Special tooling and method for electron beam welding of cavity body and beam tube of superconducting niobium cavity

A special tooling for electron beam welding of a cavity body and a beam tube of a superconducting niobium cavity, comprising a first clamping device for fixing a flange and a second clamping device for fixing a semi-cavity body, wherein the first clamping device and the second clamping device are fixedly connected through a connecting component, wherein the first clamping device comprises a pressing ring and a base plate with a clamping shaft disposed on one side, and the pressing ring is disposed around the beam tube of the superconducting niobium cavity and cooperates with the base plate to clamp and fix the flange;

• the second clamping device comprises a plurality of clamping arms evenly distributed along a circumference of the semi-cavity body, each of the plurality of clamping arms comprises a second pressing plate axially disposed along the beam tube and a pressing block that is disposed on an end portion of each second pressing plate and fixes an edge of the semi-cavity body, and each second pressing plate is provided with a second groove-shaped hole;
• and
• the connecting component comprises a plurality of connecting units one-to-one corresponding to the plurality of clamping arms, and each one of the plurality of connecting units comprises a first pressing plate and a support plate, wherein one end of each first pressing plate is connected to the base plate, and the other end is provided with a first groove-shaped hole, the first groove-shaped hole corresponds to a second groove-shaped hole of each second pressing plate of respective one of the plurality of clamping arms corresponding to the one of the plurality of connecting units, and a total length of each first pressing plate and each second pressing plate is adjustably fixed by using a connecting bolt, to allow a fixed connection between the edge of the semi-cavity body and the base plate;
• and one end of the support plate is in contact with an outer sidewall of the semi-cavity body, and the other end is connected to individual first pressing plate through cooperation between the groove-shaped holes and the connecting bolt, such that the support plate is fixed against the outer sidewall of the semi-cavity body.