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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
Hwang, J.-G.*; Kim, E.-S.*; Miyajima, Tsukasa*; Honda, Yosuke*; Harada, Kentaro*; Shimada, Miho*; Takai, Ryota*; Kume, Tatsuya*; Nagahashi, Shinya*; Obina, Takashi*; et al.
Nuclear Instruments and Methods in Physics Research A, 753, p.97 - 104, 2014/07
Times Cited Count：7 Percentile：48.36(Instruments & Instrumentation)Sakai, Hiroshi*; Furuya, Takaaki*; Takahashi, Takeshi*; Sakanaka, Shogo*; Umemori, Kensei*; Shinoe, Kenji*; Sawamura, Masaru
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2950 - 2952, 2010/05
We are developing the superconducting (SC) cavity for Energy Recovery Linac (ERL) in Japan. In order to survey the electron emission and the heating spot of the cavity inner surface in detail, cavity diagnostics with the rotating mapping system was applied. Two types of sensors, one of which is the carbon resistor and the other is the Si PIN photo diode, were set to detect the temperature rise and electron emission. By rotating the sensor arrays around the cavity axis, a lot of information is obtained all over the cavity surface in detail. This paper reports the results of vertical tests by using this rotating mapping system with Nb 9-cell ERL cavity.
Sakai, Hiroshi*; Furuya, Takaaki*; Sakanaka, Shogo*; Takahashi, Takeshi*; Umemori, Kensei*; Ishii, Atsushi*; Nakamura, Norio*; Shinoe, Kenji*; Sawamura, Masaru
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2953 - 2955, 2010/05
We started to develop an input power coupler for a 1.3 GHz ERL superconducting cavity for main linac. We fabricated power coupler components such as ceramic windows and bellows and carried out the high-power test of the components by using a CW 30 kW IOT power source. During this test, the ceramic window was broken by the sudden heat load. We found that this heat load occurred by the unexpected dipole mode. We renewed the ceramic window and successfully carried out the high power test up to CW 27 kW input power.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Sakai, Hiroshi*; Furuya, Takaaki*; Kako, Eiji*; Noguchi, Shuichi*; Sato, Masato*; Sakanaka, Shogo*; Shishido, Toshio*; Takahashi, Takeshi*; Umemori, Kensei*; Watanabe, Ken*; et al.
Proceedings of 45th Advanced ICFA Beam Dynamics Workshop on Energy Recovery Linacs (ERL '09) (Internet), p.57 - 62, 2010/05
Development of a SC Cavity Injector Cryomodule and Main linac Cryomodule for the compact ERL is being continued at KEK since 2006. Design of an injector cryomodule containing three 2-cell 1.3-GHz cavities for Injector Cryomodule and two 9-cell 1.3-GHz cavities for Main linac Cryomodule are almost completed. Status of R&D and design details are reported.
Sakai, Hiroshi*; Umemori, Kensei*; Sakanaka, Shogo*; Takahashi, Takeshi*; Furuya, Takaaki*; Shinoe, Kenji*; Ishii, Atsushi*; Nakamura, Norio*; Sawamura, Masaru
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.866 - 868, 2010/03
We started to develop an input coupler for a 1.3 GHz ERL superconducting cavity. Required input power is about 20 kW for the cavity acceleration field of 20 MV/m and the beam current of 100 mA in energy recovery operation. The input coupler is designed based on the STF-BL input coupler and some modifications are applied to the design for the CW 20 kW power operation. We fabricated input coupler components such as ceramic windows and bellows and carried out the high-power test of the components by using a 30 kW IOT power source and a test stand constructed for the high-power test. In this report, we mainly describe the results of the high-power test of ceramic window and bellows.
Sakai, Hiroshi*; Furuya, Takaaki*; Sakanaka, Shogo*; Takahashi, Takeshi*; Umemori, Kensei*; Ishii, Atsushi*; Nakamura, Norio*; Shinoe, Kenji*; Sawamura, Masaru
Proceedings of 14th International Conference on RF Superconductivity (SRF 2009) (Internet), p.684 - 688, 2009/09
We started to develop an input coupler for a 1.3GHz ERL superconducting cavity for ERL main linac. Required input power is about 20kW for the cavity acceleration field of 20MV/m and the beam current of 100mA in energy recovery operation. The input coupler is designed based on the STF-BL input coupler and some modifications are applied for the CW 20kW power operation. We fabricated input coupler components such as ceramic windows and bellows and carried out the high-power test of the components by using a 30kW IOT power source and a test stand constructed.
Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Uchiyama, Takashi*; Kobayashi, Masanori*; Muto, Toshiya*; Matsuba, Shunya*; Sakanaka, Shogo*; Sato, Kotaro*; Saito, Yoshio*; et al.
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.860 - 862, 2009/08
A newly 500 kV electron gun (2nd - 500 kV gun) for an ERL light source is designed at KEK. A new concept and state of-the-art technologies of vacuum system, ceramic insulators, high voltage power supply, photocathode and preparation system will be employed. The details are described in this report.
Nakamura, Norio*; Miyajima, Tsukasa*; Shimada, Miho*; Kobayashi, Yukinori*; Sakanaka, Shogo*; Hajima, Ryoichi
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.109 - 111, 2009/08
Tolerance study on RF amplitude and phase of main accelerating cavities and injection timing was performed for the compact ERL with a simulation code "elegant". As a result, it was found that errors of the RF amplitude and phase should be controlled within 0.01% and 0.01 deg. in rms to satisfy requirements for the arrival time and the bunch length at the exit of the 1st arc section in bunch-compression mode. In high-current and low-emittance modes, these control errors can be relaxed to 0.1% and 0.1deg. The injection timing error is allowed up to at least 200 fs, which does not deteriorate the beam quality at the exit of the 1st arc section in all the operation modes.
