Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-05T08:01:57.841Z Has data issue: false hasContentIssue false
  • English
  • Français

Reduced models of turbulent transport in helical plasmas including effects of zonal flows and trapped electrons

Part of: Focus on Fusion

Published online by Cambridge University Press:  26 May 2020

S. Toda Open the ORCID record for S. Toda [Opens in a new window] ,
M. Nunami Open the ORCID record for M. Nunami [Opens in a new window]  and
H. Sugama Open the ORCID record for H. Sugama [Opens in a new window]
S. Toda*
Affiliation:
National Institute for Fusion Science/The Graduate University for Advanced Studies, Toki 509-5292, Gifu, Japan
M. Nunami
Affiliation:
National Institute for Fusion Science/The Graduate University for Advanced Studies, Toki 509-5292, Gifu, Japan
H. Sugama
Affiliation:
National Institute for Fusion Science/The Graduate University for Advanced Studies, Toki 509-5292, Gifu, Japan
*
†Email address for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Using transport models, the impacts of trapped electrons on zonal flows and turbulence in helical field configurations are studied. The effect of the trapped electrons on the characteristic quantities of the linear response for zonal flows is investigated for two different field configurations in the Large Helical Device. The turbulent potential fluctuation, zonal flow potential fluctuation and ion energy transport are quickly predicted by the reduced models for which the linear and nonlinear simulation results are used to determine dimensionless parameters related to turbulent saturation levels and typical zonal flow wavenumbers. The effects of zonal flows on the turbulent transport for the case of the kinetic electron response are much smaller than or comparable to those in an adiabatic electron condition for the two different field configurations. It is clarified that the effect of zonal flows on the turbulent transport due to the trapped electrons changes, depending on the field configurations.

Keywords

plasma instabilitiesplasma confinementplasma simulation
Type
Research Article
Information
Journal of Plasma Physics , Volume 86 , Issue 3 , June 2020 , 815860304
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

