Czechoslovak Journal of Physics

, Volume 55, Issue 12, pp 1557–1567 | Cite as

Local 3D perturbation experiments for probing the ELM stability

  • P. T. Lang
  • J. Hobirk
  • L. D. Horton
  • A. Kallenbach
  • M. Maraschek
  • V. Mertens
  • R. Neu
  • J. Neuhauser
  • T. Putterich
  • W. Schneider
  • A. C. C. Sips
  • W. Suttrop
  • ASDEX Upgrade Team
  • J. Bucalossi
  • L. Fattorini
  • M. E. Manso
  • K. Gal
  • S. Kalvin
  • G. Kocsis
  • G. Veres
  • J. Lister
  • Y. Martin
Article

Abstract

Empirical estimates indicate that the transient divertor power load induced by type-I ELMs in the standard H-mode ITER scenario might result in intolerably short target life times. Significant experimental effort has been put on the exploration of recipes to avoid or at least mitigate the ELM size by external intervention. Experimental ELM mitigation studies (and related modeling) are of interest from different points of views. First, the active intervention gives access to new, externally controlled ELMy discharge scenarios and ELM diagnostic techniques. Second, the ELM response on the type and amplitude of the applied perturbation provides additional hints on the ELM stability. Third, mitigated ELMs, possibly different from spontaneous ones, and their scaling are of interest ‘per se’, in case that mitigation is to be finally applied in ITER. In this contribution we report on ELM mitigation results in ASDEX Upgrade, where we further restrict the scope to those methods involving 3D, local non-axisymmetric perturbations.

Perturbations applied were cryogenic pellet injection, localized supersonic pulsed injection of D gas and laser blow of from targets carrying C or Al micro pellets. The corresponding perturbations differ strongly both in the space and time domain and provide an instrument to probe the local stability. Varying the parameters of the external perturbations by e.g. changing the amount of injected material or the injection speed we mapped out the ELM trigger threshold with high spatial and temporal resolutions.

Key words

tokamak edge transport barier MHD instabilities ELM plasma control pellet 

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References

  1. [1]
    F. Federici et al.: Plasma Phys. Control. Fusion 45 (2003) 1523.CrossRefADSGoogle Scholar
  2. [2]
    A. Polevoi et al.: Nucl. Fusion 43 (2003) 1072.CrossRefADSGoogle Scholar
  3. [3]
    A. Herrmann.: Plasma Phys. Control. Fusion 44 (2002) 883.CrossRefADSGoogle Scholar
  4. [4]
    P.T. Lang et al.: Nucl. Fusion 43 (2003) 1110.CrossRefADSGoogle Scholar
  5. [5]
    A. Degeling et al.: Plasma Phys. Control. Fusion 45 (2003) 1637.CrossRefADSGoogle Scholar
  6. [6]
    P.T. Lang et al.: Nucl. Fusion 45 (2005) 502.CrossRefADSGoogle Scholar
  7. [7]
    R.A. Moyer et al.: Phys. Plasmas 12 (2005) 056119.CrossRefGoogle Scholar
  8. [8]
    S. Zoletnik et al.: Rev. Sci. Instrum. 66 (1995) 2904.CrossRefADSGoogle Scholar
  9. [9]
    S.H. Kim et al.: in Proc. 32nd EPS Conf. on Control. Fusion and Plasma Physics, Tarragona 2005, ECA, Vol. 29C, P5.014.Google Scholar
  10. [10]
    P.T. Lang et al.: Nucl. Fusion 44 (2004) 665.CrossRefGoogle Scholar
  11. [11]
    H. Urano et al.: Plasma Phys. Control. Fusion 46 (2004) A315.CrossRefGoogle Scholar
  12. [12]
    P.T. Lang et al.: Plasma Phys. Control. Fusion 47 (2005) 1495.CrossRefADSGoogle Scholar
  13. [13]
    D. Mc Neill: J. Nucl. Mater. 162–164 (1989) 476.Google Scholar
  14. [14]
    S. Kalvin et al.: in Proc. 32nd EPS Conf. on Control. Fusion and Plasma Physics, Tarragona 2005, ECA, Vol. 29C, P2.078.Google Scholar

Copyright information

© Institute of Physics, Academy of Sciences of Czech Republic 2005

Authors and Affiliations

  • P. T. Lang
    • 1
  • J. Hobirk
    • 1
  • L. D. Horton
    • 1
  • A. Kallenbach
    • 1
  • M. Maraschek
    • 1
  • V. Mertens
    • 1
  • R. Neu
    • 1
  • J. Neuhauser
    • 1
  • T. Putterich
    • 1
  • W. Schneider
    • 1
  • A. C. C. Sips
    • 1
  • W. Suttrop
    • 1
  • ASDEX Upgrade Team
    • 1
  • J. Bucalossi
    • 2
  • L. Fattorini
    • 3
  • M. E. Manso
    • 3
  • K. Gal
    • 4
  • S. Kalvin
    • 4
  • G. Kocsis
    • 4
  • G. Veres
    • 4
  • J. Lister
    • 5
  • Y. Martin
    • 5
  1. 1.Max-Planck-Institut fur PlasmaphysikEURATOM AssociationGarchingGermany
  2. 2.CEA CadaracheSt Paul-Lez-Durance CedexFrance
  3. 3.Centro de Fusao Nuclear, ISTLisboaPortugal
  4. 4.KFKI-RMKIEURATOM AssociationBudapest-114Hungary
  5. 5.CRPP-EPFLLausanneSwitzerland

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