of production of a radio frequency accelerator which has a tubular part 1 which forms an acceleration cavity, including a temporary assembly step of making a plurality of component members 11 to 14 which have shapes obtained by splitting the tubular part 1 mate with each other to temporarily assemble them into the shape of the tubular part 10 and a welding step of welding the plurality of component members 11 to 14 together. The temporary assembly step includes a step of placing, inside of the tubular part 1, support members 21 for contacting the inside surface of the tubular part 1 and supporting the tubular part 1 from the inside, and the welding step includes a step of welding the plurality of component members 11 to 14 along the butt lines 51 by friction stir welding.