Analysis of J-HBC stripper foil for the J-PARC RCS

Yoshimoto, Masahiro; Nakanoya, Takamitsu; Yamazaki, Yoshio; Saha, P. K.; Kinsho, Michikazu; Yamamoto, Shunya*; Okazaki, Hiroyuki*; Taguchi, Tomitsugu*; Yamada, Naoto*; Yamagata, Ryohei*

JPS Conference Proceedings (Internet), 33, p.011019_1 - 011019_7, 2021/03

BB2019-1209.pdf:0.86MB

https://doi.org/10.7566/JPSCP.33.011019

The multi-turn charge-exchange H beam injection scheme with stripper foils is one of the key techniques to achieve a MW-class high power proton beam. The J-PARC RCS adopts Hybrid type Boron-doped Carbon (HBC) stripper foil, which was developed in KEK to improve the lifetime. Indeed, the RCS user operation confirmed that HBC foil has the great advantage of a longer lifetime against high beam irradiation. To examine characteristics of the HBC foils, various beam studies were performed, such as the stripping efficiency measurement and long-term observation with an H beam in the J-PARC RCS, foil analysis using RBS, EDR and PIXE methods, and SEM and TEM observation after the ion beam irradiation in Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) on National Institutes for Quantum and Radiological Science and Technology (QST). Recently, the deposition apparatus for the HBC foils from the KEK Tsukuba-site was relocated to the JAEA Tokai-site, and we started fabrication of new HBC foil in 2017. (The new one fabricated in JAEA we call J-HBC foil.) And, we continue investigations in TIARA with the J-HBC foils. Furthermore, in-depth researches by changing the process parameters of the foil deposition are carried on. Recent results suggest that the amount of the boron doped in the foil is more important parameter than the ratio of the discharge amount of carbon from cathode and anode electrodes. In this presentation, we will report the details of recent analysis of the J-HBC foil.

Metamagnetic transition of itinerant ferromagnet UP under high pressure

Araki, Shingo*; Hayashida, Minami*; Nishiumi, Naoto*; Manabe, Hiroki*; Ikeda, Yoichi*; Kobayashi, Tatsuo*; Murata, Keizo*; Inada, Yoshihiko*; Winiewski, P.*; Aoki, Dai*; et al.

JPS Conference Proceedings (Internet), 3, p.011081_1 - 011081_6, 2014/06

https://doi.org/10.7566/JPSCP.3.011081

Magnetic and superconducting properties of CeRhGe and CePtSi

Hirose, Yusuke*; Nishimura, Naoto*; Honda, Fuminori*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; Kindo, Koichi*; Takeuchi, Tetsuya*; Yamamoto, Etsuji; Haga, Yoshinori; Matsuura, Masato*; et al.

Journal of the Physical Society of Japan, 80(2), p.024711_1 - 024711_12, 2011/02

https://doi.org/10.1143/JPSJ.80.024711

Highly polarized electrons from GaAs-GaAsP and InGaAs-AlGaAs strained-layer superlattice photocathodes

Nishitani, Tomohiro; Nakanishi, Tsutomu*; Yamamoto, Masahiro*; Okumi, Shoji*; Furuta, Fumio*; Miyamoto, Masaharu*; Kuwahara, Makoto*; Yamamoto, Naoto*; Naniwa, Kenichi*; Watanabe, Osamu*; et al.

Journal of Applied Physics, 97(9), p.094907_1 - 094907_6, 2005/05

https://doi.org/10.1063/1.1886888

no abstracts in English

Visualization and distribution analysis of boron for boron neutron capture therapy with accelerator-based neutron source

Nakai, Kei*; Yamamoto, Yohei*; Yamamoto, Tetsuya*; Yoshida, Fumiyo*; Matsumura, Akira*; Koka, Masashi; Yamada, Naoto; Kitamura, Akane; Sato, Takahiro; Yokoyama, Akihito; et al.

no journal, , 

no abstracts in English

Experimental evidences of light's orbital angular momentum carried by helical undulator harmonics

Sasaki, Shigemi*; Miyamoto, Atsushi*; Hosaka, Masahito*; Yamamoto, Naoto*; Kyo, Ayataro*; Kato, Masahiro*; Imazono, Takashi; Koike, Masato

no journal, , 

The phenomenon of higher harmonic radiation from a helical undulator carrying orbital angular momentum (OAM) attracts a great deal of attention because this novel property may be used as a new probe for synchrotron radiation science that would be performed in diffraction limited light source facilities. Although a diffraction limited VUV and X-ray sources do not yet exist, the 750 MeV UVSOR-III is already a diffraction limited light source in the UV region. In this ring, a tandem-aligned double-APPLE undulator system is installed. Using this set-up, we observed spiral interference patterns between two different harmonic radiations with a scanning fiber multi-channel spectrometer and a CCD camera placed at the end of BL1U beamline. By these measurements, various interference patterns such as single, double, and triple spirals were observed which concur with the theoretical prediction for every mode in the right or left circular polarization.

Discussion for thirty years of accelerator development

Harada, Hiroyuki; Yamamoto, Naoto*

no journal, , 

Young scientists must discuss the future of science and technology because they play next generation of science and technology. In Japan, this year twenty-nineteen is the milestone year exchanged from "Heisei"to "Reiwa". At the milestone year, we look back on requirement from academia and society to accelerator, technical innovation and development of accelerator during the last three decades in "Heisei". Additionally, we discuss with young scientists and students how technical innovation, how development of accelerator, and how contribution to society during the next three decades in "Reiwa". Especially, we deeply discuss high-intensity proton accelerator and synchrotron radiation source.