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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)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.
Shimada, Miho*; Hajima, Ryoichi
Physical Review Special Topics; Accelerators and Beams, 13(10), p.100701_1 - 100701_5, 2010/10
Times Cited Count:10 Percentile:56.82(Physics, Nuclear)We propose inverse Compton scattering (ICS) of coherent synchrotron radiation (CSR) from arelativistic short electron bunch in energy recovery linacs (ERL) as a high-flux subpicosecond X-ray and -ray source. An advantage of the CSR scheme over a conventional ICS source is that no externallaser is required, and synchronization between CSR pulses and electron bunches is obtained automatically. Moreover, higher-flux X-rays can be generated from the ICS of CSR in an ERL operated at a highrepetition rate, 100 MHz to 1.3 GHz. Using parameters of the Compact ERL at KEK, 110 phs/sb.w. 10% X-ray with a 100 fs-1 ps pulse duration can beobtained, for an energy range from 0.04 to 4 keV. In the case of a 5-GeV ERL, rays with energy aroundtens of MeV are generated with 110 phs/pulse b.w. 10% at a repetition rate of several hundredsof MHz.
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.
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.
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.
Harada, Kentaro*; Shimada, Miho*; Hajima, Ryoichi
Infrared Physics & Technology, 51(5), p.386 - 389, 2008/05
Times Cited Count:4 Percentile:25.11(Instruments & Instrumentation)The Compact ERL is an energy recovery LINAC (ERL) test facility that is planned for KEK. The circumference of the recirculation path will be 70 m. Initially, the beam energy will be about 65 MeV and the current about 10 mA. Although the primary purpose of the machine is to aid the development of the key technologies that are essential for building an ultra-brilliant new synchrotron light source based on an ERL, the Compact ERL itself has great potential as an intense source of terahertz radiation. To generate the intense terahertz radiation, an electron bunch of a very short bunch length is required and bunch compression is inevitable. We discuss the parameters of the Compact ERL, present the results of a simulation of bunch compression, and make an estimate of the generated coherent synchrotron radiation.
Shimada, Miho*; Hajima, Ryoichi
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Hajima, Ryoichi; Shiraga, Takashi*; Nakamura, Norio*; Harada, Kentaro*; Shimada, Miho*; Sakanaka, Shogo*; Kobayashi, Yukinori*
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Hajima, Ryoichi; Miyajima, Tsukasa*; Kobayashi, Yukinori*; Sakanaka, Shogo*; Shimada, Miho*
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Hajima, Ryoichi; Shiraga, Takashi*; Harada, Kentaro*; Shimada, Miho*; Sakanaka, Shogo*; Kobayashi, Yukinori*; Nakamura, Norio*
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Hajima, Ryoichi; Nakamura, Norio*; Shimada, Miho*
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Energy-recovery linac (ERL) is a novel type of accelerator to generate an electron beam of high quality and high average current. In an ERL, an electron beam from an injector is accelerated by time-varying RF field stored in a superconducting linac and the beam is transported to a recirculation loop. After the recirculation loop, the beam is decelerated by the same superconducting linac for the energy recovery. In this talk, challenges for the generation of ultrashort electron bunches in ERLs are discussed, and applications of ultrashort electron bunches from ERLs are presented.