Role of core radiation during slow oscillations in LHD

B. J. Peterson, Y. Nakamura, K. Yamazaki, N. Noda, J. Rice, Y. Takeiri, M. Goto, K. Narihara, K. Tanaka, K. Sato, S. Masuzaki, S. Sakakibara, K. Ida, H. Funaba, M. Shoji, M. Osakabe, M. Sato, Yuhong Xu, T. Kobuchi, N. Ashikawa & 54 others P. C. De Vries, M. Emoto, Hiroshi Idei, K. Ikeda, Inagaki Shigeru, N. Inoue, M. Isobe, S. Kado, K. Khlopenkov, S. Kubo, R. Kumazawa, T. Minami, J. Miyazawa, T. Morisaki, S. Murakami, S. Muto, T. Mutoh, Y. Nagayama, H. Nakanishi, K. Nishimura, T. Notake, Y. Liang, S. Ohdachi, Y. Oka, T. Ozaki, R. O. Pavlichenko, A. Sagara, K. Saito, R. Sakamoto, H. Sasao, M. Sasao, T. Seki, T. Shimozuma, H. Suzuki, M. Takechi, N. Tamura, K. Toi, T. Tokuzawa, Y. Torii, K. Tsumori, I. Yamada, S. Yamaguchi, S. Yamamoto, M. Yokoyama, Y. Yoshimura, K. Y. Watanabe, T. Watari, K. Kawahata, O. Kaneko, N. Ohyabu, H. Yamada, A. Komori, S. Sudo, O. Motojima

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

During experiments in LHD using stainless steel divertor plates, a slow (∼1 s) cyclic oscillation in the plasma parameters known as 'breathing' plasma was observed during NBI heated long pulse discharges. Using an average ion, corona equilibrium model for the iron impurity cooling rate, the iron impurity density profile is calculated for 0.0 < ρ < 0.8 from the measured electron temperature and density profiles and radiation profile data for these discharges in LHD. This calculated iron density oscillates out of phase with the electron density and peaks near ρ = 0.4 at a fraction of the electron density that varies by a factor of 4. This is in qualitative agreement with spectroscopic measurements of iron that show a similar oscillation. The correlation of the iron impurity concentration with the change in electron temperature and with the local power balance between radiation and beam deposition indicates that when radiation from the iron impurity dominates the local power balance the core plasma is cooled. The increase in the calculated iron density during the phase of the oscillation when the divertor electron temperature exceeds the sputtering threshold suggests that sputtering of the stainless steel divertor plate may be the source of the iron impurity. Evidence of changing transport points to the need for a closer examination of the role of impurity transport in this oscillation.

Original languageEnglish
Pages (from-to)519-525
Number of pages7
JournalNuclear Fusion
Volume41
Issue number5
DOIs
Publication statusPublished - May 1 2001

Fingerprint

iron
oscillations
radiation
impurities
electron energy
stainless steels
profiles
sputtering
breathing
temperature profiles
coronas
examination
cooling
thresholds
pulses
ions

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

Peterson, B. J., Nakamura, Y., Yamazaki, K., Noda, N., Rice, J., Takeiri, Y., ... Motojima, O. (2001). Role of core radiation during slow oscillations in LHD. Nuclear Fusion, 41(5), 519-525. https://doi.org/10.1088/0029-5515/41/5/305

Role of core radiation during slow oscillations in LHD. / Peterson, B. J.; Nakamura, Y.; Yamazaki, K.; Noda, N.; Rice, J.; Takeiri, Y.; Goto, M.; Narihara, K.; Tanaka, K.; Sato, K.; Masuzaki, S.; Sakakibara, S.; Ida, K.; Funaba, H.; Shoji, M.; Osakabe, M.; Sato, M.; Xu, Yuhong; Kobuchi, T.; Ashikawa, N.; De Vries, P. C.; Emoto, M.; Idei, Hiroshi; Ikeda, K.; Shigeru, Inagaki; Inoue, N.; Isobe, M.; Kado, S.; Khlopenkov, K.; Kubo, S.; Kumazawa, R.; Minami, T.; Miyazawa, J.; Morisaki, T.; Murakami, S.; Muto, S.; Mutoh, T.; Nagayama, Y.; Nakanishi, H.; Nishimura, K.; Notake, T.; Liang, Y.; Ohdachi, S.; Oka, Y.; Ozaki, T.; Pavlichenko, R. O.; Sagara, A.; Saito, K.; Sakamoto, R.; Sasao, H.; Sasao, M.; Seki, T.; Shimozuma, T.; Suzuki, H.; Takechi, M.; Tamura, N.; Toi, K.; Tokuzawa, T.; Torii, Y.; Tsumori, K.; Yamada, I.; Yamaguchi, S.; Yamamoto, S.; Yokoyama, M.; Yoshimura, Y.; Watanabe, K. Y.; Watari, T.; Kawahata, K.; Kaneko, O.; Ohyabu, N.; Yamada, H.; Komori, A.; Sudo, S.; Motojima, O.

