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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.
Nishimori, Nobuyuki; Hajima, Ryoichi; Nagai, Ryoji; Sawamura, Masaru
Proceedings of 56th ICFA Advanced Beam Dynamics Workshop on Energy Recovery Linacs (ERL 2015) (Internet), p.100 - 102, 2015/12
Sakai, Hiroshi*; Enami, Kazuhiro*; Furuya, Takaaki*; Kako, Eiji*; Kondo, Yoshinari*; Michizono, Shinichiro*; Miura, Takako*; Qiu, F.*; Sato, Masato*; Shinoe, Kenji*; et al.
Proceedings of 56th ICFA Advanced Beam Dynamics Workshop on Energy Recovery Linacs (ERL 2015) (Internet), p.63 - 66, 2015/12
no abstracts in English
Nishimori, Nobuyuki; Nagai, Ryoji; Sawamura, Masaru; Hajima, Ryoichi
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.508 - 510, 2015/09
no abstracts in English
-ray beamsHajima, Ryoichi; Sawamura, Masaru; Nagai, Ryoji; Nishimori, Nobuyuki; Hayakawa, Takehito; Shizuma, Toshiyuki; Angell, C.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.79 - 83, 2015/09
Generation of energy-tunable narrow-bandwidth -rays via Laser Compton Scattering (LCS) is of great interest for scientific studies and applications of MeV photons which interact with nuclei. We are developing technologies relevant to generation of high-brightness LCS -ray beams. One of the promising applications of such -rays is the nondestructive detection and assay of nuclides which are necessary for nuclear security and safeguards. We summarize R-and-D status of LCS -ray sources and overview future applications.
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
Sawamura, Masaru; Umemori, Kensei*; Sakai, Hiroshi*; Shinoe, Kenji*; Furuya, Takaaki*; Enami, Kazuhiro*; Egi, Masato*
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.579 - 582, 2015/09
no abstracts in English
Shinoe, Kenji*; Sakai, Hiroshi*; Umemori, Kensei*; Enami, Kazuhiro*; Sawamura, Masaru; Egi, Masato*; Furuya, Takaaki*
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.548 - 552, 2015/09
no abstracts in English
Numata, Naoto*; Asakawa, Tomoyuki*; Sakai, Hiroshi*; Umemori, Kensei*; Furuya, Takaaki*; Shinoe, Kenji*; Enami, Kazuhiro*; Egi, Masato*; Sakanaka, Shogo*; Michizono, Shinichiro*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.566 - 570, 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
-rays with energies of 1.17 and 1.33 MeV by a flat Si crystalMatsuba, Shunya*; Hayakawa, Takehito; Shizuma, Toshiyuki; Nishimori, Nobuyuki; Nagai, Ryoji; Sawamura, Masaru; Angell, C.; Fujiwara, Mamoru; Hajima, Ryoichi
Japanese Journal of Applied Physics, 54(5), p.052203_1 - 052203_5, 2015/05
Times Cited Count：3 Percentile：13.89(Physics, Applied)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.
Nishimori, Nobuyuki; Nagai, Ryoji; Matsuba, Shunya; Sawamura, Masaru; Hajima, Ryoichi
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1031 - 1033, 2014/10
no abstracts in English
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
Nagai, Ryoji; Sawamura, Masaru; Nishimori, Nobuyuki; Hajima, Ryoichi
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1016 - 1018, 2014/10
In order to realize a high-brightness and monochromatic light source based on accelerator technologies, increasing of the cathode surface field of an electron gun is mandatory. Dust-free technique is a key technology to realize a high-field electron gun. We propose a new style dust-free technique. In this paper, R&D status and result of the preliminary test of the dust-free technique are reported.
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.
Sakai, Hiroshi*; Enami, Kazuhiro*; Furuya, Takaaki*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru; Cenni, E.*; Aoto, Tomohiro*; Hayashi, Kyohei*; et al.
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.1787 - 1789, 2014/07
Alignment of superconducting cavities is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to liquid He temperature more precisely, we newly developed the position monitor based on the measurement of the interference of light between the measurement target and the reference point. We applied this monitor to the main linac cryomodule of Compact ERL (cERL) and successfully measured the displacement during 2 K cooling with the resolution of 10 
m.
Sato, Masato*; Enami, Kazuhiro*; Furuya, Takaaki*; Michizono, Shinichiro*; Miura, Takako*; Qiu, F.*; Sakai, Hiroshi*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru; et al.
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.2531 - 2533, 2014/07
For the main linac of ERL, high loaded Q (QL) operation is desirable to reduce the input generator power. In such operation mode, the suppression of the micophonics is important to stabilize RF amplitude and phase. One of reasons which causes microphonics is mechanical vibration, which changes the cavity frequency. The vibrations of the cavities, the cryomodule and the floor were investigated and compared with the microphnics data taken during cERL operation.
Enami, Kazuhiro*; Furuya, Takaaki*; Sakai, Hiroshi*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Michizono, Shinichiro*; Miura, Takako*; Qiu, F.*; Arakawa, Dai*; et al.
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.2534 - 2536, 2014/07
We evaluated a slidejack tuner adopted as compact ERL Main Linac tuner. The tuner compensates the frequency by extending a cavity. Tuning is driven by two system, piezo and slidejack system. Slide-jack mechanism with long stroke drives coarsely piezo adjust precisely and fast. We tested performance of the tuners on operation.
