1
|
Ogawa K, Isobe M, Nishitani T, Kobuchi T. The large helical device vertical neutron camera operating in the MHz counting rate range. Rev Sci Instrum 2018; 89:113509. [PMID: 30501311 DOI: 10.1063/1.5054818] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
In the currently performed neutral beam (NB) -heated deuterium plasma experiments, neutrons are mainly produced by a beam-plasma reaction. Therefore, time-resolved measurement of the neutron emission profile can enhance the understanding of the classical and/or anomalous transport of beam ions. To measure radial neutron emission profiles as a function of time, the vertical neutron camera (VNC) capable of operation with a counting rate in the MHz range was newly installed on the Large Helical Device (LHD). This is the world's first neutron camera for stellarator/heliotron devices. The VNC consists of a multichannel collimator, eleven fast-neutron detectors, and the digital-signal-processing-based data acquisition system (DAQ). The multichannel collimator having little cross talk was made from hematite-doped heavy concrete, which has a high shielding performance against both neutrons and gamma-rays. A stilbene crystal coupled with a photomultiplier having high-gain-stability in the high-count rate regime was utilized as a fast-neutron scintillation detector because it has a high neutron-gamma discrimination capability at high count rates. The DAQ system equipped with a field programmable logic controller was developed to obtain the waveform acquired with a 1 GHz sampling rate and the shaping parameter of each pulse simultaneously at up to 106 cps (counts per second). Neutron emission profiles were successfully obtained in the first deuterium campaign of LHD in 2017. The neutron emission profile was measured in tangentially co-injected NB-heated plasma with different magnetic axes (R ax). The neutron counts became larger in the inward-shifted configuration, which was consistent with the total neutron rate measured by the neutron flux monitor. The radial peak position of the line-integrated neutron profile which changed according to R ax showed that the VNC worked successfully as designed. The VNC demonstrated the expected performance conducive to extending energetic-particle physics studies in LHD.
Collapse
Affiliation(s)
- K Ogawa
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
| | - M Isobe
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
| | - T Nishitani
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
| | - T Kobuchi
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Japan
| |
Collapse
|
2
|
Komori A, Morisaki T, Mutoh T, Sakakibara S, Takeiri Y, Kumazawa R, Kubo S, Ida K, Morita S, Narihara K, Shimozuma T, Tanaka K, Watanabe KY, Yamada H, Yoshinuma M, Akiyama T, Ashikawa N, Emoto M, Funaba H, Goto M, Ido T, Ikeda K, Inagaki S, Isobe M, Igami H, Itoh K, Kaneko O, Kawahata K, Kobuchi T, Masuzaki S, Matsuoka K, Minami T, Miyazawa J, Muto S, Nagayama Y, Nakamura Y, Nakanishi H, Narushima Y, Nishimura K, Nishiura M, Nishizawa A, Noda N, Ohdachi S, Oka Y, Osakabe M, Ohyabu N, Ozaki T, Peterson BJ, Sagara A, Saito K, Sakamoto R, Sato K, Sato M, Seki T, Shoji M, Sudo S, Tamura N, Toi K, Tokuzawa T, Tsumori K, Uda T, Watari T, Yamada I, Yokoyama M, Yoshimura Y, Motojima O, Beidler CD, Fujita T, Isayama A, Sakamoto Y, Takenaga H, Goncharov P, Ishii K, Sakamoto M, Murakami S, Notake T, Takeuchi N, Okajima S, Sasao M. Overview of Progress in LHD Experiments. Fusion Science and Technology 2017. [DOI: 10.13182/fst06-a1229] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- A. Komori
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Morisaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Mutoh
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Sakakibara
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - Y. Takeiri
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - R. Kumazawa
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Kubo
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Ida
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Morita
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Narihara
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Shimozuma
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Tanaka
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Y. Watanabe
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Yoshinuma
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Akiyama
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - N. Ashikawa
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Emoto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Funaba
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Goto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Ido
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Ikeda
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Inagaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Isobe
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Igami
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Itoh
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - O. Kaneko
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Kawahata
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Kobuchi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Masuzaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Matsuoka
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Minami
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - J. Miyazawa
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Muto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - Y. Nagayama
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - Y. Nakamura
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Nakanishi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - Y. Narushima
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Nishimura
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Nishiura
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - A. Nishizawa
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - N. Noda
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Ohdachi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - Y. Oka
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Osakabe
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - N. Ohyabu
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Ozaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - B. J. Peterson
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - A. Sagara
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Saito
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Sato
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Sato
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Seki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Shoji
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Sudo
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - N. Tamura
