Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks

N. Yoneda; T. Shikama; F. Scotti; K. Hanada; H. Iguchi; H. Idei; T. Onchi; A. Ejiri; T. Ido; K. Kono; Y. Peng; Y. Osawa; G. Yatomi; A. Kidani; M. Kudo; R. Hiraka; K. Takeda; R. E. Bell; A. Maan; D. P. Boyle; R. Majeski; V. Soukhanovskii; M. Groth; A. McLean; R. S. Wilcox; C. Lasnier; K. Nakamura; Y. Nagashima; R. Ikezoe; M. Hasegawa; K. Kuroda; A. Higashijima; T. Nagata; S. Shimabukuro; I. Niiya; I. Sekiya; M. Hasuo

doi:10.1088/1741-4326/acd4d1

Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks

N. Yoneda, T. Shikama, F. Scotti, K. Hanada, H. Iguchi, H. Idei, T. Onchi, A. Ejiri, T. Ido, K. Kono, Y. Peng, Y. Osawa, G. Yatomi, A. Kidani, M. Kudo, R. Hiraka, K. Takeda, R. E. Bell, A. Maan, D. P. BoyleR. Majeski, V. Soukhanovskii, M. Groth, A. McLean, R. S. Wilcox, C. Lasnier, K. Nakamura, Y. Nagashima, R. Ikezoe, M. Hasegawa, K. Kuroda, A. Higashijima, T. Nagata, S. Shimabukuro, I. Niiya, I. Sekiya, M. Hasuo

Advanced Tokamak Physics

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

Spatially resolved rotational temperature of ground state hydrogen molecules desorbed from plasma-facing surface was measured in QUEST, LTX-β, and DIII-D tokamaks, and the increases of the rotational temperature with the surface temperature and due to collisional-radiative processes in the plasmas were evaluated. The increase due to collisional-radiative processes was calculated by solving rate equations considering electron and proton collisional excitation and deexcitation and spontaneous emission. The calculation results suggest a high sensitivity for the rotational temperature to electron and proton densities, but a negligible sensitivity to the electron, proton, and surface temperatures. In the three tokamaks with different plasma parameters and plasma-facing surface materials, the spatial profile of the rotational temperature was estimated using Fulcher-α emission lines (600-608 nm). In QUEST, the spatial profile of the rotational temperature was estimated from spatially resolved spectra. In the other tokamaks, the rotational temperature was evaluated assuming a single point emission with a location determined from the Fulcher-α emission profile as measured with a filtered camera. In metal-walled devices QUEST and LTX-β, the rotational temperature increased with the surface temperature, and the calculated collisional-radiative increase is consistent with measured increase assuming that the rotational temperature at the surface is approximately 500-600 K higher than the surface temperature. In DIII-D with carbon walls, a larger collisional-radiative increase than the other tokamaks was observed because of the higher density leading to a large difference from the calculated increase compared to the other smaller tokamaks. Measurement of the Fulcher-α emission profile with higher spatial resolution in DIII-D may reduce the difference and reveal the effect of the surface temperature on the rotational temperature. These results show the increases in the rotational temperature with the surface temperature and due to the collisional-radiative processes.

Original language	English
Article number	096004
Journal	Nuclear Fusion
Volume	63
Issue number	9
DOIs	https://doi.org/10.1088/1741-4326/acd4d1
State	Published - Sep 2023

Funding

The first author is supported by Mori Manufacturing Research and Technology Foundation. The authors thank M. Ono for supporting the experiment in LTX-β, and T. Abrams for supporting the experiment in DIII-D. The authors are grateful to M. Čížek for providing the cross section data. The authors would like to thank the staff members of the machine shop of Kyoto University for their help with the fabrication of the spectroscopic system used in QUEST. This work was supported by bilateral collaboration programs of NIFS (NIFS19KUTR140, NIFS20KUTR156), Japan/U. S. Cooperation in Fusion Research and Development, and USDoE under contracts DE-AC52-07NA27344 (LLNL), DE-AC02-09CH11466 (Princeton University) and DE-AC05-00OR22725 (ORNL). This material is based upon work supported by the US. Department of Energy, Office of Science, Office of Fusion Energy Sciences, using the DIII-D National Fusion Facility, a DOE Office of Science user facility, under Award(s) DE-FC02-04ER54698. The first author is supported by Mori Manufacturing Research and Technology Foundation. The authors thank M. Ono for supporting the experiment in LTX-β, and T. Abrams for supporting the experiment in DIII-D. The authors are grateful to M. Čížek for providing the cross section data. The authors would like to thank the staff members of the machine shop of Kyoto University for their help with the fabrication of the spectroscopic system used in QUEST. This work was supported by bilateral collaboration programs of NIFS (NIFS19KUTR140, NIFS20KUTR156), Japan/U. S. Cooperation in Fusion Research and Development, and USDoE under contracts DE-AC52-07NA27344 (LLNL), DE-AC02-09CH11466 (Princeton University) and DE-AC05-00OR22725 (ORNL). This material is based upon work supported by the US. Department of Energy, Office of Science, Office of Fusion Energy Sciences, using the DIII-D National Fusion Facility, a DOE Office of Science user facility, under Award(s) DE-FC02-04ER54698.

