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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)Shinoe, Kenji*; Sato, Masato*; Sakai, Hiroshi*; Umemori, Kensei*; Nakamura, Norio*; Furuya, Takaaki*; Sawamura, Masaru; Cenni, E.*
Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1026 - 1030, 2012/08
We are developing input couplers for ERL main linacs. Two couplers for cERL have been fabricated and high power test was carried out. A klystron was used for RF power source. The power was increased with a pulse mode of 10 usec with and 5 Hz repetition and reached to 100 kW. The average input power was increased by increasing the pulse width and repetition and finally reached 40 kW of CW mode.
Shinoe, Kenji*; Sakai, Hiroshi*; Umemori, Kensei*; Cenni, E.*; Sawamura, Masaru; Nakamura, Norio*; Furuya, Takaaki*
Proceedings of 8th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1300 - 1302, 2011/08
We are developing ERL main linac input coupler. Until now, prototypes of ceramic windows were created and performances were tested. Using this ceramic window, we produced a coupler prototype model. The coupler prototype was installed into an insulating vacuum chamber and cooled by liquid nitrogen, and the high power test was performed. This is the condition, where the coupler is actually used in a cryomodule. In this test, we were able to input 25 kW power. It was checked that the magnitude of generation of heat is also satisfactory. It was checked that this coupler fulfills the specification demanded from ERL main linac.
Sakai, Hiroshi*; Furuya, Takaaki*; Nakamura, Norio*; Umemori, Kensei*; Shinoe, Kenji*; Sawamura, Masaru; Cenni, E.*
Proceedings of 15th International Conference on RF Superconductivity (SRF 2011) (Internet), p.356 - 360, 2011/07
We fabricated the prototype of an input coupler with two ceramic windows for ERL main linac and performed the high power test. In high power test, the one cold window was installed into the vacuum insulating chamber and cooled by liquid nitrogen. First, the multipacting limited the power level to 10 kW. The pulse processing method for 8 hours enabled the final power level to 25 kW with standing wave condition. We could also keep 20 kW power feeding into the coupler for 16 hours. The maximum measured temperature rises under feeding the 20 kW power to coupler were 120 K near the bellows parts and these are not so severe values to operate ERL main linac. The thermal cycle test of cold window of coupler was done. After 10-times thermal cycle tests between the room temperature and liquid nitrogen temperature, no leaks or cracks were observed. From these results of high power test, this prototype coupler satisfies our thermal and RF requirements.
Hajima, Ryoichi; Shimada, Miho*; Nakamura, Norio*
Nuclear Instruments and Methods in Physics Research A, 637(1, Suppl.), p.S37 - S42, 2011/05
Times Cited Count：2 Percentile：19.86(Instruments & Instrumentation)Energy-recovery linacs (ERLs) are in operation and under development in the world for future lightsources, which cover a wide range of photon energy, from THz to 
-rays, by using various kinds of photo-emission processes, undulator radiation, free-electron lasers, laser Compton scattering (LCS), and coherent radiation. Availability of ultra-short electron beams is an essential feature of ERLs for future light sources. In this paper, we provide an overview of the generation and applications of ultra-short electron beams in ERLs. Magnetic bunch compression and velocity bunching are the two schemes of ultra-short electron beam generation that are presented with the Compact ERL test facility as an example.
Shinoe, Kenji*; Sakai, Hiroshi*; Umemori, Kensei*; Sawamura, Masaru; Nakamura, Norio*; Furuya, Takaaki*
Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.511 - 513, 2010/08
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.
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*; 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.
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.
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.
Hajima, Ryoichi; Kawata, Hiroshi*; Kasuga, Toshio*; Sato, Kotaro*; Nakamura, Norio*
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no abstracts in English
Hajima, Ryoichi; Sakanaka, Shogo*; Nakamura, Norio*; Furuya, Takaaki*
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no abstracts in English
Sakanaka, Shogo*; Kobayashi, Yukinori*; Hajima, Ryoichi; Nakamura, Norio*
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A collaborative effort towards a future ERL light source is carried out by JAEA, KEK and ISSP. We present recent results of the ERL project, which includes development of ERL components and design studies of a compact ERL.
