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Fuwa, Yasuhiro; Iwashita, Yoshihisa*; Kuriyama, Yasutoshi*; Tongu, Hiromu*; Hayano, Hitoshi*; Geng, R. L.*
Proceedings of 20th International Conference on RF Superconductivity (SRF 2021) (Internet), p.323 - 325, 2022/05
In order to evaluate the performance of a superconducting cavity, we are developing a mapping system to measure the distribution of cavity temperature, field emission X-rays, and trapped magnetic flux with high positional resolution. In order to construct a system with high positional resolution, a large number of sensors are required. However, as the number of sensors increases, so does the amount of wiring, which increases the complexity of the wiring in the cryogenic apparatus, and also increases the heat transfer through the wiring, which disturb efficient operation of cavity tests. We are developing an efficient mapping system with a multiplexer that scans the readout signal on the same circuit as the sensor in the cryogenic dewar where the cavity test is conducted. In this presentation, we report the outline and test results of the mapping system under development
Sawamura, Masaru; Hajima, Ryoichi; Kubo, Takayuki*; Saeki, Takayuki*; Iwashita, Yoshihisa*; Tongu, Hiromu*; Hokonohara, Hisao*; Cenni, E.*
Proceedings of 17th International Conference on RF Superconductivity (SRF 2015) (Internet), p.1196 - 1199, 2015/12
The spoke cavity is expected to have advantages for compact ERL accelerator for X-ray source based on laser Compton scattering. We have been developing the spoke cavity under a research program of MEXT, Japan to establish the fabrication process. Since our designed shape of the spoke cavity is complicated due to increase the RF properties, we have been designing the mold including the process of press work and the support parts for vacuum tolerance with the mechanical simulation. In this paper we present status of the spoke cavity fabrication.
Sawamura, Masaru; Hajima, Ryoichi; Nishimori, Nobuyuki; Nagai, Ryoji; Iwashita, Yoshihisa*; Tongu, Hiromu*; Kubo, Takayuki*; Saeki, Takayuki*
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.583 - 586, 2015/09
no abstracts in English
Hajima, Ryoichi; Sawamura, Masaru; Kubo, Takayuki*; Saeki, Takayuki*; Cenni, E.*; Iwashita, Yoshihisa*; Tongu, Hiromu*
Proceedings of 6th International Particle Accelerator Conference (IPAC '15) (Internet), p.2902 - 2904, 2015/06
A 5-year research program on the development of superconducting spoke cavities for electron accelerators has been funded by MEXT, Japan since 2013. The purpose of our program is establishing design and fabrication processes of superconducting spoke cavity optimized for compact X-ray sources based on laser Compton scattering. The spoke cavity is expected to realize a compact industrial-use X-ray source with a reasonable cost and easy operation. We have chosen a cavity frequency at 325 MHz due to possible operation at 4 K and carried out cavity shape optimization in terms of electromagnetic and mechanical properties. Production of press-forming dies is also in progress. In this paper, we present overview and up-to-date status of the research program.
Kubo, Takayuki*; Saeki, Takayuki*; Cenni, E.*; Iwashita, Yoshihisa*; Tongu, Hiromu*; Hajima, Ryoichi; Sawamura, Masaru
Proceedings of 6th International Particle Accelerator Conference (IPAC '15) (Internet), p.2892 - 2894, 2015/06
no abstracts in English
Kubo, Takayuki*; Saeki, Takayuki*; Cenni, E.*; Fujisawa, Hiroshi*; Iwashita, Yoshihisa*; Tongu, Hiromu*; Hajima, Ryoichi; Sawamura, Masaru
Proceedings of 27th International Linear Accelerator Conference (LINAC 2014) (Internet), p.1030 - 1033, 2014/12
A 325 MHz superconducting spoke cavity for the electron acceleration is under development to realize a compact industrial-use X-ray source with the laser-Compton scattering. Optimum designs of the spoke cavity have been searched by using the genetic algorithm, and multipactor simulations are currently in progress to finalize the detailed design. In parallel to the design-optimization efforts, studies toward fabrication processes are also being carried out. In this paper, progresses made so far and a current situation are briefly reviewed.
Sawamura, Masaru; Nagai, Ryoji; Nishimori, Nobuyuki; Hajima, Ryoichi; Iwashita, Yoshihisa*; Fujisawa, Hiroshi*; Tongu, Hiromu*; Kubo, Takayuki*; Saeki, Takayuki*
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.618 - 620, 2014/10
no abstracts in English
Noda, Akira*; Nakao, Masao*; Okamoto, Hiromi*; Osaki, Kazuya*; Yuri, Yosuke; Soda, Hikaru*; Tongu, Hiromu*; Jimbo, Koichi*; Grieser, M.*; He, Z.*; et al.
