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Journal Articles

Measurement of x-ray bremsstrahlung radiation from high energy electrons by stochastic acceleration in Heliotron J

R. Yamato, S. Kobayashi, T. Fujita, K. Nagaoka, K. Nagasaki, S. Inagaki, T. Kawate, H. Ohgaki, T. Kii, H. Zen, S. Kado, T. Minami, H. Okada, S. Ohshima, S. Konoshima, T. Mizuuchi, Y. Mototake
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 96, 033512 (2025)
https://doi.org/10.1063/5.0231450
Published: March 2025
View articletitled, Measurement of x-ray bremsstrahlung radiation from high energy electrons by stochastic acceleration in Heliotron J
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Journal Articles

MHD stability trends and improved performance of LHD inward-shifted configurations: The role of the neutral beam current drive and thermal plasma density

J. Varela, K. Nagaoka, Y. Takemura, K. Y. Watanabe, K. Ida, M. Yoshinuma, K. Nagasaki, A. Cappa, S. Sharapov, D. A. Spong, L. Garcia, Y. Ghai, J. Ortiz
Journal: Physics of Plasmas
Phys. Plasmas 31, 082504 (2024)
https://doi.org/10.1063/5.0206400
Published: August 2024
View articletitled, MHD stability trends and improved performance of LHD inward-shifted configurations: The role of the neutral beam current drive and thermal plasma density
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Journal Articles

Application of two-dimensional temperature response functions for reconstruction of divertor heat flux profile in commercial fusion reactors

X. N. S. Bui, H. Matsuura, Y. Hayashi, K. Nagaoka, S. Masuzaki
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 95, 033505 (2024)
https://doi.org/10.1063/5.0152428
Published: March 2024
View articletitled, Application of two-dimensional temperature response functions for reconstruction of divertor heat flux profile in commercial fusion reactors
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Journal Articles

Direct observation of the non-locality of non-diffusive counter-gradient electron thermal transport during the formation of hollow electron-temperature profiles in the Large Helical Device

T. I. Tsujimura, T. Kobayashi, K. Tanaka, K. Ida, K. Nagaoka, M. Yoshinuma, I. Yamada, H. Funaba, R. Seki, S. Satake, T. Kinoshita, T. Tokuzawa, N. Kenmochi, H. Igami, K. Mukai, M. Goto, Y. Kawamoto
Journal: Physics of Plasmas
Phys. Plasmas 29, 032504 (2022)
https://doi.org/10.1063/5.0074351
Published: March 2022
View articletitled, Direct observation of the non-locality of non-diffusive counter-gradient electron thermal transport during the formation of hollow electron-temperature profiles in the Large Helical Device
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Journal Articles

Validation of the distribution of stripping loss neutrals in the accelerator of the negative ion source

K. Ikeda, M. Kisaki, H. Nakano, K. Tsumori, K. Nagaoka, Y. Fujiwara, S. Masaki, E. Rattanawongnara, M. Osakabe
Journal: AIP Conference Proceedings
AIP Conf. Proc. 2373, 060001 (2021)
https://doi.org/10.1063/5.0057443
Published: July 2021
View articletitled, Validation of the distribution of stripping loss neutrals in the accelerator of the negative ion source
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Journal Articles

Development of the directional Langmuir probe for the charged particle flow measurement

S. Masaki, H. Nakano, M. Kisaki, E. Rattanawongnara, K. Nagaoka, K. Ikeda, Y. Fujiwara, M. Osakabe, K. Tsumori
Journal: AIP Conference Proceedings
AIP Conf. Proc. 2373, 090003 (2021)
https://doi.org/10.1063/5.0058837
Published: July 2021
View articletitled, Development of the directional Langmuir probe for the charged particle flow measurement
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Journal Articles

Spatial distribution of negative ion density near the plasma grid

S. Masaki, H. Nakano, M. Kisaki, Y. Haba, K. Nagaoka, K. Ikeda, Y. Fujiwara, M. Osakabe, K. Tsumori
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 91, 013512 (2020)
https://doi.org/10.1063/1.5129705
Published: January 2020
View articletitled, Spatial distribution of negative ion density near the plasma grid
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Journal Articles

Extension of high power deuterium operation of negative ion based neutral beam injector in the large helical device

K. Ikeda, K. Tsumori, K. Nagaoka, H. Nakano, M. Kisaki, Y. Fujiwara, S. Kamio, Y. Haba, S. Masaki, M. Osakabe
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 90, 113322 (2019)
https://doi.org/10.1063/1.5128529
Published: November 2019
View articletitled, Extension of high power deuterium operation of negative ion based neutral beam injector in the large helical device
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Journal Articles

Caesiated H- source operation with helium

K. Tsumori, M. Wada, H. Nakano, M. Kisaki, K. Ikeda, Y. Haba, K. Nagaoka, S. Kamio, Y. Fujiwara, M. Osakabe
Journal: AIP Conference Proceedings
AIP Conf. Proc. 2052, 040015 (2018)
https://doi.org/10.1063/1.5083749
Published: December 2018
View articletitled, Caesiated H- source operation with helium
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Journal Articles

Development of a dual beamlet monitor system for negative ion beam measurements

Y. Haba, K. Nagaoka, K. Tsumori, M. Kisaki, H. Nakano, K. Ikeda, Y. Fujiwara, S. Kamio, S. Yoshimura, M. Osakabe
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 89, 123303 (2018)
https://doi.org/10.1063/1.5056260
Published: December 2018
View articletitled, Development of a dual beamlet monitor system for negative ion beam measurements
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Journal Articles

First results of deuterium beam operation on neutral beam injectors in the large helical device