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Toi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Tokuzawa
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Tsumori
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Uda
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Watari
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - I. Yamada
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Yokoyama
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - Y. Yoshimura
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - O. Motojima
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - C. D. Beidler
- Max-Planck Institut fuer Plasmaphysik, Greifswald D-17491, Germany
| | - T. Fujita
- Japan Atomic Energy Research Institute, Naka 311-0193, Japan
| | - A. Isayama
- Japan Atomic Energy Research Institute, Naka 311-0193, Japan
| | - Y. Sakamoto
- Japan Atomic Energy Research Institute, Naka 311-0193, Japan
| | - H. Takenaga
- Japan Atomic Energy Research Institute, Naka 311-0193, Japan
| | - P. Goncharov
- Graduate University for Advanced Studies, School of Mathematical and Physical Science Department of Fusion Science, Hayama 240-0193, Japan
| | - K. Ishii
- Kyushu University, Research Institute for Applied Mechanics Kasuga 816-8580, Japan
| | - M. Sakamoto
- Kyushu University, Research Institute for Applied Mechanics Kasuga 816-8580, Japan
| | - S. Murakami
- Kyoto University, Department of Nuclear Engineering, Kyoto 606-8501, Japan
| | - T. Notake
- Nagoya University, Department of Energy Engineering and Science Nagoya 464-8603, Japan
| | - N. Takeuchi
- Nagoya University, Department of Energy Engineering and Science Nagoya 464-8603, Japan
| | - S. Okajima
- Chubu University, Kasugai, Aichi 487-8501, Japan
| | - M. Sasao
- Tohoku University, Graduate School of Engineering, Sendai 980-8579, Japan
| | | |
Collapse
|
3
|
Ida K, Yoshinuma M, Suzuki C, Kobuchi T, Watanabe KY. Measurements of Rotational Transform with Motional Stark Effect Spectroscopy. Fusion Science and Technology 2017. [DOI: 10.13182/fst10-a10824] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- K. Ida
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Yoshinuma
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - C. Suzuki
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Kobuchi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Y. Watanabe
- National Institute for Fusion Science, Toki 509-5292, Japan
| | | |
Collapse
|
4
|
Motojima O, Yamada H, Komori A, Watanabe KY, Mutoh T, Takeiri Y, Ida K, Akiyama T, Asakura N, Ashikawa N, Chikaraishi H, Cooper WA, Emoto M, Fujita T, Fujiwara M, Funaba H, Goncharov P, Goto M, Hamada Y, Higashijima S, Hino T, Hoshino M, Ichimura M, Idei H, Ido T, Ikeda K, Imagawa S, Inagaki S, Isayama A, Isobe M, Itoh T, Itoh K, Kado S, Kalinina D, Kaneba T, Kaneko O, Kato D, Kato T, Kawahata K, Kawashima H, Kawazome H, Kobuchi T, Kondo K, Kubo S, Kumazawa R, Lyon JF, Maekawa R, Mase A, Masuzaki S, Mito T, Matsuoka K, Miura Y, Miyazawa J, More R, Morisaki T, Morita S, Murakami I, Murakami S, Mutoh S, Nagaoka K, Nagasaki K, Nagayama Y, Nakamura Y, Nakanishi H, Narihara K, Narushima Y, Nishimura H, Nishimura K, Nishiura M, Nishizawa A, Noda N, Notake T, Nozato H, Ohdachi S, Ohkubo K, Ohyabu N, Oyama N, Oka Y, Okada H, Osakabe M, Ozaki T, Peterson BJ, Sagara A, Saida T, Saito K, Sakakibara S, Sakamoto M, Sakamoto R, Sasao M, Sato K, Seki T, Shimozuma T, Shoji M, Sudo S, Takagi S, Takahashi Y, Takase Y, Takenaga H, Takeuchi N, Tamura N, Tanaka K, Tanaka M, Toi K, Takahata K, Tokuzawa T, Torii Y, Tsumori K, Watanabe F, Watanabe M, Watanabe T, Watari T, Yamada I, Yamada S, Yamaguchi T, Yamamoto S, Yamazaki K, Yanagi N, Yokoyama M, Yoshida N, Yoshimura S, Yoshimura Y, Yoshinuma M. Review on the Progress of the LHD Experiment. Fusion Science and Technology 2017. [DOI: 10.13182/fst04-a535] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- O. Motojima
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - A. Komori
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Y. Watanabe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Mutoh
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Takeiri
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Ida
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Akiyama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Asakura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Ashikawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Chikaraishi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - W. A. Cooper
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Emoto
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Fujita
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Fujiwara
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Funaba
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - P. Goncharov
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Goto
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Hamada
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Higashijima
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Hino
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Hoshino
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Ichimura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Idei
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Ido
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Ikeda
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Imagawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Inagaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - A. Isayama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Isobe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Itoh
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Itoh
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Kado
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - D. Kalinina
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Kaneba
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - O. Kaneko
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - D. Kato
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Kato
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Kawahata
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Kawashima
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Kawazome
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Kobuchi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Kondo
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Kubo
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - R. Kumazawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - J. F. Lyon
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - R. Maekawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - A. Mase
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Masuzaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Mito
