Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-27T15:19:27.709Z Has data issue: false hasContentIssue false
  • English
  • Français

Studies of the fast ion confinement in the Large Helical Device by using neutron measurement and integrated codes

Part of: Focus on Fusion

Published online by Cambridge University Press:  17 June 2020

H. Nuga Open the ORCID record for H. Nuga [Opens in a new window] ,
R. Seki Open the ORCID record for R. Seki [Opens in a new window] ,
K. Ogawa Open the ORCID record for K. Ogawa [Opens in a new window] ,
S. Kamio Open the ORCID record for S. Kamio [Opens in a new window] ,
Y. Fujiwara Open the ORCID record for Y. Fujiwara [Opens in a new window] ,
M. Osakabe Open the ORCID record for M. Osakabe [Opens in a new window] ,
M. Isobe Open the ORCID record for M. Isobe [Opens in a new window] ,
T. Nishitani Open the ORCID record for T. Nishitani [Opens in a new window] ,
M. Yokoyama Open the ORCID record for M. Yokoyama [Opens in a new window]  and
LHD Experiment Group
H. Nuga*
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan
R. Seki
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
K. Ogawa
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
S. Kamio
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan
Y. Fujiwara
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan
M. Osakabe
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
M. Isobe
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
T. Nishitani
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan
M. Yokoyama
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
LHD Experiment Group
Affiliation:
National Institute for Fusion Sciences, National Institutes of Natural Sciences, Toki, Japan
*
†Email address for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The neutral beam (NB) fast ion confinement in the Large Helical Device (LHD) is studied for several full field ($B_{t}\sim 2.75~\text{T}$) magnetic configurations by a combination of neutron measurement and simulations. To investigate the NB fast ion confinement, we have performed a series of short-pulse NB injection experiments. The experiment results are analysed by the integrated code TASK3D-a. From this investigation, the effective particle diffusion coefficients of the tangential and perpendicular NBs are approximately $D^{\text{eff}}\sim 0.1~\text{m}^{2}~\text{s}^{-1}$ and $D^{\text{eff}}\sim 1~\text{m}^{2}~\text{s}^{-1}$ in the standard configuration. It is clarified that the NB fast ion confinement improves when the plasmas are shifted inward. Moreover, it is also found that the simulation, which considers the deuteron dilution effect due to the presence of impurity ions, can describe a neutron emission rate consistent with the measurement.

Keywords

fusion plasmaplasma confinementplasma heating
Type
Research Article
Information
Journal of Plasma Physics , Volume 86 , Issue 3 , June 2020 , 815860306
Copyright
© The Author(s), 2020. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adams, J. M., Jarvis, O. N., Sadler, G. J., Syme, D. B. & Watkins, N. 1993 The jet neutron emission profile monitor. Nucl. Instrum. Meth. A 329 (1–2), 277–290.CrossRefGoogle Scholar
Anderson, J. K., Capecchi, W., Eilerman, S., Koliner, J. J., Nornberg, M. D., Reusch, J. A., Sarff, J. S. & Lin, L. 2014 Fast ion confinement in the three-dimensional helical reversed-field pinch. Plasma Phys. Control. Fusion 56 (9), 094006.CrossRefGoogle Scholar
Bosch, H.-S. & Hale, G. M. 1992 Improved formulas for fusion cross-sections and thermal reactivities. Nucl. Fusion 32 (4), 611–631.CrossRefGoogle Scholar
Chen, J., Ida, K., Yoshinuma, M., Murakami, I., Kobayashi, T., Ye, M. Y. & Lyu, B. 2019 Effect of energy dependent cross-section on flow velocity measurements with charge exchange spectroscopy in magnetized plasma. Phys. Lett. A 383 (12), 1293–1299.CrossRefGoogle Scholar
