Characteristics and scaling of energy and particle losses during Type I ELMs in JET H-modes
| Autor: | A Loarte, M Becoulet, G Saibene, R Sartori, D J Campbell, T Eich, A Herrmann, M Laux, W Suttrop, B Alper, P J Lomas, G Matthews, S Jachmich, J Ongena, P Innocente, EFDA- JET Workprogramme Collaborators |
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| Rok vydání: | 2002 |
| Předmět: |
Physics
Plasma parameters Divertor Computer Science::Neural and Evolutionary Computation Magnetic confinement fusion Plasma Collisionality Condensed Matter Physics Bootstrap current Computational physics Nuclear Energy and Engineering Physics::Plasma Physics Plasma shaping Physics::Space Physics Plasma diagnostics Atomic physics |
| Zdroj: | Plasma physics and controlled fusion 44 (2002): 1815–1844. doi:10.1088/0741-3335/44/9/303 info:cnr-pdr/source/autori:A. Loarte; M. Becoulet; G. Saibene; R. Sartori; D. J. Campbell; T. Eich; A. Herrmann; M. Laux; W. Suttrop; B. Alper; P. J. Lomas; G. Matthews; S. Jachmich; J. Ongena; P. Innocente; EFDA-JET Workprogramme Collaborators/titolo:Characteristics and scaling of energy and particle losses during Type I ELMs in JET H-modes/doi:10.1088%2F0741-3335%2F44%2F9%2F303/rivista:Plasma physics and controlled fusion (Print)/anno:2002/pagina_da:1815/pagina_a:1844/intervallo_pagine:1815–1844/volume:44 |
| ISSN: | 0741-3335 |
| DOI: | 10.1088/0741-3335/44/9/303 |
| Popis: | Recent experiments on the Type I ELMy H-mode regime performed at JET with improved diagnostics have expanded the range of parameters for the study of Type I ELM energy and particle losses. Deviations from the standard behaviour of such losses in some areas of the Type I ELMy H-mode operating space have revealed that the ELM losses are correlated with the parameters (density and temperature) of the pedestal plasma before the ELM crash, while other global ELM characteristics (such as ELM frequency) are a consequence of the ELM-driven energy and particle flux and of the in-between ELM energy and particle confinement. The relative Type I ELM plasma energy loss (to the pedestal energy) is found to correlate well with the collisionality of the pedestal plasma, showing a weak dependence on the method used to achieve those pedestal plasma parameters: plasma shaping, heating, pellet injection and impurity seeding. Effects of edge plasma collisionality and transport along the magnetic field on the Type I ELM particle and energy fluxes onto the divertor target have also been observed. Two possible physical mechanisms that may give rise to the observed collisionality dependence of ELM energy losses are proposed and their consistency with the experimental measurements investigated: collisionality dependence of the edge bootstrap current with its associated influence on the ELM MHD origin and the limitation of the ELM energy loss by the impedance of the divertor target sheath to energy flow during the ELM event. |
| Databáze: | OpenAIRE |
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