Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST

K. Hanada, N. Yoshida, M. Hasegawa, A. Hatayama, K. Okamoto, I. Takagi, T. Hirata, Y. Oya, M. Miyamoto, M. Oya, T. Shikama, A. Kuzmin, Z. X. Wang, H. Long, H. Idei, Y. Nagashima, K. Nakamura, O. Watanabe, T. Onchi, H. WatanabeK. Tokunaga, A. Higashijima, S. Kawasaki, T. Nagata, S. Shimabukuro, Y. Takase, S. Murakami, X. Gao, H. Liu, J. Qian, R. Raman, M. Ono

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The fuel particle balance during long duration discharges in the Q-shu University Experiment with steady state spherical tokamak (QUEST) was investigated. QUEST has all-metal plasma facing walls (PFWs) that were temperature controlled during the experiments. The presence of a transport barrier for hydrogen (H) at the interface between a plasma-induced deposition layer and metallic substrate was confirmed by nuclear reaction analysis with exposing deuterium plasma. An effective method to evaluate global hydrogen flux to PFWs is proposed, taking advantage of the nature of wall saturation. The outgoing flux of fuel particles from the PFWs just after the plasma termination was proportional to the square of wall-stored H, which indicates that enhanced recombination of solved hydrogen played an essential role in dynamic retention and was in agreement with predictions from the H-barrier model. A simple calculation based on the combination of wall modelling and rate equations of the H states denoted a significant impact of wall modelling on the time response of the plasma density. Hence, a proper wall model including the effects of the deposition layer creating the H barrier is required to be developed, even for all-metal PFW devices.

Original languageEnglish
Article number076007
JournalNuclear Fusion
Volume59
Issue number7
DOIs
Publication statusPublished - May 23 2019

Fingerprint

hydrogen
metals
deuterium plasma
time response
nuclear reactions
plasma density
saturation
predictions
temperature

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST. / Hanada, K.; Yoshida, N.; Hasegawa, M.; Hatayama, A.; Okamoto, K.; Takagi, I.; Hirata, T.; Oya, Y.; Miyamoto, M.; Oya, M.; Shikama, T.; Kuzmin, A.; Wang, Z. X.; Long, H.; Idei, H.; Nagashima, Y.; Nakamura, K.; Watanabe, O.; Onchi, T.; Watanabe, H.; Tokunaga, K.; Higashijima, A.; Kawasaki, S.; Nagata, T.; Shimabukuro, S.; Takase, Y.; Murakami, S.; Gao, X.; Liu, H.; Qian, J.; Raman, R.; Ono, M.

In: Nuclear Fusion, Vol. 59, No. 7, 076007, 23.05.2019.

Research output: Contribution to journalArticle

Hanada, K, Yoshida, N, Hasegawa, M, Hatayama, A, Okamoto, K, Takagi, I, Hirata, T, Oya, Y, Miyamoto, M, Oya, M, Shikama, T, Kuzmin, A, Wang, ZX, Long, H, Idei, H, Nagashima, Y, Nakamura, K, Watanabe, O, Onchi, T, Watanabe, H, Tokunaga, K, Higashijima, A, Kawasaki, S, Nagata, T, Shimabukuro, S, Takase, Y, Murakami, S, Gao, X, Liu, H, Qian, J, Raman, R & Ono, M 2019, 'Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST', Nuclear Fusion, vol. 59, no. 7, 076007. https://doi.org/10.1088/1741-4326/ab1858
Hanada, K. ; Yoshida, N. ; Hasegawa, M. ; Hatayama, A. ; Okamoto, K. ; Takagi, I. ; Hirata, T. ; Oya, Y. ; Miyamoto, M. ; Oya, M. ; Shikama, T. ; Kuzmin, A. ; Wang, Z. X. ; Long, H. ; Idei, H. ; Nagashima, Y. ; Nakamura, K. ; Watanabe, O. ; Onchi, T. ; Watanabe, H. ; Tokunaga, K. ; Higashijima, A. ; Kawasaki, S. ; Nagata, T. ; Shimabukuro, S. ; Takase, Y. ; Murakami, S. ; Gao, X. ; Liu, H. ; Qian, J. ; Raman, R. ; Ono, M. / Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST. In: Nuclear Fusion. 2019 ; Vol. 59, No. 7.
@article{3885fc605c714ca2b2be15f89c9f9a88,
title = "Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST",
abstract = "The fuel particle balance during long duration discharges in the Q-shu University Experiment with steady state spherical tokamak (QUEST) was investigated. QUEST has all-metal plasma facing walls (PFWs) that were temperature controlled during the experiments. The presence of a transport barrier for hydrogen (H) at the interface between a plasma-induced deposition layer and metallic substrate was confirmed by nuclear reaction analysis with exposing deuterium plasma. An effective method to evaluate global hydrogen flux to PFWs is proposed, taking advantage of the nature of wall saturation. The outgoing flux of fuel particles from the PFWs just after the plasma termination was proportional to the square of wall-stored H, which indicates that enhanced recombination of solved hydrogen played an essential role in dynamic retention and was in agreement with predictions from the H-barrier model. A simple calculation based on the combination of wall modelling and rate equations of the H states denoted a significant impact of wall modelling on the time response of the plasma density. Hence, a proper wall model including the effects of the deposition layer creating the H barrier is required to be developed, even for all-metal PFW devices.",
author = "K. Hanada and N. Yoshida and M. Hasegawa and A. Hatayama and K. Okamoto and I. Takagi and T. Hirata and Y. Oya and M. Miyamoto and M. Oya and T. Shikama and A. Kuzmin and Wang, {Z. X.} and H. Long and H. Idei and Y. Nagashima and K. Nakamura and O. Watanabe and T. Onchi and H. Watanabe and K. Tokunaga and A. Higashijima and S. Kawasaki and T. Nagata and S. Shimabukuro and Y. Takase and S. Murakami and X. Gao and H. Liu and J. Qian and R. Raman and M. Ono",
year = "2019",
month = "5",
day = "23",
doi = "10.1088/1741-4326/ab1858",
language = "English",
volume = "59",
journal = "Nuclear Fusion",
issn = "0029-5515",
publisher = "IOP Publishing Ltd.",
number = "7",