Darrow, D. S., Herrmann, H. W., Johnson, D. W., Marsala, R. J., Palladino, R. W., Zweben, S. J. & Tuszewski, M. 1995 Measurement of loss of dt fusion products using scintillator detectors in TFTR. Rev. Sci. Instrum. 66 (1), 476–482.CrossRefGoogle Scholar
Fiksel, G., Hudson, B., Den Hartog, D. J., Magee, R. M., O’Connell, R., Prager, S. C., Beklemishev, A. D., Davydenko, V. I., Ivanov, A. A. & Tsidulko, Y. A. 2005 Observation of weak impact of a stochastic magnetic field on fast-ion confinement. Phys. Rev. Lett. 95, 125001.CrossRefGoogle ScholarPubMed
Fujii, K., Goto, M., Morita, S.& LHD Experiment Group 2015 Study of neutral hydrogen transport in LHD core plasmas based on high dynamic-range Balmer-$\unicode[STIX]{x1D6FC}$ spectroscopy. Nucl. Fusion 55 (6), 063029.CrossRefGoogle Scholar
Fujiwara, Y., Kamio, S., Yamaguchi, H., Garcia, A. V., Stagner, L., Nuga, H., Seki, R., Ogawa, K., Isobe, M., Yokoyama, M. et al. 2019 Evaluation of an energetic particle profile using a tangential-fida diagnostic in the large helical device. Plasma Fusion Res. 14, 3402129.CrossRefGoogle Scholar
Gorelenkov, N. N., Pinches, S. D. & Toi, K. 2014 Energetic particle physics in fusion research in preparation for burning plasma experiments. Nucl. Fusion 54 (12), 125001.CrossRefGoogle Scholar
Goto, M., Sawada, K., Fujii, K., Hasuo, M. & Morita, S. 2011 Evaluation of hydrogen atom density in the plasma core region based on the Balmer-$\unicode[STIX]{x1D6FC}$ line profile. Nucl. Fusion 51 (2), 023005.CrossRefGoogle Scholar
Goto, M., Sawada, K., Oishi, T. & Morita, S. 2016 Particle source and edge confinement study based on spectroscopic diagnosis in the LHD. Plasma Phys. Control. Fusion 58 (8), 084001.CrossRefGoogle Scholar
Heidbrink, W. W., Barnes, C. W., Hammett, G. W., Kusama, Y., Scott, S. D., Zarnstorff, M. C., Johnson, L. C., McCune, D., Medley, S. S., Park, H. K. et al. 1991 The diffusion of fast ions in ohmic TFTR discharges. Phys. Fluids B 3 (11), 3167–3170.CrossRefGoogle Scholar
Heidbrink, W. W., Kim, J. & Groebner, R. J. 1988 Comparison of experimental and theoretical fast ion slowing-down times in DIII-D. Nucl. Fusion 28 (10), 1897–1901.CrossRefGoogle Scholar
Heidbrink, W. W., Luo, Y., Burrell, K. H., Harvey, R. W., Pinsker, R. I. & Ruskov, E. 2007 Measurements of fast-ion acceleration at cyclotron harmonics using Balmer-alpha spectroscopy. Plasma Phys. Control. Fusion 49 (9), 1457–1475.CrossRefGoogle Scholar
Heidbrink, W. W., Miah, M., Darrow, D., LeBlanc, B., Medley, S. S., Roquemore, A. L. & Cecil, F. E. 2003 The confinement of dilute populations of beam ions in the national spherical torus experiment. Nucl. Fusion 43 (9), 883–888.CrossRefGoogle Scholar
Heidbrink, W. W. & Sadler, G. J. 1994 The behaviour of fast ions in tokamak experiments. Nucl. Fusion 34 (4), 535–615.CrossRefGoogle Scholar
Hirshman, S. P. & Whitson, J. C. 1983 Steepest-descent moment method for three-dimensional magnetohydrodynamic equilibria. Phys. Fluids 26 (12), 3553–3568.CrossRefGoogle Scholar
Huang, X., Morita, S., Oishi, T., Goto, M. & Zhang, H. 2015 Evaluation of zeff profile in low-density and high-ti discharges with carbon pellet injection based on space-resolved euv spectroscopy in LHD. Plasma Fusion Res. 10, 3402036.CrossRefGoogle Scholar
Ida, K., Yoshinuma, M., Kobayashi, T., Fujiwara, Y., Chen, J., Murakami, I., Kisaki, M., Osakabe, M.& LHD Experiment Group 2019 Verification of carbon density profile measurements with charge exchange spectroscopy using hydrogen and deuterium neutral beams. Plasma Fusion Res. 14, 1402079.CrossRefGoogle Scholar
