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Ogiwara, Norio; Hikichi, Yusuke; Namekawa, Yuya; Kamiya, Junichiro; Kinsho, Michikazu; Hatanaka, Kichiji*; Shima, Tatsushi*; Fukuda, Mitsuhiro*
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.2102 - 2104, 2016/06
beam in low energy beam transport test standArtikova, S.; Takagi, Akira*; Shibata, Takanori*; Ikegami, Kiyoshi*
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.677 - 679, 2016/06
Otani, Masashi*; Naito, Fujio*; Mibe, Tsutomu*; Yoshida, Mitsuhiro*; Hasegawa, Kazuo; Ito, Takashi; Kondo, Yasuhiro; Hayashizaki, Noriyosu*; Iwashita, Yoshihisa*; Iwata, Yoshiyuki*; et al.
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.1543 - 1546, 2016/06
We are developing a linac dedicated to the muon acceleration. It enables us to measure the muon anomalous magnetic moment with an accuracy of 0.1 ppm and search for electric dipole moment with a sensitivity of 10-21e cm to explore beyond Standard Model of elementary particle physics. As a first step for demonstration of the muon acceleration, we are developing the source of slow muon with which RFQ acceleration is conducted. This paper described status of these developments.
Otani, Masashi*; Mibe, Tsutomu*; Yoshida, Mitsuhiro*; Hasegawa, Kazuo; Kondo, Yasuhiro; Hayashizaki, Noriyosu*; Iwashita, Yoshihisa*; Iwata, Yoshiyuki*; Kitamura, Ryo*; Saito, Naohito
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.1539 - 1542, 2016/06
We have developed an interdigital H-mode (IH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The IH-DTL accelerates muons from beta 0.08 to 0.28 at an operational frequency of 324 MHz. The output beam emittances are calculated as 0.315 
and 0.195 mm mrad in the horizontal and vertical directions, respectively, which satisfies the experimental requirement.
Kondo, Yasuhiro; Hasegawa, Kazuo; Higashi, Yasuo*; Sugawara, Hirotaka*; Yoshioka, Masakazu*; Kumada, Hiroaki*; Matsumoto, Hiroshi*; Naito, Fujio*; Kurokawa, Shinichi*
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.906 - 909, 2016/06
An accelerator based boron neutron capture therapy (BNCT) facility is being planned at Okinawa institute of science and technology (OIST). The proton accelerator consists of a radio frequency quadrupole (RFQ) linac and a drift tube linac (DTL). The required beam power is 60 kW. The present beam energy and current are 10 MeV and 30 mA, respectively. The pulse length is 3.3 ms and the repetition rate is 60 Hz, therefore, the duty factor is 20%. In this paper, present design of this compact, medium current, high duty proton linac is presented.
Kinsho, Michikazu
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.999 - 1003, 2016/06
The linac energy reached to 400 MeV as a design value and also a beam current was upgraded to 50 mA by replacing a new ion source. At the 3 GeV synchrotron, a high power beam of 8.41
10
protons per pulse was demonstrated, which was equivalent to 1 MW when the repetition would be 25 Hz. At the main ring, beam loss was reduced by suppression of transverse instabilities and so on. The beam power for both the neutrino experiment and hadron experimental facility is increasing to reduce beam loss. J-PARC accelerators each have their own upgrade plan to increase beam power. The progress and future plan of J-PARC accelerators are reported in this paper.
Hotchi, Hideaki; Harada, Hiroyuki; Kato, Shinichi; Kinsho, Michikazu; Okabe, Kota; Saha, P. K.; Shobuda, Yoshihiro; Tamura, Fumihiko; Tani, Norio; Watanabe, Yasuhiro; et al.
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.592 - 594, 2016/06
The J-PARC 3-GeV RCS achieved a 1-MW beam acceleration in January 2015. Since then, a large fraction of our effort has been focused on reducing and managing beam losses. Major part of beam loss, such as space-charge induced beam loss, was well minimized by introducing injection painting. Uncontrolled beam loss arising from large-angle foil scattering during charge-exchange injection was also reduced drastically by the expansion of the transverse painting area, which was achieved by introducing quadrupole correctors and anti-correlated painting. By such recent efforts, the 1-MW beam operation is now estimated to be established within a permissible beam loss level. This paper presents the recent progress of 1-MW beam tuning, especially focusing on our approaches to beam loss issues.
Saha, P. K.; Shobuda, Yoshihiro; Hotchi, Hideaki; Harada, Hiroyuki; Hayashi, Naoki; Kinsho, Michikazu; Nomura, Masahiro; Tamura, Fumihiko; Tani, Norio; Watanabe, Yasuhiro; et al.
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.589 - 591, 2016/06
Kamiya, Junichiro; Saha, P. K.; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.2380 - 2382, 2016/06
The amount of the heat generation in the beam dump for unstripped H beam at an injection in a high power beam synchrotron becomes a few thousand watts. In such case, the temperature of the dump materials might reach unacceptable values from the aspect of the mechanical strength decrease. The thermal analysis for the injection beam dump at J-PARC 3GeV synchrotron was performed in order to evaluate the upper limit of the beam power into the dump. The temperature distribution of beam dump was calculated by modelling the detail configuration and enough large region. The upper limit of the beam power into the dump, which keep the concrete temperature below permissible value, was estimated to be about 3 kW. The comparison with the measured temperature shows the thermal resistance between the contacted materials should be considered for more accurate calculation.
Yamamoto, Masanobu; Nomura, Masahiro; Shimada, Taihei; Tamura, Fumihiko; Hara, Keigo*; Hasegawa, Katsushi*; Omori, Chihiro*; Toda, Makoto*; Yoshii, Masahito*
Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.3443 - 3445, 2016/06
The J-PARC RCS accelerates 2 bunches at the harmonic number 2. The major Fourier component of the beam current is even harmonics. However, the odd harmonics grow under some conditions even though they are very small amplitude at the beginning. Particle tracking simulation suggests that the displacement and the deformation of the bunch are caused by the odd harmonics, it is synchronized with the potential distortion, and it results in the beam instability. We describe the particle tracking simulation results for the odd harmonic beam loading effect in the RCS.
