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Kinsho, Michikazu
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.3848 - 3850, 2014/07
The J-PARC RCS has been delivered more than 300 kW beam to both the MLF and the MR with high reliability. To realize simultaneously two kinds of beam shape which are required from the MLF and the MR, two pulse dipole magnets for injection painting were installed in the beam transport line from the Linac to the RCS. It was successful to make two kinds of beam shape with injection painting bump magnets and these added pulse dipole magnets. This injection painting system is used for user operation and works well for reduction of beam losses. Not only user operation but also high power beam test was performed, and beam power of 524 kW for 35 second was achieved with low beam loss in the RCS. The loss rate was about 2% and this was acceptable because design value of the beam loss was 3%. This power corresponds to 1.6 MW for 400 MeV injection in terms of the Lasslett tune shift. In this high-intensity trial, significant progress toward design output beam power of 1 MW was demonstrated.
Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Koseki, Tadashi
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.3830 - 3832, 2014/07
After nine-months of beam shutdown by the Great Earthquake in March 2011, the J-PARC facility resumed beam operation. In December 2011, operations were carried out at low duty for beam tuning. At the beginning of January 2012, we started beam tuning at the full repetition rate of 25 Hz at the linac and the 3 GeV Rapid Cycling Synchrotron (RCS). After the tuning, user programs of the Materials and Life Science Experiment Facility (MLF), the Neutrino facility and the Hadron facility started. We have gradually increased beam power for these facilities. We have also demonstrated new record power beyond 500 kW from the RCS. The status and progress of the J-PARC accelerators are presented.
Saha, P. K.; Harada, Hiroyuki; Hayashi, Naoki; Hotchi, Hideaki; Kinsho, Michikazu; Takayanagi, Tomohiro; Tani, Norio; Irie, Yoshiro*; Kato, Shinichi*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.518 - 520, 2014/07
Suganuma, Kazuaki; Togashi, Tomohito; Watanabe, Masao; Kinsho, Michikazu
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.678 - 680, 2014/07
Technical issues of the kicker magnet system in the J-PARC 3GeV RCS are presented based on the operating experience during four years. For the high voltage cables, many scratches on the polyethylene surface were observed at the edge parts, the surfaces were reinforced by a semi-conductive layer with high-dielectric materials. For all matching resisters, the values have been increased due to deterioration with age, and the counter measure is under reviewing. For Thyratron tubes, a stable operation was established, and the beam stop rate by false operation was drastically reduced from 13% to less than 0.5%.
Saha, P. K.; Shobuda, Yoshihiro; Hotchi, Hideaki; Harada, Hiroyuki; Yamamoto, Masanobu; Holmes, J. A.*; Kato, Shinichi*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.521 - 523, 2014/07
Hayashi, Naoki; Harada, Hiroyuki; Horino, Koki; Hotchi, Hideaki; Kamiya, Junichiro; Kinsho, Michikazu; Saha, P. K.; Shobuda, Yoshihiro; Takayanagi, Tomohiro; Tani, Norio; et al.
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.3833 - 3835, 2014/07
no abstracts in English
Okabe, Kota; Yoshimoto, Masahiro; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.535 - 537, 2014/07
In the J-PARC 3-GeV Rapid Cycle Synchrotron (RCS), transverse beam halo diagnostic is required to increase the output beam power. In order to provide 1 MW high power output beam for routine user program in RCS, it is required to improve the quality of the high intensity beam. The key issue to evaluate the high intensity beam quality is the suppression of the transverse beam halo. In generally, the beam halo quantity is less than 10
of the beam core. Therefore beam profile monitors for halo measurements are required very wide dynamic range, high sensitivity and resolution, and noise rejection techniques of instruments and methods. In order to determine more detail of halo formation, Vibration Wire Monitor (VWM) was under consideration by RCS monitor group. In this poster, we focus on the relevant beam halo diagnostics by new halo monitor in J-PARC L3BT. Hardware details and beam study results for the new beam halo monitor will be appeared.
Takayanagi, Tomohiro; Hayashi, Naoki; Ueno, Tomoaki; Horino, Koki; Togashi, Tomohito; Kinsho, Michikazu; Watanabe, Yasuhiro; Irie, Yoshiro*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.681 - 683, 2014/07
The power supply of the pulse steering magnet has been produced. The power supply has the equipment used to excite the pulse current and the direct-current (DC) to correspond to two modes that the painting injection for beam users and the central injection for beam commissioning. The pulse current has been performed with good accuracy whose deviation to a setting current becomes to be less than 0.2%. In case of the central injection, the power supply excites the current in DC mode, which has been realized the ripple current below 0.01%. This paper describes the design parameters and the experimental results of the power supply.
Hotchi, Hideaki; Harada, Hiroyuki; Hayashi, Naoki; Kinsho, Michikazu; Saha, P. K.; Shobuda, Yoshihiro; Tamura, Fumihiko; Yamamoto, Kazami; Yamamoto, Masanobu; Yoshimoto, Masahiro; et al.
