2024-03-28T15:18:33Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1589232018-01-10T01:55:29Zcom_10261_119com_10261_4col_10261_498
Ion heat and toroidal momentum transport studies in the H-mode transport barrier of ASDEX Upgrade
Viezzer, Eleonora
European Commission
Ministerio de Economía y Competitividad (España)
Trabajo presentado a la 26th IAEA Fusion Energy Conference, celebrada en Kyoto (Japón) del 17 al 22 de octubre de 2016.
ASDEX Upgrade Team and the EUROfusion MST1 Team: et al.
The ion heat and toroidal momentum transport at the plasma edge of ASDEX Upgrade
(AUG) H-mode plasmas are investigated by combining measurements with interpretive and predictive modelling. The experimentally determined ion heat diffusivities, xi, are compared to neoclassical theory and the impact of edge localized modes (ELMs) on the edge ion heat transport level is studied in detail. In all analyzed cases the pre-ELM xi in the pedestal is close to the neoclassical prediction within the experimental uncertainties. During the ELM crash, the ion heat transport is increased by an order of magnitude due to the outward heat pulse propagation caused by the ELM. The perturbed heat flux is first increased at the separatrix and is then observed to penetrate inwards, i.e. first the separatrix ion temperature increases at the ELM onset, leading to a flatter ion temperature gradient, followed by a decrease of the whole edge profile up to the pedestal top. The ion heat transport is restored to its pre-ELM neoclassical level 3–4ms after the ELM crash. The edge impurity toroidal rotation shows a dependence on collisionality, with negative (counter-current) values at low collisionality, and positive (co-current) values at high collisionality. Modelling of the edge toroidal rotation based on the toroidal torque balance equation including diffusion, pinch and external momentum sources indicates that diffusion and the external sources are the dominant players at both low and high collisionality. The
sign change of the impurity toroidal rotation observed at low collisionality can be explained by a negative edge torque combined with a large differential toroidal rotation, while the main ion toroidal rotation is almost unaffected.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the European Union′s Horizon 2020 research and innovation programme under grant agreement number 633053. The support from the EUROfusion Researcher Fellowship programme under grant number WP14-FRF-IPP/Viezzer and from the Spanish Ministry of Economy and Competitiveness (FJCI-201422139) is gratefully acknowledged.
Peer Reviewed
2018-01-09T09:45:33Z
2018-01-09T09:45:33Z
2016
2018-01-09T09:45:33Z
comunicación de congreso
http://purl.org/coar/resource_type/c_5794
26th IAEA Fusion Energy Conference (2016)
http://hdl.handle.net/10261/158923
http://dx.doi.org/10.13039/501100003329
http://dx.doi.org/10.13039/501100000780
#PLACEHOLDER_PARENT_METADATA_VALUE#
info:eu-repo/grantAgreement/EC/H2020/633053
Preprint
No
open