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Matsuoka
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Miura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - J. Miyazawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - R. More
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Morisaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Morita
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - I. Murakami
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Murakami
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Mutoh
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Nagaoka
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Nagasaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Nagayama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Nakamura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Nakanishi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Narihara
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Narushima
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Nishimura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Nishimura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Nishiura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - A. Nishizawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Noda
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Notake
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Nozato
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Ohdachi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Ohkubo
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Ohyabu
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Oyama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Oka
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Okada
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Osakabe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Ozaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - B. J. Peterson
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - A. Sagara
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Saida
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Saito
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Sakakibara
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Sakamoto
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Sasao
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Sato
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Seki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Shimozuma
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Shoji
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Sudo
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Takagi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Takahashi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Takase
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - H. Takenaga
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Takeuchi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Tamura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Tanaka
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Tanaka
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Toi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Takahata
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Tokuzawa
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Torii
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Tsumori
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - F. Watanabe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Watanabe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Watanabe
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Watari
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - I. Yamada
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Yamada
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - T. Yamaguchi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Yamamoto
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - K. Yamazaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Yanagi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Yokoyama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - N. Yoshida
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - S. Yoshimura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - Y. Yoshimura
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| | - M. Yoshinuma
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu-ken 509-5292, Japan
| |
Collapse
|
5
|
Ogawa K, Isobe M, Takada E, Uchida Y, Ochiai K, Tomita H, Uritani A, Kobuchi T, Takeiri Y. Progress in development of the neutron profile monitor for the large helical device. Rev Sci Instrum 2014; 85:11E110. [PMID: 25430289 DOI: 10.1063/1.4890399] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The neutron profile monitor stably operated at a high-count-rate for deuterium operations in the Large Helical Device has been developed to enhance the research on the fast-ion confinement. It is composed of a multichannel collimator, scintillation-detectors, and a field programmable gate array circuit. The entire neutron detector system was tested using an accelerator-based neutron generator. This system stably acquires the pulse data without any data loss at high-count-rate conditions up to 8 × 10(5) counts per second.
Collapse
Affiliation(s)
- K Ogawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M Isobe
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - E Takada
- National Institute of Technology, Toyama College, 13 Hongo-machi, Toyama 939-8630, Japan
| | - Y Uchida
- National Institute of Technology, Toyama College, 13 Hongo-machi, Toyama 939-8630, Japan
| | - K Ochiai
- Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195, Japan
| | - H Tomita
- Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - A Uritani
- Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - T Kobuchi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - Y Takeiri
- National Institute for Fusion Science, Toki 509-5292, Japan
| |
Collapse
|
6
|
Isobe M, Ogawa K, Miyake H, Hayashi H, Kobuchi T, Nakano Y, Watanabe K, Uritani A, Misawa T, Nishitani T, Tomitaka M, Kumagai T, Mashiyama Y, Ito D, Kono S, Yamauchi M, Takeiri Y. Wide dynamic range neutron flux monitor having fast time response for the Large Helical Device. Rev Sci Instrum 2014; 85:11E114. [PMID: 25430293 DOI: 10.1063/1.4891049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A fast time response, wide dynamic range neutron flux monitor has been developed toward the LHD deuterium operation by using leading-edge signal processing technologies providing maximum counting rate up to ∼5 × 10(9) counts/s. Because a maximum total neutron emission rate over 1 × 10(16) n/s is predicted in neutral beam-heated LHD plasmas, fast response and wide dynamic range capabilities of the system are essential. Preliminary tests have demonstrated successful performance as a wide dynamic range monitor along the design.
