Spherical tokamaks with a high current carrying plasma center column

Autores
Lampugnani, Leandro Gabriel; Garcia Martinez, Pablo Luis; Farengo, Ricardo
Año de publicación
2018
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Spherical tokamaks (STs) have many advantages from the perspective of a fusion reactor. A further improvement would be to replace the center post by a plasma center column (PCC). In this case, biased electrodes could be used to drive current along the PCC and produce the toroidal magnetic field. Moreover, the magnetic helicity injected (HI) by the PCC can be used to form and sustain the configuration, via magnetic relaxation. The magnetic structure and stability of these so-called ST-PCC configurations are studied in detail. In particular, it is shown that stable equilibria with tokamak-like safety factor (q) profiles can be obtained in the regime of high PCC current and moderate poloidal flux amplification. Using numerical simulations, the feasibility of forming and sustaining ST-PCC configurations via HI is demonstrated. The sustainment in this case involves a significant level of fluctuations and is shown to occur at a marginally stable configuration having a q = 1 surface in the ST. This behavior is in close analogy to that of spheromaks sustained by a coaxial plasma gun but presents two major differences. First, the current density in the open flux region (PCC) is significantly larger. Second, the mean current density gradient in the ST has the opposite sign, leading to q profiles with regular magnetic shear (i.e., q increases from the magnetic axis to the separatrix, as in tokamaks). When helicity injection is switched off, the fluctuations decay and nested, closed magnetic surfaces appear. This opens the possibility of using HI to form the ST-PCC and a combination of auxiliary current drive (neutral beams and/or RF) and high bootstrap current to sustain a fluctuation free configuration.
Fil: Lampugnani, Leandro Gabriel. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina
Fil: Garcia Martinez, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Nacional de Río Negro. Sede Andina; Argentina
Fil: Farengo, Ricardo. Universidad Nacional de Río Negro. Sede Andina; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Materia
TOKAMAK
MHD
KINK
INSTABILITIES
HELICITY
INJECTION
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/112310
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/112310
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Spherical tokamaks with a high current carrying plasma center columnLampugnani, Leandro GabrielGarcia Martinez, Pablo LuisFarengo, RicardoTOKAMAKMHDKINKINSTABILITIESHELICITYINJECTIONhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Spherical tokamaks (STs) have many advantages from the perspective of a fusion reactor. A further improvement would be to replace the center post by a plasma center column (PCC). In this case, biased electrodes could be used to drive current along the PCC and produce the toroidal magnetic field. Moreover, the magnetic helicity injected (HI) by the PCC can be used to form and sustain the configuration, via magnetic relaxation. The magnetic structure and stability of these so-called ST-PCC configurations are studied in detail. In particular, it is shown that stable equilibria with tokamak-like safety factor (q) profiles can be obtained in the regime of high PCC current and moderate poloidal flux amplification. Using numerical simulations, the feasibility of forming and sustaining ST-PCC configurations via HI is demonstrated. The sustainment in this case involves a significant level of fluctuations and is shown to occur at a marginally stable configuration having a q = 1 surface in the ST. This behavior is in close analogy to that of spheromaks sustained by a coaxial plasma gun but presents two major differences. First, the current density in the open flux region (PCC) is significantly larger. Second, the mean current density gradient in the ST has the opposite sign, leading to q profiles with regular magnetic shear (i.e., q increases from the magnetic axis to the separatrix, as in tokamaks). When helicity injection is switched off, the fluctuations decay and nested, closed magnetic surfaces appear. This opens the possibility of using HI to form the ST-PCC and a combination of auxiliary current drive (neutral beams and/or RF) and high bootstrap current to sustain a fluctuation free configuration.Fil: Lampugnani, Leandro Gabriel. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Garcia Martinez, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Nacional de Río Negro. Sede Andina; ArgentinaFil: Farengo, Ricardo. Universidad Nacional de Río Negro. Sede Andina; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaAmerican Institute of Physics2018-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/112310Lampugnani, Leandro Gabriel; Garcia Martinez, Pablo Luis; Farengo, Ricardo; Spherical tokamaks with a high current carrying plasma center column; American Institute of Physics; Physics Of Plasmas; 25; 12; 12-2018; 1-131070-664XCONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://aip.scitation.org/doi/10.1063/1.5066221info:eu-repo/semantics/altIdentifier/doi/10.1063/1.5066221info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:40:45Zoai:ri.conicet.gov.ar:11336/112310instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:40:45.657CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Spherical tokamaks with a high current carrying plasma center column
title Spherical tokamaks with a high current carrying plasma center column
spellingShingle Spherical tokamaks with a high current carrying plasma center column
Lampugnani, Leandro Gabriel
TOKAMAK
MHD
KINK
INSTABILITIES