Funders	Funder number
Mori Manufacturing Research and Technology Foundation	NIFS20KUTR156, NIFS19KUTR140
U.S. Department of Energy	DE-AC52-07NA27344
Office of Science	DE-FC02-04ER54698
Fusion Energy Sciences
Lawrence Livermore National Laboratory	DE-AC02-09CH11466
Oak Ridge National Laboratory
Princeton University	DE-AC05-00OR22725

Keywords

DIII-D
LTX-β
QUEST
emission spectroscopy
hydrogen molecule
plasma-surface interaction
rotational temperature

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1088/1741-4326/acd4d1

Cite this

Yoneda, N., Shikama, T., Scotti, F., Hanada, K., Iguchi, H., Idei, H., Onchi, T., Ejiri, A., Ido, T., Kono, K., Peng, Y., Osawa, Y., Yatomi, G., Kidani, A., Kudo, M., Hiraka, R., Takeda, K., Bell, R. E., Maan, A., ... Hasuo, M. (2023). Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks. Nuclear Fusion, 63(9), Article 096004. https://doi.org/10.1088/1741-4326/acd4d1

@article{d97293fa59b342aaaeb0721026cff101,

title = "Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks",

abstract = "Spatially resolved rotational temperature of ground state hydrogen molecules desorbed from plasma-facing surface was measured in QUEST, LTX-β, and DIII-D tokamaks, and the increases of the rotational temperature with the surface temperature and due to collisional-radiative processes in the plasmas were evaluated. The increase due to collisional-radiative processes was calculated by solving rate equations considering electron and proton collisional excitation and deexcitation and spontaneous emission. The calculation results suggest a high sensitivity for the rotational temperature to electron and proton densities, but a negligible sensitivity to the electron, proton, and surface temperatures. In the three tokamaks with different plasma parameters and plasma-facing surface materials, the spatial profile of the rotational temperature was estimated using Fulcher-α emission lines (600-608 nm). In QUEST, the spatial profile of the rotational temperature was estimated from spatially resolved spectra. In the other tokamaks, the rotational temperature was evaluated assuming a single point emission with a location determined from the Fulcher-α emission profile as measured with a filtered camera. In metal-walled devices QUEST and LTX-β, the rotational temperature increased with the surface temperature, and the calculated collisional-radiative increase is consistent with measured increase assuming that the rotational temperature at the surface is approximately 500-600 K higher than the surface temperature. In DIII-D with carbon walls, a larger collisional-radiative increase than the other tokamaks was observed because of the higher density leading to a large difference from the calculated increase compared to the other smaller tokamaks. Measurement of the Fulcher-α emission profile with higher spatial resolution in DIII-D may reduce the difference and reveal the effect of the surface temperature on the rotational temperature. These results show the increases in the rotational temperature with the surface temperature and due to the collisional-radiative processes.",

keywords = "DIII-D, LTX-β, QUEST, emission spectroscopy, hydrogen molecule, plasma-surface interaction, rotational temperature",

author = "N. Yoneda and T. Shikama and F. Scotti and K. Hanada and H. Iguchi and H. Idei and T. Onchi and A. Ejiri and T. Ido and K. Kono and Y. Peng and Y. Osawa and G. Yatomi and A. Kidani and M. Kudo and R. Hiraka and K. Takeda and Bell, {R. E.} and A. Maan and Boyle, {D. P.} and R. Majeski and V. Soukhanovskii and M. Groth and A. McLean and Wilcox, {R. S.} and C. Lasnier and K. Nakamura and Y. Nagashima and R. Ikezoe and M. Hasegawa and K. Kuroda and A. Higashijima and T. Nagata and S. Shimabukuro and I. Niiya and I. Sekiya and M. Hasuo",

note = "Publisher Copyright: {\textcopyright} 2023 The Author(s). Published on behalf of IAEA by IOP Publishing Ltd.",

year = "2023",

month = sep,

doi = "10.1088/1741-4326/acd4d1",

language = "English",

volume = "63",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing",

number = "9",

}

Yoneda, N, Shikama, T, Scotti, F, Hanada, K, Iguchi, H, Idei, H, Onchi, T, Ejiri, A, Ido, T, Kono, K, Peng, Y, Osawa, Y, Yatomi, G, Kidani, A, Kudo, M, Hiraka, R, Takeda, K, Bell, RE, Maan, A, Boyle, DP, Majeski, R, Soukhanovskii, V, Groth, M, McLean, A, Wilcox, RS, Lasnier, C, Nakamura, K, Nagashima, Y, Ikezoe, R, Hasegawa, M, Kuroda, K, Higashijima, A, Nagata, T, Shimabukuro, S, Niiya, I, Sekiya, I & Hasuo, M 2023, 'Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks', Nuclear Fusion, vol. 63, no. 9, 096004. https://doi.org/10.1088/1741-4326/acd4d1

TY - JOUR

T1 - Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks

AU - Yoneda, N.