Collapse
Affiliation(s)
- M Isobe
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K Ogawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - H Miyake
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - H Hayashi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T Kobuchi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - Y Nakano
- Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603, Japan
| | - K Watanabe
- Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603, Japan
| | - A Uritani
- Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603, Japan
| | - T Misawa
- Kyoto University Research Reactor Institute, Kumatori 590-0494, Japan
| | - T Nishitani
- Japan Atomic Energy Agency, Rokkasho 039-3212, Japan
| | - M Tomitaka
- Toshiba Corporation, Fuchu 183-8511, Japan
| | - T Kumagai
- Toshiba Corporation, Fuchu 183-8511, Japan
| | | | - D Ito
- Toshiba Corporation, Fuchu 183-8511, Japan
| | - S Kono
- Toshiba Corporation, Fuchu 183-8511, Japan
| | - M Yamauchi
- Toshiba Nuclear Engineering Services Corporation, Yokohama 235-8523, Japan
| | - Y Takeiri
- National Institute for Fusion Science, Toki 509-5292, Japan
| |
Collapse
|
7
|
Kobuchi T, Sasao M, Kisaki M, Tsumori K, Tanaka N, Okamoto A, Kitajima S, Kaneko O, Shinto K, Wada M. Extraction of a strongly focusing He+ beam from three-stage concave electrodes for alpha particle measurement system in ITER. Rev Sci Instrum 2012; 83:02B120. [PMID: 22380277 DOI: 10.1063/1.3673630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A strongly focusing He(+) ion beam source equipped with concave multi-aperture electrodes was developed for production of He(-) through a charge exchange cell. The beam was extracted at a voltage less than 20 kV from 301 apertures distributed in an area of 100 mm φ, and focused at 750 mm distance. The beam current and the beam size of 2 A and 20 mm in diameter, respectively, were achieved with an arc power less than 10 kW. The optimum perveance was obtained at 0.02 A∕kV(1.5) at the beam energy less than 20 keV which is suitable for the conversion to He(-) in an alkali vapor cell.
Collapse
Affiliation(s)
- T Kobuchi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Sasao M, Kisaki M, Kobuchi T, Tsumori K, Tanaka N, Terai K, Okamoto A, Kitajima S, Kaneko O, Shinto K, Wada M. An alpha particle measurement system using an energetic neutral helium beam in ITER (invited). Rev Sci Instrum 2012; 83:02B718. [PMID: 22380323 DOI: 10.1063/1.3673493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An energetic helium neutral beam is involved in the beam neutralization measurement system of alpha particles confined in a DT fusion plasma. A full size strong-focusing He(+) ion source (2 A, the beam radius of 11.3 mm, the beam energy less than 20 keV). Present strong-focusing He(+) ion source shows an emittance diagram separated for each beamlet of multiple apertures without phase space mixing, despite the space charge of a beamlet is asymmetric and the beam flow is non-laminar. The emittance of beamlets in the peripheral region was larger than that of center. The heat load to the plasma electrode was studied to estimate the duty factor for the ITER application.