}

TY - JOUR

T1 - Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST

AU - Hanada, K.

AU - Yoshida, N.

AU - Hasegawa, M.

AU - Hatayama, A.

AU - Okamoto, K.

AU - Takagi, I.

AU - Hirata, T.

AU - Oya, Y.

AU - Miyamoto, M.

AU - Oya, M.

AU - Shikama, T.

AU - Kuzmin, A.

AU - Wang, Z. X.

AU - Long, H.

AU - Idei, H.

AU - Nagashima, Y.

AU - Nakamura, K.

AU - Watanabe, O.

AU - Onchi, T.

AU - Watanabe, H.

AU - Tokunaga, K.

AU - Higashijima, A.

AU - Kawasaki, S.

AU - Nagata, T.

AU - Shimabukuro, S.

AU - Takase, Y.

AU - Murakami, S.

AU - Gao, X.

AU - Liu, H.

AU - Qian, J.

AU - Raman, R.

AU - Ono, M.

PY - 2019/5/23

Y1 - 2019/5/23

N2 - The fuel particle balance during long duration discharges in the Q-shu University Experiment with steady state spherical tokamak (QUEST) was investigated. QUEST has all-metal plasma facing walls (PFWs) that were temperature controlled during the experiments. The presence of a transport barrier for hydrogen (H) at the interface between a plasma-induced deposition layer and metallic substrate was confirmed by nuclear reaction analysis with exposing deuterium plasma. An effective method to evaluate global hydrogen flux to PFWs is proposed, taking advantage of the nature of wall saturation. The outgoing flux of fuel particles from the PFWs just after the plasma termination was proportional to the square of wall-stored H, which indicates that enhanced recombination of solved hydrogen played an essential role in dynamic retention and was in agreement with predictions from the H-barrier model. A simple calculation based on the combination of wall modelling and rate equations of the H states denoted a significant impact of wall modelling on the time response of the plasma density. Hence, a proper wall model including the effects of the deposition layer creating the H barrier is required to be developed, even for all-metal PFW devices.

AB - The fuel particle balance during long duration discharges in the Q-shu University Experiment with steady state spherical tokamak (QUEST) was investigated. QUEST has all-metal plasma facing walls (PFWs) that were temperature controlled during the experiments. The presence of a transport barrier for hydrogen (H) at the interface between a plasma-induced deposition layer and metallic substrate was confirmed by nuclear reaction analysis with exposing deuterium plasma. An effective method to evaluate global hydrogen flux to PFWs is proposed, taking advantage of the nature of wall saturation. The outgoing flux of fuel particles from the PFWs just after the plasma termination was proportional to the square of wall-stored H, which indicates that enhanced recombination of solved hydrogen played an essential role in dynamic retention and was in agreement with predictions from the H-barrier model. A simple calculation based on the combination of wall modelling and rate equations of the H states denoted a significant impact of wall modelling on the time response of the plasma density. Hence, a proper wall model including the effects of the deposition layer creating the H barrier is required to be developed, even for all-metal PFW devices.

UR - http://www.scopus.com/inward/record.url?scp=85065514475&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85065514475&partnerID=8YFLogxK

U2 - 10.1088/1741-4326/ab1858

DO - 10.1088/1741-4326/ab1858

M3 - Article

AN - SCOPUS:85065514475

VL - 59

JO - Nuclear Fusion

JF - Nuclear Fusion

SN - 0029-5515

IS - 7

M1 - 076007

ER -