Method for manufacturing outer conductor

1. A method for manufacturing an outer conductor of a higher-order-mode coupler for a superconducting acceleration cavity, the outer conductor comprising:

a cylindrical main body that is open at a first end surface thereof;

a port formed in a side of the main body so as to penetrate therethrough; and

a protruding part formed outside a second end surface of the main body,

the method comprising:

a deep drawing step of deep-drawing a metal plate to form the main body;

a port-forming step of flanging the thus-formed main body to form the port;

a first machining step of forming a groove in a middle of the protruding part in a height direction of the protruding part by machining the main body to adjust an outer shape thereof; and

a step of deforming the second end surface of the main body by pushing the protruding part or by holding and pulling the groove, and adjusting a spacing between an inner conductor disposed in the main body and the second end surface of the main body,

wherein, in the first machining step, a thickness of the second end surface of the main body, except for a part where the protruding part is formed, is substantially even and is thinner than a thickness of a cylindrical portion of the main body.

2. The method for manufacturing the outer conductor according to claim 1 , wherein the metal plate used to perform deep drawing in the deep drawing step is thicker than a finished thickness of a cylindrical portion of the main body,

the method further comprising, before the port-forming step, a second machining step of machining the main body to the finished thickness of the cylindrical portion of the main body.

3. The method for manufacturing the outer conductor according to claim 1 , wherein the metal plate used in the deep drawing step has such a thickness that a finished thickness of the cylindrical portion of the main body is achieved after the deep drawing step.