In: Nuclear Fusion, Vol. 41, No. 5, 01.05.2001, p. 519-525.

Research output: Contribution to journalArticle

Peterson, BJ, Nakamura, Y, Yamazaki, K, Noda, N, Rice, J, Takeiri, Y, Goto, M, Narihara, K, Tanaka, K, Sato, K, Masuzaki, S, Sakakibara, S, Ida, K, Funaba, H, Shoji, M, Osakabe, M, Sato, M, Xu, Y, Kobuchi, T, Ashikawa, N, De Vries, PC, Emoto, M, Idei, H, Ikeda, K, Shigeru, I, Inoue, N, Isobe, M, Kado, S, Khlopenkov, K, Kubo, S, Kumazawa, R, Minami, T, Miyazawa, J, Morisaki, T, Murakami, S, Muto, S, Mutoh, T, Nagayama, Y, Nakanishi, H, Nishimura, K, Notake, T, Liang, Y, Ohdachi, S, Oka, Y, Ozaki, T, Pavlichenko, RO, Sagara, A, Saito, K, Sakamoto, R, Sasao, H, Sasao, M, Seki, T, Shimozuma, T, Suzuki, H, Takechi, M, Tamura, N, Toi, K, Tokuzawa, T, Torii, Y, Tsumori, K, Yamada, I, Yamaguchi, S, Yamamoto, S, Yokoyama, M, Yoshimura, Y, Watanabe, KY, Watari, T, Kawahata, K, Kaneko, O, Ohyabu, N, Yamada, H, Komori, A, Sudo, S & Motojima, O 2001, 'Role of core radiation during slow oscillations in LHD', Nuclear Fusion, vol. 41, no. 5, pp. 519-525. https://doi.org/10.1088/0029-5515/41/5/305
Peterson BJ, Nakamura Y, Yamazaki K, Noda N, Rice J, Takeiri Y et al. Role of core radiation during slow oscillations in LHD. Nuclear Fusion. 2001 May 1;41(5):519-525. https://doi.org/10.1088/0029-5515/41/5/305
Peterson, B. J. ; Nakamura, Y. ; Yamazaki, K. ; Noda, N. ; Rice, J. ; Takeiri, Y. ; Goto, M. ; Narihara, K. ; Tanaka, K. ; Sato, K. ; Masuzaki, S. ; Sakakibara, S. ; Ida, K. ; Funaba, H. ; Shoji, M. ; Osakabe, M. ; Sato, M. ; Xu, Yuhong ; Kobuchi, T. ; Ashikawa, N. ; De Vries, P. C. ; Emoto, M. ; Idei, Hiroshi ; Ikeda, K. ; Shigeru, Inagaki ; Inoue, N. ; Isobe, M. ; Kado, S. ; Khlopenkov, K. ; Kubo, S. ; Kumazawa, R. ; Minami, T. ; Miyazawa, J. ; Morisaki, T. ; Murakami, S. ; Muto, S. ; Mutoh, T. ; Nagayama, Y. ; Nakanishi, H. ; Nishimura, K. ; Notake, T. ; Liang, Y. ; Ohdachi, S. ; Oka, Y. ; Ozaki, T. ; Pavlichenko, R. O. ; Sagara, A. ; Saito, K. ; Sakamoto, R. ; Sasao, H. ; Sasao, M. ; Seki, T. ; Shimozuma, T. ; Suzuki, H. ; Takechi, M. ; Tamura, N. ; Toi, K. ; Tokuzawa, T. ; Torii, Y. ; Tsumori, K. ; Yamada, I. ; Yamaguchi, S. ; Yamamoto, S. ; Yokoyama, M. ; Yoshimura, Y. ; Watanabe, K. Y. ; Watari, T. ; Kawahata, K. ; Kaneko, O. ; Ohyabu, N. ; Yamada, H. ; Komori, A. ; Sudo, S. ; Motojima, O. / Role of core radiation during slow oscillations in LHD. In: Nuclear Fusion. 2001 ; Vol. 41, No. 5. pp. 519-525.
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abstract = "During experiments in LHD using stainless steel divertor plates, a slow (∼1 s) cyclic oscillation in the plasma parameters known as 'breathing' plasma was observed during NBI heated long pulse discharges. Using an average ion, corona equilibrium model for the iron impurity cooling rate, the iron impurity density profile is calculated for 0.0 < ρ < 0.8 from the measured electron temperature and density profiles and radiation profile data for these discharges in LHD. This calculated iron density oscillates out of phase with the electron density and peaks near ρ = 0.4 at a fraction of the electron density that varies by a factor of 4. This is in qualitative agreement with spectroscopic measurements of iron that show a similar oscillation. The correlation of the iron impurity concentration with the change in electron temperature and with the local power balance between radiation and beam deposition indicates that when radiation from the iron impurity dominates the local power balance the core plasma is cooled. The increase in the calculated iron density during the phase of the oscillation when the divertor electron temperature exceeds the sputtering threshold suggests that sputtering of the stainless steel divertor plate may be the source of the iron impurity. Evidence of changing transport points to the need for a closer examination of the role of impurity transport in this oscillation.",
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T1 - Role of core radiation during slow oscillations in LHD

AU - Peterson, B. J.