Barnes, M., Abel, I. G., Dorland, W., Görler, T., Hammett, G. W. & Jenko, F. 2010 Direct multiscale coupling of a transport code to gyrokinetic turbulence codes. Phys. Plasmas 17, 056109.CrossRefGoogle Scholar
Candy, J., Holland, C., Waltz, R. E., Fahey, M. R. & Belli, E. 2009 Tokamak profile prediction using direct gyrokinetic and neoclassical simulation. Phys. Plasmas 16, 060704.CrossRefGoogle Scholar
Candy, J. & Waltz, R. E. 2003 An Eulerian gyrokinetic-maxwell solver. J. Comput. Phys. 186, 545.CrossRefGoogle Scholar
Connor, J. W. & Wilson, H. R. 1994 Survey of theories of anomalous transport. Plasma Phys. Control. Fusion 36, 719.CrossRefGoogle Scholar
Ferrando-Margalet, S., Sugama, H. & Watanabe, T.-H. 2007 Zonal flows and ion temperature gradient instabilities in multiple-helicity magnetic fields. Phys. Plasmas 14, 122505.CrossRefGoogle Scholar
Garbet, X., Idomura, Y., Villard, L. & Watanabe, T.-H. 1994 Gyrokinetic simulations of turbulent transport. Plasma Phys. Control. Fusion 36, 719.Google Scholar
Holland, C., Schmitz, L., Rhodes, T. L., Peebles, W. A., Hillesheim, J. C., Wang, G., Zeng, L., Doyle, E. J., Smith, S. P., Prater, R. et al. 2011 Advances in validating gyrokinetic turbulence models against L- and H-mode plasmas. Phys. Plasmas 18, 056113.CrossRefGoogle Scholar
Horton, W. 2017 Turbulence Transport in Magnetized Plasmas, 2nd edn.World Scientific Publishing Co Inc.CrossRefGoogle Scholar
Ishizawa, A., Kishimoto, Y., Watanabe, T.-H., Sugama, H., Tanaka, K., Satake, S., Kobayashi, A., Nagasaki, K. & Nakamura, Y. 2017 Multi-machine analysis of turbulent transport in helical systems via gyrokinetic simulation. Nucl. Fusion 57, 066010.CrossRefGoogle Scholar
Ishizawa, A., Watanabe, T.-H., Sugama, H., Maeyama, S. & Nakajima, N. 2014 Electromagnetic gyrokinetic turbulence in finite-beta helical plasmas. Phys. Plasmas 21, 055905.CrossRefGoogle Scholar
Ishizawa, A., Watanabe, T.-H., Sugama, H., Nunami, M., Tanaka, K., Maeyama, S. & Nakajima, N. 2015 Turbulent transport of heat and particles in a high ion temperature discharge of the Large Helical Device. Phys. Plasmas 55, 043024.Google Scholar
Jenko, F. & Dorland, W. 2001 Nonlinear electromagnetic gyrokinetic simulations of tokamak plasmas. Plasma Phys. Control. Fusion 43, A141.CrossRefGoogle Scholar
Kinsey, J. E., Staebler, G. M. & Waltz, R. E. 2008 The first transport code simulations using the trapped gyro-Landau-fluid model. Phys. Plasmas 15, 055908.CrossRefGoogle Scholar
Kotschenreuther, M., Dorland, W., Beer, M. A. & Hammet, G. W. 1995 Quantitative predictions of tokamak energy confinement from first principles simulations with kinetic effects. Phys. Plasmas 2, 2381.CrossRefGoogle Scholar
Monreal, P., Calvo, I., Sánchez, E., Parra, F., Bustos, A., Könies, A., Kleiber, R. & Görler, T. 2016 Residual zonal flows in tokamaks and stellarators at arbitrary wavelengths. Plasma Phys. Control. Fusion 58, 045018.CrossRefGoogle Scholar
Nakata, M., Honda, M., Yoshida, M., Urano, H., Maeyama, S., Nunami, M. & Watanabe, T.-H. 2014 Gyrokinetic analysis of turbulent heat and particle transport on JT-60U plasmas. In 25th IAEA Fusion Energy Conference St. Petersburg, Russian Federation October 13–18, TH/P7-34.Google Scholar
Nakata, M., Honda, M., Yoshida, M., Urano, H., Nunami, M., Maeyama, S., Watanabe, T.-H. & Sugama, H. 2016 Validation studies of gyrokinetic ITG and TEM turbulence simulations in a JT-60U tokamak using multiple flux matching. Nucl. Fusion 56, 086010.CrossRefGoogle Scholar
Nunami, M., Watanabe, T.-H. & Sugama, H. 2013 A reduced model for ion temperature gradient turbulent transport in helical plasmas. Phys. Plasmas 20, 092307.CrossRefGoogle Scholar
Nunami, M., Watanabe, T.-H., Sugama, H. & Tanaka, K. 2011 Linear gyrokinetic analyses of ITG modes and zonal flows in LHD with high ion temperature. Plasma Fusion Res. 6, 1403001.CrossRefGoogle Scholar
Nunami, M., Watanabe, T.-H., Sugama, H. & Tanaka, K. 2012 Gyrokinetic turbulent transport simulation of a high ion temperature plasma in large helical device experiment. Phys. Plasmas 19, 042504.CrossRefGoogle Scholar
Rhodes, T. L., Holland, C., Smith, S. P., White, A. E., Burrell, K. H., Candy, J., DeBoo, J. C., Doyle, E. J., Hillesheim, J. C., Kinsey, J. E. et al. 2011 L-mode validation studies of gyrokinetic turbulence simulations via multiscale and multifield turbulence measurements on the DIII-D tokamak. Nucl. Fusion 51, 063022.CrossRefGoogle Scholar
Sugama, H. & Watanabe, T.-H. 2006 Collisionless damping of zonal flows in helical systems. Phys. Plasmas 13, 012501.CrossRefGoogle Scholar
Tanaka, K., Micheal, C., Vyacheslavov, L., Funaba, H., Yokoyama, M., Ida, K., Yoshinuma, M., Nagaoka, K., Murakami, S., Wakasa, A. et al. 2010 Turbulence response in the high $T_{\text{i}}$ discharge of the LHD. Plasma Fusion Res. 5, S2053.CrossRefGoogle Scholar
Toda, S., Nakata, M., Nunami, M., Ishizawa, A., Watanabe, T.-H. & Sugama, H. 2017 A reduced transport model for ion heat diffusivity by gyro-kinetic analysis with kinetic electrons in helical plasmas. Plasma Fusion Res. 12, 1303035.CrossRefGoogle Scholar
Toda, S., Nakata, M., Nunami, M., Ishizawa, A., Watanabe, T.-H. & Sugama, H. 2019a Modeling of turbulent particle and heat transport in helical plasmas based on gyrokinetic analysis. Phys. Plasmas 26, 012510.CrossRefGoogle Scholar
Toda, S., Nakata, M., Nunami, M., Ishizawa, A., Watanabe, T.-H. & Sugama, H. 2019b Transport simulation for helical plasmas by use of gyrokinetic transport model. Plasma Fusion Res. 14, 3403061.CrossRefGoogle Scholar
Toda, S., Nunami, M., Ishizawa, A., Watanabe, T.-H. & Sugama, H. 2014 How to apply a turbulent transport model based on a gyrokinetic simulation for the ion temperature gradient mode in helical plasmas. J. Phys.: Conf. Ser. 561, 012020.Google Scholar
Toda, S., Nunami, M., Murakami, S., Ishizawa, A., Watanabe, T.-H. & Sugama, H. 2015 Progress in applying gyrokinetic heat diffusivity model to transport simulations for helical plasmas. In 20th International Stellarator-Heliotron Workshop, October, Greifswald, Germany, P1S2-24.Google Scholar
Watanabe, T.-H. & Sugama, H. 2006 Velocity–space structures of distribution function in toroidal ion temperature gradient turbulence. Nucl. Fusion 46, 24.CrossRefGoogle Scholar
Watanabe, T.-H., Sugama, H. & Ferrando-Margalet, S. 2007 Gyrokinetic simulation of zonal flows and ion temperature gradient turbulence in helical systems. Nucl. Fusion 47, 1383.CrossRefGoogle Scholar
Watanabe, T.-H., Sugama, H. & Ferrando-Margalet, S. 2008 Reduction of turbulent transport with zonal flows enhanced in helical systems. Phys. Rev. Lett. 100, 195002.CrossRefGoogle ScholarPubMed
Xanthopoulos, P., Merz, F., Görler, T. & Jenko, F. 2007 Nonlinear gyrokinetic simulations of ion-temperature-gradient turbulence for the optimized Wendelstein 7-X stellarator. Phys. Rev. Lett. 99, 035002.CrossRefGoogle ScholarPubMed