Kobayashi, Yukinori*; Sakanaka, Shogo*; Sato, Kotaro*; Kasuga, Toshio*; Kawata, Hiroshi*; Hajima, Ryoichi; Nakamura, Norio*
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.66 - 69, 2009/08
Future synchrotron light source based on the Energy Recovery Linac (ERL) is expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation with a potential of the oscillating type for X-ray free electron laser. We are constructing the R&D machine which is called the compact ERL including the developments of an ultra-low emittance electron gun and superconducting cavities for both the injector and the main linacs under the collaboration between KEK, JAEA, ISSP, and other institutes. In this paper, we report recent progress of the construction for the compact ERL with a repair of a KEK east counter hall.
Hajima, Ryoichi; Nakamura, Norio*; Sakanaka, Shogo*; Kobayashi, Yukinori*
Kasokuki, 6(2), p.149 - 157, 2009/07
Energy-recovery linac (ERL), which produces a small-emittance beam with high-average current, is a promising device for future light sources. In Japan, we have organized a collaboration team toward future ERL light sources and started R&D efforts to establish accelerator technologies for the ERL light sources. In this paper, we describe status of accelerator components R&D's and on-going construction of a test facility, the compact ERL.
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Hajima, Ryoichi; Nakamura, Norio*; Sakanaka, Shogo*; Kobayashi, Yukinori*
JAEA-Research 2008-032, 188 Pages, 2008/02
JAEA-Research-2008-032.pdf:23.41MB
Energy-recovery linac (ERL) is a promising device for future X-ray light sources. In Japan, we organized a Japanese ERL collaboration team, consisting of the members of KEK, JAEA, ISSP and other laboratories, and then, started R&D efforts for the future ERL light source. In order to demonstrate accelerator technologies relevant to the ERL light source, we have decided to build a small facility, Compact ERL. This report presents a design study of the Compact ERL, which includes R&D issues for each accelerator component, studies on beam dynamics, performance of the Compact ERL as a light source of THz and X-ray.
Sawamura, Masaru; Umemori, Kensei*; Furuya, Takaaki*; Sakanaka, Shogo*; Takahashi, Takeshi*; Sakai, Hiroshi*; Shinoe, Kenji*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.610 - 612, 2008/00
Damping higher-order-modes is important for superconducting main accelerators to suppress beam breakup and to increase the beam current. Our strategy for HOM damping is (1) large beam pipe, (2) optimization of cell shapes and (3) eccentric fluted beam pipe. Two single-cell cavities and one 9-cell cavity of niobium were made to check the performance of the new design cavity. The two single-cell cavities showed the good results of vertical test of 2 K. The vertical test of 9-cell cavity will be done soon.
Sakanaka, Shogo*; Kobayashi, Yukinori*; Sato, Kotaro*; Kasuga, Toshio*; Kawata, Hiroshi*; Hajima, Ryoichi; Nakamura, Norio*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.225 - 227, 2008/00
Collaborative research efforts towards future ERL-based light sources are carried out. We present the R&D status of an electron gun and superconducting cavities, updated design study on the test facility (Compact ERL).
Shiraga, Takashi*; Nakamura, Norio*; Harada, Kentaro*; Shimada, Miho*; Sakanaka, Shogo*; Kobayashi, Yukinori*; Hajima, Ryoichi
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.589 - 591, 2008/00
An energy recovery linac (ERL) is expected to be the next generation synchrotron radiation source that can provide synchrotron radiation of higher brilliance, shorter pulse and higher coherence than the existing third-generation synchrotron light sources. The compact ERL is planned to be constructed in order to solve some problems in achievement of such synchrotron radiation and to confirm advantages of ERLs. We studied and optimized the compact ERL optics to achieve subpico-second bunch generation and efficient energy recovery and to transport the beam to the beam dump without serious beam loss. The design study of the compact ERL optics was done by using the simulation code Elegant. As a result, we succeeded in obtaining a 40-fs bunch with a charge of 77 pC just after the first TBA cell. Furthermore we could suppress the maximum beam size to less than 8.5 mm even after deceleration.
Sakai, Hiroshi*; Shinoe, Kenji*; Ishii, Atsushi*; Umemori, Kensei*; Sakanaka, Shogo*; Takahashi, Takeshi*; Furuya, Takaaki*; Sawamura, Masaru
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.592 - 594, 2008/00
We are developing a input coupler for the 1.3GHz 9-cell superconducting cavities to realize the ERL. Estimated input power is about 20kW for 20MV/m ERL operation. This coupler is based on the STF-BL input coupler, which adopts the TRISTAN type coaxial coupler, and some modifications are applied for the CW 20kW power operation. Now we are developing the high power coupler test stand to carry out the components test of the ceramic windows and bellows by using a 30kW IOT. In this paper, we report the design strategy of the input power coupler for ERL main linac and the recent status of the high power coupler test stand.
Hajima, Ryoichi; Sakanaka, Shogo*
Hoshako, 20(4), p.263 - 265, 2007/07
no abstracts in English
Sawamura, Masaru; Furuya, Takaaki*; Sakanaka, Shogo*; Suwada, Tsuyoshi*; Takahashi, Takeshi*; Umemori, Kensei*; Sakai, Hiroshi*; Shinoe, Kenji*
Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.1022 - 1024, 2007/06
An eccentric-fluted beam pipe was proposed to damp quadrupole modes. The eccentric-flute acts as a mode converter from quadrupole to dipole. Optimized parameters permit to damp both degenerate modes of quadrupole with the eccentric-flute. External Q-values measured with a low power model agreed well with those calculated with MAFIA.