K. Ikeda, K. Tsumori, M. Kisaki, H. Nakano, K. Nagaoka, M. Osakabe, S. Kamio, Y. Fujiwara, Y. Haba, Y. Takeiri
Journal: AIP Conference Proceedings
AIP Conf. Proc. 2011, 060002 (2018)
https://doi.org/10.1063/1.5053331
Published: September 2018
View articletitled, First results of deuterium beam operation on neutral beam injectors in the large helical device
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Journal Articles

Physics-based investigation of negative ion behavior in a negative-ion-rich plasma using integrated diagnostics

K. Tsumori, Y. Takeiri, K. Ikeda, H. Nakano, S. Geng, M. Kisaki, K. Nagaoka, T. Tokuzawa, M. Wada, K. Sasaki, S. Nishiyama, M. Goto, M. Osakabe
Journal: AIP Conference Proceedings
AIP Conf. Proc. 1869, 030001 (2017)
https://doi.org/10.1063/1.4995721
Published: August 2017
View articletitled, Physics-based investigation of negative ion behavior in a negative-ion-rich plasma using integrated diagnostics
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Journal Articles

Study of back streaming ion using a slot-type grounded grid in hydrogen negative-ion source

K. Ikeda, M. Kisaki, H. Nakano, K. Nagaoka, M. Osakabe, S. Kamio, K. Tsumori, S. Geng, Y. Takeiri
Journal: AIP Conference Proceedings
AIP Conf. Proc. 1869, 050004 (2017)
https://doi.org/10.1063/1.4995785
Published: August 2017
View articletitled, Study of back streaming ion using a slot-type grounded grid in hydrogen negative-ion source
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Journal Articles

Upgraded millimeter-wave interferometer for measuring the electron density during the beam extraction in the negative ion source

T. Tokuzawa, M. Kisaki, K. Nagaoka, K. Tsumori, Y. Ito, K. Ikeda, H. Nakano, M. Osakabe, Y. Takeiri, O. Kaneko
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 87, 11E105 (2016)
https://doi.org/10.1063/1.4959841
Published: August 2016
View articletitled, Upgraded millimeter-wave interferometer for measuring the electron density during the beam extraction in the negative ion source
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Journal Articles

Negative ion production and beam extraction processes in a large ion source (invited)

K. Tsumori, K. Ikeda, H. Nakano, M. Kisaki, S. Geng, M. Wada, K. Sasaki, S. Nishiyama, M. Goto, G. Serianni, P. Agostinetti, E. Sartori, M. Brombin, P. Veltri, C. Wimmer, K. Nagaoka, M. Osakabe, Y. Takeiri, O. Kaneko
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 87, 02B936 (2016)
https://doi.org/10.1063/1.4938254
Published: January 2016
View articletitled, Negative ion production and beam extraction processes in a large ion source (invited)
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Journal Articles

High-power and steady-state operation of ICRF heating in the large helical device

T. Mutoh, T. Seki, K. Saito, H. Kasahara, R. Seki, S. Kamio, R. Kumazawa, S. Kubo, T. Shimozuma, Y. Yoshimura, H. Igami, H. Takahashi, T. Ii, R. Makino, K. Nagaoka, G. Nomura, T. Shinya, LHD Experiment Group
Journal: AIP Conference Proceedings
AIP Conf. Proc. 1689, 030009 (2015)
https://doi.org/10.1063/1.4936474
Published: December 2015
View articletitled, High-power and steady-state operation of ICRF heating in the large helical device
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Journal Articles

Improvement of accelerator of negative ion source on the Large Helical Device

M. Kisaki, K. Ikeda, M. Osakabe, K. Tsumori, H. Nakano, S. Geng, K. Nagaoka, O. Kaneko, Y. Takeiri
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 87, 02B321 (2016)
https://doi.org/10.1063/1.4936249
Published: November 2015
View articletitled, Improvement of accelerator of negative ion source on the Large Helical Device
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Journal Articles

Installation of spectrally selective imaging system in RF negative ion source

K. Ikeda, D. Wünderlich, U. Fantz, B. Heinemann, M. Kisaki, K. Nagaoka, H. Nakano, M. Osakabe, K. Tsumori, S. Geng, O. Kaneko, Y. Takeiri
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 87, 02B113 (2016)
https://doi.org/10.1063/1.4932987
Published: October 2015
View articletitled, Installation of spectrally selective imaging system in RF negative ion source
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Journal Articles

Charged particle flows in the beam extraction region of a negative ion source for NBI

S. Geng, K. Tsumori, H. Nakano, M. Kisaki, K. Ikeda, M. Osakabe, K. Nagaoka, Y. Takeiri, M. Shibuya, O. Kaneko
Journal: Review of Scientific Instruments
Rev. Sci. Instrum. 87, 02B103 (2016)
https://doi.org/10.1063/1.4931796
Published: October 2015
View articletitled, Charged particle flows in the beam extraction region of a negative ion source for NBI
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Journal Articles

Heat flux and plasma flow in the far scrape-off layer of the inboard poloidal field null configuration in QUEST

T. Onchi, H. Zushi, K. Mishra, Y. Mahira, K. Nagaoka, K. Hanada, H. Idei, M. Hasegawa, K. Nakamura, A. Fujisawa, Y. Nagashima, K. Matsuoka, S. Tashima, S. Banerjee, A. Kuzmin, S. Kawasaki, H. Nakashima, A. Higashijima, O. Watanabe
Journal: Physics of Plasmas
Phys. Plasmas 22, 082513 (2015)
https://doi.org/10.1063/1.4928878
Published: August 2015
View articletitled, Heat flux and plasma flow in the far scrape-off layer of the inboard poloidal field null configuration in QUEST
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