Ishikawa, M., Takechi, M., Shinohara, K., Cheng, C.-Z., Matsunaga, G., Kusama, Y., Fukuyama, A., Nishitani, T., Morioka, A., Sasao, M. et al. 2007 Confinement degradation and transport of energetic ions due to Alfvén eigenmodes in jt-60u weak shear plasmas. Nucl. Fusion 47 (8), 849–855.CrossRefGoogle Scholar
Isobe, M., Ogawa, K., Nishitani, T., Miyake, H., Kobuchi, T., Pu, N., Kawase, H., Takada, E., Tanaka, T., Li, S. et al. 2018 Neutron diagnostics in the large helical device. IEEE Trans. Plasma Sci. 46, 2050–2058.Google Scholar
Isobe, M., Sasao, M., Okamura, S., Kondo, T., Murakami, S., Minami, T., Kado, S., Ida, K., Shimizu, A., Osakabe, M. et al. 2001 Experimental investigation of the ripple induced losses of perpendicularly injected beam ions in the low aspect ratio helical system chs. Nucl. Fusion 41 (9), 1273–1281.CrossRefGoogle Scholar
Kamio, S., Fujiwara, Y., Ogawa, K., Isobe, M., Seki, R., Nuga, H., Nishitani, T., Osakabe, M.& LHD Experiment Group 2019 Development of NPA array using single crystal cvd diamond detectors. J. Instrum. 14 (08), C08002.CrossRefGoogle Scholar
Karney, C. F. F. 1986 Fokker–Planck and quasilinear codes. Comput. Phys. Rep. 4, 183–244.CrossRefGoogle Scholar
Kawahata, K., Peterson, B. J., Akiyama, T., Ashikawa, N., Emoto, M., Funaba, H., Hamada, Y., Ida, K., Inagaki, S., Ido, T. et al. 2010 Overview of LHD plasma diagnostics. Fusion Sci. Technol. 58 (1), 331–344.CrossRefGoogle Scholar
Luo, Y., Heidbrink, W. W. & Burrell, K. H. 2004 Design of a d-alpha beam-ion profile diagnostic. Rev. Sci. Instrum. 75 (10), 3468–3470.CrossRefGoogle Scholar
Medley, S. S. & Roquemore, A. L. 1998 Construction and operation of parallel electric and magnetic field spectrometers for mass/energy resolved multi-ion charge exchange diagnostics on the tokamak fusion test reactor. Rev. Sci. Instrum. 69 (7), 2651–2662.CrossRefGoogle Scholar
Mikkelsen, D. R. 1989 Approximation for non-resonant beam target fusion reactivities. Nucl. Fusion 29 (7), 1113–1115.CrossRefGoogle Scholar
Murakami, S., Nakajima, N. & Okamoto, M. 1995 Finite beta effect on the icrf abd NBI heating in the large helical device. Trans. Fusion Technol. 27, 256–259.CrossRefGoogle Scholar
Murakami, S., Wakasa, A., Maaßberg, H., Beidler, C. D., Yamada, H., Watanabe, K. Y.& LHD Experimental Group 2002 Neoclassical transport optimization of LHD. Nucl. Fusion 42 (11), L19–L22.CrossRefGoogle Scholar
Narihara, K., Yamada, I., Hayashi, H. & Yamauchi, K. 2001 Design and performance of the thomson scattering diagnostic on LHD. Rev. Sci. Instrum. 72 (1), 1122–1125.CrossRefGoogle Scholar
Nuga, H., Seki, R., Ogawa, K., Kamio, S., Fujiwara, Y., Osakabe, M., Isobe, M., Nishitani, T., Yokoyama, M.& LHD Experiment Group 2019 Analysis of energetic particle confinement in LHD using neutron measurement and simulation codes. Plasma Fusion Res. 14, 3402075.CrossRefGoogle Scholar
Ogawa, K., Isobe, M., Nishitani, T., Murakami, S., Seki, R., Nuga, H., Kamio, S., Fujiwara, Y., Yamaguchi, H., Saito, Y. et al. 2019 Energetic ion confinement studies using comprehensive neutron diagnostics in the large helical device. Nucl. Fusion 59 (7), 076017.CrossRefGoogle Scholar
Ogawa, K., Isobe, M., Toi, K., Watanabe, F., Spong, D. A., Shimizu, A., Osakabe, M., Ohdachi, S., Sakakibara, S.& LHD Experiment Group 2010 Observation of energetic-ion losses induced by various MHD instabilities in the large helical device (LHD). Nucl. Fusion 50 (8), 084005.CrossRefGoogle Scholar
Osakabe, M., Isobe, M., Tanaka, M., Motojima, G., Tsumori, K., Yokoyama, M., Morisaki, T. & Takeiri, Y. 2018 Preparation and commissioning for the LHD deuterium experiment. IEEE Trans. Plasma Sci. 46, 2324–2331.Google Scholar