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.28 - 33, 2014/07
Sawamura, Masaru; Hajima, Ryoichi; Nagai, Ryoji; Kubo, Takayuki*; Fujisawa, Hiroshi*; Iwashita, Yoshihisa*; Tongu, Hiromu*
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.1946 - 1948, 2014/07
We have launched a 5-year research program to develop superconducting spoke cavity for laser Compton scattered (LCS) photon sources. For realizing a wide use of LCS X-ray and 
-ray sources in academic and industrial applications, we adopt 325-MHz super-conducting spoke cavity to electron beam drivers. The spoke cavity, originally invented for ion and proton acceleration, can be used for electron accelerators, in which we can make best use of features of spoke cavity: relative compactness in comparison with a TM cavity of the same frequency, robustness with respect to manufacturing inaccuracy due to its strong cell-to-cell coupling, couplers on outer conductor for the better packing in a linac, and so on. In this paper, we present our research plan and results of cavity shape optimization.
Iwashita, Yoshihisa*; Fujisawa, Hiroshi*; Tongu, Hiromu*; Hajima, Ryoichi; Nagai, Ryoji; Sawamura, Masaru; Kubo, Takayuki*
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.2543 - 2545, 2014/07
Superconducting spoke cavities for laser Compton scattered (LCS) photon sources is under development. The operating frequency is 325-MHz to accelerate electron beam for the LCS sources, where the size of the spoke cavity is less than an elliptical cavities with the same frequency. Because of the complicated shape of the cavity, it may be suffered from a strong multipactor effect. Some trial of multipactor analysis is described.
Jimbo, Koichi*; Soda, Hikaru*; Nakao, Masao*; Yuri, Yosuke; Tongu, Hiromu*; Noda, Akira*
Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1057 - 1059, 2014/06
Noda, Akira*; Nakao, Masao*; Soda, Hikaru*; Tongu, Hiromu*; Okamoto, Hiromi*; Osaki, Kazuya*; Yuri, Yosuke; Jimbo, Koichi*; Grieser, M.*; He, Z.*
Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.143 - 145, 2014/06
Yuri, Yosuke; Osaki, Kazuya*; Okamoto, Hiromi*; He, Z.*; Soda, Hikaru*; Noda, Akira*; Nakao, Masao*; Tongu, Hiromu*; Jimbo, Koichi*
Proceedings of Workshop on Beam Cooling and Related Topics (COOL '13) (Internet), p.162 - 165, 2013/11
Noda, Akira*; Nakao, Masao*; Soda, Hikaru*; Tongu, Hiromu*; Okamoto, Hiromi*; Osaki, Kazuya*; Yuri, Yosuke; Jimbo, Koichi*; Grieser, M.*; He, Z.*
Proceedings of Workshop on Beam Cooling and Related Topics (COOL '13) (Internet), p.157 - 161, 2013/11
Jimbo, Koichi*; Soda, Hikaru*; Yuri, Yosuke; Tongu, Hiromu*; Nakao, Masao*; Shirai, Toshiyuki*; Noda, Akira*
Proceedings of 25th North American Particle Accelerator Conference (NA-PAC '13) (Internet), p.886 - 888, 2013/09
Soda, Hikaru*; Nakao, Masao*; Tongu, Hiromu*; Jimbo, Koichi*; Osaki, Kazuya*; Okamoto, Hiromi*; Yuri, Yosuke; He, Z.*; Grieser, M.*; Noda, Akira*
Japanese Journal of Applied Physics, 52(3), p.030202_1 - 030202_4, 2013/03
Times Cited Count：5 Percentile：22.83(Physics, Applied)Noda, Akira*; Nakao, Masao*; Soda, Hikaru*; Tongu, Hiromu*; Jimbo, Koichi*; Okamoto, Hiromi*; Osaki, Kazuya*; Yuri, Yosuke; Meshkov, I.*; Smirnov, A.*; et al.
Proceedings of 23rd Russian Particle Accelerator Conference (RuPAC 2012) (Internet), p.48 - 52, 2012/09
Soda, Hikaru*; Nakao, Masao*; Tongu, Hiromu*; Noda, Akira*; Jimbo, Koichi*; Osaki, Kazuya*; Okamoto, Hiromi*; Yuri, Yosuke; Grieser, M.*; He, Z.*
Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.388 - 390, 2012/08
no abstracts in English
Noda, Akira*; Nakao, Masao*; Soda, Hikaru*; Tongu, Hiromu*; Jimbo, Koichi*; Okamoto, Hiromi*; Osaki, Kazuya*; Yuri, Yosuke; Grieser, M.*; He, Z.*
Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.72 - 74, 2012/08
Soda, Hikaru*; Nakao, Masao*; Noda, Akira*; Tongu, Hiromu*; Ito, Kiyokazu*; Okamoto, Hiromi*; Yuri, Yosuke; Jimbo, Koichi*; Grieser, M.*; He, Z.*
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.397 - 399, 2012/05