Collapse
Affiliation(s)
- M Sasao
- Graduate school of Engineering, Tohoku University, Sendai 980-8579, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Sasao M, Kobuchi T, Kisaki M, Takahashi H, Okamoto A, Kitajima S, Kaneko O, Tsumori K, Shinto K, Wada M. Fine-structure characteristics in the emittance images of a strongly focusing He+ beam. Rev Sci Instrum 2010; 81:02B115. [PMID: 20192421 DOI: 10.1063/1.3277211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The phase space distribution of a strongly focused He(+) ion beam source equipped with concave multiaperture electrodes was measured using a pepper-pot plate and a Kapton foil. The substructure of 301 merging He beamlets was clearly observed on a footprint of pepper-pot hole at the beam waist, where the beam density was 500 mA/cm(2). The position and the width of each beamlet substructure show the effect of interference of beamlets with surrounding one.
Collapse
Affiliation(s)
- M Sasao
- Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Suzuki C, Ida K, Kobuchi T, Yoshinuma M. Energy resolved soft x-ray imaging using a charge coupled device camera for long pulse discharges in the Large Helical Device. Rev Sci Instrum 2008; 79:10E929. [PMID: 19044584 DOI: 10.1063/1.2953676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Energy resolved soft x-ray imaging system using a charge coupled device camera and a multifilter disk has recently been installed to the Large Helical Device for the measurements in the long pulse discharges. Eight images with different cutoff energies are measured sequentially during a single discharge by rotating a filter disk mounting eight beryllium filters with different thicknesses. A tangential line-integrated profile for a specific photon energy range can be obtained by taking intensity difference between two images measured with a filter pair of adjacent thicknesses. The typical photon energy corresponding to each difference ranges from 1.9 to 4.8 keV with the bandwidth of 2-3 keV. In the initial results, the difference in the line-integrated soft x-ray profile by the energy range has been clearly observed. This diagnostic method can possibly be applied to the observation of the dependence of two dimensional soft x-ray profile on photon energy range especially if local non-Maxwellian component appears in electron energy distribution function.
Collapse
Affiliation(s)
- C Suzuki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
| | | | | | | |
Collapse
|
11
|
Kobuchi T, Kisaki M, Shinto K, Okamoto A, Kitajima S, Sasao M, Tsumori K, Kaneko O, Sakakita H, Kiyama S, Hirano Y, Wada M. Effects of filament geometry on the arc efficiency of a high-intensity He+ ion source. Rev Sci Instrum 2008; 79:10F316. [PMID: 19044629 DOI: 10.1063/1.2965781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A strongly focusing high-intensity He(+) ion source equipped with three concave electrodes has been designed and constructed as the beam source for a high-energy He(0) neutral beam probe system to diagnose fusion-produced alpha particles in thermonuclear fusion plasmas. The reduction of heat load onto the concave extraction electrodes is particularly important for a long pulse operation, as the heat load deforms the electrodes and thus the beam focal length. The effects on the arc efficiency (beam current/arc power) of the ion source due to the discharge filament structure (straight-type and L-shape-type filaments), size (filament diameters of 2 and 1.5 mm), number, and the locations have been studied. Choice of the appropriate filament structure improved the arc efficiency by 17%.
Collapse
Affiliation(s)
- T Kobuchi
- School of Engineering, Tohoku University, Sendai 980-0579, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Funaki D, Isobe M, Nishiura M, Sato Y, Okamoto A, Kobuchi T, Kitajima S, Sasao M. Full orbit calculation for lost alpha particle measurement on ITER. Rev Sci Instrum 2008; 79:10E512. [PMID: 19044496 DOI: 10.1063/1.2974810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
An orbit following calculation code with full gyromotion under the ITER magnetic field configuration has been developed to investigate escaping alpha particle orbits in ITER and to determine the geometrical arrangement for alpha particle detection. The code contained the full geometrical information of the first wall panels. It was carefully investigated whether an alpha particle escaping from the plasma through the last closed flux surface does not touch or intersect the first wall boundary before reaching the detection point. Candidates of blanket module modification have been studied to achieve effective measurement geometry for escaping alpha particle detection. The calculations showed that direct orbit loss and banana diffusion can be detected with a probe head recessed from the first wall surface.