AU - Shikama, T.

AU - Scotti, F.

AU - Hanada, K.

AU - Iguchi, H.

AU - Idei, H.

AU - Onchi, T.

AU - Ejiri, A.

AU - Ido, T.

AU - Kono, K.

AU - Peng, Y.

AU - Osawa, Y.

AU - Yatomi, G.

AU - Kidani, A.

AU - Kudo, M.

AU - Hiraka, R.

AU - Takeda, K.

AU - Bell, R. E.

AU - Maan, A.

AU - Boyle, D. P.

AU - Majeski, R.

AU - Soukhanovskii, V.

AU - Groth, M.

AU - McLean, A.

AU - Wilcox, R. S.

AU - Lasnier, C.

AU - Nakamura, K.

AU - Nagashima, Y.

AU - Ikezoe, R.

AU - Hasegawa, M.

AU - Kuroda, K.

AU - Higashijima, A.

AU - Nagata, T.

AU - Shimabukuro, S.

AU - Niiya, I.

AU - Sekiya, I.

AU - Hasuo, M.

PY - 2023/9

Y1 - 2023/9

N2 - Spatially resolved rotational temperature of ground state hydrogen molecules desorbed from plasma-facing surface was measured in QUEST, LTX-β, and DIII-D tokamaks, and the increases of the rotational temperature with the surface temperature and due to collisional-radiative processes in the plasmas were evaluated. The increase due to collisional-radiative processes was calculated by solving rate equations considering electron and proton collisional excitation and deexcitation and spontaneous emission. The calculation results suggest a high sensitivity for the rotational temperature to electron and proton densities, but a negligible sensitivity to the electron, proton, and surface temperatures. In the three tokamaks with different plasma parameters and plasma-facing surface materials, the spatial profile of the rotational temperature was estimated using Fulcher-α emission lines (600-608 nm). In QUEST, the spatial profile of the rotational temperature was estimated from spatially resolved spectra. In the other tokamaks, the rotational temperature was evaluated assuming a single point emission with a location determined from the Fulcher-α emission profile as measured with a filtered camera. In metal-walled devices QUEST and LTX-β, the rotational temperature increased with the surface temperature, and the calculated collisional-radiative increase is consistent with measured increase assuming that the rotational temperature at the surface is approximately 500-600 K higher than the surface temperature. In DIII-D with carbon walls, a larger collisional-radiative increase than the other tokamaks was observed because of the higher density leading to a large difference from the calculated increase compared to the other smaller tokamaks. Measurement of the Fulcher-α emission profile with higher spatial resolution in DIII-D may reduce the difference and reveal the effect of the surface temperature on the rotational temperature. These results show the increases in the rotational temperature with the surface temperature and due to the collisional-radiative processes.

AB - Spatially resolved rotational temperature of ground state hydrogen molecules desorbed from plasma-facing surface was measured in QUEST, LTX-β, and DIII-D tokamaks, and the increases of the rotational temperature with the surface temperature and due to collisional-radiative processes in the plasmas were evaluated. The increase due to collisional-radiative processes was calculated by solving rate equations considering electron and proton collisional excitation and deexcitation and spontaneous emission. The calculation results suggest a high sensitivity for the rotational temperature to electron and proton densities, but a negligible sensitivity to the electron, proton, and surface temperatures. In the three tokamaks with different plasma parameters and plasma-facing surface materials, the spatial profile of the rotational temperature was estimated using Fulcher-α emission lines (600-608 nm). In QUEST, the spatial profile of the rotational temperature was estimated from spatially resolved spectra. In the other tokamaks, the rotational temperature was evaluated assuming a single point emission with a location determined from the Fulcher-α emission profile as measured with a filtered camera. In metal-walled devices QUEST and LTX-β, the rotational temperature increased with the surface temperature, and the calculated collisional-radiative increase is consistent with measured increase assuming that the rotational temperature at the surface is approximately 500-600 K higher than the surface temperature. In DIII-D with carbon walls, a larger collisional-radiative increase than the other tokamaks was observed because of the higher density leading to a large difference from the calculated increase compared to the other smaller tokamaks. Measurement of the Fulcher-α emission profile with higher spatial resolution in DIII-D may reduce the difference and reveal the effect of the surface temperature on the rotational temperature. These results show the increases in the rotational temperature with the surface temperature and due to the collisional-radiative processes.

KW - DIII-D

KW - LTX-β

KW - QUEST

KW - emission spectroscopy

KW - hydrogen molecule

KW - plasma-surface interaction

KW - rotational temperature

UR - http://www.scopus.com/inward/record.url?scp=85166665953&partnerID=8YFLogxK

U2 - 10.1088/1741-4326/acd4d1

DO - 10.1088/1741-4326/acd4d1

M3 - Article

AN - SCOPUS:85166665953

SN - 0029-5515

VL - 63

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 9

M1 - 096004

ER -

Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks

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Keywords

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