Osakabe, M., Takeiri, Y., Morisaki, T., Motojima, G., Ogawa, K., Isobe, M., Tanaka, M., Murakami, S., Shimizu, A., Nagaoka, K. et al. 2017 Current status of large helical device and its prospect for deuterium experiment. Fusion Sci. Technol. 72 (3), 199–210.Google Scholar
Osakabe, M., Yamamoto, S., Toi, K., Takeiri, Y., Sakakibara, S., Nagaoka, K., Tanaka, K., Narihara, K.& LHD Experimental Group 2006 Experimental observations of enhanced radial transport of energetic particles with Alfvén eigenmode on the LHD. Nucl. Fusion 46 (10), S911–S917.CrossRefGoogle Scholar
Ruskov, E., Bell, M., Budny, R. V., McCune, D. C., Medley, S. S., Redi, M. H., Scott, S., Synakowski, E. J., von Goeler, S., White, R. B. et al. 1999 Anomalous beam-ion loss in TFTR reversed magnetic shear plasmas. Phys. Rev. Lett. 82, 924–927.CrossRefGoogle Scholar
Sato, M., Murakami, S., Fukuyama, A., Nakamura, Y., Watanabe, K. Y., Toda, S., Yokoyama, M., Funaba, H., Yamada, H. & Nakajima, N. 2008 Implementation of NBI heating module fit3d to hierarchy-integrated simulation code task3d. In Proc. 18th Int. Toki Conf. National Institute for Fusion Science.Google Scholar
Seki, R., Ogawa, K., Isobe, M., Yokoyama, M., Murakami, S., Nuga, H., Kamio, S., Fujiwara, Y., Osakabe, M.& LHD Experiment Group 2019 Evaluation of neutron emission rate with fit3d-dd code in large helical device. Plasma Fusion Res. 14, 3402126.CrossRefGoogle Scholar
Strachan, J. D., Colestock, P. L., Davis, S. L., Eames, D., Efthimion, P. C., Eubank, H. P., Goldston, R. J., Grisham, L. R., Hawryluk, R. J., Hosea, J. C. et al. 1981 Fusion neutron production during deuterium neutral-beam injection into the plt tokamak. Nucl. Fusion 21 (1), 67–81.CrossRefGoogle Scholar
Takeiri, Y. 2018a The large helical device: Entering deuterium experiment phase toward steady-state helical fusion reactor based on achievements in hydrogen experiment phase. IEEE Trans. Plasma Sci. 46, 2348–2353.Google Scholar
Takeiri, Y. 2018b Prospect toward steady-state helical fusion reactor based on progress of LHD project entering the deuterium experiment phase. IEEE Trans. Plasma Sci. 46 (5), 1141–1148.Google Scholar
Takeiri, Y., Kaneko, O., Tsumori, K., Osakabe, M., Ikeda, K., Nagaoka, K., Nakano, H., Asano, E., Kondo, T., Sato, M. et al. 2010 High performance of neutral beam injectors for extension of LHD operational regime. Fusion Sci. Technol. 58 (1), 482–488.CrossRefGoogle Scholar
Tobita, K., Tani, K., Nishitani, T., Nagashima, K. & Kusama, Y. 1994 Fast ion losses due to toroidal field ripple in jt-60u. Nucl. Fusion 34 (8), 1097–1109.CrossRefGoogle Scholar
Vincenzi, P., Bolzonella, T., Murakami, S., Osakabe, M., Seki, R. & Yokoyama, M. 2016 Upgrades and application of fit3d NBI–plasma interaction code in view of LHD deuterium campaigns. Plasma Phys. Control. Fusion 58 (12), 125008.CrossRefGoogle Scholar
Yamada, I., Narihara, K., Funaba, H., Minami, T., Hayashi, H., Kohmoto, T.& LHD Experiment Group 2010 Recent progress of the LHD Thomson scattering system. Fusion Sci. Technol. 58 (1), 345–351.CrossRefGoogle Scholar
Yokoyama, M., Seki, R., Suzuki, C., Sato, M., Emoto, M., Murakami, S., Osakabe, M., Tsujimura, T. I., Yoshimura, Y., Ido, T. et al. 2017 Extended capability of the integrated transport analysis suite, task3d-a, for LHD experiment. Nucl. Fusion 57 (12), 126016.CrossRefGoogle Scholar
Zhang, Y. P., Isobe, M., Liu, Y., Yuan, G. L., Yang, J. W., Song, X. Y., Song, X. M., Cao, J. Y., Lei, G. J., Wei, H. L. et al. 2012 Measurements of the fast ion slowing-down times in the hl-2a tokamak and comparison to classical theory. Phys. Plasmas 19 (11), 112504.Google Scholar
Zhou, H., Morita, S., Goto, M., Dong, C., Yanagibayashi, J. & Hasuo, M. 2010 $Z_{\text{eff}}$ measurement using extreme ultraviolet Bremsstrahlung emission in LHD. Rev. Sci. Instrum. 81 (10), 10D706.Google ScholarPubMed