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. Pütterich, W. Schneider, A. C.C. Sips, W. Suttrop, J. Bucalossi, L. Fattorini, M. E. Manso, K. Gal, S. Kalvin, G. Kocsis, G. Veres, J. ListerY. Martin

Research output: Contribution to journalArticle

1 Citation (Scopus)

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.

Original languageEnglish
Pages (from-to)1557-1567
Number of pages11
JournalCzechoslovak Journal of Physics
Volume55
Issue number12
DOIs
Publication statusPublished - Dec 1 2005

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Keywords

  • ELM
  • Edge transport barier
  • MHD instabilities
  • Pellet
  • Plasma control
  • Tokamak

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Lang, P. T., Hobirk, J., Horton, L. D., Kallenbach, A., Maraschek, M., Mertens, V., Neu, R., Neuhauser, J., Pütterich, T., Schneider, W., Sips, A. C. C., Suttrop, W., Bucalossi, J., Fattorini, L., Manso, M. E., Gal, K., Kalvin, S., Kocsis, G., Veres, G., ... Martin, Y. (2005). Local 3D perturbation experiments for probing the ELM stability. Czechoslovak Journal of Physics, 55(12), 1557-1567. https://doi.org/10.1007/s10582-006-0041-6