AU - Nakamura, Y.

AU - Yamazaki, K.

AU - Noda, N.

AU - Rice, J.

AU - Takeiri, Y.

AU - Goto, M.

AU - Narihara, K.

AU - Tanaka, K.

AU - Sato, K.

AU - Masuzaki, S.

AU - Sakakibara, S.

AU - Ida, K.

AU - Funaba, H.

AU - Shoji, M.

AU - Osakabe, M.

AU - Sato, M.

AU - Xu, Yuhong

AU - Kobuchi, T.

AU - Ashikawa, N.

AU - De Vries, P. C.

AU - Emoto, M.

AU - Idei, Hiroshi

AU - Ikeda, K.

AU - Shigeru, Inagaki

AU - Inoue, N.

AU - Isobe, M.

AU - Kado, S.

AU - Khlopenkov, K.

AU - Kubo, S.

AU - Kumazawa, R.

AU - Minami, T.

AU - Miyazawa, J.

AU - Morisaki, T.

AU - Murakami, S.

AU - Muto, S.

AU - Mutoh, T.

AU - Nagayama, Y.

AU - Nakanishi, H.

AU - Nishimura, K.

AU - Notake, T.

AU - Liang, Y.

AU - Ohdachi, S.

AU - Oka, Y.

AU - Ozaki, T.

AU - Pavlichenko, R. O.

AU - Sagara, A.

AU - Saito, K.

AU - Sakamoto, R.

AU - Sasao, H.

AU - Sasao, M.

AU - Seki, T.

AU - Shimozuma, T.

AU - Suzuki, H.

AU - Takechi, M.

AU - Tamura, N.

AU - Toi, K.

AU - Tokuzawa, T.

AU - Torii, Y.

AU - Tsumori, K.

AU - Yamada, I.

AU - Yamaguchi, S.

AU - Yamamoto, S.

AU - Yokoyama, M.

AU - Yoshimura, Y.

AU - Watanabe, K. Y.

AU - Watari, T.

AU - Kawahata, K.

AU - Kaneko, O.

AU - Ohyabu, N.

AU - Yamada, H.

AU - Komori, A.

AU - Sudo, S.

AU - Motojima, O.

PY - 2001/5/1

Y1 - 2001/5/1

N2 - During experiments in LHD using stainless steel divertor plates, a slow (∼1 s) cyclic oscillation in the plasma parameters known as 'breathing' plasma was observed during NBI heated long pulse discharges. Using an average ion, corona equilibrium model for the iron impurity cooling rate, the iron impurity density profile is calculated for 0.0 < ρ < 0.8 from the measured electron temperature and density profiles and radiation profile data for these discharges in LHD. This calculated iron density oscillates out of phase with the electron density and peaks near ρ = 0.4 at a fraction of the electron density that varies by a factor of 4. This is in qualitative agreement with spectroscopic measurements of iron that show a similar oscillation. The correlation of the iron impurity concentration with the change in electron temperature and with the local power balance between radiation and beam deposition indicates that when radiation from the iron impurity dominates the local power balance the core plasma is cooled. The increase in the calculated iron density during the phase of the oscillation when the divertor electron temperature exceeds the sputtering threshold suggests that sputtering of the stainless steel divertor plate may be the source of the iron impurity. Evidence of changing transport points to the need for a closer examination of the role of impurity transport in this oscillation.

AB - During experiments in LHD using stainless steel divertor plates, a slow (∼1 s) cyclic oscillation in the plasma parameters known as 'breathing' plasma was observed during NBI heated long pulse discharges. Using an average ion, corona equilibrium model for the iron impurity cooling rate, the iron impurity density profile is calculated for 0.0 < ρ < 0.8 from the measured electron temperature and density profiles and radiation profile data for these discharges in LHD. This calculated iron density oscillates out of phase with the electron density and peaks near ρ = 0.4 at a fraction of the electron density that varies by a factor of 4. This is in qualitative agreement with spectroscopic measurements of iron that show a similar oscillation. The correlation of the iron impurity concentration with the change in electron temperature and with the local power balance between radiation and beam deposition indicates that when radiation from the iron impurity dominates the local power balance the core plasma is cooled. The increase in the calculated iron density during the phase of the oscillation when the divertor electron temperature exceeds the sputtering threshold suggests that sputtering of the stainless steel divertor plate may be the source of the iron impurity. Evidence of changing transport points to the need for a closer examination of the role of impurity transport in this oscillation.

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