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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
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
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
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.
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.
Umemori, Kensei*; Enami, Kazuhiro*; Furuya, Takaaki*; Michizono, Shinichiro*; Miura, Takako*; Qiu, F.*; Sakai, Hiroshi*; Sato, Masato*; Shinoe, Kenji*; Sawamura, Masaru; et al.
Proceedings of 5th International Particle Accelerator Conference (IPAC '14) (Internet), p.2537 - 2539, 2014/07
We developed ERL main linac cryomodule for Compact ERL (cERL) project, which was constructed in KEK. The module includes two 9-cell L-band superconducting cavities. After construction of cERL recirculation loop, beam operation was started. First electron beam successfully passed the main linac cavities. After adjusting beam optics, energy recovery operation was achieved. Main linac cavity was enough stable for ERL beam operation, however, field emission was a problem for long term operation.
Shinoe, Kenji*; Sakai, Hiroshi*; Umemori, Kensei*; Enami, Kazuhiro*; Sato, Masato*; Furuya, Takaaki*; Sawamura, Masaru; Cenni, E.*
Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.950 - 952, 2014/06
no abstracts in English
Enami, Kazuhiro*; Furuya, Takaaki*; Sakai, Hiroshi*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru; Cenni, E.*
Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.602 - 604, 2014/06
no abstracts in English
Sakai, Hiroshi*; Umemori, Kensei*; Enami, Kazuhiro*; Sato, Masato*; Shinoe, Kenji*; Furuya, Takaaki*; Sawamura, Masaru; Cenni, E.*
Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.212 - 216, 2014/06
no abstracts in English
Sato, Masato*; Umemori, Kensei*; Enami, Kazuhiro*; Sakai, Hiroshi*; Shinoe, Kenji*; Furuya, Takaaki*; Sawamura, Masaru; Cenni, E.*
Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.973 - 976, 2014/06
no abstracts in English
Sakai, Hiroshi*; Aoto, Tomohiro*; Enami, Kazuhiro*; Furuya, Takaaki*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru; Cenni, E.*; Hayashi, Kyohei*; et al.
Proceedings of 16th International Conference on RF Superconductivity (SRF 2013) (Internet), p.291 - 296, 2014/02
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 by using white light interferometer. This monitor is based on the measurement of the interference of light between the measurement target and the reference point. It can measure the position from the outside of the cryomodule. 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.
Cenni, E.*; Enami, Kazuhiro*; Furuya, Takaaki*; Sakai, Hiroshi*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru
Proceedings of 16th International Conference on RF Superconductivity (SRF 2013) (Internet), p.678 - 682, 2014/02
A compact Energy Recovery Linac (cERL) is under construction at KEK in order to test the performance of the key components required for the future ERL project. The main linac L-band cavities were assembled and tested in the cryomodule under high power operation. During the test, information concerning field emission were gathered by means of PIN diodes rings and NaI scintillator located at the cavities ends. The data were analyzed by means of simulations.
Sakai, Hiroshi*; Enami, Kazuhiro*; Furuya, Takaaki*; Sato, Masato*; Shinoe, Kenji*; Umemori, Kensei*; Sawamura, Masaru; Cenni, E.*
Proceedings of 16th International Conference on RF Superconductivity (SRF 2013) (Internet), p.855 - 859, 2014/02
A main linac cryomodule have been constructed for Compact ERL project. It contains two 9-cell cavities, mounted with HOM absorbers and input couplers. After cavity string assembly, they were installed into the vacuum vessel of the cryomodule. It was placed inside radiation shield of cERL and connected to a refrigerator system. The cryomodule was successfully cooled down to 2K and low power and high power measurements were carried out.
Umemori, Kensei*; Enami, Kazuhiro*; Furuya, Takaaki*; Sakai, Hiroshi*; Sato, Masato*; Shinoe, Kenji*; Sawamura, Masaru; Cenni, E.*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.2349 - 2351, 2013/05
A main linac cryomodule have been constructed for Compact ERL project. It contains two 9-cell cavities, mounted with HOM absorbers and input couplers. After cavity string assembly, they were installed into the vacuum vessel of the cryomodule. It was placed inside radiation shield of cERL and connected to a refrigerator system. The cryomodule was successfully cooled down to 2 K and low power and high power measurements were carried out.
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.
Umemori, Kensei*; Furuya, Takaaki*; Sakai, Hiroshi*; Sato, Masato*; Shinoe, Kenji*; Sawamura, Masaru; Cenni, E.*
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.2227 - 2229, 2012/07
The Compact ERL project, which is a test facility of ERL, is ongoing in Japan. At the first step of this project, main linac cavities accelerate electron beams by 30 MV. Two 9-cell cavities were fabricated for main linac cryomodule. A series of surface treatments were applied for the cavities. For the final EP, current density was selected to be relatively low. Vertical tests were performed for both cavities. Their field successfully reached to 25 MV/m, without any field limitation. The Q-values were more than 110
, even at 20 MV/m. Field emission on-sets were to be 14 and 22 MV/m, for each cavity. Both cavities satisfied requirements for ERL main linac cavity. Details of vertical tests, with X-ray and temperature mapping data, are shown, in this paper.
Cenni, E.*; Furuya, Takaaki*; Sakai, Hiroshi*; Umemori, Kensei*; Shinoe, Kenji*; Sato, Masato*; Sawamura, Masaru
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.295 - 297, 2012/07
In order to develop the energy recovery linac at KEK, we are studying the performance of L-band superconducting cavities by means of vertical tests. One of the limiting factor for the cavities performance is power losses due to field emitted electrons. With regard to this phenomena a particle tracking code is used to study electron trajectories and deposited energy on the inner surface of the cavity. Different emitters location were tested within a range of accelerating field and phases in order to reproduce different scenario. The final goal of this study is to locate the sources of the electrons inside the cavity through a deeper understanding of the phenomena. To validate the results from the simulation the outcome data are compared with other particle tracking codes.
Umemori, Kensei*; Enami, Kazuhiro*; Furuya, Takaaki*; Sakai, Hiroshi*; Sato, Masato*; Shinoe, Kenji*; Sawamura, Masaru; Cenni, E.*
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.67 - 69, 2012/07
The Compact ERL, which is a test facility of ERL, is under construction in Japan. For the main linac, one cryomodule, containing two 9-cell superconducting cavities, is under development. Thermal design and cavity alignment have been also carefully considered. Two 9-cell cavities were already fabricated and their performances were confirmed by vertical tests. Their accelerating field reached to 25 MV/m, without field limits. Two input couplers, three HOM absorbers and two Slide-Jack tuners are also under fabrication for the cryomodule. High power processing will be applied for input couplers, at a test stand using a 300 kW klystron. Cooling tolerance and HOM damping abilities were tested for HOM absorbers. Some performance studies were also applied for the tuner at room temperature condition. Cryomodule assembly is planned on this summer. After cooling tests and high power tests will be carried out, ERL beam operation will be started.