| Title |
Optimization of C-band RF Input Coupler as a Mode Converter for 20-K Cryocooled Photocathode RF Gun |
| Authors |
- T. Tanaka, M. Inagaki, R. Nagashima, K. Nakao, K. Nogami, T. Sakaipresenter, K. Takatsuka
LEBRA, Funabashi, Japan
- M.K. Fukuda, T. Takatomi, N. Terunuma, J. Urakawa, M. Yoshida
KEK, Ibaraki, Japan
- D. Satoh
TIT, Tokyo, Japan
|
| Abstract |
Development of a cryocooled 2.6-cell C-band photocathode RF gun has been conducted at Nihon University in collaboration with KEK. An RF mode converter from square TE10 to circular TM01 mode has been employed as an RF input coupler that has a coupling coefficient of approximately 20 at 20 K to the 2.6-cell accelerating structure. In the previous design, the circular waveguide in the mode converter formed part of the accelerating cavity. After the cold test of the cavity completed in 2014, the coupler design was modified to work as a pure mode converter with a VSWR of 1 at 5712 MHz. From the design simulation using CST-STUDIO, the insertion loss in the converter is 0.2 %. The TM010 and TM011 modes excited in the circular waveguide were separated by several ten MHz from the accelerating frequency. The simulation has suggested that the amplitude of the transverse electric filed on the axis in the circular waveguide is reduced to approximately 2 % of that in the longitudinal direction.
|
| Funding |
Work supported by the Photon and Quantum Basic Research Coordinated Development Program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT). |
| Paper |
download WEPMY038.PDF [1.389 MB / 3 pages] |
| Export |
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| Conference |
IPAC2016, Busan, Korea |
| Series |
International Particle Accelerator Conference (7th) |
| Proceedings |
Link to full IPAC2016 Proccedings |
| Session |
Poster Session |
| Date |
11-May-16 16:00–18:00 |
| Main Classification |
03 Alternative Particle Sources and Acceleration Techniques |
| Sub Classification |
T02 Electron Sources |
| Keywords |
cavity, gun, coupling, simulation, insertion |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Christine Petit-Jean-Genaz (CERN, Geneva, Switzerland); Dong Eon Kim (PAL, Pohang, Republic of Korea); Kyung Sook Kim (PAL, Pohang, Republic of Korea); In Soo Ko (POSTECH, Pohang, Republic of Korea); Volker RW Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-147-2 |
| Published |
June 2016 |
| Copyright |
|
