Title :
Development of C-Band Accelerator Structure with Smooth Shape Couplers
Author :
Sugimura, T. ; Kamitani, T. ; Yokoyama, K. ; Takatomi, T. ; Kakihara, K. ; Ikeda, M. ; Ohsawa, S.
Author_Institution :
KEK, 1-1, Oho, Tsukuba, Ibaraki, Japan
Abstract :
A new C-band accelerator structure for the SuperKEKB injector linac is under development. This structure corresponds to an upstream half part in a tandem connection of two structures. A measure against RF breakdown is required because the upstream structure is exposed to higher RF field than that of the downstream structure. In order to suppress a RF breakdown around a coupler iris, a fat and smooth iris is adopted for the structure. The coupler dimensions such as an aperture of the iris and a diameter of the coupler cavity is first optimized by computer simulation and then decided by cold model measurements. Electric field symmetry is retained by shifting the coupler cavity from a beam centre. An amount of offset is also decided by simulations. The coupler body is made with a milling machine. A rather rough surface of the inner coupler is finished by an electro-polishing method. This structure will be installed in the beam line of the KEKB injector linac this summer.
Keywords :
Apertures; Computational modeling; Computer simulation; Couplers; Electric breakdown; Iris; Linear particle accelerator; Metalworking machines; Radio frequency; Shape;
Conference_Titel :
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the
Print_ISBN :
0-7803-8859-3
DOI :
10.1109/PAC.2005.1591168