Collapse
Affiliation(s)
- D Funaki
- Department of Quantum Energy Science, Tohoku University, Sendai 980-8579, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Ida K, Sakamoto Y, Takenaga H, Oyama N, Itoh K, Yoshinuma M, Inagaki S, Kobuchi T, Isayama A, Suzuki T, Fujita T, Matsunaga G, Koide Y, Yoshida M, Ide S, Kamada Y. Transition between internal transport barriers with different temperature-profile curvatures in JT-60U Tokamak plasmas. Phys Rev Lett 2008; 101:055003. [PMID: 18764400 DOI: 10.1103/physrevlett.101.055003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 03/01/2008] [Indexed: 05/26/2023]
Abstract
A spontaneous transition phenomena between two states of a plasma with an internal transport barrier (ITB) is observed in the steady-state phase of the magnetic shear in the negative magnetic shear plasma in the JT-60U tokamak. These two ITB states are characterized by different profiles of the second radial derivative of the ion temperature inside the ITB region (one has a weak concave shape and the other has a strong convex shape) and by different degrees of sharpness of the interfaces between the L mode and the ITB region, which is determined by the turbulence penetration into the ITB region.
Collapse
Affiliation(s)
- K Ida
- National Institute for Fusion Sciences, Toki, Gifu, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Ida K, Sakamoto Y, Yoshinuma M, Inagaki S, Kobuchi T, Matsunaga G, Koide Y. Measurement of derivative of ion temperature using high spatial resolution charge exchange spectroscopy with space modulation optics. Rev Sci Instrum 2008; 79:053506. [PMID: 18513068 DOI: 10.1063/1.2921702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A new technique to measure the first and second derivatives of the ion temperature profile has been developed by using a charge exchange spectroscopy system with space modulation optics. The space observed is scanned up to +/-3 cm with a cosine wave modulation frequency up to 30 Hz by shifting the object lens in front of the optical fiber bundle by 0.5 mm with a piezoelement. The first and second derivatives of ion temperature are derived from the modulation component of the ion temperature measured by using Fourier series expansion.
Collapse
Affiliation(s)
- K Ida
- National Institute for Fusion Science, Toki 509-5292, Japan
| | | | | | | | | | | | | |
Collapse
|
15
|
Ida K, Inagaki S, Yoshinuma M, Narushima Y, Itoh K, Kobuchi T, Watanabe KY, Funaba H, Sakakibara S, Morisaki T. Bifurcation phenomena of a magnetic island at a rational surface in a magnetic-shear control experiment. Phys Rev Lett 2008; 100:045003. [PMID: 18352289 DOI: 10.1103/physrevlett.100.045003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Indexed: 05/26/2023]
Abstract
Three states of a magnetic island are observed when the magnetic shear at the rational surface is modified using inductive current associated with the neutral beam current drive in the Large Helical Device. One state is the healed magnetic island with a zero island width. The second state is the saturated magnetic island with partial flattening of the T(e) profile. The third state is characterized by the global flattening of the T(e) profile in the core region. As the plasma assumes each of the three states consecutively through a bifurcation process a clear hysteresis in the relation between the size of the magnetic island and the magnetic shear is observed.
Collapse
Affiliation(s)
- K Ida
- National Institute for Fusion Sciences, Toki, Gifu 509-5292, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Kisaki M, Shinto K, Kobuchi T, Okamoto A, Kitajima S, Sasao M, Tsumori K, Nishiura M, Kaneko O, Matsuda Y, Wada M, Sakakita H, Kiyama S, Hirano Y. Development of a strongly focusing high-intensity He(+) ion source for a confined alpha particle measurement at ITER. Rev Sci Instrum 2008; 79:02C113. [PMID: 18315239 DOI: 10.1063/1.2801543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A strongly focusing high-intensity He(+) ion source has been designed and constructed as a beam source for a high-energy He(0) beam probe system for diagnosis of fusion produced alpha particles in the thermonuclear fusion plasmas. The He(+) beam was extracted from the ion source at an acceleration voltage of 18-35 kV. Temperature distributions of the beam target were observed with an IR camera. The 1/e-holding beam profile half-width was about 15 mm at optimum perveance (Perv) of 0.03 (I(beam)=2.4 A). A beam current about 3 A was achieved at an acceleration voltage of 26.7 kV with an arc power of 10 kW (Perv=0.023).