HELICITY
INJECTION
title_short Spherical tokamaks with a high current carrying plasma center column
title_full Spherical tokamaks with a high current carrying plasma center column
title_fullStr Spherical tokamaks with a high current carrying plasma center column
title_full_unstemmed Spherical tokamaks with a high current carrying plasma center column
title_sort Spherical tokamaks with a high current carrying plasma center column
dc.creator.none.fl_str_mv Lampugnani, Leandro Gabriel
Garcia Martinez, Pablo Luis
Farengo, Ricardo
author Lampugnani, Leandro Gabriel
author_facet Lampugnani, Leandro Gabriel
Garcia Martinez, Pablo Luis
Farengo, Ricardo
author_role author
author2 Garcia Martinez, Pablo Luis
Farengo, Ricardo
author2_role author
author
dc.subject.none.fl_str_mv TOKAMAK
MHD
KINK
INSTABILITIES
HELICITY
INJECTION
topic TOKAMAK
MHD
KINK
INSTABILITIES
HELICITY
INJECTION
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Spherical tokamaks (STs) have many advantages from the perspective of a fusion reactor. A further improvement would be to replace the center post by a plasma center column (PCC). In this case, biased electrodes could be used to drive current along the PCC and produce the toroidal magnetic field. Moreover, the magnetic helicity injected (HI) by the PCC can be used to form and sustain the configuration, via magnetic relaxation. The magnetic structure and stability of these so-called ST-PCC configurations are studied in detail. In particular, it is shown that stable equilibria with tokamak-like safety factor (q) profiles can be obtained in the regime of high PCC current and moderate poloidal flux amplification. Using numerical simulations, the feasibility of forming and sustaining ST-PCC configurations via HI is demonstrated. The sustainment in this case involves a significant level of fluctuations and is shown to occur at a marginally stable configuration having a q = 1 surface in the ST. This behavior is in close analogy to that of spheromaks sustained by a coaxial plasma gun but presents two major differences. First, the current density in the open flux region (PCC) is significantly larger. Second, the mean current density gradient in the ST has the opposite sign, leading to q profiles with regular magnetic shear (i.e., q increases from the magnetic axis to the separatrix, as in tokamaks). When helicity injection is switched off, the fluctuations decay and nested, closed magnetic surfaces appear. This opens the possibility of using HI to form the ST-PCC and a combination of auxiliary current drive (neutral beams and/or RF) and high bootstrap current to sustain a fluctuation free configuration.
Fil: Lampugnani, Leandro Gabriel. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina
Fil: Garcia Martinez, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Nacional de Río Negro. Sede Andina; Argentina
Fil: Farengo, Ricardo. Universidad Nacional de Río Negro. Sede Andina; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
description Spherical tokamaks (STs) have many advantages from the perspective of a fusion reactor. A further improvement would be to replace the center post by a plasma center column (PCC). In this case, biased electrodes could be used to drive current along the PCC and produce the toroidal magnetic field. Moreover, the magnetic helicity injected (HI) by the PCC can be used to form and sustain the configuration, via magnetic relaxation. The magnetic structure and stability of these so-called ST-PCC configurations are studied in detail. In particular, it is shown that stable equilibria with tokamak-like safety factor (q) profiles can be obtained in the regime of high PCC current and moderate poloidal flux amplification. Using numerical simulations, the feasibility of forming and sustaining ST-PCC configurations via HI is demonstrated. The sustainment in this case involves a significant level of fluctuations and is shown to occur at a marginally stable configuration having a q = 1 surface in the ST. This behavior is in close analogy to that of spheromaks sustained by a coaxial plasma gun but presents two major differences. First, the current density in the open flux region (PCC) is significantly larger. Second, the mean current density gradient in the ST has the opposite sign, leading to q profiles with regular magnetic shear (i.e., q increases from the magnetic axis to the separatrix, as in tokamaks). When helicity injection is switched off, the fluctuations decay and nested, closed magnetic surfaces appear. This opens the possibility of using HI to form the ST-PCC and a combination of auxiliary current drive (neutral beams and/or RF) and high bootstrap current to sustain a fluctuation free configuration.
publishDate 2018
dc.date.none.fl_str_mv 2018-12
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/112310
Lampugnani, Leandro Gabriel; Garcia Martinez, Pablo Luis; Farengo, Ricardo; Spherical tokamaks with a high current carrying plasma center column; American Institute of Physics; Physics Of Plasmas; 25; 12; 12-2018; 1-13
1070-664X
CONICET Digital
CONICET
url http://hdl.handle.net/11336/112310
identifier_str_mv Lampugnani, Leandro Gabriel; Garcia Martinez, Pablo Luis; Farengo, Ricardo; Spherical tokamaks with a high current carrying plasma center column; American Institute of Physics; Physics Of Plasmas; 25; 12; 12-2018; 1-13
1070-664X
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://aip.scitation.org/doi/10.1063/1.5066221
info:eu-repo/semantics/altIdentifier/doi/10.1063/1.5066221
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Institute of Physics
publisher.none.fl_str_mv American Institute of Physics
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.069144

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