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Yamada, Ippei; Chimura, Motoki; Kamiya, Junichiro; Kinsho, Michikazu
Journal of Physics; Conference Series, 2687, p.072018_1 - 072018_6, 2024/01
no abstracts in English
Meigo, Shinichiro; Nakano, Keita; Okubo, Nariaki; Yuyama, Takahiro*; Ishii, Yasuyuki*
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.296 - 301, 2021/10
no abstracts in English
Yamada, Ippei; Wada, Motoi*; Moriya, Katsuhiro; Kamiya, Junichiro; Saha, P. K.; Kinsho, Michikazu
Physical Review Accelerators and Beams (Internet), 24(4), p.042801_1 - 042801_13, 2021/04
Times Cited Count：3 Percentile：45.55(Physics, Nuclear)A transverse beam profile monitor that visualizes a two-dimensional beam-induced fluorescent image was developed. The monitor employs a sheet-shaped gas flow formed by a technique of rarefied gas dynamics. A simplified analysis method was developed to reconstruct the beam intensity profile from the obtained image. The developed profile monitor and the analysis method were applied to measure the J-PARC 3 MeV H
beam profile. The root mean square values of the profiles were consistent with the ones obtained by a wire-scanning-type beam profile monitor. The beam loss due to the gas sheet injection was measured as a beam-current reduction. The amount of the beam current decreased in proportion to the gas sheet flux and the reduction ranged from 0.004 to 2.5%. The assembled system was capable of reconstructing a beam profile from a single shot beam pulse (1.7
10
protons in 50 
s).
Meigo, Shinichiro; Takei, Hayanori; Matsuda, Hiroki; Yuri, Yosuke*; Yuyama, Takahiro*
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.515 - 519, 2019/07
no abstracts in English
Meigo, Shinichiro; Takei, Hayanori; Matsuda, Hiroki; Yuri, Yosuke*; Yuyama, Takahiro*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1035 - 1039, 2018/08
no abstracts in English
Miyao, Tomoaki*; Miura, Akihiko
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1031 - 1034, 2018/08
no abstracts in English
Meigo, Shinichiro
Proceedings of 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2018) (Internet), p.99 - 103, 2018/07
As the increase of beam power, beam instruments play an essential role in the Hadron accelerator facility. In J-PARC, the pitting erosion on the mercury target vessel for the spallation neutron source is one of a pivotal issue to operate with the high power of the beam operation. Since the erosion is proportional to the 4th power of the beam current density, the minimization of the peak current density is required. To achieve low current density, the beam-flattening system by nonlinear beam optics in J-PARC, by which the peak density was successfully reduced by 30% than the density with the conventional case optics. Since the ADS requires a very powerful accelerator with the beam power such as 30 MW, a robust beam profile monitor is required, especially for the observation of the beam status on the target continuously. A candidate material for the beam monitor was developed by using heavy-ion of Ar beam to give the damage efficiently.
Miura, Akihiko; Moriya, Katsuhiro; Miyao, Tomoaki*
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.5022 - 5025, 2018/06
A wire-scanner monitor using metallic wire is reliably employed for the beam-profile measurement in the J-PARC linac. Because the loading of negative hydrogen (H
) ion beam on a wire increases under high-current beam operation, we focus on using a high-durability beam profile monitors by attaching another wire material. Carbon nanotubes (CNT) are made of graphite in a cylindrical shape and have a tensile strength not less than 100 times that of steel. The electric conductivity has higher than that of metals, and hardness is endured thermally around 3000
C in a vacuum circumstance. We applied the wires made from CNT to WSM and measured transverse profiles with a 3-MeV H beam. As a result, we obtained the equivalent signal levels taken by carbon wire made of polyacrylonitrile without any damage. In this paper, the signal response when the CNT is irradiated with an H beam and the result of beam profile measurement. In addition, the surface of CNT after 3-MeV beam operation was observed.
Miura, Akihiko; Kawane, Yusuke*; Moriya, Katsuhiro; Futatsukawa, Kenta*; Miyao, Tomoaki*; Fukuoka, Shota*
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.2183 - 2186, 2018/06
In order to mitigate the beam loss during a beam transportation in the high-brilliant accelerator facilities, wire-based profile monitors are used to measure by both transverse and longitudinal beam profiles using wire-scanner monitors and bunch-shape monitors for the tuning of quadrupole magnets and buncher cavities. Signals are generated due to the direct interaction between a metallic wire and beam. We have used the tungsten wire as a high melting-point material by estimation of heat loading during the impact of beam particles. In addition, a spring is applied for the relaxing a flexure under wire's own weight. A tensile fracture test is conducted by supplying an electrical current as a simulated beam loading. As the results, we obtained the relation between the thermal limit to fracture and tension loading of tungsten wire.