Collapse
Affiliation(s)
- M Kisaki
- School of Engineering, Tohoku University, Sendai, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Tanaka N, Kikuchi M, Nagamura T, Sugawara H, Takeuchi S, Kobuchi T, Okamoto A, Shinto K, Kitajima S, Sasao M, Wada M. A beam transport system for an intense He(-) beam source. Rev Sci Instrum 2008; 79:02A512. [PMID: 18315133 DOI: 10.1063/1.2816967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We have been developing a test stand for fast He(0) beam production. One of the major issues is how to transport effectively the He(+) and He(-) beams from which the He(0) beam is produced. The beam should be focused in two transverse focal points, the center of the charge exchange cell and the electrostatic accelerator. We studied the beam transport system and effect of space charge neutralization in the test stand by experiments and calculation.
Collapse
Affiliation(s)
- N Tanaka
- Tohoku University, Aoba, Sendai, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Yamada H, Suzuki Y, Ida K, Yoshinuma M, Kobuchi T, Watanabe KY, Tanaka K, Tokuzawa T. Observation of Equilibria with a Double Magnetic Axis in LHD. Fusion Science and Technology 2007. [DOI: 10.13182/fst07-a1295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- H. Yamada
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
- Graduate University for Advanced Studies, SOKENDAI, Hayama, Kanagawa 240-0193, Japan
| | - Y. Suzuki
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
| | - K. Ida
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
- Graduate University for Advanced Studies, SOKENDAI, Hayama, Kanagawa 240-0193, Japan
| | - M. Yoshinuma
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
| | - T. Kobuchi
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
| | - K. Y. Watanabe
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
- Graduate University for Advanced Studies, SOKENDAI, Hayama, Kanagawa 240-0193, Japan
| | - K. Tanaka
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
| | - T. Tokuzawa
- National Institute for Fusion Science, 322-6 Oroshi-cho Toki, Gifu 509-5292, Japan
| | | |
Collapse
|
19
|
Ohyabu N, Ida K, Morisaki T, Narihara K, Komori A, Watanabe K, Narushima Y, Nagayama Y, Shoji M, Ashikawa N, Emoto M, Funaba H, Goto M, Idei H, Ikeda K, Inagaki S, Inoue N, Isobe M, Khlopenkov K, Kobuchi T, Kostrioukov A, Kubo S, Kumazawa R, Liang Y, Masuzaki S, Minami T, Miyazawa J, Morita S, Muto S, Mutoh T, Murakami S, Nakamura Y, Nakanishi H, Nishimura K, Noda N, Notake T, Ohkubo K, Ohdachi S, Oka Y, Osakabe M, Ozaki T, Peterson BJ, Sakamoto R, Sakakibara S, Sagara A, Saito K, Sasao M, Sato K, Sato M, Seki T, Shimozuma T, Sudo S, Suzuki H, Takeiri Y, Tanaka K, Tamura N, Toi K, Tokuzawa T, Torii Y, Tsumori K, Watanabe T, Yamazaki K, Yamada I, Yamamoto S, Yokoyama M, Yoshimura Y, Watari T, Xu Y, Kaneko O, Kawahata K, Yamada H, Motojima O. Island dynamics in the large-helical-device plasmas. Phys Rev Lett 2002; 88:055005. [PMID: 11863738 DOI: 10.1103/physrevlett.88.055005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2001] [Indexed: 05/23/2023]
Abstract
In the Large Helical Device plasma discharges, the size of an externally imposed island with mode number ( n/m = 1/1) decreases substantially when the plasma is collisionless ( nu(*)< approximately 1) and the beta is finite ( > approximately 0.1%) at the island location. For the collisional plasmas with finite beta, on the other hand, the size of the island increases. However, there is a threshold in terms of the vacuum island size below which the island enlargement is not seen.