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.3836 - 3838, 2014/07
In November 2012, we have performed a high intensity beam trial of up to 540 kW. The beam loss for 540 kW intensity beam was well reduced from 30% to 2% by injection painting. This remaining beam loss of 2%, arising from foil scattering and 100-kHz field ripple induced by injection bump field, corresponds to 650 W in power, which is still less than 1/6 of the current collimator capability of 4 kW. The numerical simulation well reproduced the experimental results. Accelerator modelling and quantitative benchmarking between experiment and numerical simulation becomes feasible. The numerical simulation very much helped us to understand the mechanism of observed beam loss. Also several beam loss mitigation ideas were proposed with a help of numerical simulation and verified by experiment.
Harada, Hiroyuki; Yamamoto, Kazami; Kato, Shinichi*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.515 - 517, 2014/07
Residual gas Ionization Profile Monitors (IPMs) are used in the J-PARC 3-GeV RCS for the observation of circulating transverse beam profile. In IPM system, the ions and electrons produced by the beam passing through chamber lead to Micro Channel Plate (MCP) by the external electric field, and the signals from the MCP are observed as the beam profile. The IPM system was performed an upgrade plan for the optimization of the electric fields and the observation of beam profile by the elections. This will be reported the status of upgraded IPM.
Ogiwara, Norio; Kamiya, Junichiro; Shobuda, Yoshihiro; Kinsho, Michikazu; Koizumi, Oji*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.3321 - 3323, 2014/07
Shimada, Taihei; Nomura, Masahiro; Tamura, Fumihiko; Yamamoto, Masanobu; Hara, Keigo*; Hasegawa, Katsushi*; Omori, Chihiro*; Toda, Makoto*; Yoshii, Masahito*; Schnase, A.*; et al.
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.2750 - 2752, 2013/06
no abstracts in English
Tamura, Fumihiko; Omori, Chihiro*; Yamamoto, Masanobu; Yoshii, Masahito*; Schnase, A.*; Nomura, Masahiro; Toda, Makoto*; Shimada, Taihei; Hasegawa, Katsushi*; Hara, Keigo*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.2540 - 2542, 2013/06
Beam loading compensation is indispensable to accelerate high intensity proton beams in the J-PARC MR. The MA-loaded rf cavities in the MR are driven by the single harmonic (h = 9) rf signals, while the cavity frequency response covers also the neighbor harmonics (h = 8, 10). The wake voltage induced by the beam consists of the three harmonics (h = 8, 9, 10). We employ the rf feedforward method to compensate the beam loading of these harmonics. The full-digital feedforward system was developed for the MR. We have successfully commissioned the feedforward patterns for all of eight cavities by using high intensity beams with 1.0
10
ppp. We present the commissioning results. The impedance seen by the beam is reduced and the longitudinal oscillations due to the beam loading are reduced. By the beam loading compensation, high power beam operation at the beam power of 200 kW has been achieved.
Nomura, Masahiro; Schnase, A.*; Shimada, Taihei; Tamura, Fumihiko; Yamamoto, Masanobu; Hara, Keigo*; Hasegawa, Katsushi*; Omori, Chihiro*; Toda, Makoto*; Yoshii, Masahito*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.2747 - 2749, 2013/06
During the development of Magnetic Alloy (MA) cores for RF cavities, the core shunt impedance was increased by lowering a core winding tension to improve the electrical insulation between MA ribbon layers. The lower winding tension reduced the core filling factor. The core shunt impedance might be reduced according to the core filling factor reduction. We study the influence of improving the electrical insulation and lowering the core winding tension on the core shunt impedance.
Watanabe, Yasuhiro; Tani, Norio
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.672 - 674, 2013/06
no abstracts in English
Tani, Norio; Hotchi, Hideaki; Kamiya, Junichiro; Kinsho, Michikazu; Takeda, Osamu; Yamamoto, Masanobu
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.2971 - 2973, 2013/06
Misalignment of several millimeters of the magnets of J-PARC 3GeV RCS in both horizontal and vertical directions was caused by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. As the result of orbit calculation showed that the beam loss was acceptable for beam operation at 300 kW, beam operation with the current placement has been implemented. Realignment of the equipment will be carried out from August to December in 2013. As the survey carried out in the summer of 2012 found out misalignment of vacuum ducts, their positioning is necessary. In this paper these measurement result and latest alignment plan for J-PARC 3GeV RCS are reported.
-rays from a 150-MeV microtronHajima, Ryoichi; Hayakawa, Takehito; Shizuma, Toshiyuki; Angell, C.; Daito, Izuru; Kando, Masaki; Ogaki, Hideaki*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.3645 - 3647, 2013/05
Shobuda, Yoshihiro; Hayashi, Naoki; Takayanagi, Tomohiro; Toyama, Takeshi*; Irie, Yoshiro*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.1742 - 1744, 2013/05
Nishimori, Nobuyuki; Nagai, Ryoji; Matsuba, Shunya; Hajima, Ryoichi; Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Iijima, Hokuto*; Kuriki, Masao*; Kuwahara, Makoto*
Proceedings of 4th International Particle Accelerator Conference (IPAC '13) (Internet), p.321 - 323, 2013/05
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.
