3D non-linear MHD simulation of the MHD response and density increase as a result of shattered pellet injection

D. Hu, E. Nardon, M. Lehnen, G. T.A. Huijsmans, D. C. van Vugt

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)

Abstract

The MHD response and the penetration of a deuterium shattered pellet into a JET plasma is investigated via the non-linear reduced MHD code JOREK with the neutral gas shielding (NGS) ablation model. The dominant MHD destabilizing mechanism by the injection is identified as the local helical cooling at each rational surface, as opposed to the global current profile contraction. Thus the injected fragments destabilize each rational surface as they pass through them. The injection penetration is found to be much better compared to MGI, with the convective transport caused by core MHD instabilities (e.g. 1/1 kink) contributing significantly to the core penetration. Moreover, the injection with realistic JET SPI system configurations is simulated in order to provide some insights into future operations, and the impact on the total assimilation and penetration depth of varying injection parameters such as the injection velocity or fineness of shattering is assessed. Further, the effect of changing the target equilibrium temperature or q profile on the assimilation and penetration is also investigated. Such analysis will form the basis of further investigation into a desirable configuration for the future SPI system in ITER.

Original languageEnglish
Article number126025
Number of pages18
JournalNuclear Fusion
Volume58
Issue number12
DOIs
Publication statusPublished - 22 Oct 2018

Fingerprint

pellets
penetration
injection
assimilation
simulation
fineness
neutral gases
profiles
configurations
temperature profiles
ablation
contraction
shielding
deuterium
fragmentation
fragments
cooling

Keywords

  • disruption mitigation
  • JOREK
  • MHD instability
  • reduced MHD
  • shattered pellet injection
  • simulation
  • tokamak

Cite this

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title = "3D non-linear MHD simulation of the MHD response and density increase as a result of shattered pellet injection",
abstract = "The MHD response and the penetration of a deuterium shattered pellet into a JET plasma is investigated via the non-linear reduced MHD code JOREK with the neutral gas shielding (NGS) ablation model. The dominant MHD destabilizing mechanism by the injection is identified as the local helical cooling at each rational surface, as opposed to the global current profile contraction. Thus the injected fragments destabilize each rational surface as they pass through them. The injection penetration is found to be much better compared to MGI, with the convective transport caused by core MHD instabilities (e.g. 1/1 kink) contributing significantly to the core penetration. Moreover, the injection with realistic JET SPI system configurations is simulated in order to provide some insights into future operations, and the impact on the total assimilation and penetration depth of varying injection parameters such as the injection velocity or fineness of shattering is assessed. Further, the effect of changing the target equilibrium temperature or q profile on the assimilation and penetration is also investigated. Such analysis will form the basis of further investigation into a desirable configuration for the future SPI system in ITER.",
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3D non-linear MHD simulation of the MHD response and density increase as a result of shattered pellet injection. / Hu, D.; Nardon, E.; Lehnen, M.; Huijsmans, G. T.A.; van Vugt, D. C.

In: Nuclear Fusion, Vol. 58, No. 12, 126025, 22.10.2018.

Research output: Contribution to journalArticleAcademicpeer-review

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AU - Hu, D.

AU - Nardon, E.

AU - Lehnen, M.

AU - Huijsmans, G. T.A.

AU - van Vugt, D. C.

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