Meigo, Shinichiro; Matsuda, Hiroki; Takei, Hayanori
Proceedings of 6th International Beam Instrumentation Conference (IBIC 2017) (Internet), p.373 - 376, 2018/03
no abstracts in English
Miura, Akihiko; Fukuoka, Shota*; Miyao, Tomoaki*; Kawane, Yusuke*; Futatsukawa, Kenta*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.560 - 562, 2017/12
no abstracts in English
Miyao, Tomoaki*; Miura, Akihiko
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.572 - 576, 2017/12
no abstracts in English
Miura, Akihiko; Okabe, Kota; Yoshimoto, Masahiro; Yamane, Isao*
Proceedings of 5th International Beam Instrumentation Conference (IBIC 2016) (Internet), p.856 - 859, 2017/03
no abstracts in English
Harada, Hiroyuki; Kato, Shinichi*
JPS Conference Proceedings (Internet), 8, p.012011_1 - 012011_6, 2015/09
The residual gas Ionization Profile Monitor (IPM) is developed in the J-PARC 3-GeV RCS. The IPM is a non-destructive beam profile monitor to observe a circulating transverse beam profile in the ring. It is very important to observe the beam profile turn-by-turn in the ring for identification of the beam loss and emittance growth source because the beam power of accelerator is limited by the beam loss from the view point of radio activation at these accelerator devices. The detail IPM system are introduced and latest results in beam commissioning will be reported in this presentation.
Nakajima, Yoshinori; Saito, Yuichi; Tajima, Satoshi
Dai-12-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.109 - 112, 1999/00
no abstracts in English
Nakashima, Hiroshi; Takada, Hiroshi; Meigo, Shinichiro; Kasugai, Yoshimi; Ikeda, Yujiro; Oyama, Yukio; Watanabe, Noboru*;
Proc. of 14th Meeting of the Int. Collaboration on Advanced Neutron Sources (ICANS-14), 1, p.457 - 467, 1998/11
no abstracts in English
Kaneko, Junichi; Katagiri, Masaki; Ikeda, Yujiro; Ara, Katsuyuki; Iguchi, Tetsuo*; Nakazawa, Masaharu*
KEK-Proceedings 96-4, 0, p.259 - 263, 1996/07
no abstracts in English
Okumura, Susumu; Fukuda, Mitsuhiro; Yokota, Wataru; Nakamura, Yoshiteru; Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Arakawa, Kazuo
Proc. of the 4th European Particle Accelerator Conf. Vol. 2; EPAC94, 0, p.1518 - 1520, 1994/00
no abstracts in English
Kato, Shinichi; Harada, Hiroyuki; Hatakeyama, Shuichiro; Kinsho, Michikazu
no journal, ,
In the J-PARC RCS, the multi-turn charge-exchange injection scheme is adopted. In addition, the painting injection method which arranges the injection beam on the wide phase-space area during the multi-turn injection has been performed to expand the circulating beam. This method is essential to mitigate the beam loss caused by the particles scattered at the charge-exchange foil and the space charge force. In the RCS, the residual gas ionization profile monitor (IPM) which is nondestructive 1D transverse profile monitor is adopted for the observation and optimization of the painting scheme. The IPM mainly consists of the divided electrodes generating the external electric field and the detection unit. For the profile measurement, the residual gas ionized by the beam is transported to the detection unit by the external transverse electric field and amplified by the Multi-Channel Plate (MCP) as the electron. After that, these electrons are detected and the 1D distribution is reconstructed. However, the distribution cannot be measured during painting injection because the noise increases and hides the signal. To solve this problem, we investigated the source of this noise and examined measures. To compare the simulation and the noise measurement results, we identified the cause of the noise as the electric field from the beam. Therefore, we developed additional electrode component to shield that field based on the simulation result. As a result, the noise was reduced to be 30 to 50 %. In addition, the change of 1D beam profile was observed during painting for the first time though the beam intensity was low of 7 kW.
Miura, Akihiko; Miyao, Tomoaki*
no journal, ,
no abstracts in English
