Abstract: An input coupler for an accelerating cavity includes a cylindrical external conductor; a cylindrical internal conductor arranged coaxially with the external conductor, inside of which a heating medium circulates; a plate provided between the inner surface of the external conductor and the outer surface of the internal conductor; a cooling part for cooling the plate from the external conductor side to the freezing point of water or lower; and a heat insulating part provided on the part at which the internal conductor and the plate are connected, the heat insulating part having lower thermal conductivity than that of the internal conductor. The plate is connected to the internal conductor via the heat insulating part.

Abstract: An input coupler for an accelerating cavity includes a cylindrical external conductor; a cylindrical internal conductor arranged coaxially with the external conductor, inside of which a heating medium circulates; a plate provided between the inner surface of the external conductor and the outer surface of the internal conductor; a cooling part for cooling the plate from the external conductor side to the freezing point of water or lower; and a heat insulating part provided on the part at which the internal conductor and the plate are connected, the heat insulating part having lower thermal conductivity than that of the internal conductor. The plate is connected to the internal conductor via the heat insulating part.

Abstract: A drift tube manufacturing method and a drift tube which can reduce cost while securing an adequate level of particle beam focusing performance. The method includes: a magnet housing stage of housing a predetermined number of permanent magnets in a housing, which has a through-hole at a center part and an annular magnet housing space on an outer circumferential side of the through-hole; a welding stage of setting a lid for covering the opening part on the opening part; and welding the lid and the housing by laser beam welding. At least a surface of the housing and a surface of the lid are formed of copper.

Abstract: The present invention provides a drift tube manufacturing method and a drift tube which can reduce cost while securing an adequate level of particle beam focusing performance. The method includes: a magnet housing stage of housing a predetermined number of permanent magnets in a housing, which has a through-hole at a center part and an annular magnet housing space on an outer circumferential side of the through-hole, from an opening part of the magnet housing space into the magnet housing space; a welding stage of setting a lid for covering the opening part on the opening part, and welding the lid and the housing by laser beam welding. At least a surface of the housing and a surface of the lid are formed of copper.