New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

https://doi.org/10.1051/epjconf/201919800003

JT-60U plasma current measurement by an optical current transformer

Arai, Takashi; Nishiyama, Tomokazu; Yagyu, Junichi; Kasai, Satoshi; Sone, Isamu*; Abe, Mitsushi*; Miya, Naoyuki

Fusion Science and Technology, 45(1), p.65 - 68, 2004/01

https://doi.org/10.13182/FST04-A428

In a nuclear fusion experiment device, a plasma discharge is to be sustained for a long time in steady state operation. In such a device an electromagnetic sensor that has a signal integrator to measure direct currents will cause a technical problem of zero point drift on signals. So, the detection device using new technology for direct current measurement, optical current transformer (optical CT), was developed. The device has an optical fiber specified for 1550nm (wavelength) was manufactured, and was applied to JT-60U experiments. A gamma ray irradiation examination was also done to the optical CT

Development of fabrication technology for ITER vacuum vessel

Nakahira, Masataka; Shibanuma, Kiyoshi; Kajiura, Soji*; Shibui, Masanao*; Koizumi, Koichi; Takeda, Nobukazu; Kakudate, Satoshi; Taguchi, Ko*; Oka, Kiyoshi; Obara, Kenjiro; et al.

JAERI-Tech 2002-029, 27 Pages, 2002/03

JAERI-Tech-2002-029.pdf:2.04MB

The ITER vacuum vessel (VV) R&D has progressed with the international collaborative efforts by the Japan, Russia and US Parties during the Engineering Design Activities (EDA). Fabrication and testing of a full-scale VV sector model and a port extension have yielded critical information on the fabrication and assembly technologies of the vacuum vessel, magnitude of welding distortions, dimensional accuracy and achievable tolerances during sector fabrication and field assembly. In particular, the dimensional tolerances of 3 mm for VV sector fabrication and 10 mm for VV sector field assembly have been achieved and satisfied the requirements of 5 mm and 20 mm, respectively. Also, the basic feasibility of the remote welding robot has been demonstrated. This report presents detailed fabrication and assembly technologies such as welding technology applicable to the thick wall without large distortion, field joint welding technology between sectors and remote welding technology through the VV R&D project.

Demonstration of ripple reduction by ferritic steel board insertion in JFT-2M

Kawashima, Hisato; Sato, Masayasu; Tsuzuki, Kazuhiro; Miura, Yukitoshi; Isei, Nobuaki; Kimura, Haruyuki; Nakayama, Takeshi*; Abe, Mitsushi*; Darrow, D. S.*; JFT-2M Group

Nuclear Fusion, 41(3), p.257 - 263, 2001/03

https://doi.org/10.1088/0029-5515/41/3/302

no abstracts in English

A Mechanical design for ferritic steels to reduce toroidal field ripple in the JFT-2M

Nakayama, Takeshi*; Yamamoto, Masahiro; Abe, Mitsushi*; Shibata, Takatoshi; Otsuka, Michio*; Akiyama, Takashi*; Sato, K.*; Kikuchi, Kazuo; Wada, Y.*; Koike, Tsuneyuki; et al.

Proceedings of the 18th IEEE/NPSS Symposium on Fusion Engineering (SOFE '99), p.227 - 230, 1999/10

no abstracts in English

Evaluation of magnetic field due to ferromagnetic vacuum vessel in tokamak

; Abe, Mitsushi*; Tadokoro, Takahiro*; Miura, Yukitoshi; Suzuki, Norio; Sato, Masayasu; Sengoku, Seio

Purazuma, Kaku Yugo Gakkai-Shi, 74(3), p.274 - 283, 1998/03

http://ci.nii.ac.jp/naid/110003826199

no abstracts in English

Two-dimensional analysis for a scrapeoff and divertor regions with an MHD model; Conceptual design study of FY86 FER

; ; Hitoki, Shigehisa*; Fujisawa, Noboru; Sugihara, Masayoshi; Yamamoto, Shin; Mizoguchi, Tadanori*; Abe, Mitsushi*; ; ; et al.

JAERI-M 87-119, 19 Pages, 1987/08

JAERI-M-87-119.pdf:0.5MB

no abstracts in English

Effect of discrete RF spectrum on fast wave current drive; Conceptual design study of FY86 FER

; ; Sugihara, Masayoshi; Yamamoto, Shin; Mizoguchi, Tadanori*; Hitoki, Shigehisa*; Abe, Mitsushi*; ; ; ; et al.

JAERI-M 87-110, 11 Pages, 1987/08

JAERI-M-87-110.pdf:0.38MB

no abstracts in English

Plasma physics design and major specifications of candidate reactors for FER design studies; Conceptual design study of FY86 FER

Sugihara, Masayoshi; Mizoguchi, Tadanori*; Hatayama, Akiyoshi*; Shinya, K.*; Yamamoto, Shin; Abe, Mitsushi*; ; ; ; ; et al.

JAERI-M 87-108, 49 Pages, 1987/08

JAERI-M-87-108.pdf:1.42MB

no abstracts in English

Effect on temperature dependence for long-term stable control of the magnetic field at sub-ppm using superconducting magnet for MRI

Sugita, Moe; Abe, Mitsushi*; Iinuma, Hiromi*; Ogane, Chiori; Ogitsu, Toru*; Sasaki, Kenichi*; Mibe, Tsutomu*; Shimomura, Koichiro*

no journal, , 

The MuSEUM experiment at J-PARC requires a long-term stability of less than 0.2 ppm time variation of magnetic field and less than 0.2 ppm (p-p) homogeneity for the ellipsoidal region of 20 cm in diameter and 30 cm in length. The superconducting magnet used in the MuSEUM experiment takes a method of shimming to adjust homogeneity by placing iron shims. The factors changing magnetic field with temperature is considered the location shift of shims due to the thermal expansion of the shimming structures and the temperature dependence of iron magnetization. Therefore, the magnetic field was measured during heating the shimming structure, and the temperature dependence of magnetic field was confirmed. In addition, location-shift and magnetization change were calculated by simulation. Based on the measurement and simulation results, it is necessary to control the room temperature within 0.2 K to keep long-term stability in the current experimental system.