Collapse
Affiliation(s)
- N Ohyabu
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Narihara K, Watanabe KY, Yamada I, Morisaki T, Tanaka K, Sakakibara S, Ida K, Sakamoto R, Ohyabu N, Ashikawa N, Emoto M, Funaba H, Goto M, Hayashi H, Idei H, Ikeda K, Inagaki S, Inoue N, Kaneko O, Kawahata K, Kobuchi T, Komori A, Kubo S, Kumazawa R, Masuzaki S, Miyazawa J, Morita S, Motojima O, Murakami S, Muto S, Mutoh T, Nagayama Y, Nakamura Y, Nakanishi H, Nishimura K, Noda N, Notake T, Ohdachi S, Oka Y, Ohkubo K, Osakabe M, Ozaki S, Peterson BJ, Sagara A, Saito K, Sasao H, Sasao M, Sato K, Sato M, Seki T, Shimozuma T, Shoji C, Sudo S, Suzuki H, Takayama A, Takechi M, Takeiri Y, Tamura N, Toi K, Tokuzawa N, Torii Y, Tsumori K, Watari T, Yamada H, Yamaguchi S, Yamamoto S, Yamazaki K, Yoshimura Y. Observation of the "self-healing" of an error field island in the large helical device. Phys Rev Lett 2001; 87:135002. [PMID: 11580597 DOI: 10.1103/physrevlett.87.135002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2001] [Indexed: 05/23/2023]
Abstract
It was observed that the vacuum magnetic island produced by an external error magnetic field in the large helical device shrank in the presence of plasma. This was evidenced by the disappearance of flat regions in the electron temperature profile obtained by Thomson scattering. This island behavior depended on the magnetic configuration in which the plasmas were produced.
Collapse
Affiliation(s)
- K Narihara
- National Institute for Fusion Science, Toki, 509-5292, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Ida K, Funaba H, Kado S, Narihara K, Tanaka K, Takeiri Y, Nakamura Y, Ohyabu N, Yamazaki K, Yokoyama M, Murakami S, Ashikawa N, deVries PC, Emoto M, Goto M, Idei H, Ikeda K, Inagaki S, Inoue N, Isobe M, Itoh K, Kaneko O, Kawahata K, Khlopenkov K, Komori A, Kubo S, Kumazawa R, Liang Y, Masuzaki S, Minami T, Miyazawa J, Morisaki T, Morita S, Mutoh T, Muto S, Nagayama Y, Nakanishi H, Nishimura K, Noda N, Notake T, Kobuchi T, Ohdachi S, Ohkubo K, Oka Y, Osakabe M, Ozaki T, Pavlichenko RO, Peterson BJ, Sagara A, Saito K, Sakakibara S, Sakamoto R, Sanuki H, Sasao H, Sasao M, Sato K, Sato M, Seki T, Shimozuma T, Shoji M, Suzuki H, Sudo S, Tamura N, Toi K, Tokuzawa T, Torii Y, Tsumori K, Yamamoto T, Yamada H, Yamada I, Yamaguchi S, Yamamoto S, Yoshimura Y, Watanabe KY, Watari T, Hamada Y, Motojima O, Fujiwara M. Reduction of ion thermal diffusivity associated with the transition of the radial electric field in neutral-beam-heated plasmas in the large helical device. Phys Rev Lett 2001; 86:5297-5300. [PMID: 11384482 DOI: 10.1103/physrevlett.86.5297] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2001] [Indexed: 05/23/2023]
Abstract
Recent large helical device experiments revealed that the transition from ion root to electron root occurred for the first time in neutral-beam-heated discharges, where no nonthermal electrons exist. The measured values of the radial electric field were found to be in qualitative agreement with those estimated by neoclassical theory. A clear reduction of ion thermal diffusivity was observed after the mode transition from ion root to electron root as predicted by neoclassical theory when the neoclassical ion loss is more dominant than the anomalous ion loss.
Collapse
Affiliation(s)
- K Ida
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, 509-5292, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Shimozuma T, Kubo S, Sato M, Idei H, Takita Y, Ito S, Kobayashi S, Mizuno Y, Yoshimura Y, Ohkubo K, Funaba H, Inagaki S, Kobuchi T, Masuzaki S, Muto S, Shoji M, Suzuki H, Noda N, Nakamura Y, Kawahata K, Ohyabu N, Motojima O. ECH system and its application to long pulse discharge in large helical device. Fusion Engineering and Design 2001. [DOI: 10.1016/s0920-3796(00)00529-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
23
|
Takahashi T, Enomoto Y, Itoi M, Itoh N, Nakayasu K, Kanai A, Kobuchi T, Nishimaki K. P 154 Effects of contact lens use to corneal epithelial barrier function by objective fluorophotometer. Vision Res 1995. [DOI: 10.1016/0042-6989(95)90470-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|