Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall

The pedestal structure of type I ELMy H-modes has been analysed for JET with the ITERlike Wall (JET-ILW). The electron pressure pedestal width is independent of ρ* and increases proportionally to √βpol,PED. Additional broadening of the width is observed, at constant βpol, PED, with increasing ν* and...

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Autores: Maggi, C.F., Frassinetti, L., Horvath, L., Lunniss, A., Saarelma, S., Jet Contributors, García Muñoz, Manuel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/100027
Acceso en línea:https://hdl.handle.net/11441/100027
https://doi.org/10.1088/1741-4326/aa7e8e
Access Level:acceso abierto
Palabra clave:H-mode
Pedestal structure
Inter-ELM pedestal evolution
JET-ILW
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spelling Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wallMaggi, C.F.Frassinetti, L.Horvath, L.Lunniss, A.Saarelma, S.Jet ContributorsGarcía Muñoz, ManuelH-modePedestal structureInter-ELM pedestal evolutionJET-ILWThe pedestal structure of type I ELMy H-modes has been analysed for JET with the ITERlike Wall (JET-ILW). The electron pressure pedestal width is independent of ρ* and increases proportionally to √βpol,PED. Additional broadening of the width is observed, at constant βpol, PED, with increasing ν* and/or neutral gas injection and the contribution of atomic physics effects in setting the pedestal width cannot as yet be ruled out. Neutral penetration alone does not determine the shape of the edge density profile in JET-ILW. The ratio of electron density to electron temperature scale lengths in the edge transport barrier region, ηe, is of order 2–3 within experimental uncertainties. Existing understanding, represented in the stationary linear peeling–ballooning mode stability and the EPED pedestal structure models, is extended to the dynamic evolution between ELM crashes in JET-ILW, in order to test the assumptions underlying these two models. The inter-ELM temporal evolution of the pedestal structure in JET-ILW is not unique, but depends on discharge conditions, such as heating power and gas injection levels. The strong reduction in pe,PED with increasing D2 gas injection at high power is primarily due to clamping of ∇Te half way through the ELM cycle and is suggestive of turbulence limiting the Te pedestal growth. The inter-ELM pedestal pressure evolution in JETILW is consistent with the EPED model assumptions at low gas rates and only at low beta at high gas rates. At higher beta and high gas rate the inter-ELM pedestal pressure evolution is qualitatively consistent with the kinetic ballooning mode (KBM) constraint but the peeling– ballooning (P–B) constraint is not satisfied and the ELM trigger mechanism remains as yet unexplainedEURATOM 633053IOP PublishingFísica Atómica, Molecular y NuclearRNM138: Física Nuclear Aplicada2017info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfapplication/pdfhttps://hdl.handle.net/11441/100027https://doi.org/10.1088/1741-4326/aa7e8ereponame:idUS. Depósito de Investigación de la Universidad de Sevillainstname:Universidad de Sevilla (US)InglésNuclear Fusion, 57 (11), 1-15.633053https://doi.org/10.1088/1741-4326/aa7e8einfo:eu-repo/semantics/openAccessoai:idus.us.es:11441/1000272026-06-17T12:51:07Z
dc.title.none.fl_str_mv Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
title Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
spellingShingle Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
Maggi, C.F.
H-mode
Pedestal structure
Inter-ELM pedestal evolution
JET-ILW
title_short Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
title_full Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
title_fullStr Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
title_full_unstemmed Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
title_sort Studies of the pedestal structure and inter-ELM pedestal evolution in JET with the ITER-like wall
dc.creator.none.fl_str_mv Maggi, C.F.
Frassinetti, L.
Horvath, L.
Lunniss, A.
Saarelma, S.
Jet Contributors
García Muñoz, Manuel
author Maggi, C.F.
author_facet Maggi, C.F.
Frassinetti, L.
Horvath, L.
Lunniss, A.
Saarelma, S.
Jet Contributors
García Muñoz, Manuel
author_role author
author2 Frassinetti, L.
Horvath, L.
Lunniss, A.
Saarelma, S.
Jet Contributors
García Muñoz, Manuel
author2_role author
author
author
author
author
author
dc.contributor.none.fl_str_mv Física Atómica, Molecular y Nuclear
RNM138: Física Nuclear Aplicada
dc.subject.none.fl_str_mv H-mode
Pedestal structure
Inter-ELM pedestal evolution
JET-ILW
topic H-mode
Pedestal structure
Inter-ELM pedestal evolution
JET-ILW
description The pedestal structure of type I ELMy H-modes has been analysed for JET with the ITERlike Wall (JET-ILW). The electron pressure pedestal width is independent of ρ* and increases proportionally to √βpol,PED. Additional broadening of the width is observed, at constant βpol, PED, with increasing ν* and/or neutral gas injection and the contribution of atomic physics effects in setting the pedestal width cannot as yet be ruled out. Neutral penetration alone does not determine the shape of the edge density profile in JET-ILW. The ratio of electron density to electron temperature scale lengths in the edge transport barrier region, ηe, is of order 2–3 within experimental uncertainties. Existing understanding, represented in the stationary linear peeling–ballooning mode stability and the EPED pedestal structure models, is extended to the dynamic evolution between ELM crashes in JET-ILW, in order to test the assumptions underlying these two models. The inter-ELM temporal evolution of the pedestal structure in JET-ILW is not unique, but depends on discharge conditions, such as heating power and gas injection levels. The strong reduction in pe,PED with increasing D2 gas injection at high power is primarily due to clamping of ∇Te half way through the ELM cycle and is suggestive of turbulence limiting the Te pedestal growth. The inter-ELM pedestal pressure evolution in JETILW is consistent with the EPED model assumptions at low gas rates and only at low beta at high gas rates. At higher beta and high gas rate the inter-ELM pedestal pressure evolution is qualitatively consistent with the kinetic ballooning mode (KBM) constraint but the peeling– ballooning (P–B) constraint is not satisfied and the ELM trigger mechanism remains as yet unexplained
publishDate 2017
dc.date.none.fl_str_mv 2017
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/11441/100027
https://doi.org/10.1088/1741-4326/aa7e8e
url https://hdl.handle.net/11441/100027
https://doi.org/10.1088/1741-4326/aa7e8e
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Nuclear Fusion, 57 (11), 1-15.
633053
https://doi.org/10.1088/1741-4326/aa7e8e
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv IOP Publishing
publisher.none.fl_str_mv IOP Publishing
dc.source.none.fl_str_mv reponame:idUS. Depósito de Investigación de la Universidad de Sevilla
instname:Universidad de Sevilla (US)
instname_str Universidad de Sevilla (US)
reponame_str idUS. Depósito de Investigación de la Universidad de Sevilla
collection idUS. Depósito de Investigación de la Universidad de Sevilla
repository.name.fl_str_mv
repository.mail.fl_str_mv
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