The role of isotope mass and transport for H-mode access in tritium containing plasmas at JET with ITER-like wall

The required heating power, , to access the high confinement regime (H-mode) in tritium containing plasmas is investigated in JET with ITER-like wall at a toroidal magnetic field of T and a plasma current of MA. , also referred to as the L-H power threshold, is determined in plasmas of pure tritium...

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Detalles Bibliográficos
Autores: Birkenmeier, Gregor, Solano, Emilia R, Carvalho, Ivo, Hillesheim, J C, Delabie, E, Gallart Escolà, Dani, Mantsinen, Mervi
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/386519
Acceso en línea:https://hdl.handle.net/2117/386519
https://dx.doi.org/10.1088/1361-6587/acc423
Access Level:acceso abierto
Palabra clave:Nuclear fusion
L-H transition
D-T plasma operation
Isotope effects
Tranasport
Isotope mixtures
Tritium plasmas
Simulació per ordinador
Àrees temàtiques de la UPC::Física
Descripción
Sumario:The required heating power, , to access the high confinement regime (H-mode) in tritium containing plasmas is investigated in JET with ITER-like wall at a toroidal magnetic field of T and a plasma current of MA. , also referred to as the L-H power threshold, is determined in plasmas of pure tritium as well as mixtures of hydrogen with tritium (H-T) and mixtures of deuterium with tritium (D-T), and is compared to the L-H power threshold in plasmas of pure hydrogen and pure deuterium. It is found that, for otherwise constant parameters, is not the same in plasmas with the same effective isotope mass, , when they differ in their isotope composition. Thus, is not sufficient to describe the isotope effect of in a consistent manner for all considered isotopes and isotope mixtures. The electron temperature profiles measured at the L-H transition in the outer half of the radius are very similar for all isotopes and isotope mixtures, despite the fact that the L-H power threshold varies by a factor of about six. This finding, together with the observation of an offset linear relation between the L-H power threshold, , and an effective heat diffusivity, , indicates that the composition-dependent heat transport in the low confinement mode (L-mode) determines, how much power is needed to reach the necessary electron temperatures at the edge, and hence .